Human adipose-derived stem cells (hADSCs) are increasingly presumed to be a prospective stem cell source for cell replacement therapy in various degenerative and/or traumatic diseases. The potential of trans-differentiating hADSCs into motor neuron cells indisputably provides an alternative way for spinal cord injury (SCI) treatment. In the present study, a stepwise and efficient hADSC trans-differentiation protocol with retinoic acid (RA), sonic hedgehog (SHH), and neurotrophic factors were developed. With this protocol hADSCs could be converted into electrophysiologically active motoneuron-like cells (hADSC-MNs), which expressed both a cohort of pan neuronal markers and motor neuron specific markers. Moreover, after being primed for neuronal differentiation with RA/SHH, hADSCs were transplanted into SCI mouse model and they survived, migrated, and integrated into injured site and led to partial functional recovery of SCI mice. When ablating the transplanted hADSC-MNs harboring HSV-TK-mCherry overexpression system with antivirial Ganciclovir (GCV), functional relapse was detected by motor-evoked potential (MEP) and BMS assays, implying that transplanted hADSC-MNs participated in rebuilding the neural circuits, which was further confirmed by retrograde neuronal tracing system (WGA). GFP-labeled hADSC-MNs were subjected to whole-cell patch-clamp recording in acute spinal cord slice preparation and both action potentials and synaptic activities were recorded, which further confirmed that those pre-conditioned hADSCs indeed became functionally active neurons in vivo. As well, transplanted hADSC-MNs largely prevented the formation of injury-induced cavities and exerted obvious immune-suppression effect as revealed by preventing astrocyte reactivation and favoring the secretion of a spectrum of anti-inflammatory cytokines and chemokines. Our work suggests that hADSCs can be readily transformed into MNs in vitro, and stay viable in spinal cord of the SCI mouse and exert multi-therapeutic effects by rebuilding the broken circuitry and optimizing the microenvironment through immunosuppression.

Multipotent human adipose-derived stromal/stem cells (hADSCs) hold a great promise for cell-based therapy for many devastating human diseases, such as spinal cord injury and stroke. If exogenous hADSCs can be cultured in a three-dimensional (3D) scaffold with effective proliferation and differentiation capacity, it will better mimic the in vivo environment, which will have profound impact on the therapeutic application of hADSCs. In this study, a group of elastic-dominant, porous bioscaffolds from photocurable chitosan and gelatin were fabricated and proven to be biocompatible with both hADSCs and hADSC-derived neuron-like cells (hADSC-NLCs) in vitro. The identity of harvested hADSCs was confirmed by their positive immunostaining of mesenchymal stem cell surface markers, CD29, CD44, and CD105, and also positive expression of stem markers, Sox-2, Oct-4, c-Myc, Nanog, and Klf4. Their multipotency was further confirmed by trilineage differentiation of hADSCs toward adipocyte, osteoblast, and chondrocyte. It was found that hADSCs could be conditioned to differentiate into neurons in vitro as determined by immunostaining the markers of Tuj1, MAP2, NeuN, and Synapsin. The hADSCs and hADSC-NLCs were proven to be biocompatible with 3D scaffold, which actually facilitated the proliferation and differentiation of hADSCs in vitro, by MTT assay and their neuronal gene expression profiling. Moreover, hADSC-NLCs, which were mixed with 3D scaffold and transplanted into traumatic brain injury mouse model, survived in vivo and led to the better repair of the damaged brain area. The immunohistochemical studies revealed that 3D scaffold indeed improved the viability of transplanted cells, their ability to incorporate into the in vivo neural circuit, and their capacity for tissue repair. This study indicates that hADSCs would have great therapeutic application potential as seeding cells for in vivo transplantation to treat various neurological diseases when co-applied with porous chitosan/gelatin bioscaffolds.

Introduction: Growing evidence has brought stem cell therapy to the forefront as new promising approaches towards stroke treatment. Of all candidate seeding cells, adipose-derived stem cells (ADSCs) are considered as one of the most appropriate for stroke treatment. However, previous experimental data could not reach to an agreement on the efficacy of ADSC transplantation for treating stroke in vivo as well as its mechanism which hinders their further clinical translational application. Methods: To explore their in vivo mechanism of hADSC administration on neurological injury, hADSC were labeled with Enhanced Green Fluorescence Protein expressing FG12 lentivirus and injected into MCAO mouse infarct area by in situ way. Neurological function was evaluated by Rogers Scaling System and their spatial learning and memory was determined by Morris Test. 2,3,5-triphenyltetrazolium chloride was carried out to compare the infarct area among groups. Histoimmunostaining was used to track the injected hADSCs for their in vivo migration, transdifferentiation and integration with the endogenous neuronal circuitry. To better address the underlying rescuing mechanism, qRT-PCR was performed on neural markers of MBP, MAP2, GFAP, microglia marker of Iba1. Results: It was found that hADSCs could promote both spatial learning and memory of MCAO mice. Co-localization of GFP and MAP2 were found in the whole cortex with significantly (P<0.01) higher percentage at the contralateral cortex compared with the ipsilateral cortex. Low percentage of GFP and GFAP co-localized cells were found at whole cortex. Meanwhile, Iba1⁺ microglia and GFAP⁺ astrocyte cells were significantly (P<0.05) suppressed by hADSC injection. Conclusions: hADSCs could transdifferentiate into neuron like cells (MAP2⁺) in vivo and probably used as seeding cells for replacement based stem cell therapy of stroke. Also, significant immunomodulation was found. Meanwhile hADSCs could significantly protect the endogenous neuron survival. This study demonstrated that hADSC intervention with MCAO mice could apparently ameliorate stroke symptoms by direct cell replacement, enhanced immnunosuppression and increasing the viability of endogenous neurons.

The role of autoimmunity in Parkinson's disease (PD), as one of the most popular research subjects, has been intensively investigated in recent years. Although the ultimate cause of PD is unknown, one major area of interest remains identifying new therapeutic targets and options for patients suffering from PD. Herein, we present a comprehensive review of the impacts of autoimmunity in neurodegenerative diseases, especially PD, and we have composed a logical argument to substantiate that autoimmunity is actively involved in the pathogenesis of PD through several proteins, including α-synuclein, DJ-1, PINK1, and Parkin, as well as immune cells, such as dendritic cells, microglia, T cells, and B cells. Furthermore, a detailed analysis of the relevance of autoimmunity to the clinical symptoms of PD provides strong evidence for the close correlation of autoimmunity with PD. In addition, the previously identified relationships between other autoimmune diseases and PD help us to better understand the disease pattern, laying the foundation for new therapeutic solutions to PD. In summary, this review aims to integrate and present currently available data to clarify the pathogenesis of PD and discuss some controversial but innovative research perspectives on the involvement of autoimmunity in PD, as well as possible novel diagnostic methods and treatments based on autoimmunity targets.

There is accumulating evidence that astrocytes play an important role in synaptic formation, plasticity, and pruning. Dicer and the fine-tuning of microRNA (miRNA) network are important for maintaining the normal functions of central nervous system and dysregulation of miRNAs is implicated in neurological disorders. However, little is known about the role of Dicer and miRNAs of astrocytes in the homeostasis of synapse as well as its plasticity. By selectively deleting Dicer in postnatal astrocytes, Dicer-deficient mice exhibited reactive astrogliosis and deficits in dendritic spine formation. Astrocyte-conditioned medium (ACM) collected from Dicer-null astrocytes caused synapse degeneration in cultured primary neurons. The expression of chemokine ligand 5 (CCL5) elevated in Dicer-deleted astrocytes which led to the significant augmentation of secreted CCL5 in ACM. In neurons treated with Dicer KO-ACM, CCL5 supplementation inhibited MAPK/CREB signaling pathway and exacerbated the synaptic formation deficiency, while CCL5 knockdown partially rescued the synapse degeneration. Moreover, we validated CCL5 as miR-324-5p targeted gene. ACM collected from miR-324-5p antagomir-transfected astrocytes mimicked the effect of CCL5 treatment on inhibiting synapse formation and MAPK/CREB signaling in Dicer KO-ACM-cocultured neurons. Furthermore, decreased miR-324-5p expression and elevated CCL5 expression were observed in the brain of aging mice. Our work reveals the non-cell-autonomous roles of astroglial miRNAs in regulation of astrocytic secretory milieu and neuronal synaptogenesis, implicating the loss or misregulation of astroglial miRNA network may contribute to neuroinflammation, neurodegeneration, and aging.

Uncontrolled microglial activation is pivotal to the pathogenesis of Parkinson’s disease (PD), which can secrete Cathepsin L (CTSL) to affect the survival of neurons in the PD patients; however, the precise mechanism has yet to be determined. We demonstrated for the first time that CTSL was mostly released by exosomes derived from α-Syn-activated microglia, resulting in neuronal damage and death. The elevation of CTSL activity was blocked by GW4869, suggesting a critical role for exosomes in mediating CTSL release. Furthermore, the P2X7R/PI3K/AKT signalling pathway was identified as the underlying molecular mechanism since specific antagonists of this signalling pathway, P2X7R knockdown and exosome release inhibitors significantly reduced the injury to cultured mouse cortical neurons. Our study suggests that increased extracellular release of CTSL from α-Syn-activated microglia through exosomes amplifies and aggravates of the neurotoxic effect of microglia, implying that CTSL may be involved in a fresh mechanism of PD pathogenesis, and serve as a potential biomarker and a target for PD drug development.