Astrogliosis in the hippocampus and cortex and cognitive deficits in rats with streptozotocin-induced diabetes: Effects of melatonin

Abstract

We examined, using a Western blot technique, the contents and compositions of a specific neuronal protein, NCAM, and of an astrocyte marker, GFAP, in the hippocampus and cortex of rats with streptozotocin (STZ)-induced diabetes and compared these indices with those in control (intact) animals and STZ-diabetic rats treated with melatonin. Behavioral cognitive indices manifested in the passive avoidance test (PAT) and Morris water maze (MWM) learning performance were also estimated in the above groups of animals. As was found, STZ-diabetic rats demonstrated clear cognitive deficits according to the values of the retention latency in the PAT and time of reaching the escape platform in the MWM performance. In these animals, the GFAP content was elevated, and the amount of degraded products of this protein increased, as compared with the control. Simultaneously, considerable down-regulation of the NCAM expression and modifications of NCAM isoform composition were found in diabetic animals. In addition, significantly increased levels of lipid peroxidation (according to the amounts of malondialdehyde + 4-hydroxyalkenals) were measured in the cortex and hippocampus of rats with stable diabetic hyperglycemia. All the above-mentioned shifts were significantly smoothed or even nearly completely compensated in the case of treatment of STZ-diabetic rats with melatonin (10 mg/kg per day). The role of diabetes-related changes in the amount and composition of specific neural and glial proteins in the development of cognitive deficits, the involvement of oxidative stress in the mechanisms of the respective shifts, and possible mechanisms of the neuroprotective effect of melatonin with respect to diabetes-related pathological biochemical and behavioral shifts are discussed.

Melatonin: new insights on its therapeutic properties in diabetic complications

“…Administration of melatonin in STZ-induced diabetic rats with elevated level of glial fibrillary acidic protein (GFAP) and S100B, as an indicator of astrogliosis, prevents lipid peroxidation, GFAP and and S100B synthesis and the loss of neural cell adhesion molecule, with these effects being associated with the improvement of cognitive ability [125,126]. Melatonin may show these effects through its antioxidant activity contributing to the increased level of brain antioxidant, decreased brain NOSs activities and plasma cytokines levels, and inhibition of astrocytes apoptosis playing an important role in the CNS homeostasis [104,127,128].…”

The effect of hyperthyroidism on the cognition processes and the state of the glial intermediate filaments in the rat brain

“…Ó í å ð â î â ³ é òêàíèí³ ïðîì³aeí³ ô³ëàìåíòè ïðåäñòàâëåí³ òðèïëåòîì á³ëê³â íåéðîô³ëàìåíò³â ³ ãë³àëüíèì ô³áðèëÿðíèì êèñëèì á³ëêîì (ÃÔÊÁ). ²ñíóþòü äàí³ ïðî çì³íó ñòðóêòóðè ïðîì³aeíèõ ô³ëàìåíò³â ³ ô³çèêî-õ³ì³÷íèõ âëàñòèâîñòåé öèòîñêåëåòíèõ á³ëê³â ïðè ïàòîëîã³ÿõ ð³çíî¿ åò³îëî㳿 ò à 䳿 óøêîäaeóâàëüíèõ ôàêòîð³â [12,26]. Âåëèêå çíà÷åííÿ ìຠâèâ÷åííÿ ³ âèêîðèñòàííÿ ïðîì³aeíèõ ô³ëàìåí-ò³â ÿê ìàðêåð³â ðîçâèòêó ïàòîëîã³÷íèõ ñòàí³â íåðâîâî¿ ñèñòåìè.…”

“…гçí³ çà ïðèðîäîþ óøêîäaeóâàëüí³ ôàêòîðè òà ìåòàáîë³÷í³ ðîçëàäè ³íäóêóþòü ãåíåðàö³þ ðåàêòèâíèõ ñïîëóê êèñíþ ó íåðâîâ³é òêàíèí³ ³ ðîçâèòîê ³íñóëüòó [11], ìîaeóòü âïëèâàòè íà åêñïðåñ³þ òà ðåöèêë³íã öèòîñêåëåòíèõ ³ ìåìáðàííèõ á³ëê³â [12,9], ù³ëüí³ñòü ñèíàïòè÷íèõ êîíòàêò³â [29] ³, òàêèì ÷èíîì, ïîðóøóâàòè ïðîöåñè íàâ÷àííÿ òà ïàìÿò³.…”

“…Îñòàíí³ì ÷àñîì îòðèìàí³ áåççàïåðå÷-ëèâ³ äîêàçè òîãî, ùî àñòðîöèòè â³ä³ãðàþòü â îêðåìèõ âèïàäêàõ ãîëîâíó àáî çíà÷íó ðîëü ó ðîçëàäàõ ÖÍÑ. Âîäíî÷àñ çàëèøàºòüñÿ íåçðîçóì³ëèì ïèòàííÿ, ÷è ìîaeëèâî äèñôóíêö³¿ àñòðîöèò³â àáî àñòðîãë³îç ïðåäñòàâèòè ÿê êë³í³÷í³ îçíàêè àáî ìåõí³çìè, ùî ïðèçâîäÿòü äî ïàòîëîã³÷íèõ çì³í ó ÖÍÑ [12].…”

Influence of cadmium contamination on brain glial cells: consequences and bioindication possibilities

“…Ключові слова: окисний стрес, гліальний фібрилярний кислий білок, глюкозо-6-фосфат-дегідрогеназа, клітини U373, біомаркер. 1 Oles Honchar Dnipro National University, Dnipro, Ukraine 2 Bingöl University, Bingöl, Turkey…”