Cytokines Induce Monkey Neural Stem Cell Differentiation through Notch Signaling

Sodium tanshinone IIA sulfonate promotes proliferation and differentiation of endogenous neural stem cells to repair rat spinal cord injury via the Notch pathway

BACKGROUND

Interventions that promote the proliferation of endogenous neural stem cells (ENSCs) and induce their differentiation into neurons after spinal cord injury (SCI) hold significant potential for SCI repair. Tanshinone IIA (TIIA) exhibits extensive neuroprotective effects, and its derivative, sodium tanshinone IIA sulfonate (STS), has enhanced water solubility, making it easier to prepare injectable formulations and increasing bioavailability. STS injections have been extensively utilized in the treatment of cardiovascular and cerebrovascular diseases, and their clinical application in SCI shows promising potential. However, it remains unclear whether STS can promote spinal cord injury repair in rats by modulating the proliferation and differentiation of ENSCs, and the underlying regulatory mechanisms are yet to be elucidated.

METHODS

In this study, an incomplete spinal cord injury model was established in rats using the NYU spinal cord impactor. The regulatory effects of STS on ENSCs in rats post-SCI were observed by detecting the NSC marker Nestin, the neuronal marker NeuN, and the astrocyte marker GFAP. Additionally, rat behavioral assessments, histopathology, serum inflammation indices, and Notch signaling pathway activation were evaluated. In vitro experiments utilized an lipopolysaccharide (LPS)-induced rats spinal cord NSCs inflammation model. The effects of STS on the proliferation and viability of rats spinal cord NSCs were assessed using the CCK-8 assay and immunofluorescence cell counting. The mechanisms by which STS regulates NSC proliferation and differentiation via the Notch pathway were verified using immunofluorescence, Western blot, and RT-PCR techniques.

RESULTS

In vitro, STS significantly reduced the levels of inflammatory indices in the LPS-induced rats NSCs inflammation model and improved the viability of rats NSCs following inflammatory injury. STS also significantly increased the proliferation of NSCs and their differentiation into neurons while reducing their differentiation into astrocytes. Moreover, LPS significantly activated the Notch pathway, similar to the effects of the Notch pathway agonist valproic acid (VPA), whereas STS intervention could inhibit the LPS- or VPA-induced activation of the Notch pathway. In vivo, STS markedly improved the hindlimb motor function of rats with SCI, decreased the levels of pro-inflammatory factors IL-6 and TNF-α, and increased the level of the anti-inflammatory factor IL-10, thereby improving the pathological morphology of the injured spinal cord in rats post-SCI. STS effectively promoted the proliferation of ENSCs post-SCI, facilitated their differentiation into neurons, and inhibited their differentiation into astrocytes. Additionally, STS suppressed the excessive activation of the Notch signaling pathway following SCI.

CONCLUSION

STS promotes the proliferation of ENSCs post-SCI in rats, induces their differentiation into neurons, and inhibits their differentiation into astrocytes, thereby improving the pathological morphology of the injured spinal cord and promoting the recovery of hindlimb motor function in rats post-SCI. Furthermore, the regulatory effects of STS on the proliferation and differentiation of ENSCs post-SCI in rats may be related to its inhibition of the excessive activation of the Notch signaling pathway.

Noggin-Loaded PLA/PCL Patch Inhibits BMP-Initiated Reactive Astrogliosis

Myelomeningocele (MMC) is a congenital birth defect of the spine and spinal cord, commonly treated clinically through prenatal or postnatal surgery by repairing the unclosed spinal canal. Having previously developed a PLA/PCL polymer smart patch for this condition, we aim to further expand the potential therapeutic options by providing additional cellular and biochemical support in addition to its mechanical properties. Bone morphogenetic proteins (BMPs) are a large class of secreted factors that serve as modulators of development in multiple organ systems, including the CNS. We hypothesize that our smart patch mitigates the astrogenesis induced, at least partly, by increased BMP activity during MMC. To test this hypothesis, neural stem or precursor cells were isolated from rat fetuses and cultured in the presence of Noggin, an endogenous antagonist of BMP action, with recombinant BMPs. We found that the developed PLA/PCL patch not only serves as a biocompatible material for developing neural stem cells but was also able to act as a carrier for BMP-Notch pathway inhibitor Noggin, effectively minimizing the effect of BMP2 or BMP4 on NPCs cultured with the Noggin-loaded patch.

The roles and applications of neural stem cells in spinal cord injury repair

Spinal cord injury (SCI), which has no current cure, places a severe burden on patients. Stem cell-based therapies are considered promising in attempts to repair injured spinal cords; such options include neural stem cells (NSCs). NSCs are multipotent stem cells that differentiate into neuronal and neuroglial lineages. This feature makes NSCs suitable candidates for regenerating injured spinal cords. Many studies have revealed the therapeutic potential of NSCs. In this review, we discuss from an integrated view how NSCs can help SCI repair. We will discuss the sources and therapeutic potential of NSCs, as well as representative pre-clinical studies and clinical trials of NSC-based therapies for SCI repair.

Neural stem cell therapy for brain disease

Brain diseases, including brain tumors, neurodegenerative disorders, cerebrovascular diseases, and traumatic brain injuries, are among the major disorders influencing human health, currently with no effective therapy. Due to the low regeneration capacity of neurons, insufficient secretion of neurotrophic factors, and the aggravation of ischemia and hypoxia after nerve injury, irreversible loss of functional neurons and nerve tissue damage occurs. This damage is difficult to repair and regenerate the central nervous system after injury. Neural stem cells (NSCs) are pluripotent stem cells that only exist in the central nervous system. They have good self-renewal potential and ability to differentiate into neurons, astrocytes, and oligodendrocytes and improve the cellular microenvironment. NSC transplantation approaches have been made for various neurodegenerative disorders based on their regenerative potential. This review summarizes and discusses the characteristics of NSCs, and the advantages and effects of NSCs in the treatment of brain diseases and limitations of NSC transplantation that need to be addressed for the treatment of brain diseases in the future.

In vitro characterization of subventricular zone isolated neural stem cells, from adult monkey and rat brain

Neural stem cells (NSCs) are multipotent, self-renewable cells who are capable of differentiating into neurons, astrocytes, and oligodendrocytes. NSCs reside at the subventricular zone (SVZ) of the adult brain permanently to guarantee a lifelong neurogenesis during neural network plasticity or undesirable injuries. Although the specious inaccessibility of adult NSCs niche hampers their in vivo identification, researchers have been seeking ways to optimize adult NSCs isolation, expansion, and differentiation, in vitro. NSCs were isolated from rhesus monkey SVZ, expanded in vitro and then characterized for NSCs-specific markers expression by immunostaining, real-time PCR, flow cytometry, and cell differentiation assessments. Moreover, cell survival as well as self-renewal capacity were evaluated by TUNEL, Live/Dead and colony assays, respectively. In the next step, to validate SVZ-NSCs identity in other species, a similar protocol was applied to isolate NSCs from adult rat's SVZ as well. Our findings revealed that isolated SVZ-NSCs from both monkey and rat preserve proliferation capacity in at least nine passages as confirmed by Ki67 expression. Additionally, both SVZ-NSCs sources are capable of self-renewal in addition to NESTIN, SOX2, and GFAP expression. The mortality was measured meager with over 95% viability according to TUNEL and Live/Dead assay results. Eventually, the multipotency of SVZ-NSCs appraised authentic after their differentiation into neurons, astrocytes, and oligodendrocytes. In this study, we proposed a reliable method for SVZ-NSCs in vitro maintenance and identification, which, we believe is a promising cell source for therapeutic approach to recover neurological disorders and injuries condition.

Targeting Liver Cancer Stem Cells: An Alternative Therapeutic Approach for Liver Cancer

The first report of cancer stem cell (CSC) from Bruce et al. has demonstrated the relatively rare population of stem-like cells in acute myeloid leukemia (AML). The discovery of leukemic CSCs prompted further identification of CSCs in multiple types of solid tumor. Recently, extensive research has attempted to identity CSCs in multiple types of solid tumors in the brain, colon, head and neck, liver, and lung. Based on these studies, we hypothesize that the initiation and progression of most malignant tumors rely largely on the CSC population. Recent studies indicated that stem cell-related markers or signaling pathways, such as aldehyde dehydrogenase (ALDH), CD133, epithelial cell adhesion molecule (EpCAM), Wnt/β-catenin signaling, and Notch signaling, contribute to the initiation and progression of various liver cancer types. Importantly, CSCs are markedly resistant to conventional therapeutic approaches and current targeted therapeutics. Therefore, it is believed that selectively targeting specific markers and/or signaling pathways of hepatic CSCs is an effective therapeutic strategy for treating chemotherapy-resistant liver cancer. Here, we provide an overview of the current knowledge on the hepatic CSC hypothesis and discuss the specific surface markers and critical signaling pathways involved in the development and maintenance of hepatic CSC subpopulations.