VEGF exhibits protective functions which prevents degeneration of neurons and pericytes, in addition to enhancing neurogenesis and angiogenesis (Melincovici et al., 2018). the ones with a long-term disease course such as AD, is limited by the delivery approach due to the presence of the brain blood barrier. So far, the most commonly used delivery approach in the therapy of neurological disorders with stem cells in preclinical and clinical studies are intracranial injection and intrathecal injection, both of which are invasive. In the present study, we use repetitive intranasal delivery of human neural stem cells (hNSCs) to the brains of APP/PS1 transgenic mice to investigate the effect of hNSCs on the pathology of AD. The results indicate Cefoselis sulfate that the intranasally transplanted hNSCs survive and exhibit extensive migration and higher neuronal differentiation, with a relatively limited glial differentiation. A proportion of intranasally transplanted hNSCs differentiate to cholinergic neurons, which rescue cholinergic dysfunction in APP/PS1 mice. In addition, intranasal transplantation of hNSCs attenuates -amyloid accumulation by upregulating the expression of -amyloid degrading enzymes, insulin-degrading enzymes, and neprilysin. Moreover, intranasal transplantation of hNSCs ameliorates other AD-like pathology including neuroinflammation, cholinergic dysfunction, and pericytic and synaptic loss, while enhancing adult hippocampal neurogenesis, eventually rescuing the cognitive deficits of APP/PS1 transgenic mice. Thus, our findings highlight that intranasal transplantation of hNSCs Cefoselis sulfate benefits cognition through multiple mechanisms, and exhibit the great potential of intranasal administration of stem cells as a noninvasive therapeutic strategy for AD. 0.05; ** 0.01; *** 0.001. Results Identification of hNSCs = 6 mice/group. * 0.05, One-way ANOVA (E). Intranasal Transplantation of hNSCs Attenuates A Accumulation in APP/PS1 Mice by Promoting Its Clearance A is one of the key initiating factors of AD pathogenesis. Accumulation of A results in loss of synapses, neuroinflammation, and ultimately cognitive deficits (Musiek and Holtzman, 2015). Thus, we investigated the function of hNSCs on A accumulation. A staining was performed using an antibody against A in mouse coronal sections. The numbers and size of A plaques were quantified in the brain sections from Cefoselis sulfate APP/PS1 mice transplanted with hNSCs and the age-matched APP/PS1 controls. The results showed that both the size and the numbers of A plaques in the hippocampus (Figures 5ACC) and cortex (Figures 5A,D,E) of hNSCs-transplanted APP/PS1 mice were decreased compared with those in control APP/PS1 Cefoselis sulfate mice. Consistent with these results, ELISA analysis showed that the levels of both soluble and insoluble A42 and A40 in the hippocampus of hNSCs-transplanted APP/PS1 mice were also decreased (Figures 5FCI). The cortical insoluble A42 also exhibited reduced levels upon hNSCs transplantation (Figure 5K). Whereas, soluble A42 and A40, together with insoluble A40 in the cortex of hNSCs-transplanted APP/PS1 mice showed a tendency to decrease, although this did not reach a statistic difference (Figures 5J,L,M). These results indicate that repetitive intranasal transplantation of hNSCs decreases A accumulation in the brains of APP/PS1 mice. Open in a separate Gata6 window Figure 5 Intranasal transplantation of hNSCs reduces A accumulation in the brains of APP/PS1 mice. (ACE) The coronal sections of host and control APP/PS1 mice were stained with an antibody against A (6E10). Representative images in the hippocampus and Cefoselis sulfate cortex are shown. Scale bars: 100 and 50 m in the images with higher magnification. The size of A plaques in the hippocampus (B) and cortex (D). The numbers of A plaques in the hippocampus (C) and cortex (E). (FCM) ELISA analysis of the levels of soluble and insoluble A42 (F,G,J,K) and A40 (H,I,L,M) in the cortex and hippocampus. Data are presented as mean SEM. = 20C40 slices from 5 mice/group for A plaques analysis; = 5 mice/group for ELISA analysis. * 0.05; ** 0.01; *** 0.01. Student = 6 mice/group. * 0.05; *** 0.01. One-way ANOVA. hNSCs Inhibit Neuroinflammation in APP/PS1 Mice Neuroinflammation is widely reported as one of the mechanisms of Alzheimer’s disease pathology (Calsolaro and Edison, 2016). Excessive neuroinflammation leads to synaptic degeneration and memory loss. We thus further examined whether intranasally transplanted hNSCs attenuate neuroinflammation in the brains of APP/PS1 mice by quantifying the density of microglia and astrocytes, the glial cells responsible in initiating neuroinflammation in the brain. The coronal sections of transgenic mice were immunostained with antibodies of Iba1 (marker of microglia) and GFAP (marker of astrocytes), respectively. As expected, saline-injected APP/PS1 mice exhibited a significantly increased density of astrocytes (Figures 7A,C,D) and microglia (Figures 7B,E,F) in both the hippocampus and cortex compared with WT mice. Whereas, hNSCs transplantation reduced the density of astrocytes (Figures 7A,C,D) and microglia (Figures 7B,E,F) to a level comparable to that of WT mice. These findings demonstrate that repetitive intranasal transplantation of hNSCs rescues neuroinflammation in the brains of APP/PS1.