Brain Derived Neurotrophic Factor: A Foray Into Predicting Neonatal Outcomes In Premature Infants

The need to accurately predict the ability of a prematurely born infant to recover from hypoxia induced damage associated with prematurity is rooted in our need to develop better interventions, with fewer side-effects, with which to treat these complicated patients. Previous work done in murine models mimicking hypoxia induced damage and its neurological sequelae have suggested hypoxia induced factor-1alpha; (HIF-1alpha), and its downstream effector molecules, brain derived neurotrophic factor (BDNF) and stromal derived factor-1 (SDF-1), may play an integral role in protecting the developing brain from the deleterious effects of low O2. Moreover, a number of single nucleotide polymorphisms (SNPs) have been identified, which affect the expression of these proteins on an individual basis. To that end, we hypothesized that BDNF expression levels gathered from venous cord blood, and genetic analysis for the presence of the rs6265 and rs1801157 SNPs in the BDNF and SDF-1 genes could be used as biochemical and genetic biomarkers to predict short term neonatal outcomes in premature infants born at Yale New Haven Hospital. BDNF levels, determined by quantitative ELISA in 23 patients, and the presence of SNPs, determined in duplicate by restriction fragment length polymorphism assay and Sanger sequencing in 53 patients, were correlated with the development of a variety of neonatal outcomes. Our results indicated that although not statistically significant, the development of bronchopulmonary dysplasia, necrtotizing enterocolitis, and early onset neonatal sepsis (EONS) trended towards an association with lower cord blood BDNF levels (p-values \u3c0.10). Likewise, the presence of the rs6265 SNP appeared to be protective against the development of culture positive EONS (p \u3c 0.08), while the presence of rs1801157 SNP appeared to be protective against the development of clinical EONS. Taken together, these data suggest that while cord blood BDNF levels and the presence of the rs6265 and rs1801157 SNPs show potential as useful molecular and genetic biomarkers for predicting outcomes of premature infants, the association between these factors and neonatal outcomes is not strong enough for the number of patients examined in this study to provide conclusive results of the utility of these biomarkers in guiding clinical decision making. Consequently, further research of these, and other, biomarkers is necessary to better elucidate their usefulness

Corneal Injury Is Associated With Stromal and Vascular Alterations Within Cranial Dura Mater

The cornea and cranial dura mater share sensory innervation. This link raises the possibility that pathological impulses mediated by corneal injury may be transmitted to the cranial dura, trigger dural perivascular/connective tissue nociceptor responses, and induce vascular and stromal alterations affecting dura mater blood and lymphatic vessel functionality. In this study, using a mouse model, we demonstrate for the first time that two weeks after the initial insult, alkaline injury to the cornea leads to remote pathological changes within the coronal suture area of the dura mater. Specifically, we detected significant pro-fibrotic changes in the dural stroma, as well as vascular remodeling characterized by alterations in vascular smooth muscle cell (VSMC) morphology, reduced blood vessel VSMC coverage, endothelial cell expression of the fibroblast specific protein 1, and significant increase in the number of podoplanin-positive lymphatic sprouts. Intriguingly, the deficiency of a major extracellular matrix component, small leucine-rich proteoglycan decorin, modifies both the direction and the extent of these changes. As the dura mater is the most important route for the brain metabolic clearance, these results are of clinical relevance and provide a much-needed link explaining the association between ophthalmic conditions and the development of neurodegenerative diseases

Therapeutic Implications of GIPC1 Silencing in Cancer

GIPC1 is a cytoplasmic scaffold protein that interacts with numerous receptor signaling complexes, and emerging evidence suggests that it plays a role in tumorigenesis. GIPC1 is highly expressed in a number of human malignancies, including breast, ovarian, gastric, and pancreatic cancers. Suppression of GIPC1 in human pancreatic cancer cells inhibits in vivo tumor growth in immunodeficient mice. To better understand GIPC1 function, we suppressed its expression in human breast and colorectal cancer cell lines and human mammary epithelial cells (HMECs) and assayed both gene expression and cellular phenotype. Suppression of GIPC1 promotes apoptosis in MCF-7, MDA-MD231, SKBR-3, SW480, and SW620 cells and impairs anchorage-independent colony formation of HMECs. These observations indicate GIPC1 plays an essential role in oncogenic transformation, and its expression is necessary for the survival of human breast and colorectal cancer cells. Additionally, a GIPC1 knock-down gene signature was used to interrogate publically available breast and ovarian cancer microarray datasets. This GIPC1 signature statistically correlates with a number of breast and ovarian cancer phenotypes and clinical outcomes, including patient survival. Taken together, these data indicate that GIPC1 inhibition may represent a new target for therapeutic development for the treatment of human cancers

Pulsed Estrogen Therapy Prevents Post-OVX Porcine Dura Mater Microvascular Network Weakening via a PDGF-BB-Dependent Mechanism

<div><p>In postmenopausal women, estrogen (E2) deficiencies are frequently associated with higher risk of intracranial hemorrhage, increased incidence of stroke, cerebral aneurysm, and decline in cognitive abilities. In younger postpartum women and those using oral contraceptives, perturbations in E2 are associated with higher risk of cerebral venous thrombosis. A number of serious intracranial pathologic conditions linked to E2 deficiencies, such as dural sinus thrombosis, dural fistulae, non-parenchymal intracranial hemorrhages, migraines, and spontaneous cerebrospinal fluid leaks, involve the vessels not of the brain itself, but of the outer fibrous membrane of the brain, the dura mater (DM). The pathogenesis of these disorders remains mysterious and how estrogen regulates structural and functional integrity of DM vasculature is largely unknown. Here, we demonstrate that post ovariectomy (OVX) DM vascular remodeling is manifested by microvessel destabilization, capillary rarefaction, increased vascular permeability, and aberrant angio-architecture, and is the result of disrupted E2-regulated PDGF-BB signaling within dura microvasculature. These changes, associated with the reduction in systemic PDGF-BB levels, are not corrected by a flat-dose E2 hormone replacement therapy (HRT), but are largely prevented using HRT schedules mimicking physiological E2 fluctuations. We demonstrate that 1) E2 regulates PDGF-BB production by endothelial cells in a dose-dependent manner and 2) optimization of PDGF-BB levels and induction of robust PDGF-mediated endothelial cell-vascular pericyte interactions require high (estrous) E2 concentrations. We conclude that high (estrous) levels of E2 are important in controlling PDGF-mediated crosstalk between endothelial cells and pericytes, a fundamental mechanism governing microvessel stability and essential for preserving intracranial homeostasis.</p></div

A, changes in microvessel wall intrinsic curvature in response to OVX, FD HRT, and P HRT. Data presented as mean ± standard error of mean. B and C, Formation of multiple focal dilations/microaneurysms (asterisks) in DM microvasculature following OVX (C) compared to intact female (IF) animals (B). D and E, Reduced pericyte decoration of pig meningeal microvessels following OVX (E) compared with intact females (IF) animals (D) as revealed by fluorescent microscopy using mesenchymal progenitor marker SBA (Soybean Agglutinin).

<p>A, changes in microvessel wall intrinsic curvature in response to OVX, FD HRT, and P HRT. Data presented as mean ± standard error of mean. B and C, Formation of multiple focal dilations/microaneurysms (asterisks) in DM microvasculature following OVX (C) compared to intact female (IF) animals (B). D and E, Reduced pericyte decoration of pig meningeal microvessels following OVX (E) compared with intact females (IF) animals (D) as revealed by fluorescent microscopy using mesenchymal progenitor marker SBA (Soybean Agglutinin).</p

Brain endothelial cells bEnd.3 and brain vascular pericytes HBVP (red) do not form 3-D networks under basal conditions (A).

<p>Low diestrous E2 level (10⁻¹¹ M) only marginally improves pericyte association with endothelial cells (B). In the presence of high estrous E2 level (10⁻¹⁰ M) bEnd.3 and HBVP form vast 3-D networks within 24 h (C). Neither control IgG (D) nor function blocking anti-VEGF antibody (E) inhibit microtubular network formation by brain endothelial cells and brain vascular pericytes in response to high E2 concentration. Function blocking anti-PDGF-BB antibody completely abolishes the ability of brain endothelial cells and brain vascular pericytes to form microtubular networks in response to high E2 level (F).</p

Vessel wall extrinsic curvature is used to describe nonlinearity of blood vessels.

<p>For the purpose of this study, extrinsic curvature of a line at a given point is a measure of how quickly the curve changes direction at that point and, therefore, is defined as the magnitude of the rate of change of the unit tangent vector T with respect to the arc length s. Thus, for the curve on the x-y plane, the extrinsic curvature k(x) is calculated by the formula shown.</p

Corneal injury is associated with stromal and vascular alterations within cranial dura mater.

The cornea and cranial dura mater share sensory innervation. This link raises the possibility that pathological impulses mediated by corneal injury may be transmitted to the cranial dura, trigger dural perivascular/connective tissue nociceptor responses, and induce vascular and stromal alterations affecting dura mater blood and lymphatic vessel functionality. In this study, using a mouse model, we demonstrate for the first time that two weeks after the initial insult, alkaline injury to the cornea leads to remote pathological changes within the coronal suture area of the dura mater. Specifically, we detected significant pro-fibrotic changes in the dural stroma, as well as vascular remodeling characterized by alterations in vascular smooth muscle cell (VSMC) morphology, reduced blood vessel VSMC coverage, endothelial cell expression of the fibroblast specific protein 1, and significant increase in the number of podoplanin-positive lymphatic sprouts. Intriguingly, the deficiency of a major extracellular matrix component, small leucine-rich proteoglycan decorin, modifies both the direction and the extent of these changes. As the dura mater is the most important route for the brain metabolic clearance, these results are of clinical relevance and provide a much-needed link explaining the association between ophthalmic conditions and the development of neurodegenerative diseases