Sirtuin 6 nuclear localization at cortical brain level of young diabetic mice: an immunohistochemical study

A study was conducted to assess the physiopathological significance of sirtuin 6 (SIRT6) at the brain cortical level. We analyzed the specific expression and subcellular localization of SIRT6 in young db/db mice, an experimental animal model of type II Diabetes mellitus. We analyzed the cytoarchitecture of the brain cortex, evaluated SIRT6 expression and its localization by immunohistochemistry comparing db/db mice to lean control mice, examining the six cortical layers and the motor and somatosensory cortex. Finally, we calculated a SIRT6 labeling index. We observed the absence of significant morphological differences between lean and db/db mice, indicating that young db/db mice showed a neuronal morphology and distribution similar to that of lean mice and also normal brain tissue architecture with intact cortical layers. Moreover, sirtuin 6 is mainly localized in the nucleus of both lean and db/db mice. In particular, the db/db mice showed few positive cells compared to lean control mice in all cortical layers. We found a lower sirtuin 6 labeling index without significant differences between the motor and somatosensory cortex. Our findings contribute to further understanding the sirtuin 6 immunohistochemical changes in the early stages of type II Diabetes mellitus and propose its possible implication in the pathogenic processes associated with Diabetes mellitus and diabetes-induced neurodegeneration.