Detection of impaired cognitive function in rat with hepatosteatosis model and improving effect of GLP-1 analogs (exenatide) on cognitive function in hepatosteatosis

Modafinil Improves Autism-like Behavior in Rats by Reducing Neuroinflammation

To evaluate the ameliorating effect of Modafinil on neuroinflammation, behavioral, and histopathological alterations in rats induced by propionic acid (PPA). Thirty male Wistar rats were used in the study, divided into 3 groups of ten subjects. One group served as a control, the subjects in the other two were given 250 mg/kg/day of PPA by intraperitoneal injection over the course of 5 days to induce autism. The experimental design was as follows: Group 1: Normal control (orally-fed control, n = 10); Group 2 (PPA + saline, n = 10): PPA and 1 ml/kg/day % 0.9 NaCl saline via oral gavage; Group 3 (PPA + Modafinil, n = 10) PPA and 30 mg/kg/day Modafinil (Modiodal tablets 100 mg, Cephalon) via oral gavage. All of the groups were investigated for behavioral, biochemical, and histological abnormality. Autism-like behaviors were reduced significantly in the rats treated with PPA. TNF-α, Nerve Growth Factor (NGF), IL-17, IL-2, and NF-KB levels as well as MDA levels and lactate were significantly higher in those treated with PPA compared to the control group. Using immunohistochemical methods, the number of neurons and GFAP immunoreactivity was significantly altered in PPA-treated rats compared to the control. Using Magnetic Resonance Spectroscopy (MRS), we found that lactate levels were significantly higher in the PPA-treated rats, while creatinine levels were significantly decreased. In the rats administered with Modafinil, behavior, neuroinflammation, and histopathological changes brought about by PPA were significantly reversed. Our results demonstrate the potential role of Modafinil in ameliorating PPA-induced neuroinflammation in rats.

Exposure to hypertonic solutions during pregnancy induces autism-like behaviors via the NFAT-5 pathway in offspring in a rat model

OBJECTIVES

to investigate the effects of hyperosmolar state (HS) on immune response and inflammation via the NFAT5 pathway and examine whether immune-mediated conditions trigger autism-like behavior in offspring.

METHODS

a pregnant rat model was performed by administering hyperosmotic solutions. Pregnant rats were divided into 2 main groups; control (group I) and hyperosmolar groups (group II). Control group rats were given % 0.25 NaCI (tap water) (n = 6), the Hyperosmolar (HO) group was further subdivided into 3 groups as; Group II a rats which were given % 3 hypertonic NaCl (n = 6), Group II b rats were given mineral water (% 3 NaHCO3+magnesium+calcium content) (n = 6), and Group II c rats were given Ayran (% 0.8 NaCl content) (n = 6). Their offspring were examined for behaviors, biochemical and histological abnormality.

RESULTS

in offspring, TNF- α, IL-17, NFAT-5, and NGF levels in the brain were significantly higher in hyperosmotic solution groups than in control rats. Exposure of pregnant rats to hyperosmotic solution resulted in autism-like behaviors in their offspring. Through immunohistochemical methods, we found that CA1 and CA2 of the hippocampus indicated decreased number of neurons in hyperosmotic solution groups compared with the control group.

CONCLUSIONS

our findings once again emphasized that the immune-mediated conditions involved in the pathophysiology of autism. NFAT5 pathway may be a key factor in the development of neuroinflammation by hyperosmotic solutions.

Impact of plasma transaminase levels on the peripheral blood glutamate levels and memory functions in healthy subjects

Background & aims

Blood aspartate aminotransferase (AST) and alanine transaminase (ALT) levels are the most frequently reliable biomarkers of liver injury. Although AST and ALT play central roles in glutamate production as transaminases, peripheral blood levels of AST and ALT have been regarded only as liver injury biomarkers. Glutamate is a principal excitatory neurotransmitter, which affects memory functions in the brain. In this study, we investigated the impact of blood transaminase levels on blood glutamate concentration and memory.

Methods

Psychiatrically, medically, and neurologically healthy subjects (n = 514, female/male: 268/246) were enrolled in this study through local advertisements. Plasma amino acids (glutamate, glutamine, glycine, d-serine, and l-serine) were measured using a high performance liquid chromatography system. The five indices, verbal memory, visual memory, general memory, attention/concentration, and delayed recall of the Wechsler Memory Scale-Revised were used to measure memory functions.

Results

Both plasma AST and ALT had a significant positive correlation with plasma glutamate levels. Plasma AST and ALT levels were significantly negatively correlated with four of five memory functions, and plasma glutamate was significantly negatively correlated with three of five memory functions. Multivariate analyses demonstrated that plasma AST, ALT, and glutamate levels were significantly correlated with memory functions even after adjustment for gender and education.

Conclusions

As far as we know, this is the first report which could demonstrate the impact of blood transaminase levels on blood glutamate concentration and memory functions in human. These findings are important for the interpretation of obesity-induced metabolic syndrome with elevated transaminases and cognitive dysfunction.

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Peripheral blood levels of AST and ALT have been regarded only as liver injury biomarkers.

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In healthy human subjects, both plasma AST and ALT had significant positive correlations with plasma glutamate levels.

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Plasma AST, ALT, and glutamate levels were significantly negatively correlated with memory functions in univariate and multivariate analyses.

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As far as we know, this is the first report which could demonstrate the impact of blood transaminase levels on blood glutamate concentration and memory functions in human.

Exenatide improves ovarian and endometrial injury and preserves ovarian reserve in streptozocin induced diabetic rats

We aimed to evaluate: (1) endometrial and ovarian tissue injury caused by the glucose toxicity in diabetic rat model and (2) the effect of GLP-1 analog (exenatide) on endometrial and ovarian diabetes induced injury with emphasizing the underlying mechanism. The study group composed of 24 female rats assigned randomly into 3 groups. Group 1 was the control group (n = 8) and received no treatment. Diabetes was induced by intraperitoneal injection of streptozocin for 16 rats which are further assigned randomly into 2 groups: 1 ml/kg intraperitoneal saline was given to Group-2 (diabetic non-treated control group, 8 rats) and 10 µg/kg/day of intraperitoneal exenatide was given to Group 3 (exenatide treated group, 8 rats) for four weeks. After four weeks, blood samples were collected and hysterectomy with bilateral oophorectomy was performed for histopathological examination. Diabetes caused endometrial and ovarian tissue injury in rats (p < 0.0001). Serum transforming growth factor beta (TGF-ß), malonylaldehyde (MDA), pentraxin-3 (PTX-3) levels were higher in diabetic rats (p < 0.0001), whereas antimullerian hormone (AMH) was lower (p < 0.001). Serum levels of these markers reflected that Diabetes induced injury in the reproductive tract occured via oxidative stress, fibrosis and severe inflammation. Diabetes diminished ovarian reserve. Exenatide treatment improved the histological degeneration and fibrosis in the endometrium and ovary with concomitant decrease in inflammatory and oxidative stress markers (p < 0.05). Exenatide also improved ovarian reserve (p < 0.05). Glucose toxicity occured severely in ovary and endometrium in DM. After exenatide treatment; ovarian and endometrial injury and fibrosis seems to decrease significantly. The effects of exenatide in rat models give hope to prevent the women with DM from premature ovarian failure and endometrial dysfunction.

Amyloid-β pathology and APOE genotype modulate retinoid X receptor agonist activity in vivo

Previous data demonstrate that bexarotene (Bex), retinoid X receptor (RXR) agonist, reduces soluble and insoluble amyloid-β (Aβ) in Alzheimer disease (AD)-transgenic mice either by increasing the levels of mouse apolipoprotein E (apoE) or increasing ABCA1/ABCG1-induced apoE lipoprotein association/lipidation. However, although the mechanism of action of RXR agonists remains unclear, a major concern for their use is human (h)-APOE4, the greatest AD genetic risk factor. If APOE4 imparts a toxic gain-of-function, then increasing apoE4 may increase soluble Aβ, likely the proximal AD neurotoxin. If the APOE4 loss-of-function is lipidation of apoE4, then induction of ABCA1/ABCG1 may be beneficial. In novel EFAD-Tg mice (overexpressing h-Aβ42 with h-APOE), levels of soluble Aβ (Aβ42 and oligomeric Aβ) are highest in E4FAD hippocampus (HP) > E3FAD-HP > E4FAD cortex (CX) > E3FAD-CX, whereas levels of lipoprotein-associated/lipidated apoE have the opposite pattern (6 months). In E4FAD-HP, short-term RXR agonist treatment (Bex or LG100268; 5.75-6 months) increased ABCA1, apoE4 lipoprotein-association/lipidation, and apoE4/Aβ complex, decreased soluble Aβ, and increased PSD95. In addition, hydrogel delivery, which mimics low sustained release, was equally effective as gavage for Bex and LG100268. RXR agonists induced no beneficial effects in the E4FAD-HP in a prevention protocol (5-6 months) and actually increased soluble Aβ levels in E3FAD-CX and E4FAD-CX with the short-term protocol, possibly the result of systemic hepatomegaly. Thus, RXR agonists address the loss-of-function associated with APOE4 and exacerbated by Aβ pathology, i.e. low levels of apoE4 lipoprotein association/lipidation. Further studies are vital to address whether RXR agonists are an APOE4-specific AD therapeutic and the systemic side effects that limit translational application.