Maternal n-3 enriched diet reprograms the offspring neurovascular transcriptome and blunts inflammation induced by endotoxin in the neonate

Infection during the perinatal period can adversely affect brain development, predispose infants to ischemic stroke and have lifelong consequences. We previously demonstrated that diet enriched in n-3 polyunsaturated fatty acids (n-3 PUFA) transforms brain lipid composition in the offspring and protects the neonatal brain from stroke, in part by blunting injurious immune responses. Critical to the interface between the brain and systemic circulation is the vasculature, endothelial cells in particular, that support brain homeostasis and provide a barrier to systemic infection. Here, we examined whether maternal PUFA-enriched diets exert reprograming of endothelial cell signalling in postnatal day 9 mice after modeling aspects of infection using LPS. Transcriptome analysis was performed on microvessels isolated from brains of pups from dams maintained on 3 different maternal diets from gestation day 1: standard, n-3 enriched or n-6 enriched diets. Depending on the diet, in endothelial cells LPS produced distinct regulation of pathways related to immune response, cell cycle, extracellular matrix, and angiogenesis. N-3 PUFA diet enabled higher immune reactivity in brain vasculature, while preventing imbalance of cell cycle regulation and extracellular matrix cascades that accompanied inflammatory response in standard diet. Cytokine analysis revealed a blunted LPS response in blood and brain of offspring from dams on n-3 enriched diet. Analysis of cerebral vasculature in offspring in vivo revealed no differences in vessel density. However, vessel complexity was decreased in response to LPS at 72 h in standard and n-6 diets. Thus, LPS modulates specific transcriptomic changes in brain vessels of offspring rather than major structural vessel characteristics during early life. N-3 PUFA-enriched maternal diet in part prevents an imbalance in homeostatic processes, alters inflammation and ultimately mitigates changes to the complexity of surface vessel networks that result from infection. Importantly, maternal diet may presage offspring neurovascular outcomes later in life

Male and Female Mice Exhibit Divergent Responses of the Cortical Vasculature to Traumatic Brain Injury

Traumatic brain injuries (TBI) occur in 1.7 million people each year in the USA. Little is known about how the cerebrovasculature is altered after TBI. We previously reported that TBI elicits acute decrements in cerebral vessels near the injury site in rats followed by revascularization over the subsequent 2 weeks. Sexual dimorphism of the brain is well documented and different hormonal levels in males and females differentially modify the recovery process after injury. However, the effects of biological sex on the temporal evolution of revascularization following TBI are understudied. Using a model of controlled cortical impact in male and female mice, we set out to determine if the injury and the repair process are affected by sex

Formulation predictive dissolution (fPD) testing to advance oral drug product development: an introduction to the US FDA funded ‘21st Century BA/BE’ project

Over the past decade, formulation predictive dissolution (fPD) testing has gained increasing attention. Another mindset is pushed forward where scientists in our field are more confident to explore the in vivo behavior of an oral drug product by performing predictive in vitro dissolution studies. Similarly, there is an increasing interest in the application of modern computational fluid dynamics (CFD) frameworks and high-performance computing platforms to study the local processes underlying absorption within the gastrointestinal (GI) tract. In that way, CFD and computing platforms both can inform future PBPK-based in silico frameworks and determine the GI-motility-driven hydrodynamic impacts that should be incorporated into in vitro dissolution methods for in vivo relevance. Current compendial dissolution methods are not always reliable to predict the in vivo behavior, especially not for biopharmaceutics classification system (BCS) class 2/4 compounds suffering from a low aqueous solubility. Developing a predictive dissolution test will be more reliable, cost-effective and less time-consuming as long as the predictive power of the test is sufficiently strong. There is a need to develop a biorelevant, predictive dissolution method that can be applied by pharmaceutical drug companies to facilitate marketing access for generic and novel drug products. In 2014, Prof. Gordon L. Amidon and his team initiated a far-ranging research program designed to integrate (1) in vivo studies in humans in order to further improve the understanding of the intraluminal processing of oral dosage forms and dissolved drug along the gastrointestinal (GI) tract, (2) advancement of in vitro methodologies that incorporates higher levels of in vivo relevance and (3) computational experiments to study the local processes underlying dissolution, transport and absorption within the intestines performed with a new unique CFD based framework. Of particular importance is revealing the physiological variables determining the variability in in vivo dissolution and GI absorption from person to person in order to address (potential) in vivo BE failures. This paper provides an introduction to this multidisciplinary project, informs the reader about current achievements and outlines future directions

Repair of the Cerebral Vasculature After Traumatic Brain Injury and the Influence of Beta-Catenin in New Vessel Formation and Injury Outcome

Traumatic brain injury (TBI) often results in damage to the cerebral vasculature which leads to hypoperfusion, edema, and hemorrhage. Repairing the injured vasculature after TBI is critical for neuroprotection and improving outcomes. While numerous studies have shown that the cerebral vessels are damaged after TBI, there are scant studies looking at repair of the vessel network following brain injury. Furthermore, there is a paucity of studies that have examined the molecular mechanisms underlying vascular repair after TBI. One possible signaling factor is β-catenin, which promotes blood vessel formation during embryonic development. To address this gap in knowledge, we developed a novel method to stain, visualize, and analyze the cerebral vasculature in the entire rodent brain. This technique, referred to as Vessel Painting (VP), effectively stains pial, penetrating, and parenchymal vessels and cerebral vessels can be imaged by wide-field fluorescent microscopy to acquire whole brain images. We introduce two complimentary methods to analyze vessel morphology and complexity in the whole brain. Our novel VP and analysis protocol was used to study the vascular alterations after TBI. Adult male mice received a moderate controlled cortical impact followed by VP at 1 and 7 days post injury (dpi). We assessed β-catenin inside blood vessels around the injury site and utilized a Wnt reporter mouse line (TCF/LEF:H2B-GFP) to monitor Wnt gene expression. We report that TBI results in vascular loss at 1 dpi followed by an increase in new vessels at 7 dpi. We observed an acute increase in β-catenin expression and increased Wnt reporter activity in cerebral vessels after TBI. To assess the role of β-catenin in vascular repair, we utilized Lithium to increase β-catenin expression and JW74 to reduce β-catenin expression. Lithium treatment after TBI enhanced vascular repair and lead to elongated vessel segments at 7 dpi while JW74 treatment after TBI reduced vascular repair and lead to fragmented vessels. Overall, these findings suggest that β-catenin becomes activated after TBI to initiate vascular repair. Treatment strategies to enhance β-catenin appear to contribute to vascular repair after TBI and represents a potential target for future therapeutics

Response of the cerebral vasculature following traumatic brain injury

The critical role of the vasculature and its repair in neurological disease states is beginning to emerge particularly for stroke, dementia, epilepsy, Parkinson's disease, tumors and others. However, little attention has been focused on how the cerebral vasculature responds following traumatic brain injury (TBI). TBI often results in significant injury to the vasculature in the brain with subsequent cerebral hypoperfusion, ischemia, hypoxia, hemorrhage, blood-brain barrier disruption and edema. The sequalae that follow TBI result in neurological dysfunction across a host of physiological and psychological domains. Given the importance of restoring vascular function after injury, emerging research has focused on understanding the vascular response after TBI and the key cellular and molecular components of vascular repair. A more complete understanding of vascular repair mechanisms are needed and could lead to development of new vasculogenic therapies, not only for TBI but potentially vascular-related brain injuries. In this review, we delineate the vascular effects of TBI, its temporal response to injury and putative biomarkers for arterial and venous repair in TBI. We highlight several molecular pathways that may play a significant role in vascular repair after brain injury

Vascular topology is acutely impacted by experimental febrile status epilepticus

Febrile status epilepticus (FSE) is an important risk factor for temporal lobe epilepsy and early identification is vital. In a rat model of FSE, we identified an acute novel MRI signal in the basolateral amygdala (BLA) at 2 hours post FSE that predicted epilepsy in adulthood. This signal remains incompletely understood and hypothesized that it might derive from changes to vascular topology. Experimental FSE was induced in rat pups and compared to normothermic littermate controls. We examined cerebral vascular topology at 2 hours, using a novel vessel painting and analysis protocol. Blood vessel density of the cortical vasculature was significantly reduced in FSE rats, and this effect was lateralized, as reported for the MRI signal. The middle cerebral artery (MCA) exhibited abnormal topology in FSE pups but not in controls. In the BLA, significant vessel junction reductions and decreased vessel diameter were observed, together with a strong trend for reduced vessel length. In summary, FSE results in acute vascular topological changes in the cortex and BLA that may underlie the acute MRI signal that predicts progression to future epilepsy. The altered vasculature may be amenable to intervention treatments to potentially reduce the probability of progression to epilepsy following FSE