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Systemic Administration of Induced Neural Stem Cells Regulates Complement Activation in Mouse Closed Head Injury Models

View Article: PubMed Central - PubMed

ABSTRACT

Complement activation plays important roles in the pathogenesis of central nervous system (CNS) diseases. Patients face neurological disorders due to the development of complement activation, which contributes to cell apoptosis, brain edema, blood-brain barrier dysfunction and inflammatory infiltration. We previously reported that induced neural stem cells (iNSCs) can promote neurological functional recovery in closed head injury (CHI) animals. Remarkably, we discovered that local iNSC grafts have the potential to modulate CNS inflammation post-CHI. In this study, we aimed to explore the role of systemically delivered iNSCs in complement activation following CNS injury. Our data showed that iNSC grafts decreased the levels of sera C3a and C5a and down-regulated the expression of C3d, C9, active Caspase-3 and Bax in the brain, kidney and lung tissues of CHI mice. Furthermore, iNSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice. Subsequently, we explored the mechanisms underlying these effects. With flow cytometry analysis, we observed a dramatic increase in complement receptor type 1-related protein y (Crry) expression in iNSCs after CHI mouse serum treatment. Moreover, both in vitro and in vivo loss-of-function studies revealed that iNSCs could modulate complement activation via Crry expression.

No MeSH data available.


INSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice.(a,b) Representative staining for C3d+ (green, a), C5b-9+ (green, b), and NeuN+ (red) cells depicted the distribution of C3d+/NeuN+ (a) and C5b-9+/NeuN+ (b) neurons in the injured cortex among the PBS, iNSC and sham groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (c,d) Representative staining for C3d+ (green, c), C5b-9+ (green, d), and Map2+ (red) cells depicted the distribution of C3d+/Map2+ (c) and C5b-9+/Map2+ (d) neurons in the injured cortex among the three groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (e–h) Histograms showed the numbers of C3d+/NeuN+ (e), C5b-9+/NeuN+ (f), C3d+/Map2+ (g), and C5b-9+/Map2+ (h) cells in the injured cortex among the three groups on day 7 post-CHI (n = 6/group; (a) P < 0.05 versus iNSC group; (b) P < 0.05 versus sham group). Scale bar = 25 μm (5 μm).
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f2: INSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice.(a,b) Representative staining for C3d+ (green, a), C5b-9+ (green, b), and NeuN+ (red) cells depicted the distribution of C3d+/NeuN+ (a) and C5b-9+/NeuN+ (b) neurons in the injured cortex among the PBS, iNSC and sham groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (c,d) Representative staining for C3d+ (green, c), C5b-9+ (green, d), and Map2+ (red) cells depicted the distribution of C3d+/Map2+ (c) and C5b-9+/Map2+ (d) neurons in the injured cortex among the three groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (e–h) Histograms showed the numbers of C3d+/NeuN+ (e), C5b-9+/NeuN+ (f), C3d+/Map2+ (g), and C5b-9+/Map2+ (h) cells in the injured cortex among the three groups on day 7 post-CHI (n = 6/group; (a) P < 0.05 versus iNSC group; (b) P < 0.05 versus sham group). Scale bar = 25 μm (5 μm).

Mentions: To determine the role of iNSC transplantation in neuronal survival following complement activation, we performed double-labelling experiments to measure the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortex on day 7 post-CHI (Fig. 2). An average of 20 equally spaced slides (100-μm intervals) containing samples from throughout the injured cortex (a series of 5-mm coronal sections) of each brain was assessed18. Cortical fields (0.73 mm2 each) in both the lesion core and the peri-lesion area were selected from each brain, and the numbers of positively stained cells in these fields were counted18. All of these double-labelling cells were rarely detected in the sham group. However, staining of brain cryosections from CHI mice showed that C3d and C5b-9 immunostaining was detected in the NeuN+ and Map2+ neurons in the injured cortex. Furthermore, the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons were significantly lower in the iNSC group than in the PBS group (n = 6/group, P < 0.05). These findings revealed that systemic administration of iNSCs could efficiently decrease the detrimental effects of complement activation on neurons after CHI.


Systemic Administration of Induced Neural Stem Cells Regulates Complement Activation in Mouse Closed Head Injury Models
INSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice.(a,b) Representative staining for C3d+ (green, a), C5b-9+ (green, b), and NeuN+ (red) cells depicted the distribution of C3d+/NeuN+ (a) and C5b-9+/NeuN+ (b) neurons in the injured cortex among the PBS, iNSC and sham groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (c,d) Representative staining for C3d+ (green, c), C5b-9+ (green, d), and Map2+ (red) cells depicted the distribution of C3d+/Map2+ (c) and C5b-9+/Map2+ (d) neurons in the injured cortex among the three groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (e–h) Histograms showed the numbers of C3d+/NeuN+ (e), C5b-9+/NeuN+ (f), C3d+/Map2+ (g), and C5b-9+/Map2+ (h) cells in the injured cortex among the three groups on day 7 post-CHI (n = 6/group; (a) P < 0.05 versus iNSC group; (b) P < 0.05 versus sham group). Scale bar = 25 μm (5 μm).
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Related In: Results  -  Collection

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f2: INSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice.(a,b) Representative staining for C3d+ (green, a), C5b-9+ (green, b), and NeuN+ (red) cells depicted the distribution of C3d+/NeuN+ (a) and C5b-9+/NeuN+ (b) neurons in the injured cortex among the PBS, iNSC and sham groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (c,d) Representative staining for C3d+ (green, c), C5b-9+ (green, d), and Map2+ (red) cells depicted the distribution of C3d+/Map2+ (c) and C5b-9+/Map2+ (d) neurons in the injured cortex among the three groups on day 7 post-CHI. Nuclei were counterstained with DAPI (blue). (e–h) Histograms showed the numbers of C3d+/NeuN+ (e), C5b-9+/NeuN+ (f), C3d+/Map2+ (g), and C5b-9+/Map2+ (h) cells in the injured cortex among the three groups on day 7 post-CHI (n = 6/group; (a) P < 0.05 versus iNSC group; (b) P < 0.05 versus sham group). Scale bar = 25 μm (5 μm).
Mentions: To determine the role of iNSC transplantation in neuronal survival following complement activation, we performed double-labelling experiments to measure the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortex on day 7 post-CHI (Fig. 2). An average of 20 equally spaced slides (100-μm intervals) containing samples from throughout the injured cortex (a series of 5-mm coronal sections) of each brain was assessed18. Cortical fields (0.73 mm2 each) in both the lesion core and the peri-lesion area were selected from each brain, and the numbers of positively stained cells in these fields were counted18. All of these double-labelling cells were rarely detected in the sham group. However, staining of brain cryosections from CHI mice showed that C3d and C5b-9 immunostaining was detected in the NeuN+ and Map2+ neurons in the injured cortex. Furthermore, the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons were significantly lower in the iNSC group than in the PBS group (n = 6/group, P < 0.05). These findings revealed that systemic administration of iNSCs could efficiently decrease the detrimental effects of complement activation on neurons after CHI.

View Article: PubMed Central - PubMed

ABSTRACT

Complement activation plays important roles in the pathogenesis of central nervous system (CNS) diseases. Patients face neurological disorders due to the development of complement activation, which contributes to cell apoptosis, brain edema, blood-brain barrier dysfunction and inflammatory infiltration. We previously reported that induced neural stem cells (iNSCs) can promote neurological functional recovery in closed head injury (CHI) animals. Remarkably, we discovered that local iNSC grafts have the potential to modulate CNS inflammation post-CHI. In this study, we aimed to explore the role of systemically delivered iNSCs in complement activation following CNS injury. Our data showed that iNSC grafts decreased the levels of sera C3a and C5a and down-regulated the expression of C3d, C9, active Caspase-3 and Bax in the brain, kidney and lung tissues of CHI mice. Furthermore, iNSC grafts decreased the levels of C3d+/NeuN+, C5b-9+/NeuN+, C3d+/Map2+ and C5b-9+/Map2+ neurons in the injured cortices of CHI mice. Subsequently, we explored the mechanisms underlying these effects. With flow cytometry analysis, we observed a dramatic increase in complement receptor type 1-related protein y (Crry) expression in iNSCs after CHI mouse serum treatment. Moreover, both in vitro and in vivo loss-of-function studies revealed that iNSCs could modulate complement activation via Crry expression.

No MeSH data available.