Neural stem cells transplantation combined with ethyl stearate improve PD rats motor behavior by promoting NSCs migration and differentiation

Human neural stem cells promote mitochondrial genesis to alleviate neuronal damage in MPTP-induced cynomolgus monkey models

Currently, there is no effective treatment for Parkinson's disease (PD), and the regenerative treatment of neural stem cells (NSCs) is considered the most promising method. This study aimed to investigate the protective effect and mechanism of NSCs on neurons in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced cynomolgus monkey (Macaca fascicularis) model of PD. We first found that injecting NSCs into the subarachnoid space relieved motor dysfunction in PD cynomolgus monkeys, as well as reduced dopaminergic neuron loss and neuronal damage in the substantia nigra (SN) and striatum. Besides, NSCs decreased 17-estradiol (E2) level, an estrogen, in the cerebrospinal fluid (CSF) of PD cynomolgus monkeys, which shows NSCs may provide neuro-protection by controlling estrogen levels in the CSF. Furthermore, NSCs elevated proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a), mitofusin 2 (MFN2), and optic atrophy 1 (OPA1) expression, three genes mediating mitochondrial biogenesis, in the SN and striatum of PD monkeys. In addition, NSCs suppress reactive oxygen species (ROS) production caused by MPTP, as well as mitochondrial autophagy, therefore preserving dopaminergic neurons. In summary, our findings show that NSCs may preserve dopaminergic and neuronal cells in an MPTP-induced PD cynomolgus monkey model. These protective benefits might be attributed to NSCs' ability of modulating estrogen balance, increasing mitochondrial biogenesis, and limiting oxidative stress and mitochondrial autophagy. These findings add to our understanding of the mechanism of NSC treatment and shed light on further clinical treatment options.

Survival and maturation of human induced pluripotent stem cell-derived dopaminergic progenitors in the parkinsonian rat brain is enhanced by transplantation in a neurotrophin-enriched hydrogel

Objective.Although human induced pluripotent stem cell (iPSC)-derived cell replacement for Parkinson's disease has considerable reparative potential, its full therapeutic benefit is limited by poor graft survival and dopaminergic maturation. Injectable biomaterial scaffolds, such as collagen hydrogels, have the potential to address these issues via a plethora of supportive benefits including acting as a structural scaffold for cell adherence, shielding from the host immune response and providing a reservoir of neurotrophic factors to aid survival and differentiation. Thus, the aim of this study was to determine if a neurotrophin-enriched collagen hydrogel could improve the survival and maturation of iPSC-derived dopaminergic progenitors (iPSC-DAPs) after transplantation into the rat parkinsonian brain.Approach.Human iPSC-DAPs were transplanted into the 6-hydroxydopamine-lesioned striatum either alone, with the neurotrophins GDNF and BDNF, in an unloaded collagen hydrogel, or in a neurotrophin-loaded collagen hydrogel.Post-mortem, human nuclear immunostaining was used to identify surviving iPSC-DAPs while tyrosine hydroxylase immunostaining was used to identify iPSC-DAPs that had differentiated into mature dopaminergic neurons.Main results.We found that iPSC-DAPs transplanted in the neurotrophin-enriched collagen hydrogel survived and matured significantly better than cells implanted without the biomaterial (8 fold improvement in survival and 16 fold improvement in dopaminergic differentiation). This study shows that transplantation of human iPSC-DAPs in a neurotrophin-enriched collagen hydrogel improves graft survival and maturation in the parkinsonian rat brain.Significance.The data strongly supports further investigation of supportive hydrogels for improving the outcome of iPSC-derived brain repair in Parkinson's disease.

Therapeutic role of neural stem cells in neurological diseases

The failure of endogenous repair is the main feature of neurological diseases that cannot recover the damaged tissue and the resulting dysfunction. Currently, the range of treatment options for neurological diseases is limited, and the approved drugs are used to treat neurological diseases, but the therapeutic effect is still not ideal. In recent years, different studies have revealed that neural stem cells (NSCs) have made exciting achievements in the treatment of neurological diseases. NSCs have the potential of self-renewal and differentiation, which shows great foreground as the replacement therapy of endogenous cells in neurological diseases, which broadens a new way of cell therapy. The biological functions of NSCs in the repair of nerve injury include neuroprotection, promoting axonal regeneration and remyelination, secretion of neurotrophic factors, immune regulation, and improve the inflammatory microenvironment of nerve injury. All these reveal that NSCs play an important role in improving the progression of neurological diseases. Therefore, it is of great significance to better understand the functional role of NSCs in the treatment of neurological diseases. In view of this, we comprehensively discussed the application and value of NSCs in neurological diseases as well as the existing problems and challenges.

Dual effect of C-C motif chemokine receptor 5 on ischemic stroke: More harm than benefit?

Ischemic stroke involves a series of complex pathological mechanisms, of which neuroinflammation is currently the most widely recognized. C-C motif chemokine receptor 5 (CCR5) has recently been shown to be upregulated after cerebral ischemia. Notably, CCR5 is not only involved in neuroinflammation, but also in the blood-brain barrier, neural structures, and connections. Accumulating experimental studies indicate that CCR5 has a dual effect on ischemic stroke. In the acute phase after cerebral ischemia, the pro-inflammatory and disruptive effect of CCR5 on the blood-brain barrier predominates. However, in the chronic phase, the effect of CCR5 on the repair of neural structures and connections is thought to be cell-type dependent. Interestingly, clinical evidence has shown that CCR5 might be harmful rather than beneficial. CCR5-Δ32 mutation or CCR5 antagonist exerts a neuroprotective effect in patients with ischemic stroke. Considering CCR5 as an attractive potential target, we introduce the current research progress of the entangled relationships between CCR5 and ischemic stroke. Clinical data are still needed to determine the efficacy of activating or inactivating CCR5 in the treatment of ischemic stroke, especially for potential phase- or cell type-dependent treatments in the future.