Laura Vinci

Immunohistochemical markers of neural progenitor cells in the early embryonic human cerebral cortex

The development of the human central nervous system represents a delicate moment of embryogenesis. The purpose of this study was to analyze the expression of multiple immunohistochemical markers in the stem/progenitor cells in the human cerebral cortex during the early phases of development. To this end, samples from cerebral cortex were obtained from 4 human embryos of 11 weeks of gestation. Each sample was formalin-fixed, paraffin embedded and immunostained with several markers including GFAP, WT1, Nestin, Vimentin, CD117, S100B, Sox2, PAX2, PAX5, Tβ4, Neurofilament, CD44, CD133, Synaptophysin and Cyclin D1. Our study shows the ability of the different immunohistochemical markers to evidence different zones of the developing human cerebral cortex, allowing the identification of the multiple stages of differentiation of neuronal and glial precursors. Three important markers of radial glial cells are evidenced in this early gestational age: Vimentin, Nestin and WT1. Sox2 was expressed by the stem/progenitor cells of the ventricular zone, whereas the postmitotic neurons of the cortical plate were immunostained by PAX2 and NSE. Future studies are needed to test other important stem/progenitor cells markers and to better analyze differences in the immunohistochemical expression of these markers during gestation.

WT1 expression in the human fetus during development

Wilms’ Tumor 1 (WT1) is a transcription factor involved in the development of the urogenital system. The purpose of this study was to analyze the immunoreactivity for WT1 protein in different tissues and organs in human fetuses in early phases of gestation. To this end, samples from multiple organs were obtained from 4 human fetuses, ranging from 7 up to 12 weeks of gestation. Each sample was formalin-fixed, paraffin embedded and immunostained for WT1. Our data show that WT1 is involved in development of multiple human organs in a more vast series of cells types than previously reported. Immunostaining for WT1 was characterized by a predominant cytoplasmic reactivity in the vast majority of cell types. Mesenchimal progenitors in the fetal lung, ductal plate progenitors in fetal liver, cap mesenchimal cells in the developing kidney, fetal zone cells in adrenal glands, atrial and ventricular cardiomyocytes in the fetal heart, radial glial cells in the fetal cerebral cortex and skeletal muscle cell precursors showed the highest levels of WT1 immunoreactivity. Future studies will be needed to detect differences in the expression of WT1 in various organs at different gestational ages, in order to better evaluate the role of WT1 in cell proliferation and differentiation during intrauterine human development.

Immunohistochemical markers of stem/progenitor cells in the developing human kidney.

The aim of this study was to better define, by immunohistochemistry, the molecular markers of renal stem/progenitor cells localized in the different niches of ten human preterm kidneys with gestational age ranging from 11 up to 25 weeks. Our data evidence the existence of multiple stem/progenitor pools in different zones of the human developing kidney that are characterized by different phenotypes: capsular stem cells were EMA (MUC1)+, MDM2+, Vimentin+ and Wnt1+; progenitors of the sub-capsular nephrogenic zone were MDM2+ and Wnt1+; cap mesenchymal cells were EMA (MUC1)+, CD15+, vimentin+, Wt1+, CD10+, Bcl2+, Wnt1+ and PAX2+; interstitial progenitor cells were Vimentin+, Wt1+ and α1Anti-tripsin+. Our data evidence the existence of multiple stem/progenitor cell pools in the fetal and neonatal human kidney. Progenitors of these different pools are characterized by a peculiar phenotype, indicating a different differentiation stage of these renal progenitors. A better knowledge of the molecular markers expressed by renal stem/progenitors might represent a relevant datum for researchers involved in renal regenerative medicine.

Interstitial stromal progenitors during kidney development: here, there and everywhere

Abstract In recent years, the renal interstitium has been identified as the site of multiple cell types, giving rise to multiple contiguous cellular networks with multiple fundamental structural and functional roles. Few studies have been carried out on the morphological and functional properties of the stromal/interstitial renal cells during the intrauterine life. This work was aimed at reviewing the peculiar features of renal interstitial stem/progenitor cells involved in kidney development. The origin of the renal interstitial progenitor cells remains unknown. During kidney development, besides the Six2 + cells of the cap mesenchyme, a self-renewing progenitor population, characterized by the expression of Foxd1, represents the first actor of the non-nephrogenic lineage. Foxd1 + interstitial progenitors originate the cortical and the renal medullary interstitial progenitors. Here, the most important stromal/interstitial compartments present in the developing human kidney will be analyzed: capsular stromal cells, cortical interstitial cells, medullary interstitial cells, the interstitium inside the renal stem cell niche, Hilar interstitial cells and Ureteric interstitial cells. Data reported here indicate that the different interstitial compartments of the developing kidney are formed by different cell types that characterize the different renal areas. Further studies are needed to better characterize the different pools of renal interstitial progenitors and their role in human nephrogenesis.

Adrenal stem cell niches are located between adrenal and renal capsules

The human adrenal glands arise around the 4 th week of gestation and during the intrauterine life produce many substances that are responsible for the maintenance of fetal homeostasis and organ maturation. Stem cell niches represent the microenvironment suitable for life and replication of adrenal stem cells. Adrenal gland stem cells have the capacity to self-renew and generate functional differentiated daughter cells that replenish lost cells. Morphologically the adrenal stem cells appeared as small, polymorphic cells, closed together, with basophilic nucleus, located between adrenal and renal capsules. This study was mainly based on a morphological and immunohistochemical approach, particularly on characterization and localization of the multiple stem/progenitor cells that contribute to the development of the human adrenal gland. Proceedings of the 2 nd International Course on Perinatal Pathology (part of the 11 th International Workshop on Neonatology · October 26 th -31 st , 2015) · Cagliari (Italy) · October 31 st , 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

Stem/progenitor cells in the cerebral cortex of the human preterm: a resource for an endogenous regenerative neuronal medicine?

The development of the central nervous system represents a very delicate period of embryogenesis. Premature interruption of neurogenesis in human preterm newborns can lead to motor deficits, including cerebral palsy, and significant cognitive, behavioral or sensory deficits in childhood. Preterm infants also have a higher risk of developing neurodegenerative diseases later in life. In the last decade, great importance has been given to stem/progenitor cells and their possible role in the development and treatment of several neurological disorders. Several studies, mainly carried out on experimental models, evidenced that immunohistochemistry may allow the identification of different neural and glial precursors inside the developing cerebral cortex. However, only a few studies have been performed on markers of human stem cells in the embryonic period. This review aims at illustrating the importance of stem/progenitor cells in cerebral cortex during pre- and post-natal life. Defining the immunohistochemical markers of stem/progenitor cells in the human cerebral cortex during development may be important to develop an “endogenous” target therapy in the perinatal period. Proceedings of the 2 nd International Course on Perinatal Pathology (part of the 11 th International Workshop on Neonatology · October 26 th -31 st , 2015) · Cagliari (Italy) · October 31 st , 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

The small intestinal mucosa and its stem cells

In the first part of this review a brief summary of the embryology and histology of the gastrointestinal tract is provided. In the second part intestinal stem cells (ISCs) are discussed. Several signaling pathways play a crucial role in the crypt base in the regulation of ISC proliferation and self-renewal; Wnt, Notch, BMP, Ephrin, JAK/STAT1, PTEN, AKT, PI3K and many more. Numerous investigators are involved in studying the location, number, and behavior of ISCs within the base of the intestinal crypts. Several markers are espressed by ISCs. Among these, Leucine-rich-repeat-containing G-protein-coupled receptor-5 (Lgr5), Sox9, Prominin-1, DCAMKL-1, EphB2, p-PTEN, p-AKT, Fgfr3, m-TER, and CD44. Stem cell therapy has shown promise for the treatment of some diseases characterized by tissue damage with ischemic and inflammatory lesions like inflammatory bowel disease (IBD) and necrotizing enterocolitis (NEC). Proceedings of the 2 nd International Course on Perinatal Pathology (part of the 11 th International Workshop on Neonatology · October 26 th -31 st , 2015) · Cagliari (Italy) · October 31 st , 2015 · Stem cells: present and future Guest Editors: Gavino Faa, Vassilios Fanos, Antonio Giordano

Structural and cellular changes in fetal renal papilla during development

The mature renal papilla is characterized by medullary collecting ducts, Henle’s loops, vasa recta and the interstitium. Cortical and medullary stromal cells are essential for the regulation of urine concentration and other specialized kidney functions. Mechanisms that direct the renal papilla development are not clearly understood. In recent years, the renal papilla has been identified as a niche for renal stem/progenitor cells in the adult mouse. Studies on experimental animals evidenced a probably common interstitial progenitor for the medullary and cortical stromal cells, characterized by the Foxd1+/PAX2- phenotype. Moreover, Hox10 and Hox11 expression is required for differentiation and patterning of the multiple subtypes of developing medullary interstitial cells. Given the scarcity of morphological and molecular studies on the human renal papilla, this work aimed to evidence morphological changes during human gestation, both in the architecture of the medullary interstitium and in cell types differentiating between the collecting tubules and the Henle’s loops. Future immunohistochemical studies are needed to better identify different interstitial cell types giving rise to the mature interstitium of the renal papilla.

Immunoreactivity pattern of calretinin in the developing human cerebellar cortex

The immunohistochemical expression of the calcium-binding protein calretinin during human cerebellar development has been investigated in this study. Human cerebellum samples, obtained from 7 fetuses and newborns ranging from 11 to 38 weeks of gestation, were 10% formalin-fixed, routinely processed and paraffin-embedded. 3μm-tick sections were immunostained with an anti-calretinin antibody. Our study evidenced a different immunoreactivity for calretinin in Purkinje cells and in several cerebellar interneurons at different intrauterine developmental stages. Whereas at 11 weeks of gestation calretinin immunoreactivity was not detected in the developing cerebellum, from the 18th to the 24th week, calretinin expression was found in Purkinje cells migrating from the ventricular neuroepithelium and in migrating cerebellar interneurons. From the 30th to the 38th week, calretinin was expressed by most of Purkinje cells and by migrating cerebellar interneurons. Furthermore, granule cells in the internal granular layer were also immunoreactive for calretinin. Our data show that calretinin, other than for developing Purkinje cells, is a useful marker also for migrating cerebellar interneurons and for some neuronal elements related to the granular layer. Moreover, given the critical role of calcium in a great variety of neuronal processes in the central nervous system, our findings suggest that calretinin may play a pivotal role in the regulation of neuronal excitability during intrauterine cerebellar development.