Choline and Choline alphoscerate Do Not Modulate Inflammatory Processes in the Rat Brain

Choline is involved in relevant neurochemical processes. In particular, it is the precursor and metabolite of acetylcholine (ACh). Choline is an essential component of different membrane phospholipids that are involved in intraneuronal signal transduction. On the other hand, cholinergic precursors are involved in ACh release and carry out a neuroprotective effect based on an anti-inflammatory action. Based on these findings, the present study was designed to evaluate the effects of choline and choline precursor (Choline alphoscerate, GPC) in the modulation of inflammatory processes in the rat brain. Male Wistar rats were intraperitoneally treated with 87 mg of choline chloride/kg/day (65 mg/kg/day of choline), and at choline-equivalent doses of GPC (150 mg/kg/day) and vehicle for two weeks. The brains were dissected and used for immunochemical and immunohistochemical analysis. Inflammatory cytokines (Interleukin-1β, IL-1β; Interleukin-6 , IL-6 and Tumor Necrosis Factor-α, TNF-α) and endothelial adhesion molecules (Intercellular Adhesion Molecule, ICAM-1 and Vascular cell Adhesion Molecule, VCAM-1) were studied in the frontal cortex, hippocampus, and cerebellum. The results clearly demonstrated that treatment with choline or GPC did not affect the expression of the inflammatory markers in the different cerebral areas evaluated. Therefore, choline and GPC did not stimulate the inflammatory processes that we assessed in this study

Direct interaction between the catalytic subunit of Protein Phosphatase 1 and pRb

BACKGROUND: The product of the retinoblastoma-susceptibility gene (pRb) is a substrate for Protein Phosphatase 1 (PP1). At mitotic exit, all three PP1 isoforms, α, γ1 and δ, bind to pRb and dephosphorylate its Ser/Thr sites in a sequential and site-specific way. The pRb-C terminal has been reported to be necessary and sufficient for PP1α binding. The present study investigated whether the three PP1 isoforms from mitotic or asynchronous HeLa cells associate differentially with wild-type and pRb mutants, as well as the holoenzyme composition of the pRb-directed PP1. RESULTS: The requirement for the entire pRb molecule to achieve optimal PP1-binding was indicated by the fact that full-length pRb displayed the highest affinity for all three PP1 isoforms. Ser/Thr-to-Ala substitution for up to 14 pRb sites did not affect the ability of pRb to bind the PP1 isoforms derived from mitotic or asynchronous HeLa cells, thus suggesting that the phosphate-accepting residues on pRb do not regulate the interaction with PP1. To probe for the presence of PP1 targeting subunits in the pRb-directed PP1 complex, PP1 from mitotic or asynchronous HeLa cells was isolated by affinity chromatography on GST-Rb (either full-length or its deletion mutants Rb-big pocket or Rb-C-terminal). The PP1 was always obtained as free catalytic subunit, displaying all three isoforms, thus suggesting direct interaction between pRb and PP1. The direct association was confirmed by the ability of pRb to pull-down purified PP1 catalytic subunits and by in vitro reconstitution of a complex between PP1 catalytic subunit and the pRb-C-terminal. CONCLUSION: The work indicated that the full length of the pRb molecule is required for optimal interaction with the PP1 isoforms and that the association between pRb and PP1 isoforms is direct

Obesity and Age-Related Changes in the Brain of the Zucker Lepr fa/fa Rats

Metabolic syndrome (MetS) is an association between obesity, dyslipidemia, hyperglycemia, hypertension, and insulin resistance. A relationship between MetS and vascular dementia was hypothesized. The purpose of this work is to investigate brain microanatomy alterations in obese Zucker rats (OZRs), as a model of MetS, compared to their counterparts lean Zucker rats (LZRs). 12-, 16-, and 20-weeks-old male OZRs and LZRs were studied. General physiological parameters and blood values were measured. Immunochemical and immunohistochemical techniques were applied to analyze the brain alterations. The morphology of nerve cells and axons, astrocytes and microglia were investigated. The blood–brain barrier (BBB) changes occurring in OZRs were assessed as well using aquaporin-4 (AQP4) and glucose transporter protein-1 (GLUT1) as markers. Body weight gain, hypertension, hyperglycemia, and hyperlipidemia were found in OZRs compared to LZRs. In the frontal cortex and hippocampus, a decrease of neurons was noticeable in the older obese rats in comparison to their age-matched lean counterparts. In OZRs, a reduction of neurofilament immunoreaction and gliosis was observed. The BBB of older OZRs revealed an increased expression of AQP4 likely related to the development of edema. A down-regulation of GLUT1 was found in OZRs of 12 weeks of age, whereas it increased in older OZRs. The behavioral analysis revealed cognitive alterations in 20-week-old OZRs. Based on these results, the OZRs may be useful for understanding the mechanisms through which obesity and related metabolic alterations induce neurodegeneration

Effects of acetylcholine precursors on inflammation markers in rat brain

Choline is involved in important neurochemical processes. It is a precursor and metabolite of acetylcholine and plays a pivotal role in single-carbon metabolism and it is a fundamental constituent of membrane phospholipids such as phosphatidylcholine. The role of choline and its precursors (e.g. choline alphoscerate, GPC) was recently investigated in experimental endotoxic shock. The obtained results suggest that these molecules may be useful in the treatment of endotoxemia/sepsis. On the other hand, a neuroprotective effect of choline precursors is well-documented and these actions may be related to their activity on inflammatory processes. Based on these findings, the present study was designed to evaluate the effects of choline and GPC in inflammatory processes modulation in the rat brain. Male Wistar rats were treated orally with choline, and GPC at choline-equivalent doses for 2 weeks or were left untreated. After this period, the brains were processed for Western blot analysis and immunohistochemistry. Inflammatory cytokines (IL1, IL6, and TNF) and endothelial inflammatory markers (ICAM-1, and VCAM-1) were studied in different cerebral areas (frontal cortex, hippocampus and cerebellum). Treatment with choline or GPC has not influenced the expression of the inflammatory markers investigated in the brain areas examined. Hence, in this non-pathologic model, GPC, in spite of its neuroprotective effects [1,2], probably does not change or modulate brain inflammatory processes

Brain Alterations in High Fat Diet Induced Obesity: Effects of Tart Cherry Seeds and Juice

Evidence suggests that obesity adversely affects brain function. High body mass index, hypertension, dyslipidemia, insulin resistance, and diabetes are risk factors for increasing cognitive decline. Tart cherries (Prunus Cerasus L.) are rich in anthocyanins and components that modify lipid metabolism. This study evaluated the effects of tart cherries on the brain in diet-induced obese (DIO) rats. DIO rats were fed with a high-fat diet alone or in association with a tart cherry seeds powder (DS) and juice (DJS). DIO rats were compared to rats fed with a standard diet (CHOW). Food intake, body weight, fasting glycemia, insulin, cholesterol, and triglycerides were measured. Immunochemical and immunohistochemical techniques were performed. Results showed that body weight did not differ among the groups. Blood pressure and glycemia were decreased in both DS and DJS groups when compared to DIO rats. Immunochemical and immunohistochemical techniques demonstrated that in supplemented DIO rats, the glial fibrillary acid protein expression and microglial activation were reduced in both the hippocampus and in the frontal cortex, while the neurofilament was increased. Tart cherry intake modified aquaporin 4 and endothelial inflammatory markers. These findings indicate the potential role of this nutritional supplement in preventing obesity-related risk factors, especially neuroinflammation

Effects of Prunus cerasus L. Seeds and Juice on Liver Steatosis in an Animal Model of Diet-Induced Obesity

The accumulation of adipose tissue increases the risk of several diseases. The fruits-intake, containing phytochemicals, is inversely correlated with their development. This study evaluated the effects of anthocyanin-rich tart cherries in diet-induced obese (DIO) rats. DIO rats were exposed to a high-fat diet with the supplementation of tart cherry seeds powder (DS) and seed powder plus juice (DJS). After 17 weeks, the DIO rats showed an increase of body weight, glycaemia, insulin, and systolic blood pressure. In the DS and DJS groups, there was a decrease of systolic blood pressure, glycaemia, triglycerides, and thiobarbituric reactive substances in the serum. In the DJS rats, computed tomography revealed a decrease in the spleen-to-liver attenuation ratio. Indeed, sections of the DIO rats presented hepatic injury characterized by steatosis, which was lower in the supplemented groups. In the liver of the DIO compared with rats fed with a standard diet (CHOW), a down-regulation of the GRP94 protein expression and a reduction of LC3- II/LC3-I ratio were found, indicating endoplasmic reticulum stress and impaired autophagy flux. Interestingly, tart cherry supplementation enhanced both unfolded protein response (UPR) and autophagy. This study suggests that tart cherry supplementation, although it did not reduce body weight in the DIO rats, prevented its related risk factors and liver steatosis

Effects of Prunus cerasus L. Seeds and Juice on Liver Steatosis in an Animal Model of Diet-Induced Obesity

The accumulation of adipose tissue increases the risk of several diseases. The fruits-intake, containing phytochemicals, is inversely correlated with their development. This study evaluated the effects of anthocyanin-rich tart cherries in diet-induced obese (DIO) rats. DIO rats were exposed to a high-fat diet with the supplementation of tart cherry seeds powder (DS) and seed powder plus juice (DJS). After 17 weeks, the DIO rats showed an increase of body weight, glycaemia, insulin, and systolic blood pressure. In the DS and DJS groups, there was a decrease of systolic blood pressure, glycaemia, triglycerides, and thiobarbituric reactive substances in the serum. In the DJS rats, computed tomography revealed a decrease in the spleen-to-liver attenuation ratio. Indeed, sections of the DIO rats presented hepatic injury characterized by steatosis, which was lower in the supplemented groups. In the liver of the DIO compared with rats fed with a standard diet (CHOW), a down-regulation of the GRP94 protein expression and a reduction of LC3- II/LC3-I ratio were found, indicating endoplasmic reticulum stress and impaired autophagy flux. Interestingly, tart cherry supplementation enhanced both unfolded protein response (UPR) and autophagy. This study suggests that tart cherry supplementation, although it did not reduce body weight in the DIO rats, prevented its related risk factors and liver steatosis

A multidisciplinary approach to study the brain injury in Diet-Induced Obesity (DIO) rats

Obesity represents an independent risk factor for the development of cerebrovascular disease and cognitive impairment. The systemic effects, such as increased fat mass, hypertension, insulin resistance and general metabolic dysfunction, have been identified as factors that may lead to impaired cognitive function. To clarify the possible relationships between obesity and nervous system changes, high-caloric Diet-Induced Obesity (DIO) rats 7 weeks-old, were studied after 17 weeks of hypercaloric diet compared to control rats with not fat diet (Chow) or to rats not developing obesity (DIO-resistant DR). Food consumption, fat mass content, blood pressure and blood parameters were assessed. Different behavioural tests were used to estimate cognitive performance. RT-qPCR, immunochemical and immunohistochemical analysis were performed to evaluate neuronal, glial and vascular markers. The obese phenotype developd after 5 weeks of high fat diet exposure and body weight values remained higher in DIO rats compared to the control group and DR rats during the treatment. Systolic blood pressure, glycaemia and insulin were higher in DIO rats only after 17 weeks. No differences in values of total cholesterol and triglycerides were observed. Furthermore increase of thiobarbituric reactive substances and increase of oxidated proteins, was observed in the serum of DIO rats compared to Chow rats. The open-field test revealed, in the older DIO rats, a decrease of cumulative distance travelled and in the number of rearings and an increase of total immobility time. Older DIO rats only, showed a reduction of retention latency time in the passive avoidance test. RT-qPCR, immunochemical and immunohistochemical analysis showed an increased expression of the glial-fibrillary acid protein in the frontal cortex and hippocampus of older DIO rats compared to age-matched Chow and DR rats. A decrease of neurofilament expression was found in the hippocampus of older DIO rats without changes in the number of neurons. A modulation in the Transient Receptor Potential (TRP) channels and synaptic components was highlighted in cerebral areas. These results indicate that obesity in rats, in addition to the development of correlate cerebrovascular risk factors, causes brain injury characterized by astrogliosis, neurodegeneration and impaired learning and memory tasks. The identification of neurodegenerative changes in DIO rats may represent the first step to better characterize the neuronal modifications occurring in the obesity and propose pharmacological treatments or food strategies to counter them

Obesity-related nervous system injury: preliminary evidences in diet induced obesity (DIO) rats.

Increased food intake, reduced physical activity and altered metabolic processes are the variables that affect energy balance inducing obesity. Obesity is now considered an increas-ingly medical challenge. Actually, the prevalence of obesity has increased dramatically worldwide over the last decades and has now reached epidemic proportions. On the other hand, obesity is associated with the development of chronic diseases such as cerebrovascu-lar disease promoting the cognitive decline. Caloric-dense diet induced obesity (DIO), provides a useful animal model sharing several common features with human obesity. DIO rats of 7 weeks of age are expose to high fat (45 %) diet ad libitum and after 5 weeks the obese phenotype starts to be develop. To clarify the possible relationships between obesity and nervous system changes, DIO rats were studied after 5 weeks and 17 weeks of hypercaloric diet compared to the control rats with not fat diet (Chow). Memory performance were measured using different cognitive tests. Moreover, ultrasonographic (US) and computed tomography (CT) evaluations were per-formed to detect adipose tissue changes. Magnetic resonance imaging (MRI) to highlight brain morphological alterations was used. Morphological changes of brain areas (frontal cor-tex, hippocampus) were evaluated by immunohistochemical analysis. The results confirmed the developed of obesity after 5 weeks of fat diet. At long-term (17 weeks) high fat diet exposure, rats increased significantly their body weight in comparison to the control group and the youngest DIO rats. The US and CT analysis indicated an increase of deposition of both visceral and subcutaneous adipose tissue and evidences a decrease of hepatic attenuation in the older DIO rats.MRI images did not show vascular and morphologi-cal alterations in brain. Instead, immuhistochemical and immunochemical analysis, revealed an increase expression of glial-fibrillary acidic protein (GFAP) in the older DIO rats compared to the age- matched Chow rats both in frontal cortex and in hippocampus. DIO rats showed a reduction of retention latency time in the emotional learning task. These preliminary findings indicate that the development of obesity, does not determined gross anatomy alteration in brain, but the occurrence of injury characterized by astrogliosis. The identification of neurodegenerative changes in DIO may represent the first insight to better characterize the neuronal involvement in obesity