Influenza A virus elicits peri-vascular adipose tissue inflammation and vascular dysfunction of the aorta in pregnant mice.

Influenza A virus (IAV) infection during pregnancy initiates significant aortic endothelial and vascular smooth muscle dysfunction, with inflammation and T cell activation, but the details of the mechanism are yet to be clearly defined. Here we demonstrate that IAV disseminates preferentially into the perivascular adipose tissue (PVAT) of the aorta in mice. IAV mRNA levels in the PVAT increased at 1-3 days post infection (d.p.i) with the levels being ~4-8 fold higher compared with the vessel wall. IAV infection also increased Ly6Clow patrolling monocytes and Ly6Chigh pro-inflammatory monocytes in the vessel wall at 3 d.p.i., which was then followed by a greater homing of these monocytes into the PVAT at 6 d.p.i. The vascular immune phenotype was characteristic of a "vascular storm"- like response, with increases in neutrophils, pro-inflammatory cytokines and oxidative stress markers in the PVAT and arterial wall, which was associated with an impairment in endothelium-dependent relaxation to acetylcholine. IAV also triggered a PVAT compartmentalised elevation in CD4+ and CD8+ activated T cells. In conclusion, the PVAT of the aorta is a niche that supports IAV dissemination and a site for perpetuating a profound innate inflammatory and adaptive T cell response. The manifestation of this inflammatory response in the PVAT following IAV infection may be central to the genesis of cardiovascular complications arising during pregnancy.

Kidney functional reserve and damage biomarkers in subclinical chronic kidney disease and acute kidney injury.

Significant loss of kidney function is not easily identified by serum creatinine (sCr)-based measurements. In the presence of normal sCr, decreased kidney functional reserve (KFR) may identify a significant loss of function. We evaluated KFR in experimental subclinical chronic kidney disease (sCKD) before and after brief ischemia-reperfusion injury (IRI). Using fluorescein isothiocyanate-labeled sinistrin, glomerular filtration rate (GFR) was measured transcutaneously before and after adenine-induced sCKD, and 1 and 2 wk after brief IRI, and compared with urinary kidney damage biomarkers. sCKD reduced stimulated and unstimulated GFR by ∼20% while reducing KFR by 50%. IRI reduced unstimulated GFR for 14 days, but KFR remained relatively unchanged in sCKD and transiently increased in control kidneys at 7 days. sCr increased and creatinine clearance (CrCl) decreased only immediately after IRI; sCr and CrCl correlated poorly with measured GFR except on day 1 after IRI. Heterogeneity in sCr and CrCl resulted from variation in tubular creatinine secretion. The increase in damage biomarker concentrations persisted for up to 14 days after IRI, allowing retrospective detection of sCKD before AKI by urine clusterin/urine kidney injury molecule-1 with an area under the curve of 1.0. sCr and CrCl are unreliable unless sCr is acutely elevated. Measurement of KFR and urine damage biomarker excretion detected sCKD despite normal sCr and CrCl. After IRI, the urine clusterin-to-urine kidney injury molecule-1 ratio may identify prior sCKD.NEW & NOTEWORTHY Early kidney function loss is poorly identified by serum creatinine (sCr)-based measurements. Direct kidney functional reserve (KFR) measurement before kidney injury and elevated urinary biomarkers clusterin and kidney injury molecule-1 detect subclinical chronic kidney disease (sCKD) after kidney injury despite normal range sCr and creatinine clearance. Reliance on sCr masks underlying sCKD. Acute kidney injury risk evaluation requires direct glomerular filtration rate measurement and KFR, whereas kidney damage biomarkers facilitate identification of prior subclinical injury.

Electronic alerts and a care bundle for acute kidney injury-an Australian cohort study.

BACKGROUND: Early recognition of hospital-acquired acute kidney injury (AKI) may improve patient management and outcomes. METHODS: This multicentre study was conducted at three hospitals (H1-intervention; H2 and H3-controls) served by a single laboratory. The intervention bundle [an interruptive automated alerts (aAlerts) showing AKI stage and baseline creatinine in the eMR, a management guide and junior medical staff education] was implemented only at H1. Outcome variables included length-of-stay (LOS), all-cause in-hospital mortality and management quality. RESULTS: Over 6 months, 639 patients developed AKI (265 at H1 and 374 at controls), with 94.7% in general wards; 537 (84%) patients developed Stage 1, 58 (9%) Stage 2 and 43 (7%) Stage 3 AKI. Median LOS was 9 days (IQR 4-17) and was not different between intervention and controls. However, patients with AKI stage 1 had shorter LOS at H1 [median 8 versus 10 days (P = 0.021)]. Serum creatinine had risen prior to admission in most patients. Documentation of AKI was better in H1 (94.8% versus 83.4%; P = 0.001), with higher rates of nephrology consultation (25% versus 19%; P = 0.04) and cessation of nephrotoxins (25.3 versus 18.8%; P = 0.045). There was no difference in mortality between H1 versus controls (11.7% versus 13.0%; P = 0.71). CONCLUSIONS: Most hospitalized patients developed Stage 1 AKI and developed AKI in the community and remained outside the intensive care unit (ICU). The AKI eAlert bundle reduced LOS in most patients with AKI and increased AKI documentation, nephrology consultation rate and cessation of nephrotoxic medications.

Plasma arginine metabolites in health and chronic kidney disease.

BACKGROUND: Elevated plasma asymmetric and symmetric dimethylarginine (ADMA and SDMA) are risk factors for chronic kidney disease (CKD) and cardiovascular disease. Using plasma cystatin C (pCYSC)-based estimated glomerular filtration rate (eGFR) trajectories, we identified a cohort at high risk of poor kidney-related health outcomes amongst members of the Dunedin Multidisciplinary Health and Development Study (DMHDS). We therefore examined associations between methylarginine metabolites and kidney function in this cohort. METHODS: ADMA, SDMA, L-arginine and L-citrulline were measured in plasma samples from 45-year-olds in the DMHDS cohort by liquid chromatography-tandem mass spectrometry. RESULTS: In a healthy DMHDS subset (n = 376), mean concentrations were: ADMA (0.40 ± 0.06 µmol/L), SDMA (0.42 ± 0.06 µmol/L), L-arginine (93.5 ± 23.1 µmol/L) and L-citrulline (24.0 ± 5.4 µmol/L). In the total cohort (n = 857), SDMA correlated positively with serum creatinine (Pearson's r = 0.55) and pCYSC (r = 0.55), and negatively with eGFR (r = 0.52). A separate cohort of 38 patients with stage 3-4 CKD (eGFR 15-60 mL/min/1.73 m2) confirmed significantly higher mean ADMA (0.61 ± 0.11 µmol/L), SDMA (0.65 ± 0.25 µmol/L) and L-citrulline (42.7 ± 11.8 µmol/L) concentrations. DMHDS members classified as high-risk of poor kidney health outcomes had significantly higher mean concentrations of all four metabolites compared with individuals not at risk. ADMA and SDMA individually predicted high-risk of poor kidney health outcomes with areas under the ROC curves (AUCs) of 0.83 and 0.84, and together with an AUC of 0.90. CONCLUSIONS: Plasma methylarginine concentrations facilitate stratification for risk of CKD progression.

Influenza A virus causes maternal and fetal pathology via innate and adaptive vascular inflammation in mice.

Influenza A virus (IAV) infection during pregnancy causes severe maternal and perinatal complications, despite a lack of vertical transmission of IAV across the placenta. Here, we demonstrate a significant alteration in the maternal vascular landscape that underpins the maternal and downstream fetal pathology to IAV infection in mice. In IAV infection of nonpregnant mice, the local lung inflammatory response was contained to the lungs and was self-resolving, whereas in pregnant mice, virus dissemination to major maternal blood vessels, including the aorta, resulted in a peripheral "vascular storm," with elevated proinflammatory and antiviral mediators and the influx of Ly6Clow and Ly6Chigh monocytes, plus neutrophils and T cells. This vascular storm was associated with elevated levels of the adhesion molecules ICAM and VCAM and the pattern-recognition receptors TLR7 and TLR9 in the vascular wall, resulting in profound vascular dysfunction. The sequalae of this IAV-driven vascular storm included placental growth retardation and intrauterine growth restriction, evidence of placental and fetal brain hypoxia, and increased circulating cell free fetal DNA and soluble Flt1. In contrast, IAV infection in nonpregnant mice caused no obvious alterations in endothelial function or vascular inflammation. Therefore, IAV infection during pregnancy drives a significant systemic vascular alteration in pregnant dams, which likely suppresses critical blood flow to the placenta and fetus. This study in mice provides a fundamental mechanistic insight and a paradigm into how an immune response to a respiratory virus, such as IAV, is likely to specifically drive maternal and fetal pathologies during pregnancy.

Cystatin C kidney functional reserve: a simple method to predict outcome in chronic kidney disease.

BACKGROUND: Kidney functional reserve (KFR), the only clinical kidney stress test, is not routinely measured because the complexity of measurement has limited clinical application. We investigated the utility of plasma cystatin C (CysC) after oral protein loading (PL) to determine KFR in Stages 3 and 4 chronic kidney disease (CKD). METHODS: Following a 24-h low-protein diet, KFR was measured after oral protein by hourly plasma CysC and compared with simultaneous creatinine clearance (CrCl) and radionuclide 99technetium diethylenetriaminepentaacetatic acid (Tc-99m-DTPA) measured glomerular filtration rate (mGFR) measurement in an observational, single-centre cohort study of adults with CKD Stages 3 and 4. Subjects were followed for 3 years for fast (F) or slow (S) CKD progression, dialysis requirement or death or a combination of major adverse kidney events (MAKEs). RESULT: CysC, CrCl and Tc-99m-DTPA mGFR measurements of KFR in 19 CKD Stage 3 and 21 CKD Stage 4 patients yielded good agreement. KFR was not correlated with baseline kidney function. Eight CKD Stage 3 (42%) and 11 CKD Stage 4 (52%) subjects reached their lowest serum CysC concentration 4 h after PL. CysC KFR and baseline serum creatinine (sCr) predicted death or dialysis or MAKE-F with a respective area under the curve (AUC) of 0.73 [95% confidence interval (CI) 0.48-0.89] and 0.71 (95% CI 0.51-0.84). Including CysC KFR, age, baseline sCr and nadir CysC predicted a decrease in sCr-estimated GFR >1.2 mL/min/year (MAKE-S) with an AUC of 0.89. CONCLUSIONS: Serial CysC avoided timed urine collection and radionuclide exposure and yielded equivalent estimates of KFR. Serial CysC may facilitate monitoring of KFR in clinical practice.

The kinetic estimated glomerular filtration rate ratio predicts acute kidney injury.

AIM: Kinetic estimated Glomerular Filtration Rate (KeGFR) approximates GFR under non-steady-state conditions. We investigated whether the ratio of KeGFR difference to baseline eGFR could predict acute kidney injury (AKI) earlier than a creatinine-based algorithm that triggered an AKI electronic Alert (eAlert). METHODS: This retrospective, single-centre, proof-of-concept cohort study assessed all patients diagnosed with AKI by an automated serum creatinine-based eAlert. The kinetic eGFR, the kinetic eGFR difference from baseline and the ratio of difference to baseline was calculated in subjects with at least two serum creatinine (sCr) measurements within 72 h of AKI. RESULTS: Patients in the AKI cohort (n = 140) had a significant decline in KeGFR ratio (AKI: 17% IQR 7% to 29%, Non-AKI: 0 IQR -12% to 9%; P-value <.0001). A decrease of the ratio greater than 10% predicted AKI with a sensitivity of 66%, a specificity of 77%, a positive predictive value of 63%, and negative predictive value of 80%. The median lead time between KeGFR ratio decrease and AKI was 24 h (IQR: 19-27 h). CONCLUSIONS: KeGFR ratio is a cheap, simple method that predicted AKI 24 h before laboratory detection. KeGFR may facilitate triaging patients to increased monitoring or intervention.

Targeted protection of proximal tubular cells by nanoparticle-enhanced delivery of a TLR9-antagonist.

The kidney target site for injury that leads to acute kidney injury (AKI) is the proximal tubule. Nanoparticle-encapsulation enhanced delivery of a selective Toll-like receptor 9 antagonist to mouse proximal tubules and attenuated experimental ischemia-reperfusion injury in a mouse model of AKI.

Histologic Healing Is More Strongly Associated with Clinical Outcomes in Ileal Crohn's Disease than Endoscopic Healing.

BACKGROUND & AIMS: Deep remission, based on clinical remission and evidence of healing during endoscopic evaluation, are goals of medical treatments for Crohn's disease (CD). We investigated whether histologic healing is associated with outcomes of patients with CD ileitis. METHODS: We performed a retrospective study of 101 patients with CD (52% male) isolated to the terminal ileum who had a colonoscopy between September 2005 and June 2015. Our analysis included patients in clinical remission at colonoscopy who had biopsies collected from colon and ileum. The ileum was evaluated for endoscopic healing (no ulceration) and histologic evidence of healing (no active inflammation, erosions, ulceration, or neutrophil infiltration). We compared times of clinical relapse-free survival, medication escalation, corticosteroid use, or hospitalization secondary to disease activity between patients with and without histological and endoscopic healing, followed for a median 21 months. We identified factors associated with survival using Kaplan Meier analysis and Cox proportional hazard model. RESULTS: At ileo-colonoscopy, 63% of patients had endoscopic healing and 55% had histologic evidence of healing. The level of agreement between endoscopic and histologic activity was fair (62%, K = 0.2250, P = .0064). Forty-two patients had clinical relapse, 45 had medication escalation, 30 required corticosteroids, and 17 were hospitalized (3 required surgery). On multivariate analysis, only histologic healing was associated with decreased risk of clinical relapse (hazard ratio [HR], 2.05; 95% CI, 1.07-3.94; P = .031), medication escalation (HR, 2.17; 95% CI, 1.2-3.96; P = .011), and corticosteroid use (HR, 2.44; 95% CI, 1.17-5.09; P = .018). No factors were associated with hospitalization. CONCLUSIONS: In patients with ileal CD in clinical remission, histologic healing but not endoscopic healing is associated with decreased risk of clinical relapse, medication escalation, or corticosteroid use.

Hyponatraemia in heart failure.

Hyponatraemia is common in heart failure (HF). It is estimated that over 20% of patients admitted to hospital with HF have hyponatraemia. It has also been repeatedly shown to be a surrogate marker of increased morbidity and mortality in this specific population. This review focuses on the pathophysiology of hyponatraemia through the activation of neurohormonal cascades in HF, the clinical implications of sustained hyponatraemia and treatment options in the management of this challenging phenomenon.

Histologic Normalization Occurs in Ulcerative Colitis and Is Associated With Improved Clinical Outcomes.

BACKGROUND & AIMS: Mucosal healing, determined by histologic analysis, is a potential therapeutic target for patients with ulcerative colitis (UC). However, the histologic features of tissue normalization, as an outcome of treatment, have not been well described. We examined the prevalence and predictive values of normalization of the colonic mucosa, based on histologic analysis (histologic normalization) in patients with UC, and determined its association with risk of clinical relapse, compared with histologic disease quiescence and endoscopic mucosal healing. METHODS: We performed a retrospective study of 646 patients with confirmed UC who underwent colonoscopy at a tertiary medical center from August 2005 through October 2013. We reviewed reports from pathology analyses of random mucosal biopsies from each colon segment, and categorized them into 3 groups based on histology findings: (1) normalization (completely normal mucosa with no features of chronicity present), (2) quiescence (crypt atrophy or branching without signs of active inflammation including erosions, abscesses, or focal neutrophil infiltration), or (3) active disease (epithelial infiltration by neutrophils, crypt abscesses, erosions, or ulceration). Histology findings were compared with clinical and endoscopic findings. We assessed variables associated with histology findings and, in patients in clinical remission (Simple Clinical Colitis Activity Index score ≤2 and subscore of ≤1 for stool frequency or rectal bleeding), predictive values for clinical relapse at follow-up evaluations 6 months later or more were calculated. RESULTS: Of the 646 patients included in the study, 60% had endoscopic mucosal healing, 40% had histologic quiescence, and 10% had histologic normalization. The level of agreement between mucosal and histologic activity was moderate (agreement for 68% of samples; κ = 0.50; P < .001). On multivariate analysis, only proctitis associated with histologic normalization (P = .002). Of 310 patients in clinical remission at initial review, 25% had a clinical relapse, after a median time of 16 months (interquartile range, 10-23 months). Histologic normalization was independently associated with increased odds of relapse-free survival compared with histologic quiescence (hazard ratio, 4.31; 95% confidence interval, 1.48-12.46; P = .007) and histologic activity (hazard ratio, 6.69; 95% confidence interval, 2.16-20.62; P = .001); mucosal healing was not associated with increased odds of relapse-free survival compared with no mucosal healing (hazard ratio, 1.02; 95% confidence interval, 0.56-1.85; P = .954). CONCLUSIONS: Histologic normalization of colonic mucosa can be used as a clinical endpoint for patients with UC. We associated histologic normalization with increased odds of relapse-free survival compared with endoscopic healing or histologic quiescence. Further studies are needed to determine whether histologic normalization should be a goal of treatment for patients with UC.

How do clinical and psychological variables relate to quality of life in end-stage renal disease? Validating a proximal-distal model.

PURPOSE: The aims of this study were to: (1) validate the proximal-distal (PD) model in predialysis and early dialysis and (2) examine the role of hemoglobin on quality of life (QoL) in these patient groups. METHODS: Cross-sectional observational studies of 475 participants recruited from four major university teaching hospitals were conducted. The multi-sample structural equation modeling with latent composite techniques was employed to test the PD model. Seven factors were measured, including QoL, positive affect, depression, physical functioning, kidney disease symptoms, comorbidity and hemoglobin. RESULTS: The results showed that both the equality-constrained and equality-unconstrained PD models were supported by fit statistics. The chi square difference test of the two models was non-significant, indicating that the PD model was consistent across groups. The alternative models were rejected by fit statistics, suggesting that hemoglobin does not impact on psychological states but QoL. CONCLUSIONS: This study validates the PD model across the end-stage renal disease (ESRD) patient groups and shows a hierarchical causal relationship between clinical factors, physical functioning, psychological states and QoL, with hemoglobin as an exception. This model provides an empirical framework for integrating and studying a range of clinical factors and health outcomes in ESRD.

TLR9 Monotherapy in Immune-Competent Mice Suppresses Orthotopic Prostate Tumor Development.

Prostate cancer is ranked second in the world for cancer-related deaths in men, highlighting the lack of effective therapies for advanced-stage disease. Toll-like receptors (TLRs) and immunity have a direct role in prostate cancer pathogenesis, but TLR9 has been reported to contribute to both the progression and inhibition of prostate tumorigenesis. To further understand this apparent disparity, we have investigated the effect of TLR9 stimulation on prostate cancer progression in an immune-competent, syngeneic orthotopic mouse model of prostate cancer. Here, we utilized the class B synthetic agonist CPG-1668 to provoke a TLR9-mediated systemic immune response and demonstrate a significant impairment of prostate tumorigenesis. Untreated tumors contained a high abundance of immune-cell infiltrates. However, pharmacological activation of TLR9 resulted in smaller tumors containing significantly fewer M1 macrophages and T cells. TLR9 stimulation of tumor cells in vitro had no effect on cell viability or its downstream transcriptional targets, whereas stimulation in macrophages suppressed cancer cell growth via type I IFN. This suggests that the antitumorigenic effects of CPG-1668 were predominantly mediated by an antitumor immune response. This study demonstrated that systemic TLR9 stimulation negatively regulates prostate cancer tumorigenesis and highlights TLR9 agonists as a useful therapeutic for the treatment of prostate cancer.

Low dose aspirin prevents endothelial dysfunction in the aorta and foetal loss in pregnant mice infected with influenza A virus.

Influenza A virus (IAV) infection in pregnancy resembles a preeclamptic phenotype characterised by vascular dysfunction and foetal growth retardation. Given that low dose aspirin (ASA) is safe in pregnancy and is used to prevent preeclampsia, we investigated whether ASA or NO-conjugated aspirin, NCX4016, resolve vascular inflammation and function to improve offspring outcomes following IAV infection in pregnant mice. Pregnant mice were intranasally infected with a mouse adapted IAV strain (Hkx31; 104 plaque forming units) and received daily treatments with either 200µg/kg ASA or NCX4016 via oral gavage. Mice were then culled and the maternal lungs and aortas collected for qPCR analysis, and wire myography was performed on aortic rings to assess endothelial and vascular smooth muscle functionality. Pup and placentas were weighed and pup growth rates and survival assessed. IAV infected mice had an impaired endothelial dependent relaxation response to ACh in the aorta, which was prevented by ASA and NCX4016 treatment. ASA and NCX4016 treatment prevented IAV dissemination and inflammation of the aorta as well as improving the pup placental ratios in utero, survival and growth rates at post-natal day 5. Low dose ASA is safe to use during pregnancy for preeclampsia and this study demonstrates that ASA may prove a promising treatment for averting the significant vascular complications associated with influenza infection during pregnancy.

Adjunctive ultrasonography during carotid artery stenting to minimize iodine contrast use.

Carotid artery stenting (CAS) in patients with chronic kidney disease carries a significant risk of contrast-induced nephropathy. We report a case of CAS with adjunctive sonography to reduce the amount of contrast medium during angiography. A 71-year-old man presented with a symptomatic right carotid stenosis. He was selected for CAS due to significant medical comorbidity, which included severe renal impairment. A preoperative noncontrast CT was performed to assess anatomical suitability and to plan arch vessel cannulation. We undertook CAS with the use of intraoperative ultrasound. Sonography was used to monitor the manipulation of wires, catheters, and stents. Four milliliters of contrast was required to complete the procedure successfully with no deterioration in postoperative renal function. Adjunctive ultrasound is feasible to reduce contrast use in patients with severe renal impairment undergoing CAS.

ACEIs for cardiovascular risk reduction--have we taken our eye off the ball?

BACKGROUND: Hypertensive patients have an increased risk of cardiovascular (CV) events. There is debate whether angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) offer similar reductions in CV risk. OBJECTIVE: This article discusses some of the recent evidence for the prevention of CV events and mortality with ACEIs and ARBs, and the rationale for using an ACEI as the preferred agent for comprehensive CV risk reduction in specific patient populations. DISCUSSION: ACEIs and ARBs are structurally and functionally very different agents; they are not interchangeable. Prescriptions for ARBs are increasing in Australia. However, clinical trial evidence suggests possible advantages of ACEIs over ARBs, particularly in terms of survival benefit. Many patients with hypertension have other CV risk factors that may affect medication choice. The aim of treatment should not be just to lower blood pressure, but to reduce absolute CV risk.

TLR7 promotes chronic airway disease in RSV-infected mice.

Respiratory syncytial virus (RSV) commonly infects the upper respiratory tract (URT) of humans, manifesting with mild cold or flu-like symptoms. However, in infants and the elderly, severe disease of the lower respiratory tract (LRT) often occurs and can develop into chronic airway disease. A better understanding of how an acute RSV infection transitions to a LRT chronic inflammatory disease is critically important to improve patient care and long-term health outcomes. To model acute and chronic phases of the disease, we infected wild-type C57BL/6 and toll-like receptor 7 knockout (TLR7 KO) mice with RSV and temporally assessed nasal, airway and lung inflammation for up to 42 days post-infection. We show that TLR7 reduced viral titers in the URT during acute infection but promoted pronounced pathogenic and chronic airway inflammation and hyperreactivity in the LRT. This study defines a hitherto unappreciated molecular mechanism of lower respiratory pathogenesis to RSV, highlighting the potential of TLR7 modulation to constrain RSV pathology to the URT.

The psychosocial correlates of quality of life in the dialysis population: a systematic review and meta-regression analysis.

PURPOSE: The psychosocial correlates of quality-of-life (QoL) research in end-stage renal disease (ESRD) are important in identifying risk and protective factors that may account for the QoL variability. Thus, the present study provides a meta-analysis of these research results. METHODS: Published studies reporting associations between any psychosocial factors and QoL were retrieved from Medline, Embase, and PsycINFO. Mean effect sizes were calculated for the associations across psychosocial constructs (affect, stress, cognitive appraisal, social support, personality attributes, and coping process). Multiple hierarchical meta-regressions were applied to moderator analyses. RESULTS: Eighty-one studies covering a combined sample of 13,240 participants were identified resulting in 377 effect sizes of the association between psychosocial factors and QoL. The overall effect size of the association was medium (0.38). Stress, affect, and cognitive appraisal had the largest effect sizes. Location of study, dialysis type, gender, age and QoL domains measured (general well-being, subjective QoL, and health-related QoL) were significant substantive moderators for the associations. CONCLUSIONS: The present study shows that there is a moderate association between psychosocial variables and QoL in patients with ESRD, consistent across different QoL domains. The psychosocial constructs that have the strongest association with QoL are stress, affect, and cognitive appraisal.

Endothelial NOX4 Oxidase Negatively Regulates Inflammation and Improves Morbidity During Influenza A Virus Lung Infection in Mice.

Endosomal NOX2 oxidase-dependent ROS production promotes influenza pathogenicity, but the role of NOX4 oxidase, which is highly expressed in the lung endothelium, is largely unknown. The aim of this study was to determine if endothelial NOX4 expression can influence viral pathology in vivo, using a mouse model of influenza infection. WT and transgenic endothelial NOX4 overexpressing mice (NOX4 TG) were infected intranasally with the Hong Kong H3N2 X-31 influenza A virus (104 PFU; HK x-31) or PBS control. Mice were culled at either 3 or 7 days post-infection to analyse: airway inflammation by bronchoalveolar lavage fluid (BALF) cell counts; NOX4, as well as inflammatory cytokine and chemokine gene expression by QPCR; and ROS production by an L-012-enhanced chemiluminescence assay. Influenza A virus infection of WT mice resulted in a significant reduction in lung NOX4 mRNA at day 3, which persisted until day 7, when compared to uninfected mice. Influenza A virus infection of NOX4 TG mice resulted in significantly less weight loss than that of WT mice at 3-days post infection. Viral titres were decreased in infected NOX4 TG mice compared to the infected WT mice, at both 3- and 7-days post infection and there was significantly less lung alveolitis, peri-bronchial inflammation and neutrophil infiltration. The oxidative burst from BALF inflammatory cells extracted from infected NOX4 TG mice was significantly less than that in the WT mice. Expression of macrophage and neutrophil chemoattractants CXCL10, CCL3, CXCL1 and CXCL2 in the lung tissue were significantly lower in NOX4 TG mice compared to the WT mice at 3-days post infection. We conclude that endothelial NOX4 oxidase is protective against influenza morbidity and is a potential target for limiting influenza A virus-induced lung inflammation.

Cigarette Smoke Exposure Induces Neurocognitive Impairments and Neuropathological Changes in the Hippocampus.

Background and Objective: Neurocognitive dysfunction is present in up to ∼61% of people with chronic obstructive pulmonary disease (COPD), with symptoms including learning and memory deficiencies, negatively impacting the quality of life of these individuals. As the mechanisms responsible for neurocognitive deficits in COPD remain unknown, we explored whether chronic cigarette smoke (CS) exposure causes neurocognitive dysfunction in mice and whether this is associated with neuroinflammation and an altered neuropathology. Methods: Male BALB/c mice were exposed to room air (sham) or CS (9 cigarettes/day, 5 days/week) for 24 weeks. After 23 weeks, mice underwent neurocognitive tests to assess working and spatial memory retention. At 24 weeks, mice were culled and lungs were collected and assessed for hallmark features of COPD. Serum was assessed for systemic inflammation and the hippocampus was collected for neuroinflammatory and structural analysis. Results: Chronic CS exposure impaired lung function as well as driving pulmonary inflammation, emphysema, and systemic inflammation. CS exposure impaired working memory retention, which was associated with a suppression in hippocampal microglial number, however, these microglia displayed a more activated morphology. CS-exposed mice showed changes in astrocyte density as well as a reduction in synaptophysin and dendritic spines in the hippocampus. Conclusion: We have developed an experimental model of COPD in mice that recapitulates the hallmark features of the human disease. The altered microglial/astrocytic profiles and alterations in the neuropathology within the hippocampus may explain the neurocognitive dysfunction observed during COPD.