Effects of systemic anticoagulation in a murine model of compensatory lung growth.

BACKGROUND: Neonates with congenital diaphragmatic hernia (CDH) suffer from pulmonary hypoplasia (PH) and may require extracorporeal membrane oxygenation (ECMO) and anticoagulation, often with unfractionated heparin (UFH). UFH interacts with vascular endothelial growth factor (VEGF), a factor important in lung development. We investigated the effects of UFH, low molecular weight heparin (LMWH), and bivalirudin (BV) on a murine model of compensatory lung growth (CLG). METHODS: Proliferation and apoptosis were assessed in microvascular lung endothelial cells (HMVEC-L) treated with anticoagulants. Eight-week-old C57Bl/6J mice underwent left pneumonectomy and anticoagulation with low- or high-dose UFH, LMWH, BV, or saline control. Lung volume, pulmonary function tests, morphometrics, treadmill exercise tolerance, and pulmonary protein expression were examined. RESULTS: UFH and LMWH inhibited HMVEC-L proliferation. BV promoted proliferation and decreased apoptosis. UFH and LMWH-treated mice had reduced lung volume, total lung capacity, alveolar volume, and septal surface area compared to controls, while BV did not affect these measures. UFH and LMWH-treated mice had lower exercise tolerance compared to controls. CONCLUSIONS: UFH and LMWH impair pulmonary growth, alveolarization, and exercise tolerance, while BV does not. Alternative anticoagulants to heparin may be considered to improve functional outcomes for neonates with CDH and pulmonary hypoplasia. IMPACT: Unfractionated heparin and low molecular weight heparin may modify compensatory lung growth by reducing microvascular lung endothelial cell proliferation and affecting pulmonary angiogenic signaling. Functional effects of unfractionated heparin and low molecular weight heparin on murine compensatory lung growth include reduction in exercise tolerance. Bivalirudin, a direct thrombin inhibitor, may increase microvascular lung endothelial cell proliferation and preserves lung volume, alveolarization, and exercise tolerance in a murine compensatory lung growth model. Anticoagulants alternative to heparin should be further investigated for use in neonates with pulmonary hypoplastic diseases to optimize lung growth and development and improve outcomes.

Supraventricular Tachycardia in Infants With Congenital Diaphragmatic Hernia: Prevalence, Associations, and Outcomes.

OBJECTIVES: To characterize the prevalence, associations, management, and outcomes of supraventricular tachycardia (SVT) in neonates with congenital diaphragmatic hernia (CDH). DESIGN: Retrospective chart and cardiology code review within a cohort of patients with CDH was used to define a subpopulation with atrial arrhythmia. SVT mechanisms were confirmed by electrocardiogram analysis. Cox proportional hazard regression identified risk factors for SVT and association with clinical outcomes. SETTING: Medical Surgical ICU in a single, tertiary center, Boston Children's Hospital. PATIENTS: Eligible patients included neonates presenting with classic Bochdalek posterolateral CDH between 2005 and 2017, excluding newborns with Morgagni hernia or late diagnoses of CDH (>28 d). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: SVT arose in 25 of 232 neonates with CDH, (11%); 14 of 25 infants (56%) had recurrent SVT; atrioventricular node-dependent tachycardia was the most frequent mechanism (32%). The majority (71%) of SVT episodes received intervention. Nine patients (36%) received preventative antiarrhythmic medications. SVT was associated with lower Apgar score at 1 min, structural heart disease, larger defect size, extracorporeal membrane oxygenation (ECMO) support, and prostaglandin therapy for ductal patency as well as hospital stay greater than or equal to 8 weeks and use of supplemental oxygen at discharge. CONCLUSIONS: SVT can occur in neonates with CDH and frequently requires treatment. Odds of occurrence are increased with greater CDH disease severity, ECMO, and prostaglandin use. In unadjusted logistic regression analysis, SVT was associated with adverse hospital outcomes, underscoring the importance of recognition and management in this vulnerable population.

Surgical Repair of Congenital Diaphragmatic Hernia After Extracorporeal Membrane Oxygenation Cannulation: Early Repair Improves Survival.

OBJECTIVE: To determine the optimal timing of congenital diaphragmatic hernia (CDH) repair after extracorporeal membrane oxygenation (ECMO) cannulation. SUMMARY BACKGROUND DATA: The timing of CDH repair after ECMO cannulation remains a controversial topic due to studies with low power or strong selection bias. METHODS: This is a 2-aim retrospective cohort study based on the CDH Study Group registry for the period of 2007-2017. Aim 1-Compare On versus After ECMO repair. Aim 2-Compare Early versus Late repair on ECMO. In order to minimize selection bias and account for non-repairs, subjects in each aim were stratified into study groups based on their treatment center's characteristics. In each aim, the study groups were matched based on propensity score (PS). The main outcomes included mortality rate and incidence of non-repair. RESULTS: In aim 1, 136 patients remained in each group after PS matching. Compared to the After ECMO group, patients in the On ECMO group demonstrated a lower mortality rate, hazard ratio (HR) 0.54 (0.38, 0.77) (P < 0.001), and lower incidence of non-repair, 5.9% versus 33.8% (P < 0.001). In aim 2, 77 patients remained in each group after PS matching. Compared to the Late group, Early repair of CDH on ECMO was associated with a lower mortality rate, HR 0.51 (0.33, 0.77) (P = 0.002), and lower incidence of non-repair, 9.1% versus 44.2% (P < 0.001). CONCLUSIONS: The approach of early repair after ECMO cannulation is associated with improved survival compared to delayed surgical correction.

PR1P Stabilizes VEGF and Upregulates Its Signaling to Reduce Elastase-induced Murine Emphysema.

Emphysema is a progressive and fatal lung disease with no cure that is characterized by thinning, enlargement, and destruction of alveoli, leading to impaired gas exchange. Disease progression is due in part to dysregulation of VEGF (vascular endothelial growth factor) signaling in the lungs and increased lung-cell apoptosis. Here we asked whether PR1P (Prominin-1-derived peptide), a novel short peptide we designed that increases VEGF binding to endothelial cells, could be used to improve outcome in in vitro and in vivo models of emphysema. We used computer simulation and in vitro and in vivo studies to show that PR1P upregulated endogenous VEGF receptor-2 signaling by binding VEGF and preventing its proteolytic degradation. In so doing, PR1P mitigated toxin-induced lung-cell apoptosis, including from cigarette-smoke extract in vitro and from LPS in vivo in mice. Remarkably, inhaled PR1P led to significantly increased VEGF concentrations in murine lungs within 30 minutes that remained greater than twofold above that of control animals 24 hours later. Finally, inhaled PR1P reduced acute lung injury in 4- and 21-day elastase-induced murine emphysema models. Taken together, these results highlight the potential of PR1P as a novel therapeutic agent for the treatment of emphysema or other lung diseases characterized by VEGF signaling dysregulation.

Roxadustat (FG-4592) accelerates pulmonary growth, development, and function in a compensatory lung growth model.

Children with hypoplastic lung disease associated with congenital diaphragmatic hernia (CDH) continue to suffer significant morbidity and mortality secondary to progressive pulmonary disease. Current management of CDH is primarily supportive and mortality rates of the most severely affected children have remained unchanged in the last few decades. Previous work in our lab has demonstrated the importance of vascular endothelial growth factor (VEGF)-mediated angiogenesis in accelerating compensatory lung growth. In this study, we evaluated the potential for Roxadustat (FG-4592), a prolyl hydroxylase inhibitor known to increase endogenous VEGF, in accelerating compensatory lung growth. Treatment with Roxadustat increased lung volume, total lung capacity, alveolarization, and exercise tolerance compared to controls following left pneumonectomy. However, this effect was likely modulated not only by increased VEGF, but rather also by decreased pigment epithelium-derived factor (PEDF), an anti-angiogenic factor. Furthermore, this mechanism of action may be specific to Roxadustat. Vadadustat (AKB-6548), a structurally similar prolyl hydroxylase inhibitor, did not demonstrate accelerated compensatory lung growth or decreased PEDF expression following left pneumonectomy. Given that Roxadustat is already in Phase III clinical studies for the treatment of chronic kidney disease-associated anemia with minimal side effects, its use for the treatment of pulmonary hypoplasia could potentially proceed expeditiously.

Longitudinal Analysis of Ventilation Perfusion Mismatch in Congenital Diaphragmatic Hernia Survivors.

OBJECTIVE: To determine the natural history of pulmonary function for survivors of congenital diaphragmatic hernia (CDH). STUDY DESIGN: This was a retrospective cohort study of survivors of CDH born during 1991-2016 and followed at our institution. A generalized linear model was fitted to assess the longitudinal trends of ventilation (V), perfusion (Q), and V/Q mismatch. The association between V/Q ratio and body mass index percentile as well as functional status was also assessed with a generalized linear model. RESULTS: During the study period, 212 patients had at least one V/Q study. The average ipsilateral V/Q of the cohort increased over time (P < .01), an effect driven by progressive reduction in relative perfusion (P = .012). A higher V/Q ratio was correlated with lower body mass index percentile (P < .001) and higher probability of poor functional status (New York Heart Association class III or IV) (P = .045). CONCLUSIONS: In this cohort of survivors of CDH with more severe disease characteristics, V/Q mismatch worsens over time, primarily because of progressive perfusion deficit of the ipsilateral side. V/Q scans may be useful in identifying patients with CDH who are at risk for poor growth and functional status.

Longitudinal Analysis of Pulmonary Function in Survivors of Congenital Diaphragmatic Hernia.

OBJECTIVE: To analyze longitudinal trends of pulmonary function testing in patients with congenital diaphragmatic hernia (CDH) followed in our multidisciplinary clinic. STUDY DESIGN: This was a retrospective cohort study of CDH patients born between 1991 and 2013. A linear mixed effects model was fitted to estimate the trends of percent predicted forced expiratory volume in 1 second (FEV1pp), percent predicted forced vital capacity (FVCpp), and FEV1/FVC over time. RESULTS: Of 268 patients with CDH who survived to discharge, 119 had at least 1 pulmonary function test study. The FEV1pp (P < .001), FVCpp (P = .017), and FEV1/FVC (P = .001) decreased with age. Compared with defect size A/B, those with defect size C/D had lower FEV1pp by an average of 11.5% (95% CI, 2.9%-20.1%; P = .010). A history of oxygen use at initial hospital discharge also correlated with decreased FEV1pp by an average of 8.0% (95% CI, 1.2%-15.0%; P = .023). CONCLUSIONS: In a select cohort of CDH survivors, average pulmonary function declines with age relative to expected population normative values. Those with severe CDH represent a population at risk for worsening pulmonary function test measurements who may benefit from recognition and monitoring for complications.

Optimizing Duration of Empiric Management of Suspected Central Line-Associated Bloodstream Infections in Pediatric Patients with Intestinal Failure.

OBJECTIVES: To assess whether a 24-hour length of hospitalization and empiric antibiotic therapy to exclude central line-associated bloodstream infection (CLABSI) in children with intestinal failure is potentially as safe as 48 hours, which is the duration most commonly used but not evidence based. STUDY DESIGN: A prospective single-institution observational cohort study was conducted among pediatric patients with intestinal failure from July 1, 2015, through June 30, 2018, to identify episodes of suspected CLABSI. The primary end point was time from blood sampling to positive blood culture. Secondary end points included presenting symptoms, laboratory test results, responses to a parent/legal guardian-completed symptom survey, length of inpatient stay, costs, and charges. RESULTS: Seventy-three patients with intestinal failure receiving nutritional support via central venous catheters enrolled; 35 were hospitalized with suspected CLABSI at least once during the study. There were 49 positive blood cultures confirming CLABSI in 128 episodes (38%). The median time from blood sampling to positive culture was 11.1 hours. The probability of a blood culture becoming positive after 24 hours was 2.3%. Elevated C-reactive protein and neutrophil predominance in white blood cell count were associated with positive blood cultures. Estimated cost savings by transitioning from a 48-hour to a 24-hour admission to rule-out CLABSI was $4639 per admission. CONCLUSIONS: A 24-hour duration of empiric management to exclude CLABSI may be appropriate for patients with negative blood cultures and no clinically concerning signs. A multi-institutional study would more robustly differentiate patients safe for discharge after 24 hours from those who warrant longer empiric treatment.

Early Left Ventricular Dysfunction and Severe Pulmonary Hypertension Predict Adverse Outcomes in "Low-Risk" Congenital Diaphragmatic Hernia.

OBJECTIVES: Given significant focus on improving survival for "high-risk" congenital diaphragmatic hernia, there is the potential to overlook the need to identify risk factors for suboptimal outcomes in "low-risk" congenital diaphragmatic hernia cases. We hypothesized that early cardiac dysfunction or severe pulmonary hypertension were predictors of adverse outcomes in this "low-risk" congenital diaphragmatic hernia population. DESIGN: This is a retrospective cohort study using data from the Congenital Diaphragmatic Hernia Study Group registry. "Low-risk" congenital diaphragmatic hernia was defined as Congenital Diaphragmatic Hernia Study Group defect size A/B without structural cardiac and chromosomal anomalies. Examined risk factors included left ventricular dysfunction, right ventricular dysfunction, and severe pulmonary hypertension on the first postnatal echocardiogram. The primary outcome was composite adverse events, defined as either death, extracorporeal membrane oxygenation utilization, oxygen requirement on day 30 of life, or hospitalization greater than or equal to 8 weeks. Multivariable adjustment was performed with logistic regression and inverse probability weighting. SETTING: Neonatal index hospitalization for congenital diaphragmatic hernia. PATIENTS: "Low-risk" congenital diaphragmatic hernia infants born between January 2015 and December 2018. INTERVENTIONS: First postnatal echocardiogram performed within 24 hours from birth. MEASUREMENTS AND MAIN RESULTS: Seven-hundred seventy-eight patients were identified as "low-risk" congenital diaphragmatic hernia. Left ventricular dysfunction, right ventricular dysfunction, and severe pulmonary hypertension were present in 10.8%, 20.5%, and 57.5%, respectively. The primary outcome occurred in 21.3%. Death occurred in 3.0% and 9.1% used extracorporeal membrane oxygenation. On unadjusted analysis, all three risk factors were associated with the primary outcome. On all multivariable adjustment methods, left ventricular dysfunction and severe pulmonary hypertension remained significant predictors of adverse outcomes while right ventricular dysfunction no longer demonstrated any effect. CONCLUSIONS: Early left ventricular dysfunction and severe pulmonary hypertension are independent predictors of adverse outcomes among "low-risk" congenital diaphragmatic hernia infants. Early recognition may lead to interventions that can improve outcome in this at-risk cohort.

Heparin-Binding Epidermal Growth Factor-Like Growth Factor as a Critical Mediator of Tissue Repair and Regeneration.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the EGF family. It contains an EGF-like domain as well as a heparin-binding domain that allows for interactions with heparin and cell-surface heparan sulfate. Soluble mature HB-EGF, a ligand of human epidermal growth factor receptors 1 and 4, is cleaved from the membrane-associated pro-HB-EGF by matrix metalloproteinase or a disintegrin and metalloproteinase in a process called ectodomain shedding. Signaling through human epidermal growth factor receptors 1 and 4 results in a variety of effects, including cellular proliferation, migration, adhesion, and differentiation. HB-EGF levels increase in response to different forms of injuries as well as stimuli, such as lysophosphatidic acid, retinoic acid, and 17ß-estradiol. Because it is widely expressed in many organs, HB-EGF plays a critical role in tissue repair and regeneration throughout the body. It promotes cutaneous wound healing, hepatocyte proliferation after partial hepatectomy, intestinal anastomosis strength, alveolar regeneration after pneumonectomy, neurogenesis after ischemic injury, bladder wall thickening in response to urinary tract obstruction, and protection against ischemia/reperfusion injury to many cell types. Additionally, innovative strategies to deliver HB-EGF to sites of organ injury or to increase the endogenous levels of shed HB-EGF have been attempted with promising results. Harnessing the reparatory properties of HB-EGF in the clinical setting, therefore, may produce therapies that augment the treatment of various organ injuries.

Heparin impairs angiogenic signaling and compensatory lung growth after left pneumonectomy.

Children with hypoplastic lung diseases, such as congenital diaphragmatic hernia, can require life support via extracorporeal membrane oxygenation and systemic anticoagulation, usually in the form of heparin. The role of heparin in angiogenesis and organ growth is inconclusive, with conflicting data reported in the literature. This study aimed to investigate the effects of heparin on lung growth in a model of compensatory lung growth (CLG). Compared to the absence of heparin, treatment with heparin decreased the vascular endothelial growth factor (VEGF)-mediated activation of VEGFR2 and mitogenic effect on human lung microvascular endothelial cells in vitro. Compared to non-heparinized controls, heparinized mice demonstrated impaired pulmonary mechanics, decreased respiratory volumes and flows, and reduced activity levels after left pneumonectomy. They also had lower lung volume, pulmonary septal surface area and alveolar density on morphometric analyses. Lungs of heparinized mice displayed decreased phosphorylation of VEGFR2 compared to the control group, with consequential downstream reduction in markers of cellular proliferation and survival. The use of bivalirudin, an alternative anticoagulant that does not interact with VEGF, preserved lung growth and pulmonary mechanics. These results demonstrated that heparin impairs CLG by reducing VEGFR2 activation. These findings raise concern for the clinical use of heparin in the setting of organ growth or regeneration.

Vascular endothelial growth factor accelerates compensatory lung growth by increasing the alveolar units.

BackgroundDeficiency of vascular endothelial growth factor (VEGF) is associated with hypoplastic lung diseases, such as congenital diaphragmatic hernia. Provision of VEGF has been demonstrated to be beneficial in hyperoxia-induced bronchopulmonary dysplasia, and hence could induce lung growth and improve the outcome in hypoplastic lung diseases. We aimed to determine the effects of exogenous VEGF in a rodent model of compensatory lung growth after left pneumonectomy.MethodsEight-to-ten-week-old C57Bl6 male mice underwent left pneumonectomy, followed by daily intra-peritoneal injections of saline or VEGF (0.5 mg/kg). Lung volume measurement, pulmonary function tests, and morphometric analyses were performed on post-operative day (POD) 4 and 10. The pulmonary expression of angiogenic factors was analyzed by quantitative polymerase chain reaction and western blot.ResultsLung volume on POD 4 was higher in the VEGF-treated mice (P=0.03). On morphometric analyses, VEGF increased the parenchymal volume (P=0.001), alveolar volume (P=0.0003), and alveolar number (P<0.0001) on POD 4. The VEGF group displayed higher levels of phosphorylated-VEGFR2/VEGFR2 (P=0.03) and epidermal growth factor (EGF) messenger RNA (P=0.01).ConclusionVEGF accelerated the compensatory lung growth in mice, by increasing the alveolar units. These changes may be mediated by VEGFR2 and EGF-dependent mechanisms.

Technique and perioperative management of left pneumonectomy in neonatal piglets.

BACKGROUND: Although commonly performed in adult swine, unilateral pneumonectomy in piglets requires significant modifications in the surgical approach and perioperative care because of their smaller size and limited physiological reserve. METHODS: Nineteen neonatal piglets underwent a left pneumonectomy. They were allowed 5-7 d of preoperative acclimation and nutritional optimization. Preoperative weight gain and laboratory values were obtained before the time of surgery. A "ventro-cranial" approach is adopted where components of the pulmonary hilum were sequentially identified and ligated, starting from the most ventral and cranial structure, the superior pulmonary vein. The principle of gentle ventilation was followed throughout the entire operation. RESULTS: The median age of the piglets at the time of surgery was 12 (10-12) d. The median preoperative weight gain and albumin level were 20% (16-26%) and 2.3 (2.1-2.4) g/dL, respectively. The median operative time was 59 (50-70) min. Five of the first nine piglets died from complications, two from poor preoperative nutritional optimization (both with <10% weight gain and 2 g/dL for albumin), one from an intubation complication, one from intra-operative bleeding, and one in the postoperative period from a ruptured bulla. No mortality occurred for the next 10 cases. CONCLUSIONS: Successful outcomes for unilateral pneumonectomy in piglets require special attention to preoperative nutritional optimization, gentle ventilation, and meticulous surgical dissection. Preoperative weight gain and albumin levels should be used to identify appropriate surgical candidates. The "ventro-cranial" approach allows for a technically straightforward completion of the procedure.

Variability of characteristics and outcomes following cardiopulmonary resuscitation events in diverse ICU settings in a single, tertiary care children's hospital*.

OBJECTIVE: The primary objective of this study was to compare and contrast the characteristics and survival outcomes of cardiopulmonary resuscitation for "monitored" events in pediatric patients treated with chest compressions more than or equal to 1 minute in varied ICU settings. DESIGN: Retrospective observational study. SETTING: Three different specialized ICUs in a single, tertiary care, academic children's hospital. PATIENTS: We collected demographic information, preexisting conditions, preevent characteristics, event characteristics, and outcome data. The primary outcome measure was survival to hospital discharge. Secondary outcome measures included return of spontaneous circulation, 24-hour survival, and survival with good neurologic outcome. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four hundred eleven patients treated with chest compressions for more than or equal to 1 minute were included in the analysis: 170 patients were located in the cardiovascular ICU, 157 patients in the neonatal ICU, and 84 patients in the PICU. Arrest durations were longer in the cardiovascular ICU than other ICUs. Use of extracorporeal cardiopulmonary resuscitation was more prevalent in the cardiovascular ICU (cardiovascular ICU, 17%; neonatal ICU, 3%; PICU, 4%). Return of spontaneous circulation, 24-hour survival, survival to hospital discharge, and good neurologic outcome were highest among neonatal ICU patients (survival to discharge, 53%) followed by cardiovascular ICU patients (survival to discharge, 46%) and PICU patients (survival to discharge, 36%). In a multivariable model controlling for patient and event characteristics, using cardiovascular ICU as reference, adjusted odds of survival in PICU were 0.33 (95% CI, 0.14-0.76; p = 0.009) and odds of survival in neonatal ICU were 0.80 (95% CI, 0.31-2.11; p = 0.65). CONCLUSIONS: Comparative analysis of pediatric patients undergoing cardiopulmonary resuscitation in three different ICU settings demonstrated a significant variation in baseline, preevent, and event characteristics. Although outcomes vary significantly among the three different ICUs, it was difficult to ascertain if this difference was due to variation in the disease process or variation in the location of the patient.

Incidence and development of cholestasis in surgical neonates receiving an intravenous mixed-oil lipid emulsion.

BACKGROUND: Intestinal failure-associated liver disease (IFALD), initially manifesting as cholestasis, is a complication in neonates receiving parenteral nutrition (PN). Soybean oil lipid emulsion (SOLE), though implicated in IFALD, was the only US Food and Drug Administration (FDA)-approved initial intravenous lipid emulsion (ILE) for infants and children in the United States. A mixed-oil lipid emulsion (MOLE) gained popularity in patients at risk for IFALD and was recently FDA approved as an initial ILE in children. Given the presence of soybean oil in MOLE, we hypothesized that MOLE would not be effective at preventing cholestasis in surgical neonates. METHODS: Neonates with gastrointestinal surgical conditions necessitating PN for ≥14 days and receiving MOLE (SMOFlipid) from July 2016 to July 2019 were analyzed retrospectively. Unpaired and pair-matched historical surgical neonates treated with SOLE (Intralipid) served as controls. The primary outcome measure was development of cholestasis (direct bilirubin ≥2 mg/dl). RESULTS: Overall, 63% (10 of 16) of MOLE patients and 22% (30 of 136) of SOLE patients developed cholestasis after ≥14 days of therapy (P = 0.005). The latency to developing cholestasis was significantly shorter in MOLE patients compared with SOLE patients. CONCLUSION: In surgical neonates, MOLE may not prevent cholestasis and should not be considered hepatoprotective. Regardless of ILE source, all surgical neonates should be closely monitored for development of IFALD. To date, there is still no ILE able to prevent IFALD.

A medium-chain fatty acid analogue prevents hepatosteatosis and decreases inflammatory lipid metabolites in a murine model of parenteral nutrition-induced hepatosteatosis.

BACKGROUND: Parenteral (intravenous) nutrition is lifesaving for patients with intestinal failure, but long-term use of parenteral nutrition often leads to liver disease. SEFA-6179 is a synthetic medium-chain fatty acid analogue designed to target multiple fatty acid receptors regulating metabolic and inflammatory pathways. We hypothesized that SEFA-6179 would prevent hepatosteatosis and lipotoxicity in a murine model of parenteral nutrition-induced hepatosteatosis. METHODS: Two in vivo experiments were conducted. In the first experiment, six-week-old male mice were provided an ad lib fat-free high carbohydrate diet (HCD) for 19 days with orogastric gavage of either fish oil, medium-chain triglycerides, or SEFA-6179 at a low (0.3mmol/kg) or high dose (0.6mmol/kg). In the second experiment, six-week-old mice were provided an ad lib fat-free high carbohydrate diet for 19 days with every other day tail vein injection of saline, soybean oil lipid emulsion, or fish oil lipid emulsion. Mice then received every other day orogastric gavage of medium-chain triglyceride vehicle or SEFA-6179 (0.6mmol/kg). Hepatosteatosis was assessed by a blinded pathologist using an established rodent steatosis score. Hepatic lipid metabolites were assessed using ultra-high-performance liquid chromatography-mass spectrometry. Effects of SEFA-6179 on fatty acid oxidation, lipogenesis, and fatty acid uptake in human liver cells were assessed in vitro. RESULTS: In the first experiment, mice receiving the HCD with either saline or medium-chain triglyceride treatment developed macrovesicular steatosis, while mice receiving fish oil or SEFA-6179 retained normal liver histology. In the second experiment, mice receiving a high carbohydrate diet with intravenous saline or soybean oil lipid emulsion, along with medium chain triglyceride vehicle treatment, developed macrovescular steatosis. Treatment with SEFA-6179 prevented steatosis. In each experiment, SEFA-6179 treatment decreased arachidonic acid metabolites as well as key molecules (diacylglycerol, ceramides) involved in lipotoxicity. SEFA-6179 increased both ß- and complete fatty oxidation in human liver cells, while having no impact on lipogenesis or fatty acid uptake. CONCLUSIONS: SEFA-6179 treatment prevented hepatosteatosis and decreased toxic lipid metabolites in a murine model of parenteral nutrition-induced hepatosteatosis. An increase in both ß- and complete hepatic fatty acid oxidation may underlie the reduction in steatosis.

Structurally-engineered fatty acid 1024 (SEFA-1024) improves diet-induced obesity, insulin resistance, and fatty liver disease.

Obesity is a global epidemic that drives morbidity and mortality through cardiovascular disease, diabetes, and non-alcoholic fatty liver disease (NAFLD). No definitive therapy has been approved to improve glycemic control and treat NAFLD in obese patients. Here, we investigated a semi-synthetic, long chain, structurally-engineered fatty acid-1024 (SEFA-1024), as a treatment for obesity-induced hyperglycemia, insulin-resistance, and fatty liver disease in rodent models. A single dose of SEFA-1024 was administered to evaluate glucose tolerance and active glucagon-like peptide 1 (GLP-1) in lean rats in the presence and absence of a DPP-4 inhibitor. The effects of SEFA-1024 on weight loss and glycemic control were assessed in genetic (ob/ob) and environmental (high-fat diet) murine models of obesity. Liver histology, serum liver enzymes, liver lipidomics, and hepatic gene expression were also assessed in the high-fat diet murine model. SEFA-1024 reversed obesity-associated insulin resistance and improved glycemic control. SEFA-1024 increased active GLP-1. In a long-term model of diet-induced obesity, SEFA-1024 reversed excessive weight gain, hepatic steatosis, elevated liver enzymes, hepatic lipotoxicity, and promoted fatty acid metabolism. SEFA-1024 is an enterohepatic-targeted, eicosapentaenoic acid derivative that reverses obesity-induced dysregulated glucose metabolism and hepatic lipotoxicity in genetic and dietary rodent models of obesity. The mechanism by which SEFA-1024 works may include increasing aGLP-1, promoting fatty acid oxidation, and inhibiting hepatic triglyceride formation. SEFA-1024 may serve as a potential treatment for obesity-related diabetes and NAFLD.

Investigation of the mechanisms of VEGF-mediated compensatory lung growth: the role of the VEGF heparin-binding domain.

Morbidity and mortality for neonates with congenital diaphragmatic hernia-associated pulmonary hypoplasia remains high. These patients may be deficient in vascular endothelial growth factor (VEGF). Our lab previously established that exogenous VEGF164 accelerates compensatory lung growth (CLG) after left pneumonectomy in a murine model. We aimed to further investigate VEGF-mediated CLG by examining the role of the heparin-binding domain (HBD). Eight-week-old, male, C57BL/6J mice underwent left pneumonectomy, followed by post-operative and daily intraperitoneal injections of equimolar VEGF164 or VEGF120, which lacks the HBD. Isovolumetric saline was used as a control. VEGF164 significantly increased lung volume, total lung capacity, and alveolarization, while VEGF120 did not. Treadmill exercise tolerance testing (TETT) demonstrated improved functional outcomes post-pneumonectomy with VEGF164 treatment. In lung protein analysis, VEGF treatment modulated downstream angiogenic signaling. Activation of epithelial growth factor receptor and pulmonary cell proliferation was also upregulated. Human microvascular lung endothelial cells (HMVEC-L) treated with VEGF demonstrated decreased potency of VEGFR2 activation with VEGF121 treatment compared to VEGF165 treatment. Taken together, these data indicate that the VEGF HBD contributes to angiogenic and proliferative signaling, is required for accelerated compensatory lung growth, and improves functional outcomes in a murine CLG model.