Glucagon-Like Peptide-1 (GLP-1) Treatment Ameliorates Cognitive Impairment by Attenuating Arc Expression in Type 2 Diabetic Rats.

BACKGROUND Glucagon-like peptide-1 (GLP-1) has been reported to exert some beneficial effects on the central nervous system (CNS). However, the effect of GLP-1 on cognitive impairment associated with type 2 diabetes is not well known. This study investigated the effect of GLP-1 on ameliorating memory deficits in type 2 diabetic rats. MATERIAL AND METHODS Type 2 diabetic rats were induced by a high-sugar, high-fat diet, followed by streptozotocin (STZ) injection and then tested in the Morris Water Maze (MWM) 1 week after the induction of diabetes. The mRNA expression of Arc, APP, BACE1, and PS1 were determined by real-time quantitative PCR, and the Arc protein was analyzed by immunoblotting and immunohistochemistry. RESULTS Type 2 diabetic rats exhibited a significant decline in learning and memory in the MWM tests, but GLP-1 treatment was able to protect this decline and significantly improved learning ability and memory. The mRNA expression assays showed that GLP-1 treatment markedly reduced Arc, APP, BACE1, and PS1 expressions, which were elevated in the diabetic rats. Immunoblotting and immunohistochemistry results also confirmed that Arc protein increased in the hippocampus of diabetic rats, but was reduced after GLP-1 treatment. CONCLUSIONS Our findings suggest that GLP-1 treatment improves learning and memory deficits in type 2 diabetic rats, and this effect is likely through the reduction of Arc expression in the hippocampus.

[Glucagon-like peptide 1 improves learning and memory abilities of rats with type 2 diabetes].

OBJECTIVE: To investigate the effect of glucagon-like peptide 1 (GLP-1) on cognitive dysfunction in diabetic rats. METHODS: Male SD rats were randomly divided into normal control group, diabetes mellitus (DM) group, and GLP-1 treatment group. Rat models of type 2 diabetes were established by high-sugar and high-fat feeding and streptozotocin (STZ) injection, and 25 days after the onset of diabetes, GLP-1 was infused in GLP-1 treatment group at the rate of 30 pmol·kg-1·min-1 via a subcutaneous osmotic pump for 7 days. The learning and cognitive ability of the rats was assessed with Morris water maze test, and the expression of cognition-related genes in the hippocampus tissue was detected with real-time PCR, Western blotting and immunohistochemical staining. RESULTS: Compared with the normal control group, the diabetic rats showed significantly decreased learning and memory abilities (P<0.05) with increased hippocampal expressions of APP, BACE1, Arc, ERK1/2, PKA, and PKC mRNAs (P<0.05) and Arc protein. Compared with diabetic rats, GLP-1-treated rats showed significantly improvements in the learning and memory function (P<0.05) with decreased expressions of APP, BACE1, Arc, ERK1/2, and PKA mRNAs (P<0.05) and Arc protein. CONCLUSION: GLP-1 can improve cognitive dysfunctions in diabetic rats possibly by regulating the PKC, PKA, and ERK1/2 pathways and inhibiting Arc expression in the hippocampus.

Penta-aqua-(1H-benzimidazole-5,6-di-carboxyl-ato-κN)copper(II) penta-hydrate.

The title compound, [Cu(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, contains one crystallographically independent Cu(II) atom and one 1H-benzimidazole-5,6-dicarboxyl-ate (bdc) ligand, along with five coordinated and five uncoordinated water mol-ecules. The Cu(II) atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water mol-ecules, giving an octa-hedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water mol-ecules into a three-dimensional network.

[Effect of nerve growth factor on the promotion of sensory recovery of large skin graft in patients].

OBJECTIVE: To analyze the influence of topical application of nerve growth factor (NGF) on nerve ending regeneration of large skin grafts in patients. METHODS: Sixty wounds from 48 adult patients with small or moderate burn area and scar excision were randomly divided into NGF and control groups, with 30 wounds in each group. The wounds in control group were treated with simple saline solution, while those in NGF group, the graft was first wrapped in a piece of gauze holding 100 ml saline solution containing 9000 AU NGF before operation, and then flushed with same amount of NGF saline underneath skin after application of the graft. From 20 post-operative day on, NGF was injected at multiple points every other day for one month. In control group, only normal saline was used. The texture of the graft, pain sensation, temperature and two - point discrimination, BMRC grade were observed for 12 months. Skin specimens were obtained from 6 wounds in control group, 5 wounds in NGF group, and 4 specimens from normal skin for immunohistological examination of protein gene product 9.5 (PGP 9.5), synaptophysin (SYN), and neuron specific enolase (NSE). The nerve endings regeneration and distribution were also observed. RESULTS: Compared with those in control group, each index of feeling recovered earlier and better in NGF group, with better two - point discrimination ratio and BMRC grade. One year after operation, 17 skin grafts in NGF group reached S4 grade, with two - point discrimination ratio of 1.11 +/- 0.14, while only 5 grafts in control group reached S4 grade, with two - point discrimination ratio of 1.56 +/- 0.73. Six months after operation, rich nerve endings, with integral adnexae were observed in microvascular bed of skin - graft region and tissue interspace around fibromas tissue in subcutaneous tissue in NGF group, while nerve endings were found to be scanty and slender in subcutaneous tissue in control group. CONCLUSION: Local application of NGF can promote nerve regeneration and sensory recovery of grafted skin.