The triple-I (interactive, intersectorial, interdisciplinary) approach to validate “omics” investigations on body fluids and tissues in perinatal medicine

Lessons learned from proteome analysis of perinatal neurovascular pathologies

INTRODUCTION

Perinatal and pediatric diseases related to neurovascular disorders cause significant problems during life, affecting a population with a long life expectancy. Early diagnosis and assessment of the severity of these diseases are crucial to establish an appropriate neuroprotective treatment. Currently, physical examination, neuroimaging and clinical judgment are the main tools for diagnosis, although these tests have certain limitations. There is growing interest in the potential value of noninvasive biomarkers that can be used to monitor child patients at risk of brain damage, allowing accurate, and reproducible measurements.

AREAS COVERED

This review describes potential biomarkers for the diagnosis of perinatal neurovascular diseases and discusses the possibilities they open for the classification and treatment of neonatal neurovascular diseases.

EXPERT OPINION

Although high rates of ischemic and hemorrhagic stroke exist in pediatric populations, most studies have focused on biomarkers of hypoxic-ischemic encephalopathy. Inflammatory and neuronal biomarkers such as S-100B and GFAP, in combination with others yet to be discovered, could be considered as part of multiplex panels to diagnose these diseases and potentially for monitoring response to treatments. Ideally, noninvasive biofluids would be the best source for evaluating these biomarkers in proteomic assays in perinatal patients.

Each niche has an actor: multiple stem cell niches in the preterm kidney

The preterm kidney cannot be simply considered as a kidney small in size: as compared to the adult kidney, the developing organ of the preterm infant is characterized by marked differences regarding the architecture and cell components. At macroscopy, fine linear demarcations indenting the renal surface characterize the fetal and preterm kidney. At microscopy, multiple major architectural changes differentiate the developing kidney from the adult one: a large capsule with a high cellularity; the branching ureteric bud, extending from the hilum towards the renal capsule; striking morphological differences among superficial (just born) and deep (more mature) glomeruli; persistence of remnants of the metanephric mesenchyme in the hylum; incomplete differentiation of developing proximal and distal tubules. At cellular level, kidneys of preterm infants are characterized by huge amounts of stem/precursor cells showing different degrees of differentiation, admixed with mature cell types. The most striking difference between the preterm and adult kidney is represented by the abundance of stem/progenitor cells in the former. Multiple stem cell niches may be identified in the preterm kidney, including the capsule, the sub-capsular nephrogenic zone, the cap mesenchyme embracing the ureteric bud tips, the cortical and medullary interstitium, and the hilar zone in proximity of the ureteric origin. The sub-capsular area represents the major stem cell niche in the prenatal kidney. It has been defined “blue strip”, due to the scarcity of cytoplasm of the undifferentiated stem/progenitors, which appear as small cells arranged in a solid pattern. All these data taken together, the morphological approach to the analysis of the preterm kidney appears completely different from that typically utilized in kidney biopsies from adult subjects. Such a different structure should be taken into account when evaluating renal function in a preterm infant in clinical practice. Moreover, a better knowledge of molecular biology of the blue strip stem/progenitor cells could be at the basis of a new “endogenous” regenerative medicine, finalized to maintain and protect the nephrogenic potential of preterm infants till the 36th week of post-conceptional age, allowing them to escape oligonephronia and chronic kidney disease later in life.