Cell-to-cell communication and vascular dementia

Genetic susceptibility to vascular cognitive impairment: a pathophysiological view

The heterogeneity of the vascular cognitive impairment (VCI) creates challenges for research on its genetic basis and pathophysiology. Despite well-known monogenic forms may be useful to understand some pathogenic mechanisms leading to VCI, most of VCIs are sporadic disorders resulting from the interaction between environmental, vascular and genetic factors. Genetic investigation for VCI may encompass both candidate genes that affect critical biological processes to VCI and common and rare genetic variants identified across the entire genome study technology, thereby enabling us to confirm or expose new biological mechanisms in VCI and develop new therapeutic and preventive approaches. Notwithstanding genetic susceptibility to VCI remains largely unknown owing to methodological issues. Collaborative efforts emerge as an interesting strategy to overcome these problems.

Protective effect of carnosine after chronic cerebral hypoperfusion possibly through suppressing astrocyte activation

AIM

Subcortical ischemic vascular dementia (SIVD) induced by chronic hypoperfusion is a common cause of vascular dementia. The aim of this study was to determine whether the protective effect of carnosine on white matter lesion after chronic cerebral hypoperfusion through suppressing astrocyte activation.

METHODS

Adult male mice (C57BL/6 strain) were subjected to permanent occlusion of the right unilateral common carotid arteries (rUCCAO) and treated with carnosine or histidine. Open field test, freezing test, Klüver-Barrera staining, immunohistochemical analyses and western blot were performed after rUCCAO.

RESULTS

We found that carnosine ameliorated white matter lesion and cognitive impairment after rUCCAO. Carnosine suppressed the activation of astrocyte in both wide type mice and histidine decarboxylase knockout mice. However, administration of histidine did not show the same effect. We found that there were no differences between rUCCAO group and sham group for the expression of glutamate transporter-1 (GLT-1) and glutamate/aspartate transporter (GLAST). Furthermore, carnosine significantly attenuated the increase of inflammatory cytokine interferon gama.

CONCLUSION

These data suggest carnosine induced neuroprotection during SIVD in mice is not dependent on the histaminergic pathway or the regulation of the expression of GLT-1 and GLAST, but may be due to a suppression of astrocyte activation and inflammatory cytokine release.

Qingnaoyizhi decoction suppresses the formation of glial fibrillary acidic protein-positive cells in cultured neural stem cells by inhibiting the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway

OBJECTIVE

Inactivation of the Janus kinase 2 in treated NSCs. Furthermore, QNYZD may play a direct role in suppressing the formation of GFAP-positive cells and enhancing neuronal differentiation by inhibiting JAK2/STAT3 activation. Overall, these results provide insights into the possible mechanism underlying QNYZD-mediated neurogenesis. (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling axis plays a crucial role in determining the fate of neural stem cells (NSCs). Qingnaoyizhi decoction (QNYZD) has been used for the treatment of vascular dementia and has shown to improve synaptic remodeling. The aim of this study was to evaluate the effect of cerebrospinal fluid (CSF) containing QNYZD (CSF-QNYZD) on the differentiation of cultured NSCs and the involvement of the JAK2/STAT3 pathway.

METHODS

The protein expression levels of glial fibrillary acidic protein (GFAP), tubulin, drosophila mothers against decapentaplegic protein (SMAD-1), STAT3, and phosphorylated-STAT3 were detected by western immunoblot analysis in the groups: control, CSF, JAK/STAT inhibitor (AG490), CSF-QNYZD, and CSF-XDZ (CSF-Xidezhen). The differentiation of NSCs was determined by immunofluorescence staining. The proliferation of NSCs was measured using the Cell Counting Kit-8 proliferation assay.

RESULTS

Compared with the control group, CSF-QNYZD and AG490 significantly increased the number and expression of tubulin-positive cells, reduced the number and expression of GFAP-positive cells, and down-regulated the expression of p-STAT3. However, CSF-QNYZD also decreased the expression of SMAD-1 and STAT3.

CONCLUSION

Enhanced neuronal differentiation may be associated with the down-regulation of glial differentiation instead of promoting proliferation in treated NSCs. Furthermore, QNYZD may play a direct role in suppressing the formation of GFAP-positive cells and enhancing neuronal differentiation by inhibiting JAK2/STAT3 activation. Overall, these results provide insights into the possible mechanism underlying QNYZD-mediated neurogenesis.

Cell-cell communication in the resistance vasculature: the past, present, and future

Cell-cell communication among neighboring vascular cells plays an important role in blood flow control. In this overview, we highlight a series of expert opinion articles focused on key issues related to the foundational nature and functional importance of electrical and second messenger communication. These manuscripts are written in an opinionated manner to provoke thought and to illuminate new emerging areas of investigation.