INTRODUCTION: The loss of oligodendrocyte progenitor cells leading to overall hypomyelination of the brain is a major hallmark in perinatal brain damage. Experimental transplantations of mesenchymal stem cells (MSC) in animal models of perinatal brain damage strongly indicate that
the regenerative effects rely on released factors such as MSC-derived exosomes.
METHODS: Thus, the aim of this study is to investigate the capacity of exosomes from human Wharton’s jelly-derived MSC (WJ-MSC) to determine neural progenitor cells (NPC) towards oligodendroglial cell fate. WJ-MSC-derived exosomes were isolated from culture supernatants by serial high-speed and ultracentrifugations. Exosome microRNA (miRNA) content was assessed by real-time PCR. After 72 h of co-culture with WJ-MSC-derived EV, NPC were evaluated for the expression of markers involved in oligodendroglial specification and differentiation by real-time PCR.
RESULTS: miRNA that are involved in oligodendroglial cell fate specification and differentiation (miR-338, miR-9, miR-19b, miR-138) were present in WJ-MSC-derived exosomes. The expression of miR-338-3p, known to trigger oligodendrocyte specification, was significantly increased in NPC after co-culture with exosomes. In addition, the gene expression of the transcription factor neurogenic differentiation factor 1 (Neurod1), which blocks oligodendrogenic specification and is repressed by miR-338, was significantly reduced in NPC after co-culture with exosomes. Furthermore, the gene expression of the transcription factor Hairy and enhancer of split (HES1) induced by the Notch signaling pathway, which is activated during oligodendroglial specification, was significantly elevated in NPC after incubation with exosomes.
CONCLUSION: In conclusion, isolated WJ-MSC-derived exosomes expressed miRNA having key roles in oligodendrogenesis. Exosomes induced NPC towards oligodendroglial cell fate, ascribing a promising role in neuroregeneration to WJ-MSC-derived exosomes. Financial support by Gottfried and Julia Bangerter-Rhyner Foundation
Abstract Background: Effective management of Inflammatory bowel diseases (IBD) before and during pregnancy is crucial as women with well-controlled IBD at conception tend to remain in remission throughout pregnancy, experiencing outcomes similar to women without IBD. Most IBD medications are considered safe during pregnancy, except for methotrexate. Despite reassuring data, previous studies have highlighted that women often have negative perceptions and fears related to IBD medications, leading to poor adherence. There is a lack of data regarding how IBD is treated before and during pregnancy in Switzerland. We aimed to assess the prevalence and usage patterns of various IBD medications in Switzerland before and during pregnancy over time. Methods: A descriptive study using the MAMA cohort based on Swiss health insurance claims from 2012 to 2019. We identified pregnancies with a pharmaceutical cost group (PCG) indicating IBD and at least one prescribed IBD medication before pregnancy. We defined three groups based on dispensation timing: continuers (dispensation in pre-pregnancy and in or after trimester 2), switchers (different dispensation between pre-pregnancy and in or after trimester 2), and discontinuers (dispensation in pre-pregnancy but no dispensation in or after trimester 2). Results: Among 104,098 deliveries, 0.3% had a PCG code for IBD with an IBD medication dispensed in pre-pregnancy. Over half of these pregnancies were exposed to Aminosalicylates, with a consistent proportion over time. Pregnancies exposed to biologics increased over time, while immunosuppressant use remained steady. Roughly one-third with IBD medication before pregnancy discontinued treatment, a consistent rate throughout the study. Conclusions: Aminosalicylates were the most prescribed medication to treat IBD despite the lack of evidence to support their use as first-line therapy. The increase in biologics' prescriptions likely reflects the growing evidence on the safety of these medications during pregnancy. One in three women discontinued all treatment during pregnancy, with a stable proportion over time. It is not known whether women discontinued treatment due to quiescent disease or concerns about medication harm. If the latter, these women should be identified and counseled, preferably during the pre-conception period, about the risks and benefits of disease and treatment.
The development of a mammalian brain is a complex and long-lasting process. Not surprisingly, preterm birth is the leading cause of death in newborns and children. Advances in perinatal care reduced mortality, but morbidity still represents a major burden. New therapeutic approaches are thus desperately needed. Given that mesenchymal stem/stromal cells (MSCs) emerged as a promising candidate for cell therapy, we transplanted MSCs derived from the Wharton's Jelly (WJ-MSCs) to reduce the burden of immature brain injury in a murine animal model. WJ-MSCs transplantation resulted in protective activity characterized by reduced myelin loss and astroglial activation. WJ-MSCs improved locomotor behavior as well. To address the underlying mechanisms, we tested the key regulators of responses to DNA-damaging agents, such as cyclic AMP-dependent protein kinase/calcium-dependent protein kinase (PKA/PKC), cyclin-dependent kinase (CDK), ataxia-telangiectasia-mutated/ATM- and Rad3-related (ATM/ATR) substrates, protein kinase B (Akt), and 14-3-3 binding protein partners. We characterized WJ-MSCs using a specific profiler polymerase chain reaction array. We provide evidence that WJ-MSCs target pivotal regulators of the cell fate such as CDK/14-3-3/Akt signaling. We identified leukemia inhibitory factor as a potential candidate of WJ-MSCs' induced modifications as well. We hypothesize that WJ-MSCs may exert adaptive responses depending on the type of injury they are facing, making them prominent candidates for cell therapy in perinatal injuries.
Preterm white matter injury (WMI) is an important cause for long-term disability. Stem cell transplantation has been proposed as a novel therapeutic approach. However, intracerebral transplantation is not feasible for clinical purpose in newborns. Intranasal delivery of cells to the brain might be a promising, noninvasive therapeutic approach to restore the damaged brain. Therefore, our goal is to study the remyelinating potential of human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) after intranasal delivery. Wistar rat pups, previously brain-damaged by a combined hypoxic-ischemic and inflammatory insult, received hWJ-MSC (150,000 cells in 3 μL) that were intranasally delivered twice to each nostril (600,000 cells total). WMI was assessed by immunohistochemistry and western blot for myelination, astrogliosis, and microgliosis. The expression of preoligodendrocyte markers, and neurotrophic factors, was analyzed by real-time polymerase chain reaction. Animals treated with intranasally delivered hWJ-MSC showed increased myelination and decreased gliosis compared to untreated animals. hWJ-MSC may, therefore, modulate the activation of microglia and astrocytes, resulting in a change of the brain microenvironment, which facilitates the maturation of oligodendrocyte lineage cells. This is the first study to show that intranasal delivery of hWJ-MSC in rats prevented hypomyelination and microgliosis in a model of WMI in the premature rat brain. Further studies should address the dose and frequency of administration.
