Subventricular zone stem cell niche injury is associated with intestinal perforation in preterm infants and predicts future motor impairment

Brain injury is highly associated with preterm birth. Complications of prematurity, including spontaneous or necrotizing enterocolitis (NEC)-associated intestinal perforations, are linked to lifelong neurologic impairment, yet the mechanisms are poorly understood. Early diagnosis of preterm brain injuries remains a significant challenge. Here, we identified subventricular zone echogenicity (SVE) on cranial ultrasound in preterm infants following intestinal perforations. The development of SVE was significantly associated with motor impairment at 2 years. SVE was replicated in a neonatal mouse model of intestinal perforation. Examination of the murine echogenic subventricular zone (SVZ) revealed NLRP3-inflammasome assembly in multiciliated FoxJ1+ ependymal cells and a loss of the ependymal border in this postnatal stem cell niche. These data suggest a mechanism of preterm brain injury localized to the SVZ that has not been adequately considered. Ultrasound detection of SVE may serve as an early biomarker for neurodevelopmental impairment after inflammatory disease in preterm infants.

The Ependymal Region Prevents Glioblastoma From Penetrating Into the Ventricle via a Nonmechanical Force

Background

Intraventricular penetration is rare in glioblastoma (GBM). Whether the ependymal region including the ependyma and subventricular zone (SVZ) can prevent GBM invasion remains unclear.

Methods

Magnetic resonance imaging (MRI) and haematoxylin–eosin (HE) staining were performed to evaluate the size and anatomical locations of GBM. Binary logistic regression analysis was used to assess the correlation between tumor-ependyma contact, ventricle penetration and clinical characteristics. Cell migration and invasion were assessed via Transwell assays and an orthotopic transplantation model.

Results

Among 357 patients with GBM, the majority (66%) showed ependymal region contact, and 34 patients (10%) showed ventricle penetration of GBM. GBM cells were spread along the ependyma in the orthotopic transplantation model. The longest tumor diameter was an independent risk factor for GBM-ependymal region contact, as demonstrated by univariate (OR = 1.706, p < 0.0001) and multivariate logistic regression analyses (OR = 1.767, p < 0.0001), but was not associated with ventricle penetration. Cerebrospinal fluid (CSF) could significantly induce tumor cell migration (p < 0.0001), and GBM could grow in CSF. Compared with those from the cortex, cells from the ependymal region attenuated the invasion of C6 whether cocultured with C6 or mixed with Matrigel (p = 0.0054 and p = 0.0488). Immunofluorescence analysis shows a thin gap with GFAP expression delimiting the tumor and ependymal region.

Conclusion

The ependymal region might restrict GBM cells from entering the ventricle via a non-mechanical force. Further studies in this area may reveal mechanisms that occur in GBM patients and may enable the design of new therapeutic strategies.

Gliosarcoma with primitive neuronal, chondroid, osteoid and ependymal elements

A 51-year-old man presented with a 2-week history of malaise. MRI revealed a large solid and cystic lesion with ring enhancement measuring 6.5 cm in diameter in the right frontal lobe. Histologically, the tumor consisted of various components: diffuse growth of atypical astrocytic cells consistent with glioblastoma, fascicular proliferation of atypical spindle cells such as fibrosarcoma, clusters of primitive neuronal cells, and foci of ependymal cells. The sarcomatous component also focally exhibited chondroid and osteoid differentiation. Immunohistochemically, tumor cells in the primitive neuronal component were immunoreactive for synaptophysin and CD56. The spindle cells were immunopositive for Slug and Twist, regulators of epithelial-mesenchymal transition. Direct DNA sequencing demonstrated C228T mutation in the TERT promoter in astrocytic, sarcomatous and primitive neuronal components, suggesting their identical origin. Although a few cases of gliosarcoma with primitive neuronal differentiation have previously been described, the finding that neuronal, glial and sarcomatous components share an identical mutation of the TERT promoter has not been reported. The tumor recurred at the original site 11 months after the first surgery. Interestingly, the recurrent tumor was composed exclusively of a glioblastomatous component, unlike past cases of recurrent gliosarcoma.

Cellular reactions of the central nervous system

Major cell types of the central nervous system comprise neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells, and microglia), choroid plexus cells, cells related to blood vessels and coverings. These cells show a wide range of reactions to various noxious agents, which can be detected in routine stainings. Some of these reactions are nonspecific to different injuries; however some, such as the appearance of inclusion bodies, can be highly disease-specific. Immunohistochemical markers are widely used in neuropathologic diagnostic practice and help to understand the pathogenesis of diseases. The most widely used neuronal markers comprise phosphorylated and nonphosphorylated neurofilaments, microtubule-associated protein-2, NeuN, or synaptic markers such as synaptophysin. The best antibody for the detection of astrocytes is anti-GFAP (glial fibrillar acidic protein); however, to support a glial origin, S100 or vimentin is also used in the diagnostic practice. Further astroglial markers include connexin-43, excitatory amino acid transporters, aquaporin-4, heat shock protein Hsp27, and α-B-crystallin. Depending whether the tissue is fixed or nonfixed, different oligodendroglial markers are available, such as myelin basic protein, myelin oligodendrocyte glycoprotein, myelin-associated glycoprotein, proteolipid protein, Olig2, NG2, 2' 3'-cyclic nucleotide 3-phosphodiesterase (CNPase), and tubulin polymerization-promoting protein/p25 alpha (TPPP/p25). A wide range of microglia functions is recognized. Apart from a role in immune-mediated disorders, inflammation, and response to injury, microglia are important during the development and aging of the brain. The best markers include the clone CR3/43, Iba1, and CD68. Evaluation of cell reactions is the first step in the diagnostic procedure.

Discovering the Structure of Nerve Tissue: Part 2: Gabriel Valentin, Robert Remak, and Jan Evangelista Purkyně

During the 1830s, the use of improved microscopic techniques together with new histological methods, including tissue fixation, allowed more precise data to be obtained concerning the structure of nerve tissue of animals as well as humans. The present article, based on the translations of original texts never before published, brings together for the first time the discoveries of famous scholars Gustav Valentin, Robert Remak, and Jan Evangelista Purkyně, who made their significant discoveries in the field of neuroscience almost simultaneously and shows how their findings affected each other. In addition, this article also contains digitally remastered and reconstructed figures published in the original works of Valentin, Remak, and Purkyně and they are displayed for the first time in high quality. Although the fundamental discoveries of these famous scholars did not imply the discovery of nerve cells as we know them today, they were certainly a very important basis for further research of many other eminent scholars during the second half of the nineteenth century.