BN Rats Research Articles

Quercetin Prevents Hypertension in Dahl Salt-sensitive Rats F ed a High-salt Diet Through Balancing Endothelial Nitric Oxide Synthase and Sirtuin 1.

A high-salt diet is a leading dietary risk factor for elevated blood pressure and cardiovascular disease. Quercetin reportedly exhibits cardioprotective and antihypertensive therapeutic effects. The objective of this study is to examine the effect of quercetin on high-salt dietinduced elevated blood pressure in Dahl salt-sensitive (SS) rats and determine the underlying molecular mechanism. Rats of the Dahl SS and control SS-13 BN strains were separated into five groups, SS-13 BN rats fed a low-salt diet (BL group), SS-13 BN rats fed a high-salt diet (BH group), Dahl SS rats fed a low-salt diet (SL group), Dahl SS rats fed a high-salt diet (SH group), and SH rats treated with quercetin (SHQ group). Blood pressure was checked three weeks into the course of treatment, and biochemical markers in the urine and serum were examined. Additionally, western blot was done to evaluate the sirtuin 1 (SIRT1) and endothelial nitric oxide synthase (eNOS) expression levels. Immunohistochemical analysis was performed to verify SIRT1 levels. We demonstrated that a high-salt diet elevated blood pressure in both SS-13 BN and Dahl SS rats, and quercetin supplementation alleviated the altered blood pressure. Compared with the SH group, quercetin significantly elevated the protein expression of SIRT1 and eNOS. Immunohistochemistry results further confirmed that quercetin could improve the protein expression of SIRT1. Quercetin reduced blood pressure by enhancing the expression of SIRT1 and eNOS in Dahl SS rats fed a high-salt diet.

Mingjing granule inhibits the subretinal fibrovascular membrane of two-stage laser-induced neovascular age-related macular degeneration in rats.

The study aims to investigate the protective effect of Mingjing granule (MG) in a fibrovascular membrane rat model of neovascular age-related macular degeneration (nAMD) and explore the underlying mechanism. The nAMD fibrovascular membrane model was established by two-stage laser photocoagulation. BN rats were randomly divided into four groups: the model group was gavaged with distilled water, the anti-VEGF group was given an intravitreous injection of ranibizumab, the MG + anti-VEGF group was gavaged with MG combined with an intravitreous injection of ranibizumab, and the normal group not modeled only fed conventionally. Lesions were evaluated by color fundus photograph, optical coherence tomography, fundus fluorescein angiography, and retinal pigment epithelial-choroid-sclera flat mount. The changes in the retinal structure were observed by histopathology. The expression of inflammatory cell markers F4/80, Iba-1, and glial fibrillary acidic protein (GFAP); the fibrosis-related factors collagen-1, fibronectin, α-smooth muscle actin (α-SMA), and transforming growth factor-beta (TGF-β); and the complement system-related factors C3a and C3aR in the retina were detected by immunofluorescence or qRT-PCR. The current study revealed that MG + anti-VEGF administration more significantly reduced the thickness of fibrovascular lesions, suppressed vascular leakage (exudation area and mean density value), inhibited the area of fibrovascular lesions, and restrained the formation of the fibrovascular membrane than the anti-VEGF agent alone in the two-stage laser-induced rat model. The fluorescence intensities of F4/80, Iba-1, collagen-1, fibronectin, TGF-β, and C3aR showed more significant inhibition in MG + anti-VEGF-treated rats than the anti-VEGF agent alone. The mRNA expression levels of F4/80, Iba-1, GFAP, collagen-1, fibronectin, α-SMA, TGF-β, and C3a showed lower levels in rats treated with MG + anti-VEGF than the anti-VEGF agent alone. Combining MG with anti-VEGF treatment inhibits the growth of the fibrovascular membrane more effectively than using anti-VEGF treatment alone. The mechanism underlying this effect may involve limiting inflammatory cell aggregation, controlling complement system activation, and decreasing the expression of the fibrotic protein.

Differential impact of unilateral stroke on the bihemispheric motor cortex representation of the jaw and tongue muscles in young and aged rats.

Dysphagia commonly occurs after stroke, yet the mechanisms of post-stroke corticobulbar plasticity are not well understood. While cortical activity associated with swallowing actions is bihemispheric, prior research has suggested that plasticity of the intact cortex may drive recovery of swallowing after unilateral stroke. Age may be an important factor as it is an independent predictor of dysphagia after stroke and neuroplasticity may be reduced with age. Based on previous clinical studies, we hypothesized that cranial muscle activating volumes may be expanded in the intact hemisphere and would contribute to swallowing function. We also hypothesized that older age would be associated with limited map expansion and reduced function. As such, our goal was to determine the impact of stroke and age on corticobulbar plasticity by examining the jaw and tongue muscle activating volumes within the bilateral sensorimotor cortices. Using the middle cerebral artery occlusion rat stroke model, intracortical microstimulation (ICMS) was used to map regions of sensorimotor cortex that activate tongue and jaw muscles in both hemispheres. Young adult (7 months) and aged (30 months) male F344 × BN rats underwent a stroke or sham-control surgery, followed by ICMS mapping 8 weeks later. Videofluoroscopy was used to assess oral-motor functions. Increased activating volume of the sensorimotor cortex within the intact hemisphere was found only for jaw muscles, whereas significant stroke-related differences in tongue activating cortical volume were limited to the infarcted hemisphere. These stroke-related differences were correlated with infarct size, such that larger infarcts were associated with increased jaw representation in the intact hemisphere and decreased tongue representation in the infarcted hemisphere. We found that both age and stroke were independently associated with swallowing differences, weight loss, and increased corticomotor thresholds. Laterality of tongue and jaw representations in the sham-control group revealed variability between individuals and between muscles within individuals. Our findings suggest the role of the intact and infarcted hemispheres in the recovery of oral motor function may differ between the tongue and jaw muscles, which may have important implications for rehabilitation, especially hemisphere-specific neuromodulatory approaches. This study addressed the natural course of recovery after stroke; future work should expand to focus on rehabilitation.

Green tea polyphenols alleviate β-conglycinin-induced anaphylaxis by modulating gut microbiota in rats

Heretofore, there are no effective therapeutic interventions for food allergies induced by β-conglycinin, an major allergen in soybean. The objective of this study was to explore the alleviating effect and underlying mechanism of green tea polyphenols (GTPs) on β-conglycinin-induced anaphylaxis. Twenty-one-day-old weaned BN rats were sensitized by gavage of β-conglycin and then given drinking water containing 1% GTPs. The results showed that β-conglcyinin sensitized rats had increased serum IgE levels and IL-4 level in spleen cell culture supernatant compared with the control group. However, total IgE, β-conglycin-specific IgE and IL-4 levels were significantly decreased by GTPs, suggesting that it weakened Th2-type immune response and restored cytokine homeostasis. The impact of GTPs on gut microbiota mainly focused on the changes in specific microbes, characterized by a significant increase of Bacteroides and other beneficial bacteria, which would contribute to the recovery of gastrointestinal allergies. This study is the first to demonstrate that GTPs, as good immunomodulator, played an important role in alleviating soybean protein allergy, which were associated with the alterations in gut microbiota. These results contribute to the development and application of green tea and provided an effective nutritional therapy strategy for the prevention and treatment of allergic diseases caused by soybean allergens.

The Power of the Heterogeneous Stock Rat Founder Strains in Modeling Metabolic Disease.

Metabolic diseases are a host of complex conditions, including obesity, diabetes mellitus, and metabolic syndrome. Endocrine control systems (eg, adrenals, thyroid, gonads) are causally linked to metabolic health outcomes. N/NIH Heterogeneous Stock (HS) rats are a genetically heterogeneous outbred population developed for genetic studies of complex traits. Genetic mapping studies in adult HS rats identified loci associated with cardiometabolic risks, such as glucose intolerance, insulin resistance, and increased body mass index. This study determined underappreciated metabolic health traits and the associated endocrine glands within available substrains of the HS rat founders. We hypothesize that the genetic diversity of the HS rat founder strains causes a range of endocrine health conditions contributing to the diversity of cardiometabolic disease risks. ACI/EurMcwi, BN/NHsdMcwi, BUF/MnaMcwi, F344/StmMcwi, M520/NRrrcMcwi, and WKY/NCrl rats of both sexes were studied from birth until 13 weeks of age. Birth weight was recorded, body weight was measured weekly, metabolic characteristics were assessed, and blood and tissues were collected. Our data show wide variation in endocrine traits and metabolic health states in ACI, BN, BUF, F344, M520, and WKY rat strains. This is the first report to compare birth weight, resting metabolic rate, endocrine gland weight, hypothalamic-pituitary-thyroid axis hormones, and brown adipose tissue weight in these rat strains. Importantly, this work unveils new potential for the HS rat population to model early life adversity and adrenal and thyroid pathophysiology. The HS population likely inherited risk alleles for these strain-specific traits, making the HS rat a powerful model to investigate interventions on endocrine and metabolic health.

Genetic background in the rat affects endocrine and metabolic outcomes of bisphenol F exposure.

Environmental bisphenol compounds like bisphenol F (BPF) are endocrine-disrupting chemicals (EDCs) affecting adipose and classical endocrine systems. Genetic factors that influence EDC exposure outcomes are poorly understood and are unaccounted variables that may contribute to the large range of reported outcomes in the human population. We previously demonstrated that BPF exposure increased body growth and adiposity in male N/NIH heterogeneous stock (HS) rats, a genetically heterogeneous outbred population. We hypothesize that the founder strains of the HS rat exhibit EDC effects that were strain- and sex-dependent. Weanling littermate pairs of male and female ACI, BN, BUF, F344, M520, and WKY rats randomly received either vehicle (0.1% EtOH) or 1.125 mg BPF/l in 0.1% EtOH for 10 weeks in drinking water. Body weight and fluid intake were measured weekly, metabolic parameters were assessed, and blood and tissues were collected. BPF increased thyroid weight in ACI males, thymus and kidney weight in BUF females, adrenal weight in WKY males, and possibly increased pituitary weight in BN males. BUF females also developed a disruption in activity and metabolic rate with BPF exposure. These sex- and strain-specific exposure outcomes illustrate that HS rat founders possess diverse bisphenol-exposure risk alleles and suggest that BPF exposure may intensify inherent organ system dysfunction existing in the HS rat founders. We propose that the HS rat will be an invaluable model for dissecting gene EDC interactions on health.

Genetic Predisposition to Hepatocellular Carcinoma.

Liver preneoplastic and neoplastic lesions of the genetically susceptible F344 and resistant BN rats cluster, respectively, with human HCC with better (HCCB) and poorer prognosis (HCCP); therefore, they represent a valid model to study the molecular alterations determining the genetic predisposition to HCC and the response to therapy. The ubiquitin-mediated proteolysis of ERK-inhibitor DUSP1, which characterizes HCC progression, favors the unrestrained ERK activity. DUSP1 represents a valuable prognostic marker, and ERK, CKS1, or SKP2 are potential therapeutic targets for human HCC. In DN (dysplastic nodule) and HCC of F344 rats and human HCCP, DUSP1 downregulation and ERK1/2 overexpression sustain SKP2-CKS1 activity through FOXM1, the expression of which is associated with a susceptible phenotype. SAM-methyl-transferase reactions and SAM/SAH ratio are regulated by GNMT. In addition, GNMT binds to CYP1A, PARP1, and NFKB and PREX2 gene promoters. MYBL2 upregulation deregulates cell cycle and induces the progression of premalignant and malignant liver. During HCC progression, the MYBL2 transcription factor positively correlates with cells proliferation and microvessel density, while it is negatively correlated to apoptosis. Hierarchical supervised analysis, regarding 6132 genes common to human and rat liver, showed a gene expression pattern common to normal liver of both strains and BN nodules, and a second pattern is observed in F344 nodules and HCC of both strains. Comparative genetics studies showed that DNs of BN rats cluster with human HCCB, while F344 DNs and HCCs cluster with HCCP.

VR-10 polypeptide interacts with CD36 to induce cell apoptosis and autophagy in choroid-retinal endothelial cells: Identification of VR-10 as putative novel therapeutic agent for choroid neovascularization (CNV) treatment

Choroid neovascularization (CNV) is important adverse pathological changes that contributes to the aggravation of hypoxic-ischemic eye diseases, and our preliminary work evidences that the thrombospondin-1 (TSP-1) synthetic polypeptide VR-10 may be the candidate therapeutic agent for the treatment of CNV, but its detailed effects and molecular mechanisms are not fully delineated. In this study, the CNV models in BN rats were established by using the laser photocoagulation method, which were further subjected to VR-10 peptide treatment. The RNA-seq and bioinformatics analysis suggested that VR-10 peptide significantly altered the expression patterns of genes in the rat ocular tissues, and the changed genes were especially enriched in the CD36-associated signal pathways. Next, by performing the Real-Time qPCR and Western Blot analysis, we expectedly found that VR-10 upregulated the anti-angiogenesis biomarker (PEDF) and downregulated pro-angiogenesis biomarkers (VEGF, HIF-1 and IL-17) in rat tissues. In addition, we evidenced that VR-10 downregulated CDK2, CDK4, CDK6, Cyclin D1 and Cyclin D2 to induce cell cycle arrest, upregulated cleaved Caspase-3, Bax and downregulated Bcl-2 to promote cell apoptosis, and increased LC3B-II/I ratio and facilitate p62 degradation to promote cell autophagy in RF/6A cells, which were all reversed by knocking down CD36. Moreover, VR-10 upregulated PEDF, and decreased the expression levels of VEGF, HIF-1 and IL-17 to block angiogenesis of RF/6A cells in a CD36-dependent manner. Taken together, VR-10 peptide interacts with its receptor CD36 to regulate the biological functions of RF/6A cells, and these data suggest that VR-10 peptide may be the putative therapeutic drug for the treatment of CNV in clinic.

422.2: Investigating Galectin-3 as a Novel Therapeutic Target To Block Inflammation and Reduce Ischemia Reperfusion Injury During Vascular Composite Allograft Transplantation

Introduction: Vascularized Composite Allograft (VCA) transplantation is a treatment option for complex injuries that leave patients with structural and functional deficits that cannot be adequately reconstructed. During transplantation, grafts are subjected to hypoxic/ischemic injury during procurement, storage, and reperfusion. Skin and muscle containing VCA are highly susceptible to ischemia reperfusion injury. Galectin-3 is an endogenous β-galactoside binding lectin known to play a role in driving inflammatory responses in response to hypoxic/ischemic stress. Blocking galectin-3 using known inhibitors including modified citrus pectin (MCP) has been shown in animal models to reduce inflammation and fibrosis. We hypothesized that galectin-3 significantly contributes to VCA IRI and that blocking galectin-3 can serve as a novel therapeutic approach to prevent or reduce IRI. We aimed to determine the role of galectin-3 in VCA ischemia reperfusion injury and the effect of blocking galectin-3 using MCP in syngeneic VCA models. Method: Male Brown Norway rats underwent syngeneic hind limb transplantation following 0, 6 or 24 hours of cold ischemia time. A group of rats receiving hind limbs subjected to 24 hours of static cold storage were treated with MCP (1% w/v) in the drinking water starting one week prior to transplantation. Recipient serum and donor VCA tissues were collected at end-of-study 6 days post transplantation. Sera and tissues collected from naive Brown Norway rats were included as controls. Sera levels of galectin-3 were determined by sandwich ELISA (Novus Biologics, Inc). Galectin-3 expression in the muscle was determined by Western Blotting. The degree of inflammation in the muscle tissue was determined by H&E. Results: Sera galectin-3 levels averaged 0.854±0.557ng/ml in naïve BN rats (n=7), 4.232±2.134ng/ml in recipients of grafts transplanted immediately without static cold storage (n=3), 12.86±1.292ng/ml in recipients of grafts subjected to 6 hours cold storage without MCP treatment (n=3),20.10±3.185ng/ml in recipients of grafts subjected to 24 hours cold storage without MCP treatment (n=6), and 12.77±2.098ng/ml in recipients of grafts subjected to 24 hours cold storage with MCP treatment (n=9) (Figure 1A). Galectin-3 expression in the VCA muscle increased according to the extent of cold ischemia. MCP treatment decreased muscle galectin-3 expression (Figure 1B) and inflammation in the muscle (Figure 2) post transplantation.Conclusion: Galectin-3 levels significantly increased in recipient sera and donor muscle within a week in rats transplanted with donor VCA grafts subjected to prolonged ischemia. Blocking galectin-3 using MCP can reduce the amount of galectin-3 in circulation and muscle tissue post transplantation and may decrease inflammation associated with VCA IRI. Galectin-3 may serve as a novel therapeutic target to reduce inflammation associated with ischemic injury and improve VCA outcomes. DOD CDMRP RTRP W81XWH1910163 RT180168.

The dual mTORC1/2 inhibitor AZD2014 inhibits acute graft rejection in a rat liver transplantation model

To investigate the inhibitory effect of AZD2014, a dual mTORC1/2 inhibitor, against acute graft rejection in a rat model of allogeneic liver transplantation. Liver transplantation from Lewis rat to recipient BN rat (a donor-recipient combination that was prone to induce acute graft rejection) was performed using Kamada's two-cuff technique. The recipient BN rats were randomized into 2 groups for treatment with daily intraperitoneal injection of AZD2014 (5 mg/kg, n=4) or vehicle (2.5 mL/kg, n=4) for 14 consecutive days, starting from the first day after the transplantation. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) levels of the rats were measured 3 days before and at 1, 3, 5, 7, 10, and 14 days after the transplantation, and the survival time of the rats within 14 days were recorded. Immunohistochemical staining was used to examine the expressions of CD3 and Foxp3 in the liver graft, and acute graft rejection was assessed using HE staining based on the Banff schema. Three rats in the control group died within 14 days after the surgery, while no death occurred in the AZD2014 group, demonstrating a significantly longer survival time of the rats in AZD2014 group (χ2=4.213, P=0.04). Serum ALT, AST and TBIL levels in the control group increased progressively after the surgery and were all significantly higher than those in AZD2014 group at the same time point (P < 0.05). Pathological examination revealed significantly worse liver graft rejection in the control group than in AZD2014 group based on assessment of the rejection index (P < 0.01); the rats in the control group showed more serious T lymphocyte infiltration and significantly fewer Treg cells in the liver graft than those in AZD2014 group (P < 0.01). AZD2014 can effectively inhibit acute graft rejection in rats with allogeneic liver transplantation.

Bone marrow mesenchymal stem cells modified with heme oxygenase-1 alleviate rejection of donation after circulatory death liver transplantation by inhibiting dendritic cell maturation in rats

Immature dendritic cells induce immune tolerance and mature dendritic cells induce acute rejection. We infused bone marrow mesenchymal stem cells (BMMSCs) expressing heme oxygenase 1 (HO-1) (HO-1/BMMSCs) into donation after circulatory death (DCD) livers using normothermic machine perfusion (NMP), and then performed transplantation, with the aim of determining the effects of HO 1/BMMSCs on liver DC maturation and graft rejection. A rat model of acute liver transplantation rejection was established from Lewis to BN rats, in which six experimental groups were set up: Sham operation, static cold storage, NMP, BMMSCs + NMP, HO-1/BMMSCs + NMP (HBP), and NMP + FK506 gavage. Flow cytometry was performed to detect the maturation of DCs and the activation of CD4+ T cells in the liver. In vitro, HO-1/BMMSCs were cocultured with liver DCs, and then the phenotype and ability to stimulate lymphocyte proliferation of DCs were measured. MAPK inhibitors were added to observe the effect of MAPK signaling on DC maturation. The resultsindicatedthatHO-1/BMMSCs could stably colonize the transplanted liver. In the HBP group, rejection was reduced, the maturation of DCs was inhibited, and the infiltration and activation of CD4+ T cells were reduced. In vitro, DCs cocultured with HO-1/BMMSCs showed an immature phenotype and inhibited T cell proliferation. HO-1/BMMSCs inhibited the maturation of DCs by blocking the phosphorylation of p38 and ERK1/2. This study suggested that infusion of HO-1/BMMSCs into DCD livers could reduce acute rejection significantly by inhibiting DC maturation. DC maturation regulation by HO-1/BMMSCs involves ERK1/2/MAPK and p38/MAPK signaling.

MiR-199a-3p may be an early warning marker for acute rejection after liver transplantation in rats.

Prevention of acute rejection is the key of the success of liver transplantation. However, there are no specific indicators available for prediction of acute rejection after liver transplantation. MicroRNAs (miRNAs) are highly conserved and small noncoding RNA molecules that can be detected in peripheral blood. Here, we evaluated the potential of circulating miRNAs to serve as noninvasive biomarkers for acute rejection after liver transplantation in rats. The liver grafts retrieved from Lewis rats were orthotopically transplanted into BN rats or Lewis rats in the acute rejection and immune tolerance group respectively, and the BN rats in the immune intervention group was intraperitoneally injected with transforming growth factor-β1 overexpressed immature dendritic cells to suppress acute rejection before orthotopically transplanted with livers from Lewis rats. MiRNAs profiling studies were used to determine the regulation of circulating miRNAs in plasma samples of rats. Candidate miRNA was verified by quantitative reverse transcriptase polymerase chain reaction. Furthermore, the relationship between candidate miRNA and acute rejection was also evaluated. Microarray analysis revealed that miR-199a-3p was the mostly differentially regulated miRNAs in plasma samples among the three groups. The plasmid PCDH-CMV-EGFP-hTGF-β1 was identified by PCR and DNA sequencing, and successfully expressed in imDCs. There were differences in the expression of miR-199a-3p in the liver tissues of the AR group on the 3rd, 7th and 10th day after liver transplantation (all p<0.01). With time, the RAI score increased gradually, and the difference of miR-199a-3p expression gradually increased (rs=0.92, p<0.001), suggesting that it may be related to acute rejection. The expression of miR-199a-3p in the serum of the AR and TGF-β1-imDCs groups gradually increased, reaching a peak at day 7 and then decreasing. There was positive relationship between the expression of miR-199a-3p and RAIs within 7days post operation. (rs=0.942, p<0.05). miR-199a-3p might be an early warning marker for acute rejection after liver transplantation in rats.

Effects of almonds on ameliorating salt-induced hypertension in dahl salt-sensitive rats.

Excessive dietary salt intake is related to an increased risk of hypertension. Dietary functional foods probably could help to improve salt-induced hypertension. In this study, Dahl salt-sensitive (DSS) rats were used to investigate their metabolic differences from those of salt-resistant SS.13BN rats and determine whether dietary protein-rich almonds could ameliorate salt-induced elevation of blood pressure in DSS rats. After high-salt intake, the systolic blood pressure and mean arterial pressure of the DSS rats increased dramatically. Metabolomics analysis indicated abnormal amino acid metabolism in their kidneys. Their renal nitric oxide (NO) content and nitric oxide synthase activity decreased significantly after high-salt diet. Oxidative stress also occurred in DSS rats. After the DSS rats received almond supplementation, the levels of various amino acids in their kidney increased, and renal arginine and NO contents were upregulated. Their renal hydrogen peroxide and malonaldehyde levels decreased, whereas renal catalase, superoxide dismutase and glutathione peroxidase activities and glutathione levels increased. The renal abnormal amino acid metabolism of DSS rats contributed to the impaired NO production in response to high-salt intake. Together with salt-induced oxidative stress, high-salt diet intake ultimately led to an increase in the blood pressure of DSS rats. Protein-rich almond supplementation might prevent the development of salt-induced hypertension by restoring arginine and NO regeneration and alleviating salt-induced oxidative stress. © 2021 Society of Chemical Industry.

Abstract 35: Gamma Adducin Dysfunction Leads To Cerebrovascular Distention, Blood Brain Barrier Leakage, And Cognitive Deficits In The Fawn-hooded Hypertensive Rats

We have previously identified an inactivating mutation of ADD3 in FHH rats which is associated with impaired myogenic reactivity of renal arterioles and podocyte function, and contributes to the development of CKD. We have found that SNPs in human ADD1 or ADD3 in the same region as Add3 in FHH rats are linked to reductions in brain volumes and impaired performance on cognitive tests in 4,286 elderly patients (67-90 years old) in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS), but the mechanisms of these pathologies are unclear. The present study examined cerebral hemodynamics and cognitive function in FHH versus FHH.1BN and FHH. Add3 rats that express the WT Add3 gene. The myogenic responses of the middle cerebral artery (MCA) and parenchymal arterioles (PA) were impaired in FHH rats. MCA diameter decreased by 15-20% in FHH.1BN (n = 27) and FHH. Add3 (n = 10) transgenic rats, but increased by 9 ± 3% in FHH rats (n = 15) when perfusion pressure was increased from 40 to 160 mmHg. PA diameter increased by 3.16 ± 2.79% in FHH (n = 5) rats versus a 19 ± 3% and 13 ± 2% decrease FHH. Add3 (n = 4) and FHH.1BN (n = 6), respectively, when pressure was increased from 10 to 40 mmHg. Autoregulation of surface and deep cortical blood flow was impaired in FHH rats and rose by 48 ± 3% (n = 22) and 41 ± 3% (n = 12), respectively, versus 32 ± 3% (n = 7) and 16 ± 5% (n = 6) in FHH. Add3 rats when MAP was increased from 100 to 160 mmHg. By using a fluorescent microscope to examine 60 μm brain sections, it was revealed that the outer diameters of PAs were distended in FHH in comparison to FHH.1BN and FHH. Add3 transgenic rats when systemic pressure was increased to 160 mmHg. Blood brain barrier leakage was also greater in FHH rats than in FHH.1BN and FHH. Add3 rats after acute elevations in pressure. FHH (n=16) rats took 40- 50% longer to navigate an eight-arm water maze than FHH. Add3 (n=11) and FHH.1BN (n=7) rats. These results indicate that variants that alter Add3 function promote cognitive dysfunction in FHH rats by altering cerebral hemodynamics and may play a similar role in cognitive deficits in elderly patients in the ARIC-NCS study. This study suggests that blood pressure should be strictly controlled in hypertensive patients identified with ADD3 variants to prevent dementia.

Dietary DHA prevents cognitive impairment and inflammatory gene expression in aged male rats fed a diet enriched with refined carbohydrates

The consumption of a processed foods diet (PD) enriched with refined carbohydrates, saturated fats, and lack of fiber has increased in recent decades and likely contributed to increased incidence of chronic disease and weight gain in humans. These diets have also been shown to negatively impact brain health and cognitive function in rodents, non-human primates, and humans, potentially through neuroimmune-related mechanisms. However, mechanisms by which PD impacts the aged brain are unknown. This gap in knowledge is critical, considering the aged brain has a heightened state of baseline inflammation, making it more susceptible to secondary challenges. Here, we showed that consumption of a PD, enriched with refined carbohydrate sources, for 28 days impaired hippocampal- and amygdalar-dependent memory function in aged (24 months), but not young (3 months) F344 × BN rats. These memory deficits were accompanied by increased expression of inflammatory genes, such as IL-1β, CD11b, MHC class II, CD86, NLRP3, and complement component 3, in the hippocampus and amygdala of aged rats. Importantly, we also showed that when the same PD is supplemented with the omega-3 polyunsaturated fatty acid DHA, these memory deficits and inflammatory gene expression changes were ameliorated in aged rats, thus providing the first evidence that DHA supplementation can protect against memory deficits and inflammatory gene expression in aged rats fed a processed foods diet. Lastly, we showed that while PD consumption increased weight gain in both young and aged rats, this effect was exaggerated in aged rats. Aging was also associated with significant alterations in hypothalamic gene expression, with no impact by DHA on weight gain or hypothalamic gene expression. Together, our data provide novel insights regarding diet-brain interactions by showing that PD consumption impairs cognitive function likely through a neuroimmune mechanism and that dietary DHA can ameliorate this phenomenon.

IRF7-Associated Immunophenotypes Have Dichotomous Responses to Virus/Allergen Coexposure and OM-85-Induced Reprogramming.

High risk for virus-induced asthma exacerbations in children is associated with an IRF7lo immunophenotype, but the underlying mechanisms are unclear. Here, we applied a Systems Biology approach to an animal model comprising rat strains manifesting high (BN) versus low susceptibility (PVG) to experimental asthma, induced by virus/allergen coexposure, to elucidate the mechanism(s)-of-action of the high-risk asthma immunophenotype. We also investigated potential risk mitigation via pretreatment with the immune training agent OM-85. Virus/allergen coexposure in low-risk PVG rats resulted in rapid and transient airways inflammation alongside IRF7 gene network formation. In contrast, responses in high-risk BN rats were characterized by severe airways eosinophilia and exaggerated proinflammatory responses that failed to resolve, and complete absence of IRF7 gene networks. OM-85 had more profound effects in high-risk BN rats, inducing immune-related gene expression changes in lung at baseline and reducing exaggerated airway inflammatory responses to virus/allergen coexposure. In low-risk PVG rats, OM-85 boosted IRF7 gene networks in the lung but did not alter baseline gene expression or cellular influx. Distinct IRF7-associated asthma risk immunophenotypes have dichotomous responses to virus/allergen coexposure and respond differentially to OM-85 pretreatment. Extrapolating to humans, our findings suggest that the beneficial effects OM-85 pretreatment may preferentially target those in high-risk subgroups.

L-phenylalanine attenuates high salt-induced hypertension in Dahl SS rats through activation of GCH1-BH4.

Amino acid metabolism plays an important role in controlling blood pressure by regulating the production of NO and ROS. The present study examined amino acid levels in the serum of Dahl SS rats and SS.13BN rats fed a low or high salt diet. We observed that 8 of 27 amino acids responded to a high salt diet in SS rats. Thus, we hypothesized that a defect in amino acids may contribute to the development of salt-induced hypertension. L-phenylalanine was used to treat SS rats with a low or high salt diet. The results demonstrated that L-phenylalanine supplementation significantly enhanced the serum nitrite levels and attenuated the high salt-induced hypertension in SS rats. Low levels of BH4 and nitrite and the impaired vascular response to acetylcholine were rescued by L-phenylalanine supplementation. Moreover, increased GTP cyclohydrolase (GCH1) mRNA, levels of BH4 and nitrite, and reduced superoxide production were observed in the kidneys of hypertensive SS rats with L-phenylalanine. The antihypertensive effects of L-phenylalanine might be mediated by enhancing BH4 biosynthesis and decreasing superoxide production from NO synthase, thereby protecting vascular and kidney function with reduced ROS and elevated NO levels. The present study demonstrated that L-phenylalanine supplementation restored vascular function, suggesting L-phenylalanine represented a potential target to attenuate high salt-sensitive hypertension through GCH1-BH4.

Establishment of animal models of epidermal growth factor receptor inhibitor-related rashes

To establish animal models epidermal growth factor receptor inhibitor-related skin rashes using cetuximab, gefitinib or erlotinib. Female SCID mice were randomly divided into blank control group and high-, moderate-, and low-dose cetuximab groups. The mice in control group received intraperitoneal injection of saline, and those in the 3 cetuximab groups were injected with 80, 40, and 20 mg/kg cetuximab (3 times a week for 4 weeks), respectively. The general skin appearance and skin pathologies of the mice were observed. Female BN rats were randomly divided into blank group, ovalbumin group, gefitinib group and erlotinib group, and in the latter 3 groups, the rats were given ovalbumin (1 mg), gefitinib (37.5 mg/kg), and erlotinib (23.5 mg/kg) by lavage once daily for 45 days, respectively. Skin pathologies of the rats were observed, and serum levels of TNF-α, IL-6 and other inflammatory factors were detected using ELISA. Intraperitoneal injection of cetuximab did not induce typical skin rashes, scabs or obvious skin inflammation in the mice. In female BN rats, lavage of gefitinib caused obvious skin rashes, scabs and exudation, and obvious inflammatory cell infiltration, keratinosis, spinous layer release and epidermal thickening were observed in the skin. No obvious skin inflammation were observed in the rats in the control, ovalbumin or erlotinib groups. While IgE (P=0.061) and TNF-α concentrations (P=0.057) did not differ significantly among the groups, serum levels of IL-6 was significantly higher in gefitinib group than in the blank control group (P=0.016) but similar between erlotinib group and the blank group (P=0.910). Intraperitoneal injection of cetuximab can not induce epidermal growth factor receptor inhibitor-related skin rashes in SCID mice. Lavage of gefitinib, but not erlotinib, can be used to establish models of epidermal growth factor receptor inhibitor-related rashes in BN rats.

Successful i-GONAD in Brown Norway Rats by Modification of in vivo Electroporation Conditions

Improved-Genome editing via Oviductal Nucleic Acids Delivery (i-GONAD) was developed for in situ genome editing of the preimplantation embryos present within the oviductal lumen of mice. This method is based on intra-oviductal instillation of genome editing components and subsequent in vivo electroporation (EP) in the entire oviduct. Therefore, i-GONAD differs from the previous methods (i.e., zygote microinjection and in vitro EP) in producing genome-edited mice, which relied on ex vivo handling of preimplantation embryos and egg transfer to the recipient females. We have previously demonstrated that i-GONAD can be successfully applied to produce genome-edited rats, including albino Sprague-Dawley and albino Lewis rats (however, not pigmented Brown Norway [BN] rats). We observed that the successful i-GONAD was dependent on the mouse strain used; for example, in random-bred mice, such as ICR and C3H/He × C57BL/6, it was successful under relatively stringent electrical conditions but not in the C57BL/6 strain. Under less stringent conditions, i-GONAD was successful in the C57BL/6 strain. We speculated that this would also be true for i-GONAD using BN rats. On applying a current of &gt;500 mA, we failed to obtain rat offspring (fetuses/newborns); however, i-GONAD under a current of 100-300 mA using NEPA21 (NEPA GENE) led to the production of genome-edited BN rats with efficiencies of 75%-100%. Similarly, i-GONAD, under a current of 150-200 mA using CUY21EDIT II (BEX Co.) led to the production of genome-edited BN rats with efficiencies of 24%-55%. These experiments suggest the importance of selecting the appropriate current value, depending on the rat strain used, when performing i-GONAD.

Revealing metabolic pathways relevant to prediabetes based on metabolomics profiling analysis

AimsDahl salt-sensitive (SS) rats develop similar prediabetes lesion characteristics, such as impaired glucose tolerance (IGT), when compared with the salt resistant rat. In this study, we evaluate the risk of high glucose intake during prediabetes and reveal the metabolic pathways relevant to the pathophysiology of prediabetes to diabetes using the SS rat model and compared this with the salt-resistant consomic SS.13BN rat model. MethodsSS rats were fed with normal chow ±10% glucose solution ad libitum for five weeks. The same experimental treatment was performed on the SS.13BN rats. Metabolites derived from the serum and liver tissue were measured through biochemical and metabolomics analyses. Multivariate, pathway enrichment, and metabolic correlation network analyses were performed based on the metabolomics data. ResultsBiochemical analysis revealed that serum triglyceride (TG) significantly increased with a significant decrease in serum total cholesterol (TC) after high glucose intake in the SS rat. Metabolic pathway analysis revealed that high glucose intake interfered with galactose, glyoxylate, and dicarboxylate metabolism, most evidently in the SS rat. Hepatic l-lactic acid content increased in the SS rat after high glucose intake, whereas the opposite was observed in SS.13BN rats. Metabolic correlation network analysis based on serum metabolites revealed that urea and l-valine had higher metabolic centrality in the SS rat. ConclusionOur findings revealed that high glucose intake can significantly stimulate hypertriglyceridemia and reduce serum TC level. The profoundly altered metabolic pathway included galactose, glyoxylate, and dicarboxylate metabolism. l-lactic acid was screened as a biomarker in liver, whereas l-valine and urea were screened as hub metabolites in serum.