Retrieval of germinal zone neural stem cells from the cerebrospinal fluid of premature infants with intraventricular hemorrhage

Stem cell therapies: a new era in the treatment of multiple sclerosis

Multiple Sclerosis (MS) is an immune-mediated condition that persistently harms the central nervous system. While existing treatments can slow its course, a cure remains elusive. Stem cell therapy has gained attention as a promising approach, offering new perspectives with its regenerative and immunomodulatory properties. This article reviews the application of stem cells in MS, encompassing various stem cell types, therapeutic potential mechanisms, preclinical explorations, clinical research advancements, safety profiles of clinical applications, as well as limitations and challenges, aiming to provide new insights into the treatment research for MS.

Neuroendoscopic Lavage and Third Ventriculostomy for the Treatment of Intraventricular Hemorrhage and Hydrocephalus in Neonates. A Prospective Study with 18 Months of Follow-Up

BACKGROUND

 Neonatal intraventricular hemorrhage (IVH) may evolve into posthemorrhagic hydrocephalus and cause neurodevelopmental impairment, becoming a common complication of premature infants, occurring in up to 40% of preterm infants weighing less than 1,500 g at birth. Around 10 to 15% of preterm infants develop severe (grades III-IV) IVH. These infants are at high risk of developing posthemorrhagic hydrocephalus. Neuroendoscopic lavage (NEL) is a suitable alternative for the management of this pathology. In this study, an endoscopic surgical approach directed toward the removal of intraventricular hematoma was evaluated for its safety and efficacy.

METHODS

 Between August 2016 and December 2019 (29 months), 14 neonates with posthemorrhagic hydrocephalus underwent NEL for removal of intraventricular blood by a single senior neurosurgeon. Complications such as reintervention and ventriculoperitoneal (VP) shunt placement were evaluated prospectively with an 18-month follow-up on average.

RESULTS

 In total, 14 neonates with IVH grades III and IV were prospectively recruited. Of these, six neonates did not need a VP shunt in the follow-up after neuroendoscopy (group 1), whereas eight neonates underwent a VP shunt placement (group 2). Nonsignificant difference between the groups was found concerning days after neuroendoscopy, clot extraction, third ventriculostomy, lamina terminalis fenestration, and septum pellucidum fenestration. In group 2, there was shunt dysfunction in five cases with shunt replacement in four cases.

CONCLUSION

 NEL is a feasible technique to remove intraventricular blood degradation products and residual hematoma in neonates suffering from posthemorrhagic hydrocephalus. In our series, endoscopic third ventriculostomy (ETV) + NEL could be effective in avoiding hydrocephalus after hemorrhage (no control group studied). Furthermore, patients without the necessity of VP-shunt had a better GMFCS in comparison with shunted patients.

Design of a Stem Cell-Based Therapy for Ependymal Repair in Hydrocephalus Associated With Germinal Matrix Hemorrhages

BACKGROUND

In preterm birth germinal matrix hemorrhages (GMHs) and the consequent posthemorrhagic hydrocephalus (PHH), the neuroepithelium/ependyma development is disrupted. This work is aimed to explore the possibilities of ependymal repair in GMH/PHH using a combination of neural stem cells, ependymal progenitors (EpPs), and mesenchymal stem cells.

METHODS

GMH/PHH was induced in 4-day-old mice using collagenase, blood, or blood serum injections. PHH severity was characterized 2 weeks later using magnetic resonance, immunofluorescence, and protein expression quantification with mass spectrometry. Ependymal restoration and wall regeneration after stem cell treatments were tested in vivo and in an ex vivo experimental approach using ventricular walls from mice developing moderate and severe GMH/PHH. The effect of the GMH environment on EpP differentiation was tested in vitro. Two-tailed Student t or Wilcoxon-Mann-Whitney U test was used to find differences between the treated and nontreated groups. ANOVA and Kruskal-Wallis tests were used to compare >2 groups with post hoc Tukey and Dunn multiple comparison tests, respectively.

RESULTS

PHH severity was correlated with the extension of GMH and ependymal disruption (means, 88.22% severe versus 19.4% moderate). GMH/PHH hindered the survival rates of the transplanted neural stem cells/EpPs. New multiciliated ependymal cells could be generated from transplanted neural stem cells and more efficiently from EpPs (15% mean increase). Blood and TNFα (tumor necrosis factor alpha) negatively affected ciliogenesis in cells committed to ependyma differentiation (expressing Foxj1 [forkhead box J1] transcription factor). Pretreatment with mesenchymal stem cells improved the survival rates of EpPs and ependymal differentiation while reducing the edematous (means, 18% to 0.5% decrease in severe edema) and inflammatory conditions in the explants. The effectiveness of this therapeutical strategy was corroborated in vivo (means, 29% to 0% in severe edema).

CONCLUSIONS

In GMH/PHH, the ependyma can be restored and edema decreased from either neural stem cell or EpP transplantation in vitro and in vivo. Mesenchymal stem cell pretreatment improved the success of the ependymal restoration.

Therapeutic strategies to recover ependymal barrier after inflammatory damage: relevance for recovering neurogenesis during development

The epithelium covering the surfaces of the cerebral ventricular system is known as the ependyma, and is essential for maintaining the physical and functional integrity of the central nervous system. Additionally, the ependyma plays an essential role in neurogenesis, neuroinflammatory modulation and neurodegenerative diseases. Ependyma barrier is severely affected by perinatal hemorrhages and infections that cross the blood brain barrier. The recovery and regeneration of ependyma after damage are key to stabilizing neuroinflammatory and neurodegenerative processes that are critical during early postnatal ages. Unfortunately, there are no effective therapies to regenerate this tissue in human patients. Here, the roles of the ependymal barrier in the context of neurogenesis and homeostasis are reviewed, and future research lines for development of actual therapeutic strategies are discussed.

Bioengineered tissue and cell therapy products are efficiently cryopreserved with pathogen-inactivated human platelet lysate-based solutions

BACKGROUND

There remains much interest in improving cryopreservation techniques for advanced therapy medicinal products (ATMPs). Recently, human platelet lysate (hPL) has emerged as a promising candidate to replace fetal bovine serum (FBS) as a xeno-free culture supplement for the expansion of human cell therapy products. Whether hPL can also substitute for FBS in cryopreservation procedures remains poorly studied. Here, we evaluated several cryoprotective formulations based on a proprietary hPL for the cryopreservation of bioengineered tissues and cell therapy products.

METHODS

We tested different xenogeneic-free, pathogen-inactivated hPL (ihPL)- and non-inactivated-based formulations for cryopreserving bioengineered tissue (cellularized nanostructured fibrin agarose hydrogels (NFAHs)) and common cell therapy products including bone marrow-derived mesenchymal stromal cells (BM-MSCs), human dermal fibroblasts (FBs) and neural stem cells (NSCs). To assess the tissue and cellular properties post-thaw of NFAHs, we analyzed their cell viability, identity and structural and biomechanical properties. Also, we evaluated cell viability, recovery and identity post-thaw in cryopreserved cells. Further properties like immunomodulation, apoptosis and cell proliferation were assessed in certain cell types. Additionally, we examined the stability of the formulated solutions. The formulations are under a bidding process with MD Bioproducts (Zurich, Switzerland) and are proprietary.

RESULTS

Amongst the tissue-specific solutions, Ti5 (low-DMSO and ihPL-based) preserved the viability and the phenotype of embedded cells in NFAHs and preserved the matrix integrity and biomechanical properties similar to those of the standard cryopreservation solution (70% DMEM + 20% FBS + 10% DMSO). All solutions were stable at - 20 °C for at least 3 months. Regarding cell-specific solutions, CeA maintained the viability of all cell types > 80%, preserved the immunomodulatory properties of BM-MSCs and promoted good recovery post-thaw. Besides, both tested solutions were stable at - 20 °C for 18 months. Finally, we established that there is a 3-h window in which thawed NFAHs and FBs maintain optimum viability immersed in the formulated solutions and at least 2 h for BM-MSCs.

CONCLUSIONS

Our results show that pathogen-inactivated solutions Ti5 allocated for bioengineered tissues and CeA allocated for cells are efficient and safe candidates to cryopreserve ATMPs and offer a xenogeneic-free and low-DMSO alternative to commercially available cryoprotective solutions.

Endogenous neural stem cells characterization using omics approaches: Current knowledge in health and disease

Neural stem cells (NSCs), an invaluable source of neuronal and glial progeny, have been widely interrogated in the last twenty years, mainly to understand their therapeutic potential. Most of the studies were performed with cells derived from pluripotent stem cells of either rodents or humans, and have mainly focused on their potential in regenerative medicine. High-throughput omics technologies, such as transcriptomics, epigenetics, proteomics, and metabolomics, which exploded in the past decade, represent a powerful tool to investigate the molecular mechanisms characterizing the heterogeneity of endogenous NSCs. The transition from bulk studies to single cell approaches brought significant insights by revealing complex system phenotypes, from the molecular to the organism level. Here, we will discuss the current literature that has been greatly enriched in the “omics era”, successfully exploring the nature and function of endogenous NSCs and the process of neurogenesis. Overall, the information obtained from omics studies of endogenous NSCs provides a sharper picture of NSCs function during neurodevelopment in healthy and in perturbed environments.

Brain Organoids to Evaluate Cellular Therapies

Animal models currently used to test the efficacy and safety of cell therapies, mainly murine models, have limitations as molecular, cellular, and physiological mechanisms are often inherently different between species, especially in the brain. Therefore, for clinical translation of cell-based medicinal products, the development of alternative models based on human neural cells may be crucial. We have developed an in vitro model of transplantation into human brain organoids to study the potential of neural stem cells as cell therapeutics and compared these data with standard xenograft studies in the brain of immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice. Neural stem cells showed similar differentiation and proliferation potentials in both human brain organoids and mouse brains. Our results suggest that brain organoids can be informative in the evaluation of cell therapies, helping to reduce the number of animals used for regulatory studies.

Relationship of plasma MBP and 8-oxo-dG with brain damage in preterm

Preterm infants face a significant risk of brain injury in the perinatal period, as well as potential long-term neurodevelopmental disabilities. However, preterm children with brain injury lack specific clinical manifestations in the early days. Therefore, timely and accurate diagnosis of brain injury is of vital importance. This study was to explore the diagnostic efficiency of myelin basic protein (MBP) and 8-oxo-deoxyguanosine (8-oxo-dG) serum levels in brain injury of premature infants. A total of 75 preterm infants with gestational age between 28 and 32 weeks and birth weight higher than 1,000 g were prospectively included. MBP serum levels were significantly higher in premature infants with white matter injury (WMI). 8-oxo-dG serum levels were significantly increased in both WMI and periventricular–intraventricular hemorrhages (PIVH). MBP and 8-oxo-dG were significantly correlated. The area under the curve was 0.811 [95% confidence interval (CI) 0.667–0.955; p = 0.002] in MBP and 0.729 (95% CI 0.562–0.897; p = 0.020) in 8-oxo-dG. Therefore, the results showed that high MBP levels indicated a possibility of WMI in the premature brain during the early postnatal period, while high 8-oxo-dG levels were closely related to both WMI and PIVH, thus suggesting that MBP and 8-oxo-dG could be used as potential neuro-markers of preterm brain injury.

AQP4, Astrogenesis, and Hydrocephalus: A New Neurological Perspective

Aquaporin 4 (AQP4) is a cerebral glial marker that labels ependymal cells and astrocytes’ endfeet and is the main water channel responsible for the parenchymal fluid balance. However, in brain development, AQP4 is a marker of glial stem cells and plays a crucial role in the pathophysiology of pediatric hydrocephalus. Gliogenesis characterization has been hampered by a lack of biomarkers for precursor and intermediate stages and a deeper understanding of hydrocephalus etiology is needed. This manuscript is a focused review of the current research landscape on AQP4 as a possible biomarker for gliogenesis and its influence in pediatric hydrocephalus, emphasizing reactive astrogliosis. The goal is to understand brain development under hydrocephalic and normal physiologic conditions.

Multicentric Glioma: An Ideal Model to Reveal the Mechanism of Glioma

As a special type of glioma, multicentric glioma provides an ideal pathological model for glioma research. According to the stem-cell-origin theory, multiple lesions of multicentric glioma share the same neuro-oncological origin, both in gene level and in cell level. Although the number of studies focusing on genetic evolution in gliomas with the model of multicentric gliomas were limited, some mutations, including IDH1 mutations, TERTp mutations and PTEN deletions, are found to be at an early stage in the process of genetic aberrance during glioma evolution based on the results of these studies. This article reviews the clinical reports and genetic studies of multicentric glioma, and intends to explain the various clinical phenomena of multicentric glioma from the perspective of genetic aberrance accumulation and tumor cell evolution. The malignant degree of a glioma is determined by both the tumorigenicity of early mutant genes, and the stemness of early suffered cells.

Modeling chronic cervical spinal cord injury in aged rats for cell therapy studies

With an expanding elderly population, an increasing number of older adults will experience spinal cord injury (SCI) and might be candidates for cell-based therapies, yet there is a paucity of research in this age group. The objective of the present study was to analyze how aged rats tolerate behavioral testing, surgical procedures, post-operative complications, intra-spinal cell transplantation and immunosuppression, and to examine the effectiveness of human iPSC-derived Neural Progenitor Cells (IMR90-hiPSC-NPCs) in a model of SCI. We performed behavioral tests in rats before and after inducing cervical hemi-contusions at C4 level with a fourth-generation Ohio State University Injury Device. Four weeks later, we injected IMR90-hiPSC-NPCs in animals that were immunosuppressed by daily cyclosporine injection. Four weeks after injection we analyzed locomotor behavior and mortality, and histologically assessed the survival of transplanted human NPCs. As rats aged, their success at completing behavioral tests decreased. In addition, we observed high mortality rates during behavioral training (41.2%), after cervical injury (63.2%) and after cell injection (50%). Histological analysis revealed that injected cells survived and remained at and around the grafted site and did not cause tumors. No locomotor improvement was observed in animals four weeks after IMR90-hiPSC-NPC transplantation. Our results show that elderly rats are highly vulnerable to interventions, and thus large groups of animals must be initially established to study the potential efficacy of cell-based therapies in age-related chronic myelopathies.

Human Neural Stem Cells for Cell-Based Medicinal Products

Neural stem cells represent an attractive tool for the development of regenerative therapies and are being tested in clinical trials for several neurological disorders. Human neural stem cells can be isolated from the central nervous system or can be derived in vitro from pluripotent stem cells. Embryonic sources are ethically controversial and other sources are less well characterized and/or inefficient. Recently, isolation of NSC from the cerebrospinal fluid of patients with spina bifida and with intracerebroventricular hemorrhage has been reported. Direct reprogramming may become another alternative if genetic and phenotypic stability of the reprogrammed cells is ensured. Here, we discuss the advantages and disadvantages of available sources of neural stem cells for the production of cell-based therapies for clinical applications. We review available safety and efficacy clinical data and discuss scalability and quality control considerations for manufacturing clinical grade cell products for successful clinical application.

Advances and Perspectives in Dental Pulp Stem Cell Based Neuroregeneration Therapies

Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs. We also review the recent progress on neuroprotective and immunomodulatory capacity of hDPSCs and their secreted extracellular vesicles, as well as their combination with scaffold materials to improve their functional integration on the injured central nervous system (CNS) and peripheral nervous system (PNS). Finally, we offer some perspectives on the current and possible future applications of hDPSCs in neuroregenerative cell therapies.

Retrieval of germinal zone neural stem cells from the cerebrospinal fluid of premature infants with intraventricular hemorrhage

Intraventricular hemorrhage is a common cause of morbidity and mortality in premature infants. The rupture of the germinal zone into the ventricles entails loss of neural stem cells and disturbs the normal cytoarchitecture of the region, compromising late neurogliogenesis. Here we demonstrate that neural stem cells can be easily and robustly isolated from the hemorrhagic cerebrospinal fluid obtained during therapeutic neuroendoscopic lavage in preterm infants with severe intraventricular hemorrhage. Our analyses demonstrate that these neural stem cells, although similar to human fetal cell lines, display distinctive hallmarks related to their regional and developmental origin in the germinal zone of the ventral forebrain, the ganglionic eminences that give rise to interneurons and oligodendrocytes. These cells can be expanded, cryopreserved, and differentiated in vitro and in vivo in the brain of nude mice and show no sign of tumoral transformation 6 months after transplantation. This novel class of neural stem cells poses no ethical concerns, as the fluid is usually discarded, and could be useful for the development of an autologous therapy for preterm infants, aiming to restore late neurogliogenesis and attenuate neurocognitive deficits. Furthermore, these cells represent a valuable tool for the study of the final stages of human brain development and germinal zone biology.