Rat Model System Research Articles

Skeletal and Uterotrophic Effects of Endoxifen in Female Rats.

Endoxifen, the primary active metabolite of tamoxifen, is currently being investigated as a novel endocrine therapy for the treatment of breast cancer. Tamoxifen is a selective estrogen receptor modulator that elicits potent anti-breast cancer effects. However, long-term use of tamoxifen also induces bone loss in premenopausal women and is associated with an increased risk of endometrial cancer in postmenopausal women. For these reasons, we have used a rat model system to comprehensively characterize the impact of endoxifen on the skeleton and uterus. Our results demonstrate that endoxifen elicits beneficial effects on bone in ovary-intact rats and protects against bone loss following ovariectomy. Endoxifen is also shown to reduce bone turnover in both ovary-intact and ovariectomized rats at the cellular and biochemical levels. With regard to the uterus, endoxifen decreased uterine weight but maintained luminal epithelial cell height in ovariectomized animals. Within luminal epithelial cells, endoxifen resulted in differential effects on the expression levels of estrogen receptors α and β as well as multiple other genes previously implicated in regulating epithelial cell proliferation and hypertrophy. These studies analyze the impact of extended endoxifen exposure on both bone and uterus using a Food and Drug Administration-recommended animal model. Although endoxifen is a more potent breast cancer agent than tamoxifen, the results of the present study demonstrate that endoxifen does not induce bone loss in ovary-intact rats and that it elicits partial agonistic effects on the uterus and skeleton in ovariectomized animals.

Corticosterone oscillations during mania induction in the lateral hypothalamic kindled rat-Experimental observations and mathematical modeling.

Changes in the hypothalamic-pituitary-adrenal (HPA) axis activity constitute a key component of bipolar mania, but the extent and nature of these alterations are not fully understood. We use here the lateral hypothalamic-kindled (LHK) rat model to deliberately induce an acute manic-like episode and measure serum corticosterone concentrations to assess changes in HPA axis activity. A mathematical model is developed to succinctly describe the entwined biochemical transformations that underlay the HPA axis and emulate by numerical simulations the considerable increase in serum corticosterone concentration induced by LHK. Synergistic combination of the LHK rat model and dynamical systems theory allows us to quantitatively characterize changes in HPA axis activity under controlled induction of acute manic-like states and provides a framework to study in silico how the dynamic integration of neurochemical transformations underlying the HPA axis is disrupted in these states.

Expression of microRNAs and target proteins in skeletal muscle of rats selectively bred for high and low running capacity.

Impairments in mitochondrial function and substrate metabolism are implicated in the etiology of obesity and Type 2 diabetes. MicroRNAs (miRNAs) can degrade mRNA or repress protein translation and have been implicated in the development of such disorders. We used a contrasting rat model system of selectively bred high- (HCR) or low- (LCR) intrinsic running capacity with established differences in metabolic health to investigate the molecular mechanisms through which miRNAs regulate target proteins mediating mitochondrial function and substrate oxidation processes. Quantification of select miRNAs using the rat miFinder miRNA PCR array revealed differential expression of 15 skeletal muscles (musculus tibialis anterior) miRNAs between HCR and LCR rats (14 with higher expression in LCR; P < 0.05). Ingenuity Pathway Analysis predicted these altered miRNAs to collectively target multiple proteins implicated in mitochondrial dysfunction and energy substrate metabolism. Total protein abundance of citrate synthase (CS; miR-19 target) and voltage-dependent anion channel 1 (miR-7a target) were higher in HCR compared with LCR cohorts (~57 and ~26%, respectively; P < 0.05). A negative correlation was observed for miR-19a-3p and CS (r = 0.32, P = 0.015) protein expression. To determine whether miR-19a-3p can regulate CS in vitro, we performed luciferase reporter and transfection assays in C2C12 myotubes. MiR-19a-3p binding to the CS untranslated region did not change luciferase reporter activity; however, miR-19a-3p transfection decreased CS protein expression (∼70%; P < 0.05). The differential miRNA expression targeting proteins implicated in mitochondrial dysfunction and energy substrate metabolism may contribute to the molecular basis, mediating the divergent metabolic health profiles of LCR and HCR rats.

Changes in the Brain Endocannabinoid System in Rat Models of Depression

A growing body of evidence implicates the endocannabinoid (eCB) system in the pathophysiology of depression. The aim of this study was to investigate the influence of changes in the eCB system, such as levels of neuromodulators, eCB synthesizing and degrading enzymes, and cannabinoid (CB) receptors, in different brain structures in animal models of depression using behavioral and biochemical analyses. Both models used, i.e., bulbectomized (OBX) and Wistar Kyoto (WKY) rats, were characterized at the behavioral level by increased immobility time. In the OBX rats, anandamide (AEA) levels were decreased in the prefrontal cortex, hippocampus, and striatum and increased in the nucleus accumbens, while 2-arachidonoylglycerol (2-AG) levels were increased in the prefrontal cortex and decreased in the nucleus accumbens with parallel changes in the expression of eCB metabolizing enzymes in several structures. It was also observed that CB1 receptor expression decreased in the hippocampus, dorsal striatum, and nucleus accumbens, and CB2 receptor expression decreased in the prefrontal cortex and hippocampus. In WKY rats, the levels of eCBs were reduced in the prefrontal cortex (2-AG) and dorsal striatum (AEA) and increased in the prefrontal cortex (AEA) with different changes in the expression of eCB metabolizing enzymes, while the CB1 receptor density was increased in several brain regions. These findings suggest that dysregulation in the eCB system is implicated in the pathogenesis of depression, although neurochemical changes were linked to the particular brain structure and the factor inducing depression (surgical removal of the olfactory bulbs vs. genetic modulation).

The long non-coding RNA NEAT1 is responsive to neuronal activity and is associated with hyperexcitability states

Despite their abundance, the molecular functions of long non-coding RNAs in mammalian nervous systems remain poorly understood. Here we show that the long non-coding RNA, NEAT1, directly modulates neuronal excitability and is associated with pathological seizure states. Specifically, NEAT1 is dynamically regulated by neuronal activity in vitro and in vivo, binds epilepsy-associated potassium channel-interacting proteins including KCNAB2 and KCNIP1, and induces a neuronal hyper-potentiation phenotype in iPSC-derived human cortical neurons following antisense oligonucleotide knockdown. Next generation sequencing reveals a strong association of NEAT1 with increased ion channel gene expression upon activation of iPSC-derived neurons following NEAT1 knockdown. Furthermore, we show that while NEAT1 is acutely down-regulated in response to neuronal activity, repeated stimulation results in NEAT1 becoming chronically unresponsive in independent in vivo rat model systems relevant to temporal lobe epilepsy. We extended previous studies showing increased NEAT1 expression in resected cortical tissue from high spiking regions of patients suffering from intractable seizures. Our results indicate a role for NEAT1 in modulating human neuronal activity and suggest a novel mechanistic link between an activity-dependent long non-coding RNA and epilepsy.

SAT-131 - AKT inhibitor ARQ 092 and sorafenib additively inhibit progression of hepatocellular carcinoma and improve immune system in cirrhotic rat model

SAT-131 - AKT inhibitor ARQ 092 and sorafenib additively inhibit progression of hepatocellular carcinoma and improve immune system in cirrhotic rat model

Fetal Exposure to Low Levels of the Plasticizer DEHP Predisposes the Adult Male Adrenal Gland to Endocrine Disruption.

In utero exposure to endocrine disrupting chemicals (EDCs) may affect adult health. Di-(2-ethylhexyl) phthalate (DEHP) is an EDC widely used in the production of polyvinyl chloride products and an ubiquitous environmental contaminant. We used a rat model system to show that fetal exposure to DEHP decreased levels of major steroid hormones in adulthood and that environmentally-relevant levels of DEHP affected both gene expression and epigenomic loci that were affected by exposure to high levels. In the adrenal gland, we reported that the peroxisome proliferator-activated receptor (PPAR) and cholesterol biosynthesis pathways were sensitive targets of DEHP. We hypothesized that low levels of DEHP exposure insult the endocrine system (a "first hit") and increase its susceptibility to later exposure ("second hit") and subsequent disease. Here, we demonstrate that a second hit in the adult offspring exposed in utero to low levels of DEHP affected serum aldosterone levels. To unveil the first hit influence of early DEHP exposure, we treated in utero DEHP-exposed adult offspring with stressors that targeted the PPAR or cholesterol biosynthesis pathways. Treatment with the PPAR-gamma antagonist T0070907 reduced serum aldosterone compared to animals not exposed to DEHP in utero. Analysis of gene expression in animals that were subjected to both early and late exposure revealed deregulation of genes for the potassium channel Kcnk5 and the retinoid-X receptors (RXR) Rxra and Rxrb, indicating that these entities are linked to endocrine disruption. We propose that early exposure to environmental doses of DEHP predisposes the animal for disease later in life.

Chitosan Wound Dressings Incorporating Exosomes Derived from MicroRNA-126-Overexpressing Synovium Mesenchymal Stem Cells Provide Sustained Release of Exosomes and Heal Full-Thickness Skin Defects in a Diabetic Rat Model.

There is a need to find better strategies to promote wound healing, especially of chronic wounds, which remain a challenge. We found that synovium mesenchymal stem cells (SMSCs) have the ability to strongly promote cell proliferation of fibroblasts; however, they are ineffective at promoting angiogenesis. Using gene overexpression technology, we overexpressed microRNA‐126‐3p (miR‐126‐3p) and transferred the angiogenic ability of endothelial progenitor cells to SMSCs, promoting angiogenesis. We tested a therapeutic strategy involving controlled‐release exosomes derived from miR‐126‐3p‐overexpressing SMSCs combined with chitosan. Our in vitro results showed that exosomes derived from miR‐126‐3p‐overexpressing SMSCs (SMSC‐126‐Exos) stimulated the proliferation of human dermal fibroblasts and human dermal microvascular endothelial cells (HMEC‐1) in a dose‐dependent manner. Furthermore, SMSC‐126‐Exos also promoted migration and tube formation of HMEC‐1. Testing this system in a diabetic rat model, we found that this approach resulted in accelerated re‐epithelialization, activated angiogenesis, and promotion of collagen maturity in vivo. These data provide the first evidence of the potential of SMSC‐126‐Exos in treating cutaneous wounds and indicate that modifying the cells—for example, by gene overexpression—and using the exosomes derived from these modified cells provides a potential drug delivery system and could have infinite possibilities for future therapy. Stem Cells Translational Medicine 2017;6:736–747

Prominent Vascularization Capacity of Mesenchymal Stem Cells in Collagen-Gold Nanocomposites.

The ideal characteristics of surface modification on the vascular graft for clinical application would be with excellent hemocompatibility, endothelialization capacity, and antirestenosis ability. Here, Fourier transform infrared spectroscopy (FTIR), surface enhanced Raman spectroscopy (SERS), atomic force microscopy (AFM), contact angle (θ) measurement, and thermogravimetric analysis (TGA) were used to evaluate the chemical and mechanical properties of collagen-gold nanocomposites (collagen+Au) with 17.4, 43.5, and 174 ppm of Au and suggested that the collagen+Au with 43.5 ppm of Au had better biomechanical properties and thermal stability than pure collagen. Besides, stromal-derived factor-1α (SDF-1α) at 50 ng/mL promoted the migration of mesenchymal stem cells (MSCs) on collagen+Au material through the α5β3 integrin/endothelial oxide synthase (eNOS)/metalloproteinase (MMP) signaling pathway which can be abolished by the knockdown of vascular endothelial growth factor (VEGF). The potentiality of collagen+Au with MSCs for vascular regeneration was evaluated by our in vivo rat model system. Artery tissues isolated from an implanted collagen+Au-coated catheter with MSCs expressed substantial CD-31 and α-SMA, displayed higher antifibrotic ability, antithrombotic activity, as well as anti-inflammatory response than all other materials. Our results indicated that the implantation of collagen+Au-coated catheters with MSCs could be a promising strategy for vascular regeneration.

Les relations entre le bisphénol A et les troubles du spectre autistique se précisent : la sérotonine est-elle le lien manquant ?

The etiology of autism spectrum disorders (ASD) is believed to be multifactorial and to involve genetic and environmental components. Environmental chemical exposures are increasingly understood to be important in causing neurotoxicity in fetuses and newborns. Recent data from the Centers for Disease Control and Prevention in the United States suggest a substantial increase in ASD prevalence, only partly explicable by factors such as diagnostic substitution. Bisphenol A (BPA) is an ubiquitous xenoestrogen widely employed in a variety of consumer products including plastic and metal food and beverage containers, dental sealants and fillings, medical equipment and thermal receipts. Therefore, most people are exposed almost continuously to BPA in industrialized countries. Sources of BPA exposure are predominantly diet, but also through inhalation or dermal absorption. BPA can be measured in many human fluids and tissues including saliva, serum, urine, amniotic fluid, follicular fluid, placental tissue and breast milk. There is concern that BPA exposure may influence human brain development and may contribute to the increasing prevalence of neurodevelopmental and behavioural problems. Epigenetic mechanisms are suggested by a mouse study that demonstrated that BPA exposure during gestation had long lasting, transgenerational effects on social recognition. Previous epidemiological studies suggested a relationship between maternal BPA exposure and ASD. A recent study of 46 children with ASD and 52 controls found for the first time a direct association between children with ASD and BPA exposure and demonstrated that BPA is not metabolized well in children with ASD. The metabolomic analyses showed a correlation between ASD and essential amino acid metabolism pathways. Essential amino acids are precursors of neurotransmitters, for example tryptophan for serotonin. Fetal and prenatal BPA exposure was suggested to perturb the serotonergic system in rat and mice models. On the other hand, hyperserotonemia was reported in approximately one-third of autistic patients and also in relatives. Moreover, neuroimaging studies revealed two fundamentally different types of serotonin synthesis abnormality in children with autism compared to age-matched nonautistic children, a difference in whole-brain capacity and focal abnormalities. Finally, decreased serotonin transporter and serotonin receptor binding have been reported in both children and adults with autism. So, the link between BPA and autism could be a defect of the normal in utero or perinatal serotonergic system development. In France, BPA was banned in baby bottles in 2010 and in any food or beverage packaging since January 2015. Therefore, there is an urgent need to find safe alternatives in the use of BPA in the manufacture of industrial products.

Effects of antidepressants on osteoporosis related protein OPG, RANKL and RANK in ovariectomized rat model with depressive disorder

Objective To investigate the effects of antidepressant therapy on whole regulating function of OPG/RANKL/RANK system in ovariectomized(OVX) rat model with depressive disorder. Methods Forty sexually mature female SD rats were used as subjects. The rats were randomly divided into 8 groups as following: sham group(Sn), depression group(Dn), the OVX group(On), the OVX with depression group(ODn), OVX with depression + sertraline group (ODs), and OVX with depression + citalopram (ODx), OVX with depression + reboxetine group(ODr), OVX with depression + venlafaxine group(ODw). Bilateral oophorectomy was applied to establish the ovariectomized rats model.Chronic unpredictable mild stress(CUMS) was used to estalish depression model. Open-field test and sugar consumption experiment were applied before the experiment and the 28th day of the experiment. Immunohistochemistry and Quantitative Real-time PCR were used to observe the expression of OPG, RANKL and RANK. Results After chronic unpredictable mild stress the scores of horizontal motion, vertical motion and percentage of sugar consumption experiment in Dn group were decreased contrast to the in control Sn group (P<0.05)and the scores in ODn group were decreased in contrast to the On group (P<0.05). The protein and gene expression of RANK in Dn group and On group were increased in contrast to the Sn group (P<0.05). The protein and gene expression of RANKL in Dn group and On group were increased in contrast to the Sn group (P<0.05). The gene expression of OPG in ODs group(5.94±0.79), ODw group(5.99±1.08) and ODr group(6.59±0.69)was decreased in contrast to the ODn group(4.96±0.51)(P<0.05). The gene expression of RANK in ODs group(2.82±0.23), ODx group(3.03±0.04)was increased in contrast to the ODn group(3.44±0.18)(P<0.05). The gene expression of RANKL in ODs group(4.82±0.94), ODx group(5.00±0.82) and ODw group(5.23±0.88)was decreased in contrast to the ODn group(3.69±0.69)(P<0.05). Conclusion The expression of RANK and RANKL in femoral neck is increased both in depressive disorder model rats and ovariectomized model rats.The antidepressant can up-regulate the expression of RANK, and down-regulate the expression of OPG and RANKL in the OVX with depression group. Of the effect, sertraline is the strongest, however reboxetine mesylate is the poorest. Key words: Antidepressant; Depressive disorder rats model; Ovariectomized rats model; Osteoprotegerin; Receptor activator of NF-κB

H2S Regulates Hypobaric Hypoxia-Induced Early Glio-Vascular Dysfunction and Neuro-Pathophysiological Effects

Hypobaric Hypoxia (HH) is an established risk factor for various neuro-physiological perturbations including cognitive impairment. The origin and mechanistic basis of such responses however remain elusive. We here combined systems level analysis with classical neuro-physiological approaches, in a rat model system, to understand pathological responses of brain to HH. Unbiased ‘statistical co-expression networks’ generated utilizing temporal, differential transcriptome signatures of hippocampus—centrally involved in regulating cognition—implicated perturbation of Glio-Vascular homeostasis during early responses to HH, with concurrent modulation of vasomodulatory, hemostatic and proteolytic processes. Further, multiple lines of experimental evidence from ultra-structural, immuno-histological, substrate-zymography and barrier function studies unambiguously supported this proposition. Interestingly, we show a significant lowering of H2S levels in the brain, under chronic HH conditions. This phenomenon functionally impacted hypoxia-induced modulation of cerebral blood flow (hypoxic autoregulation) besides perturbing the strength of functional hyperemia responses. The augmentation of H2S levels, during HH conditions, remarkably preserved Glio-Vascular homeostasis and key neuro-physiological functions (cerebral blood flow, functional hyperemia and spatial memory) besides curtailing HH-induced neuronal apoptosis in hippocampus. Our data thus revealed causal role of H2S during HH-induced early Glio-Vascular dysfunction and consequent cognitive impairment.

Western diet enhances benzo(a)pyrene-induced colon tumorigenesis in a polyposis in rat coli (PIRC) rat model of colon cancer.

Consumption of Western diet (WD), contaminated with environmental toxicants, has been implicated as one of the risk factors for sporadic colon cancer. Our earlier studies using a mouse model revealed that compared to unsaturated dietary fat, the saturated dietary fat exacerbated the development of colon tumors caused by B(a)P. The objective of this study was to study how WD potentiates B(a)P-induced colon carcinogenesis in the adult male rats that carry a mutation in the Apc locus - the polyposis in the rat colon (PIRC) rats. Groups of PIRC rats were fed with AIN-76A standard diet (RD) or Western diet (WD) and received 25, 50, or 100 μg B(a)P/kg body weight (wt) via oral gavage for 60 days. Subsequent to exposure, rats were euthanized; colons were retrieved and preserved in 10% formalin for counting the polyp numbers, measuring the polyp size, and histological analyses. Blood samples were collected and concentrations of cholesterol, triglycerides, glucose, insulin and leptin were measured. Rats that received WD + B(a)P showed increased levels of cholesterol, triglycerides, and leptin in comparison to RD + B(a)P groups or controls. The colon tumor numbers showed a B(a)P dose-response relationship. Adenomas with high grade dysplasia were prominent in B(a)P + WD rats compared to B(a)P + RD rats and controls (p < 0.05). The larger rat model system used in this study allows for studying more advanced tumor phenotypes over a longer duration and delineating the role of diet - toxicant interactions in sporadic colon tumor development.

Effect of Nigella sativa on reproductive system in experimental menopause rat model.

Menopause is the condition when regular menstrual periods cease and may be accompanied by psychological and physical symptoms. The purpose of current study was to determine Nigella sativa effects on reproductive system in experimental menopause animal models. A series of experiments was conducted to investigate the effects of different dosages of N. sativa (first experiment), various extracts of N. sativa (second experiment) and some of its ingredients (third experiment) on selected menopausal parameters of ovariectomized (OVX) rats. Forty different OVX rats were equally divided into 5 groups and administered with one of the following treatments for 21 days: conjugated equine estrogen (positive control), distilled water or olive oil (negative control), treatment groups (N. sativa300, 600 and 1200 mg/kg in the first experiment), (300mg/kg methanol, hexane and SFE extracts of N. sativa in the second experiment) and (linoleic acid 50 mg/kg, gamma linolenic acid 10mg/kg, and thymoquinone 15mg/kg in the third experiment). The results demonstrated that N.sativa exert estrogenic effect were exhibited through uterotrophic assay and vaginal cell cornification as well as blood estrogen level. Furthermore, low dose N. sativa, methanol extract and linoleic acid had prominent estrogenic like effects which were significantly different from those of control group (p<0.05) in different experiments. The finding indicated the probable beneficial role for N. sativa in the treatment of postmenopausal symptoms and possibility of using N. sativa as an alternative to hormone replacement therapy (HRT) for post menopause in human.

Effects of Propofol on the Liver Oxidative-Antioxidant Balance in a Rat Model of Parkinson's Disease.

Parkinson's disease is caused by the destruction of dopaminergic neurons in the substantia nigra of the midbrain. One of the possible factors involved in the pathogenesis of Parkinson's disease is impaired oxidativeantioxidative balance. The present study aimed to evaluate selected parameters of the liver oxidative-antioxidative system in a Wistar rat model with Parkinson's disease treated with propofol. Experiments were performed on 32 rats divided into 4 groups: 1 - control, 2 - Parkinson's disease, 3 - control with propofol, 4 - Parkinson's disease with propofol. The rats were decapitated at 8 weeks of age and their livers were collected. In the liver, the activities of catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST), glutathione reductase (GR) and the concentrations of: Malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS) were assessed. The study demonstrated a decrease in CAT activity and an increase in MDA, TOS concentrations in group 2 compared to that of group 1. Administration of propofol in rats of group 4 caused an increase in CAT activity and a decrease in MDA concentration compared to that of group 2 and an increase in TAC, CAT, GR levels, decrease in MDA levels compared to that of group 1. There was also an increase in GR and TAC in group 3 compared to that of group 1. Propofol in Parkinson's disease stimulates the production of antioxidant enzymes in the liver, simultaneously decreasing oxidative stress, which has a beneficial effect on the oxidative-antioxidative balance.

Role of sympathetic nervous system in rat model of chronic visceral pain.

Changes in central pain modulation have been implicated in generalized pain syndromes such as irritable bowel syndrome (IBS). We have previously demonstrated that reduced descending inhibition unveils a role of sympathoneuronal outflow in decreasing peripheral sensory thresholds, resulting in stress-induced hyperalgesia. We investigated whether sympathetic nervous system (SNS) exacerbation of pain sensation when central pain inhibition is reduced is relevant to chronic pain disorders using a rat colon irritation (CI) model of chronic visceral hypersensitivity with hallmarks of IBS. Rats were treated to a series of colorectal balloon distensions (CRD) as neonates resulting in visceral and somatic hypersensitivity and altered stool function that persists into adulthood. The visceral sensitivity was assessed by recording electromyographic (EMG) responses to CRD. Somatic sensitivity was assessed by paw withdrawal thresholds to radiant heat. The effects on the hypersensitivity of (i) inhibiting sympathoneuronal outflow with pharmacological and surgical interventions and (ii) enhancing the outflow with water avoidance stress (WAS) were tested. The alpha2-adrenergic agonist, clonidine, and the alpha1-adrenergic antagonist, prazosin, reduced the visceral hypersensitivity and WAS enhanced the pain. Chemical sympathectomy with guanethidine and surgical sympathectomy resulted in a loss of the chronic visceral hypersensitivity. The results support a role of the SNS in driving the chronic visceral and somatic hypersensitivity seen in CI rats. The findings further suggest that treatments that decrease sympathetic outflow or block activation of adrenergic receptors on sensory nerves could be beneficial in the treatment of generalized pain syndromes.

Hepatopulmonary syndrome-related changes in D-dimer, prothrombin time, fibrinogen, CD4 and CD8 in a rat model system

To determine the changes in levels of D-dimer, prothrombin time (PT), fibrinogen (Fib), CD4 and CD8 in relation to hepatopulmonary syndrome (HPS) by using a rat model system and to assess the association with pathologic changes in lung. Forty male Sprague-Dawley rats were divided into equal groups for modeling of cirrhosis and HPS. The two groups were assessed by blood gas analysis, standard biochemical tests to measure D-dimer, PT, Fib, CD4 and CD8, and pathological examination of lung tissues. The HPS rats showed significantly lower PaO2 than the cirrhosis rats (58.20+/-3.19 mmHg vs. 85.00+/-2.53 mmHg, P = 0.000). The HPS rats showed significantly higher levels of D-dimer, Fib and CD8 than the cirrhosis rats (0.39+/-0.09 mg/ml vs. 0.25+/-0.05 mg/ml, P = 0.000; 1.77+/-0.10 g/L vs. and 1.49+/-0.09 g/L, P = 0.010; 32.32+/-4.45/mm3 vs. 20.13+/-6.09/mm3, P = 0.014). The HPS rats showed significantly lower levels of PT, CD4 and CD4/CD8 than the cirrhosis rats (14.86+/-1.04 s vs. 16.23+/-0.75 s, P = 0.036; 20.45+/-3.86/mm3 vs. 26.75+/-5.32/mm3, P = 0.000; 0.64+/-0.09 vs. 1.32+/-0.13, P = 0.000). The lung tissues of the HPS rats showed microthrombosis in pulmonary vessels, which were not observed in lung tissues of the cirrhosis rats. HPS-related differential levels of D-dimer, PT, Fib, CD4, CD8 and CD4/CD8 may represent a biomarker profile suggestive of incidence of thromboembolism in lung.

Reversal of liver fibrosis through AG490 inhibitor-mediated inhibition of the TGFbeta1-STAT3 pathway

To investigate the role of TGF-beta1 and STAT3 signaling in liver fibrosis using a rat model system and to determine the therapeutic mechanism of AG490 in relation to this signaling pathway. Rats were randomly divided into a control group and DENA-induced liver fibrosis model group, and then subdivided into AG490 treatment groups. During fibrosis development, liver tissue samples were collected at different time points (0, 4 and 8 weeks) and evaluated according to the Scheuer scoring system. Expression of STAT3, TGFbeta1, alpha-SMA, E-cadherin, MMP2 and TIMP1 was measured by PCR (mRNA) and immunohistochemistry and western blotting (protein). Increasing degrees of inflammation and fibrosis were observed in liver tissues of DENA-treated rats throughout model establishment. The mRNA expression of TGFbeta1 and STAT3 was significantly increased in DENA-induced rats with advanced fibrosis (AF) compared to those with early fibrosis (EF) (P = 0.034 and P = 0.012 respectively). The protein expression of TGF-beta1, phospho-Smad2, alpha-SMA, E-cadherin, STAT3 and phospho-STAT3 was significantly increased in DENA-induced rats with AF compared to the unmodeled control group (P = 0.048, P = 0.003, P = 0.002, P = 0.028, P = 0.009 and P = 0.039). The protein expression of E-cadherin was lower in the DENA-induced rats with AF than in those with EF (P = 0.026). STAT3 and TGF-beta1 co-expression was detected in AF tissues. DENA-induced AG490-treated rats with AF showed substantially lower protein expression of STAT3, TGF-beta1, MMP2 and TIMP1 compared to DENA-induced untreated rats with AF (P = 0.006, P = 0.018, P = 0.010 and P = 0.005); in addition, the degrees of fibrosis and inflammation were also greatly reduced in the DENA-induced AG490-treated rats with AF compared to DENA-induced untreated rats with AF (P = 0.042 and P = 0.021). Conclusions STAT3 signal transduction may regulate the TGF-beta1 pathway and affect liver fibrosis, especially in the advanced phase. AG490 can inhibit TGFbeta1-STAT3 signaling, resulting in reversal of liver fibrosis.

Alterations in the motor cortical and striatal glutamatergic system and d-serine levels in the bilateral 6-hydroxydopamine rat model for Parkinson's disease

Parkinson's disease (PD) is hallmarked by progressive degeneration of the substantia nigra pars compacta (SNc) neurons and is associated with aberrant glutamatergic activity. However, studies on the glutamatergic system in the motor cortex and striatum, two motor loop-related areas, are lacking in the clinically relevant bilateral SNc 6-hydroxydopamine (6-OHDA) rat model, and therefore led to the rationale behind the present investigations. Using Western blotting, the expression levels of the glial glutamate transporters, GLT-1 and GLAST, as well as xCT, the specific subunit of system xc−, and the vesicular glutamate transporters, VGLUT1 and 2 were investigated at two different time points (1 week and 2 weeks) post-lesion. In addition, the total content of glutamate was measured. Moreover, the total d-serine levels were, to the best of our knowledge, studied for the first time in these two PD-related areas in the bilateral 6-OHDA rat model. In the motor cortex, no significant changes were observed in the different glutamate transporter expression levels in the bilaterally-lesioned rats. In the striatum, GLAST expression was significantly decreased at both time points whereas VGLUT1 and 2 expressions were significantly decreased 2 weeks after bilateral 6-OHDA lesion. Interestingly, bilateral 6-OHDA SNc lesion resulted in an enhancement of the total d-serine content in both motor cortex and striatum at 1 week post-lesion suggesting its possible involvement in the pathophysiology of PD. In conclusion, this study demonstrates disturbed glutamate and d-serine regulation in the bilateral SNc-lesioned brain which could contribute to the behavioral impairments in PD.

Neurodegenerative and Morpho-functional Alterations During Senescence: Positive Modulation by Lipoic Acid and Superoxide Dismutase Ocular Senescence in a Rat Model

We have evaluated the modulation of degenerative events at the retinal and optic nerve level in a rat model system. Degeneration was ameliorated in aging rats by the combined oral administration of -lipoic acid and superoxide dismutase. Twenty four month-old rats were fed ad libitum with a diet supplemented by these two compounds. Positive control rats received a compound-free diet, while the negative control group consisted of untreated young animals. The cyto-protective effects of -lipoic acid and superoxide dismutase were investigated by morphological analysis of retinal and optic nerve head sections. The level of nuclear DNA damage was assessed by TUNEL fluorescent reaction. Lipo-peroxidation assays evaluated the oxidative stress and consequent alteration of the cell membrane function. Apoptotic phenomena were investigated by immuno-localization and Western blotting to measure the expression of caspase-3 and inducible nitric oxide synthase. The results reported in this work provide evidence that-lipoic acid and superoxide dismutase counteract the degenerative damage in aging animals, reducing the effects of oxidative stress. Keywords-lipoic Acid; Apoptosis; Oxidative Stress; Rat Model