Abstract
Rats intracerebroventricularily (icv) treated with streptozotocin (STZ), shown to generate an insulin resistant brain state, were used as an animal model for the sporadic form of Alzheimer’s disease (sAD). Previously, we showed in an in vivo study that 3 months after STZ icv treatment hippocampal adult neurogenesis (AN) is impaired. In the present study, we examined the effects of STZ on isolated adult hippocampal neural stem cells (NSCs) using an in vitro approach. We revealed that 2.5 mM STZ inhibits the proliferation of NSCs as indicated by reduced number and size of neurospheres as well as by less BrdU-immunoreactive NSCs. Double immunofluorescence stainings of NSCs already being triggered to start with their differentiation showed that STZ primarily impairs the generation of new neurons, but not of astrocytes. For revealing mechanisms possibly involved in mediating STZ effects we analyzed expression levels of insulin/glucose system-related molecules such as the glucose transporter (GLUT) 1 and 3, the insulin receptor (IR) and the insulin-like growth factor (IGF) 1 receptor. Applying quantitative Real time-PCR (qRT-PCR) and immunofluorescence stainings we showed that STZ exerts its strongest effects on GLUT3 expression, as GLUT3 mRNA levels were found to be reduced in NSCs, and less GLUT3-immunoreactive NSCs as well as differentiating cells were detected after STZ treatment. These findings suggest that cultured NSCs are a good model for developing new strategies to treat nerve cell loss in AD and other degenerative disorders.
Highlights
Streptozotocin (STZ) is a glucosamine derivative of nitrosourea produced by Streptomyces achromogens and toxic to the insulinproducing β cells of the pancreas in mammals (Eileen Dolan, 1997)
With an in vitro approach using hippocampal neural stem cells (NSCs) we investigated the possible influence of STZ on the proliferation of NSCs, their migration and differentiation, and whether STZ treatment alters the expression levels of genes related to the insulin system such as the insulin receptor (IR), insulin-like growth factor (IGF)-1 receptor (IGF-1R) and GLUT1 and 3
Cells were collected by centrifugation at 110 g for 7 min (RT) and re-suspended in proliferation cell culture medium composed of NeuroCultTM NS-A Basal medium supplemented with NeurocultTM NS-A proliferation supplement, epidermal growth factor (EGF) (20 ng/ml, Peprotech, Germany), basic fibroblast growth factor and Heparin (2 μg/ml, STEMMCELL, USA)
Summary
Streptozotocin (STZ) is a glucosamine derivative of nitrosourea produced by Streptomyces achromogens and toxic to the insulinproducing β cells of the pancreas in mammals (Eileen Dolan, 1997) It is used in medicine for treating certain cancers of the Islets of Langerhans (Murray-Lyon et al, 1968; Brentjens and Saltz, 2001) and used in research to produce animal models for type 1 diabetes mellitus (T1DM) via high dose intraperitoneal (i.p.) injections (Like and Rossini, 1976) and type 2 diabetes mellitus (T2DM) with low doses i.p. injections (Reaven and Ho, 1991; Wang and Gleichmann, 1998; Yuan et al, 2016). Insulin resistance in the brain may trigger pathophysiological key events of neurodegenerative disorders such as Alzheimer’s disease (AD) and can be linked to these disorders (Correia et al, 2011; Talbot et al, 2012)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
