scholarly journals Exogenous Hydrogen Sulfide Ameliorates Diabetes-Associated Cognitive Decline by Regulating the Mitochondria-Mediated Apoptotic Pathway and IL-23/IL-17 Expression in db/db Mice

2017 ◽  
Vol 41 (5) ◽  
pp. 1838-1850 ◽  
Author(s):  
Shuainan Ma ◽  
Di Zhong ◽  
Pingwei Ma ◽  
Guozhong Li ◽  
Wei Hua ◽  
...  

Background: Diabetes-associated cognitive decline (DACD) is one of the complications of diabetes and leads to cognitive impairment and an increased risk of dementia. However, the exact mechanism of DACD has not been fully characterized, and a successful therapy for this issue has not been established. This study aimed to detect the anti-apoptotic and anti-inflammatory effects of hydrogen sulfide (H2S) on DACD. Methods: We used a behavioural scoring method, Western blot, TUNEL staining and immunofluorescence staining to investigate the expression of the mitochondrial apoptotic pathway and the IL-23/IL-17 axis in db/db mice with or without sodium hydrosulfide (NaHS) administration. Results: NaHS administration mice exhibited reduced time to find the platform and a shorter swimming distance (P<0.05), while the time spent in the target quadrant was increased compared to that of the db/db group (P<0.05). Pro-apoptotic proteins, including cleaved Caspase-3, cleaved Caspase-9, Bax and cytochrome C, were elevated in the db/db group (P<0.01) but were downregulated in the db/db+NaHS group (P<0.05). Exogenous H2S decreased the numbers of TUNEL-positive cells in the db/db mice (P<0.05). The Western blot analysis showed that the expression levels of IL-23/IL-17 were lower in the NaHS administration group than in the db/db group (P<0.05). Conclusion: We demonstrated that H2S improved the spatial learning and memory abilities of the db/db mice by modulating the mitochondrial apoptotic pathway and the IL-23/IL-17 axis, which were found to be associated with DACD. H2S treatment may help prevent the progression of apoptotic hippocampal neurons in db/db mice and inform the development of a new therapeutic target.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Liang Yue ◽  
Lei Zhao ◽  
Haixiao Liu ◽  
Xia Li ◽  
Bodong Wang ◽  
...  

Glutamate- (Glu-) induced excitotoxicity plays a critical role in stroke. This study aimed to investigate the effects of APN on Glu-induced injury in HT22 neurons. HT22 neurons were treated with Glu in the absence or the presence of an APN peptide. Cell viability was assessed using the MTT assay, while cell apoptosis was evaluated using TUNEL staining. Levels of LDH, MDA, SOD, and GSH-Px were detected using the respective kits, and ROS levels were detected using dichlorofluorescein diacetate. Western blot was used to detect the expression levels of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), cleaved caspase-3, Bax, and Bcl-2. In addition to the western blot, immunofluorescence was used to investigate the expression levels of SIRT1 and PGC-1α. Our results suggest that APN peptide increased cell viability, SOD, and GSH-Px levels and decreased LDH release, ROS and MDA levels, and cell apoptosis. APN peptide upregulated the expression of SIRT1, PGC-1α, and Bcl-2 and downregulated the expression of cleaved caspase-3 and Bax. Furthermore, the protective effects of the APN peptide were abolished by SIRT1 siRNA. Our findings suggest that APN peptide protects HT22 neurons against Glu-induced injury by inhibiting neuronal apoptosis and activating SIRT1-dependent PGC-1αsignaling.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Lina Liu ◽  
Fei Ge ◽  
Haoran Yang ◽  
Huilian Shi ◽  
Weiting Lu ◽  
...  

Xiao-Yao-San (XYS) decoction is a traditional Chinese medicine formula. This study aimed to investigate the effect of XYS on cognitive abilities and its underlying mechanism in ovariectomized rats. Female Sprague-Dawley rats were ovariectomized and treated with XYS (3 g/kg or 9 g/kg) by gavage, with subcutaneous injection of 17-β estradiol (E2, 2 μg/kg) as a positive drug control and gavage of 1 ml saline (0.9%) as a placebo control. After 6 weeks of treatment, rats were examined using the Morris water maze test. The estradiol level in the serum and hippocampus was measured by ELISA. Golgi staining was performed to observe neuronal morphology in the hippocampus. Apoptosis of hippocampal cells was observed by TUNEL staining. The protein content of N-methyl-D-aspartate receptor (NMDAR) 2A and 2B in the hippocampal CA1 region was determined by Western blot and immunohistochemistry. Expression of estrogen receptor (ER) and PI3K signaling was detected by Western blot. Compared with the sham group, both learning and memory were impaired in ovariectomized rats. Rats treated with E2 or high-dose XYS showed better learning and memory compared with the saline-treated rats. High-dose XYS significantly reduced escape latency in the spatial acquisition trial; meanwhile, the cross times and duration in the probe quadrant were increased in the spatial probe trial. High-dose XYS promoted the de novo synthesis of E2 content in the hippocampus but had no significant effect on the serum E2 level. Golgi staining indicated that high-dose XYS could increase the branch number and density of dendritic spines in the hippocampal CA1 area. TUNEL staining showed that high-dose XYS alleviated ovariectomy-induced neuronal apoptosis. The expression level of NMDAR2A and NMDAR2B in hippocampal CA1 was upregulated by XYS treatment. The beneficial effect of XYS was through activating ERα-PI3K signaling. In conclusion, high-dose XYS treatment can improve the cognitive abilities of ovariectomized rats by protecting the hippocampal neurons and restoring the hippocampal E2 level.


2021 ◽  
Author(s):  
Cellas A Hayes ◽  
Erik L Hodges ◽  
Jessica P Marshall ◽  
Sreemathi Logan ◽  
Julie A Farley ◽  
...  

Reductions in insulin-like growth factor-1 (IGF-1) are associated with cognitive impairment and increased risk of neurodegenerative disease in advanced age. In mouse models, reduced IGF-1 early-in-life leads to memory impairments and synaptic dysfunction; however, these models are limited by systemic reductions in IGF-1. We hypothesized that IGF-1 continues to promote hippocampal neuron structure and function after development, and as such, the loss of IGF-1 signaling in adult neurons would lead to impaired spatial learning and memory. To test this, the IGF-1 receptor (IGF-1R) was genetically targeted in hippocampal neurons of adult male and female mice. Male mice deficient in neuronal IGF-1R exhibited spatial learning impairments as evidenced by increased pathlength and errors in the radial arm water maze. No differences in learning and memory were observed in female mice. Golgi-Cox staining revealed a reduced number of dendritic boutons of neurons the CA1 region of the hippocampus in male mice. Decreased MAPK and increased ROCK activity were also observed in these tissues. In vitro studies revealed that impaired neurite outgrowth due to inhibited IGF-1R signaling could be rescued by pharmacological inhibitors of ROCK. However, ROCK inhibition in neuronal IGF-1R deficient mice did not fully rescue learning impairments or bouton numbers. Together, our study highlights that IGF-1 continues to support spatial learning and memory and neuronal structure in adulthood.


2020 ◽  
Vol 19 (17) ◽  
pp. 2108-2119
Author(s):  
Yang Jin ◽  
Li Lv ◽  
Shu-Xiang Ning ◽  
Ji-Hong Wang ◽  
Rong Xiao

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.


2021 ◽  
Vol 10 (7) ◽  
pp. 1532
Author(s):  
Eleni Rebelos ◽  
Juha O. Rinne ◽  
Pirjo Nuutila ◽  
Laura L. Ekblad

Imaging brain glucose metabolism with fluorine-labelled fluorodeoxyglucose ([18F]-FDG) positron emission tomography (PET) has long been utilized to aid the diagnosis of memory disorders, in particular in differentiating Alzheimer’s disease (AD) from other neurological conditions causing cognitive decline. The interest for studying brain glucose metabolism in the context of metabolic disorders has arisen more recently. Obesity and type 2 diabetes—two diseases characterized by systemic insulin resistance—are associated with an increased risk for AD. Along with the well-defined patterns of fasting [18F]-FDG-PET changes that occur in AD, recent evidence has shown alterations in fasting and insulin-stimulated brain glucose metabolism also in obesity and systemic insulin resistance. Thus, it is important to clarify whether changes in brain glucose metabolism are just an epiphenomenon of the pathophysiology of the metabolic and neurologic disorders, or a crucial determinant of their pathophysiologic cascade. In this review, we discuss the current knowledge regarding alterations in brain glucose metabolism, studied with [18F]-FDG-PET from metabolic disorders to AD, with a special focus on how manipulation of insulin levels affects brain glucose metabolism in health and in systemic insulin resistance. A better understanding of alterations in brain glucose metabolism in health, obesity, and neurodegeneration, and the relationships between insulin resistance and central nervous system glucose metabolism may be an important step for the battle against metabolic and cognitive disorders.


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