5-Lipoxygenase-activating protein (FLAP) inhibitor MK-0591 prevents aberrant alveolarization in newborn mice exposed to 85% oxygen in a dose- and time-dependent manner

A high-throughput cell-based screening method for Zika virus protease inhibitor discovery

Zika virus (ZIKV) continues to pose a significant global public health threat, with recurring regional outbreaks and potential for pandemic spread. Despite often being asymptomatic, ZIKV infections can have severe consequences, including neurological disorders and congenital abnormalities. Unfortunately, there are currently no approved vaccines or antiviral drugs for the prevention or treatment of ZIKV. One promising target for drug development is the ZIKV NS2B-NS3 protease due to its crucial role in the virus life cycle. In this study, we established a cell-based ZIKV protease inhibition assay designed for high-throughput screening (HTS). Our assay relies on the ZIKV protease's ability to cleave a cyclised firefly luciferase fused to a natural cleavage sequence between NS2B and NS3 protease within living cells. We evaluated the performance of our assay in HTS setting using the pharmacologic controls (JNJ-40418677 and MK-591) and by screening a Library of Pharmacologically Active Compounds (LOPAC). The results confirmed the feasibility of our assay for compound library screening to identify potential ZIKV protease inhibitors.

Antileukotrienes for the prevention and treatment of chronic lung disease in very preterm newborns: a systematic review

BACKGROUND

Very preterm infants are at high risk of developing chronic lung disease, which requires respiratory support and might have long-term sequelae. As lung inflammation plays an important role in pathogenesis, antileukotrienes have been explored in both clinical and animal studies. We aimed to assess the benefits and harms of antileukotrienes for the prevention and treatment of respiratory morbidity and mortality in very preterm newborns.

METHODS

In this systematic review, we included randomized trials and non-randomized studies in humans and animals reporting the effects of antileukotrienes in very preterm infants or other mammals within 10 days of birth. Our pre-specified primary outcomes were all-cause mortality and any harm, and, for the clinical studies, incidence of chronic lung disease. Included studies underwent risk of bias-assessment and data extraction performed by two authors independently. There were no language restrictions.

RESULTS

Fifteen studies totally met our inclusion criteria: one randomized trial and four non-randomized studies in humans and 10 animal studies (five in rodents, two in lambs and one in either guinea pigs, rabbits or caprinae). All five clinical studies used montelukast and had a small sample size, ranging from 4 to 77 infants. The randomized trial (n = 60) found no difference in the incidence of chronic lung disease between the groups. Only one clinical study, which enrolled four very preterm infants and had a critical overall risk of bias, reported long-term outcomes. All other studies had unclear or greater overall risk of bias and meta-analyses were therefore deemed unfeasible. Eight of ten animal studies used leukotriene receptor antagonists as antileukotriene (montelukast in three of ten studies) and seven had an experimental study design (i.e. some animals were not exposed to antileukotrienes but no randomization). Three of the ten animal studies assessed different doses. Animal studies found no effect on the outcomes mortality, growth, or lung function related surrogate outcomes.

CONCLUSIONS

Use of antileukotrienes in very preterm infants to prevent or treat chronic lung disease is not supported by the available evidence. Large randomized trials focusing on outcomes relevant to patients, including long-term outcomes, are needed. Studies should also minimize risk of bias.

The efficacy and safety of Montelukast sodium in the prevention of bronchopulmonary dysplasia

Purpose

The purpose of this study was to evaluate the efficacy and safety of Montelukast sodium in the prevention of bronchopulmonarydysplasia (BPD).

Methods

The Interventional study was designed as a multicenter, prospective, and randomized trial, with open labeled and parallel-experimental groups, 66 infants were enrolled and allocated to either the case group (n=30) or the control group (n=36) based on gestational age (GA). Infants in the case group were given Montelukast sodium (Singulair) based on their body weight (BW). Zero week was defined as the start time of the study.

Results

The incidence of moderate to severe BPD was not different between the groups (case group: 13 of 30 [43.3%] vs. control group: 19 of 36 [52.8%], P=0.912). Additionally, secondary outcomes such as ventilation index, mean airway pressure and resort to systemic steroids were not significantly different. There were no serious adverse drug reactions in either group, and furthermore the rate of occurrence of mild drug related-events were not significantly different (case group: 10 of 42 [23.8%] vs. control group: 6 of 48 (15.8%), P=0.414).

Conclusion

Montelukast was not effective in reducing moderate or severe BPD. There were no significant adverse drug events associated with Montelukast treatment.

pPKCα mediated-HIF-1α activation related to the morphological modifications occurring in neonatal myocardial tissue in response to severe and mild hyperoxia

In premature babies birth an high oxygen level exposure can occur and newborn hyperoxia exposure can be associated with free radical oxygen release with impairment of myocardial function, while in adult animal models short exposure to hyperoxia seems to protect heart against ischemic injury. Thus, the mechanisms and consequences which take place after hyperoxia exposure are different and related to animals age. The aim of our work has been to analyze the role played by HIF-1α in the occurrence of the morphological modifications upon hyperoxia exposure in neonatal rat heart. Hyperoxia exposure induces connective compartment increase which seems to allow enhanced blood vessels growth. An increased hypoxia inducible factor-1α (HIF-1α) translocation and vascular endothelial growth factor (VEGF) expression has been found upon 95% oxygen exposure to induce morphological modifications. Upstream pPKC-α expression increase in newborn rats exposed to 95% oxygen can suggest PKC involvement in HIF-1α activation. Since nitric oxide synthase (NOS) are involved in heart vascular regulation, endothelial NOS (e-NOS) and inducible NOS (i-NOS) expression has been investigated: a lower eNOS and an higher iNOS expression has been found in newborn rats exposed to 95% oxygen related to the evidence that hyperoxia provokes a systemic vasoconstriction and to the iNOS pro-apoptotic action, respectively. The occurrence of apoptotic events, evaluated by TUNEL and Bax expression analyses, seems more evident in sample exposed to severe hyperoxia. All in all such results suggest that in newborn rats hyperoxia can trigger oxygen free radical mediated membrane injury through a pPKCα mediated HIF-1α signalling system, even though specificity of such response could be obtained by in vivo administration to the rats of specific inhibitors of PKCα. This intracellular signalling can switch molecular events leading to blood vessels development in parallel to pro-apoptotic events due to an immature anti-oxidant defensive system in newborn rat hearts.