Plasma Accumulation Research Articles

Single- and Multiple-dose Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of ASP1128, a Novel Peroxisome Proliferator-activated Receptor δ Modulator, in Healthy Participants.

Peroxisome proliferator-activated receptor δ (PPARδ) plays a central role in modulating mitochondrial function in ischemia-reperfusion injury. ASP1128, a potent and selective modulator of PPARδ, is currently under investigation for treating acute kidney injury. This randomized, first-in-human study assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of ASP1128 administered intravenously in healthy participants. Forty-nine participants received a single dose of ASP1128 0.3-10mg (n=37) or placebo (n=12) and 53 received daily (7days) doses of ASP1128 3-100mg (n=39) or placebo (n=14), including a cohort aged ≥65years (ASP1128 100mg, n=3; placebo, n=2). Treatment-emergent adverse events occurred in 37.8%, 59.0%, and 33.3%-35.7% of participants in the single ASP1128, multiple ASP1128, and placebo groups, respectively. All were mild in severity, and the frequency of adverse events did not appear to be dose-related. One participant (multiple ASP1128 3mg group) withdrew with an infusion site erythema, possibly related to study drug. Exposure was roughly dose-proportional, and elimination was generally consistent across doses (mean t½ 14.6-17.4hours in the 10, 30, and 100mg groups on day 7). There was little accumulation in plasma following multiple dosing; steady state was reached after ∼4days. ASP1128 treatment led to rapid and dose-related upregulation of six fatty acid oxidation-related PPARδ target genes at ≥10mg, which lasted >24hours postdose. In conclusion, single and multiple intravenous doses of ASP1128 were generally well tolerated, with dose-dependent pharmacokinetics and target gene engagement in healthy participants.

Tumor Necrosis Factor-α Alters Maternal and Embryonic Zinc Metabolism and Is Developmentally Toxic in Mice

We tested the hypothesis that tumor necrosis factor-α (TNF-α) would be teratogenic in mice due in part to its effects on zinc metabolism. In Experiment 1, nonpregnant mice were injected with a single dose of TNF-α (40,000 U) or PBS and then received a 65Zn-labeled meal. Mice killed 10 h after TNF-α treatment had high liver 65Zn and low plasma 65Zn, compared with controls. In Experiment 2, gestation day 8 (GD 8) mice were injected with PBS or TNF-α and then received a 65Zn-labeled meal. Dams killed 10 h after TNF-α treatment had higher liver and kidney 65Zn and lower plasma and embryonic 65Zn accumulation than controls. In Experiment 3, TNF-α dosing from GD 7–12 was associated with high maternal liver Zn and metallothionein concentrations on GD 13 and a high frequency of exencephaly on GD 18. In Experiment 4, dams fed diets containing 4.5, 12.5 or 50.0 µg Zn/g were given PBS or TNF-α on GD 7–12. Gross fetal defects were not observed in the PBS-treated litters evaluated on GD 18. In contrast, TNF-α-treated litters were characterized by multiple defects, with the incidence and severity being highest in the low Zn diet group. In Experiment 5, embryos cultured in serum from TNF-α-treated animals exhibited a high frequency of defects; the developmental toxicity of this serum was ameliorated when it was supplemented with Zn. Thus, the developmental toxicity of TNF-α is due in part to its influence on Zn metabolism.

Safety and pharmacokinetics of GB1211, an oral galectin-3 inhibitor: a single- and multiple-dose first-in-human study in healthy participants

PurposeGalectin-3, a β-galactoside-binding lectin, plays a key role in several cellular pathways involved in chronic inflammation, heart disease and cancer. GB1211 is an orally bioavailable galectin-3 inhibitor, developed to be systemically active. We report safety and pharmacokinetics (PK) of GB1211 in healthy participants.MethodsThis phase 1, double-blind, placebo-controlled, first-in-human study (NCT03809052) included a single ascending-dose phase (with a food-effect cohort) where participants across seven sequential cohorts were randomized 3:1 to receive oral GB1211 (5, 20, 50, 100, 200 or 400 mg) or placebo. In the multiple ascending-dose phase, participants received 50 or 100 mg GB1211 or placebo twice daily for 10 days. All doses were administered in the fasted state except in the food-effect cohort where doses were given 30 min after a high-fat meal.ResultsAll 78 participants received at least one GB1211 dose (n = 58) or placebo (n = 20) and completed the study. No safety concerns were identified. Following single and multiple oral doses under fasted conditions, maximum GB1211 plasma concentrations were reached at 1.75–4 h (median) post-dose; mean half-life was 11–16 h. There was a ~ twofold GB1211 accumulation in plasma with multiple dosing, with steady-state reached within 3 days; 30% of the administered dose was excreted in urine as unchanged drug. Absorption in the fed state was delayed by 2 h but systemic exposure was unaffected.ConclusionGB1211 was well tolerated, rapidly absorbed, and displayed favorable PK, indicating a potential to treat multiple disease types. These findings support further clinical development of GB1211.Clinical trial registrationThe study was registered with ClinicalTrials.gov (identifier: NCT03809052).

Food-Derived Uremic Toxins in Chronic Kidney Disease.

Patients with chronic kidney disease (CKD) have a higher cardiovascular risk compared to the average population, and this is partially due to the plasma accumulation of solutes known as uremic toxins. The binding of some solutes to plasma proteins complicates their removal via conventional therapies, e.g., hemodialysis. Protein-bound uremic toxins originate either from endogenous production, diet, microbial metabolism, or the environment. Although the impact of diet on uremic toxicity in CKD is difficult to quantify, nutrient intake plays an important role. Indeed, most uremic toxins are gut-derived compounds. They include Maillard reaction products, hippurates, indoles, phenols, and polyamines, among others. In this review, we summarize the findings concerning foods and dietary components as sources of uremic toxins or their precursors. We then discuss their endogenous metabolism via human enzyme reactions or gut microbial fermentation. Lastly, we present potential dietary strategies found to be efficacious or promising in lowering uremic toxins plasma levels. Aligned with current nutritional guidelines for CKD, a low-protein diet with increased fiber consumption and limited processed foods seems to be an effective treatment against uremic toxins accumulation.

Heavy Metal Accumulation in Soil, Forage and Blood Plasma of Horses in Central Punjab, Pakistan

Heavy Metal Accumulation in Soil, Forage and Blood Plasma of Horses in Central Punjab, Pakistan

Doravirine and Rilpivirine Intra Cellular Accumulation in the Clinical Setting

Background: Doravirine (DOR) and Rilpivirine (RPV) are the NNRTIs currently most used in the clinical setting, in dual and triple drug regimens (2DR and 3DR). Intracellular (IC) Pharmacokinetics (PK) of these drugs has not been fully elucidated. Our aim was to compare plasma PK and IC accumulation in real-life experienced patients (pts). Methods: Pts on DOR- and RPV-including Antiretroviral (ARV) regimen were considered. DOR and RPV plasma and IC (PBMCs) concentrations were measured at 12 (37%) (T12) and 24 ± 4 hours (63%) (T24) after last drug intake by means of UHPLC-MSMS validated methods. Results: 90 pts (65% on 3DR and 35% on 2DR) were included: 52% on DOR- and 48% on RPV-containing ARV. RPV IC/plasma ratio was significantly higher than DOR IC/plasma ratio: 6.034 (4.878-7.186) vs. 1.479 (1.256-1.702) (p=0.001) independently from timing T12 (p=0.003) and T24 (p<0.001). RPV in 3DR resulted to have higher plasma and IC accumulation compared to 2DR. Linear and significative correlations between DOR and RPV plasma and IC concentrations were found (+0.749, p<0.001 and +0.733, p<0.001). No significative correlation between overall DOR and RPV PK and creatinine, BMI or age or difference by gender was found. Conclusion: RPV proved to accumulate in PBMCs at a higher degree as compared to DOR: RPV and DOR IC levels were 498% and 50% higher than in plasma. RPV showed an IC PBMC/plasma ratio 3-fold higher than DOR. Potential explanation could rely on the higher lipophilicity of RPV. Clinical significance of these data needs to be investigated in further studies.

1282. Safety, Tolerability, and Pharmacokinetics of BRII-732, A Medoxomil Carbonate Prodrug of Islatravir in Healthy Adult Subjects

Abstract Background BRII-732, a prodrug of islatravir (ISL), is a potent HIV-1 nucleotide reverse transcriptase translocation inhibitor. Following oral absorption, BRII-732 is rapidly converted to ISL, which is metabolized intracellularly to the active metabolite, ISL triphosphate (ISL-TP). Single doses of ISL as low as 0.5 mg significantly suppressed HIV-1 RNA by more than 1.0 log at day 7 in treatment-naive adults with HIV-1 infection. Current development work with BRII-732 is designed to provide optimal drug exposure to enable once weekly (QW) dosing, to be part of combination antiretroviral therapy to provide improved patient convenience and treatment adherence. Methods This was a Phase 1, randomized, double-blind, placebo-controlled study consisting of healthy adult subjects enrolled in five single ascending dose and two multiple ascending dose cohorts. The objectives of the study were to assess the safety, tolerability, and PK profiles of BRII-732 and ISL in plasma; ISL-DP and ISL-TP in human PBMCs. BRII-732 was orally administered in the fasted state using an oral solution formulation. Safety-related assessments included physical examinations, ECGs, vital signs, AEs, and standard clinical laboratory tests. Results BRII-732 as single dose or multiple doses was generally safe and well-tolerated when administered to healthy adult subjects. There were no Grade ≥ 3 AEs, SAEs, drug-related AEs leading to withdrawal or graded lymphocyte abnormalities. BRII-732 rapidly converted to ISL post BRII-732 oral administration with no detectable level (LLOQ = 1.0 ng/mL) of BRII-732 in systemic circulation at 0.5h. Dose proportional ISL exposure increases were observed over the dose range of 10 mg to 200 mg of BRII-732. No meaningful ISL accumulation in plasma was observed after 3 QW BRII-732 doses. ISL-DP and ISL-TP exposures in PBMC cells increased dose-dependently. Approximately 1.7-2.0 fold accumulation ratios for ISL-DP and ISL-TP are consistent with observed long terminal half-lives of 110-150 hours. Conclusion Safety, tolerability and PK profiles including ISL in plasma and ISL-TP in PBMC cells after single and multiple oral administrations of BRII-732 supports further development of BRII-732 as part of oral weekly combination antiretroviral therapy. Disclosures David A. Margolis, MD MPH, Brii Biosciences: Stocks/Bonds Ji Ma, PhD, Brii Biosciences: Stocks/Bonds Michael Watkins, PharmD, Brii Biosciences: Stocks/Bonds Yujin Wang, M.Sc., Brii Biosciences: Stocks/Bonds Chetana Trivedi, B.A., Brii Biosciences: Stocks/Bonds Chi-Chi Peng, PhD, Brii Biosciences: Stocks/Bonds Xuelian Wei, PhD, Brii Biosciences: Stocks/Bonds Lijie Zhong, PhD, Brii Biosciences: Stocks/Bonds Kamlesh Patel, PhD, Brii Biosciences: Stocks/Bonds Jean-Luc Girardet, PhD, Brii Biosciences: Stocks/Bonds Michael Wang, PhD MBA, Brii Biosciences: Stocks/Bonds Annalise VonderEmbse, PhD, Brii Biosciences: Stocks/Bonds Li Yan, MD PhD, Brii Biosciences: Stocks/Bonds Zhi Hong, PhD, Brii Biosciences: Ownership Interest Lianhong Xu, PhD, Brii Biosciences: Stocks/Bonds.

1283. Safety, Tolerability, and Pharmacokinetics of BRII-778, A Modified-Release Oral Formulation of Rilpivirine in Healthy Adult Subjects

Abstract Background BRII-778 is a modified release (MR) formulation of rilpivirine for once-weekly (QW) oral administration. BRII-778 aims to prolong oral absorption, lower Cmax, relatively, and reduce peak to trough ratio achieved with a MR formulation of rilpivirine, within the known efficacy and safety bounds established by once daily oral administration of rilpivirine. QW BRII-778 dosing may have advantages over once daily rilpirvirine in terms of patient convenience, and treatment adherence. Multiple MR formulations of rilpivirine were evaluated in healthy adult subjects in this Phase 1 study. Methods This was a Phase 1, randomized, double-blinded, placebo-controlled, study of single ascending dose (SAD) and multiple ascending dose (MAD) cohorts, evaluating the safety, tolerability, and PK of BRII-778. Three MR formulations of rilpivirine, BRII-778-A1, -A2, and -A3, were evaluated in this study. Rilpivirine PK profiles after single or multiple doses of the three BRII-778 formulations were characterized under the fed state over the dose range of 150 mg to 750 mg. Food effect was assessed after a single oral dose of BRII-778-A3 750 mg. Exploratory concentration-QTc (C-QTc) analysis was conducted using combined SAD and MAD data. Results BRII-778 as single dose or multiple doses was generally safe and well-tolerated when administered to healthy adult subjects. There were no Grade ≥3 AEs, SAEs or AEs leading to withdrawal in BRII-778 dosing arms. PK profiles of BRII-778 were consistent with slower oral absorption with MR formulation. The increase in exposure was less than dose proportional. Mild accumulation in plasma was observed after 3 QW BRII-778-A3 doses. BRII-778-A3 750 mg under the fed state enhanced bioavailability by improving gastric dissolution and/or subsequent absorption. Exploratory C-QTc analysis confirmed a concentration-dependent effect on the QTc interval with escalating doses of BRII-778, but the interpretations are limited by small sample size. There were no clinically significant EKG changes and no individual subject met QTc stopping criteria. Conclusion SAD and MAD administration of BRII-778 formulations were generally safe and well tolerated. Rilpivirine PK profiles post BRII-778 dosing supports further evaluation of BRII-778 for potential QW regimen. Disclosures David A. Margolis, MD MPH, Brii Biosciences: Stocks/Bonds Ji Ma, PhD, Brii Biosciences: Stocks/Bonds Michael Watkins, PharmD, Brii Biosciences: Stocks/Bonds Yujin Wang, M.Sc., Brii Biosciences: Stocks/Bonds Chetana Trivedi, B.A., Brii Biosciences: Stocks/Bonds Xuelian Wei, PhD, Brii Biosciences: Stocks/Bonds Lijie Zhong, PhD, Brii Biosciences: Stocks/Bonds Kamlesh Patel, PhD, Brii Biosciences: Stocks/Bonds Li Yan, MD PhD, Brii Biosciences: Stocks/Bonds Zhi Hong, PhD, Brii Biosciences: Ownership Interest Jean-Luc Girardet, PhD, Brii Biosciences: Stocks/Bonds Lianhong Xu, PhD, Brii Biosciences: Stocks/Bonds.

Pharmacokinetics and tolerability of the dual TORC1/2 inhibitor sapanisertib in combination with the MEK inhibitor trametinib in dogs.

Activation of one or both the Ras/MAPK and PI3K/Akt/mTOR signal transduction pathways are known to mediate oncogenicity of several canine and human cancers, including mucosal melanomas. Reciprocal cross activation between the two pathways can be a source of drug resistance. Consequently, oral dosing for plasma pharmacokinetic (PK) analysis and tolerability to a combination of sapanisertib, a dual TORC1/2 inhibitor, and trametinib, a MEK inhibitor, was evaluated in nontumor-bearing laboratory dogs for its potential application in parallel pathway targeting. Twelve dogs, divided into three equal cohorts, received either the combination or single agents. Animals were monitored for PK following single dose and 17-day repeat dosing, and by clinical observations, hematology, serum biochemistry, coagulation studies and urinalyses. A single trametinib dose (0.025 mg/kg), sulfated as dimethyl sulfoxide which enhanced its absorption, reached mean maximum concentration (Cmax) 0.64 ng/mL [18% coefficient of variation (CV)] at a median time to maximum concentration (Tmax) of 1.5 h (hr), and mean area under the concentration-time curve (AUC) 16.8 hr*ng/mL (14%CV), which were similar when given alone or in combination with sapanisertib. A prolonged half-life afforded 3-4-fold plasma accumulation of trametinib with daily dosing, analogous to humans. Trametinib PK mirrored previous regulatory data in dogs, while exposure approximated some published human values but generally not all patients. Sapanisertib-alone in canine plasma following single 0.1 mg/kg dose [mean Cmax 26.3 ng/mL (21%CV), median Tmax 2.0 hr, and mean AUC 248 hr*ng/mL (41%CV)] resembled levels in human therapeutic trials; whereas canine sapanisertib exposure was reduced when combined with trametinib, a known cytochrome P450 CYP3A4 inducer. Sex differences were not observed for either drug. Side effects upon repeat dosing with either or both drugs may include body weight loss, maldigestion, and cutaneous discoloration. The combination was tolerated without dose limiting toxicity, although clinical laboratory analyses revealed drug-induced acute-phase inflammation, proteinuria, and decreased blood reticulocytes, mild changes not necessitating intervention. Short-term results in dogs with this combination would appear to hold translational promise for clinical trial evaluation to target canine and possibly human melanoma, as well as other cancers having one or both signal transduction pathway activations.

Effect of Diets on Plasma and Aorta Lipidome: A Study in the apoE Knockout Mouse Model.

Specific lipid molecules circulating in plasma at low concentrations have emerged as biomarkers of atherosclerotic risk. The aim of the present study is that of evaluating, in an athero-prone mouse model, how different diets can affect plasma and aorta lipidome. Thirty-six apoE knockout mice are divided in three groups and feed 12 weeks with diets differing for cholesterol and fatty acid content. Atherosclerosis is measured at the aortic sinus and aorta. Lipids are quantified in plasma and aorta with mass spectrometry. The cholesterol content of the diets is the main driver of lipid accumulation in plasma and aorta. The fatty acid composition of the diets affects plasma levels both of essential (linoleic acid) and nonessential (myristic and arachidonic acid) ones. Lipidomics show a comparable distribution, in plasma and aorta, of the main lipid components of oxidized LDL, including cholesteryl esters and lysophosphatidylcholines. Interestingly, lactosylceramide, glucosyl/galactosylceramide, and individual ceramide species are found to accumulate in diseased aortic segments. Both the cholesterol and fatty acid content of the diets profoundly affect plasma lipidome. Aorta lipidome is likewise affected with the accumulation of specific lipids known as markers of atherosclerosis.

Amyloidogenic amylin deposits on red blood cells of stroke patients

AbstractBackgroundAmylin, a 37‐residue amyloidogenic peptide, is co‐secreted with insulin by pancreatic beta‐cells (Verma et al. 2020). Vascular deposition of amylin has been noted in patients with diabetes and neurocognitive disorders (Ly et al., 2017) Emergent large vessel occlusions (ELVOs) result in severe ischemic strokes without appropriate treatment. Growth factors, including erythropoietin (EPO), are involved in post‐stroke recovery as a potential neuroprotectant target, inhibiting apoptosis and decreasing inflammation (Jerndal et al., 2010). Here, amylin accumulation in plasma, red blood cells (RBCs), and ELVOs (where available) and plasma EPO levels were compared between stroke and control patients. Due to amylin’s amyloidogenic propensity, we hypothesized that there would be an association between amylin uptake and stroke incidence.MethodA prospective registry (Blood and Clot Thrombectomy Registry and Collaboration; BACTRAC) was developed to analyze blood and thrombus directly in patients presenting with an ELVO. Total protein concentration and amylin concentrations of clot lysates, plasma, and RBC lysates were obtained via bicinchoninic acid assay (BCA) and competitive enzyme‐linked immunosorbent assay (ELISA), respectively. Plasma EPO concentrations were obtained via ELISA. An amylin uptake coefficient (the level of amylin in RBC lysates divided by the sum of amylin present in RBC lysates and plasma) was calculated to determine the degree to which circulating amylin is depositing on RBCs.ResultDue to a significant difference between control and stroke RBCs (p = 0.0012, Figure 1) in total protein concentration, all downstream analyses were normalized to respective protein concentrations. A significant difference in amylin uptake by RBCs between stroke and control patients is shown in Figure 2 (p = 0.0073). An uptake coefficient greater than 0.50 indicates uptake of amylin by RBCs. Finally, a significant difference in plasma EPO concentration was observed between stroke and control (p = 0.0017; Figure 3).ConclusionConsistent with our hypotheses, the present data indicates that amylin uptake by RBCs is significantly increased in stroke patients than in control patients. However, both groups show evidence of accumulation, as indicated by uptake coefficients greater than 0.50. Further, levels of erythropoietin are significantly increased in stroke patients. Further investigation into whether amylin may be thrombogenic is warranted.

Inferring Therapeutic Targets in Candida albicans and Possible Inhibition through Natural Products: A Binding and Physiological Based Pharmacokinetics Snapshot.

Despite being responsible for invasive infections, fungal pathogens have been underrepresented in computer aided therapeutic target mining and drug design. Excess of Candida albicans causes candidiasis, causative of thrush and vaginal infection due to off-balance. In this study, we attempted to mine drug targets (n = 46) using a subtractive proteomic approach in this pathogenic yeast and screen natural products with inhibition potential against fructose-bisphosphate aldolase (FBA) of the C. albicans. The top compound selected on the basis of best docking score from traditional Indian medicine/Ayurvedic library was (4-Hydroxybenzyl)thiocarbamic acid, from the ZINC FBA inhibitor library was ZINC13507461 (IUPAC name: [(2R)-2-hydroxy-3-phosphonooxypropyl] (9E,12E)-octadeca-9,12-dienoate), and from traditional Tibetan medicine/Sowa rigpa was Chelerythrine (IUPAC name: 1,2-Dimethoxy-12-methyl-9H-[1,3]benzodioxolo[5,6-c]phenanthridin-12-ium), compared to the control (2E)-1-(4-nitrophenyl)-2-[(4-nitrophenyl)methylidene]hydrazine. No Ames toxicity was predicted for prioritized compounds while control depicted this toxicity. (4-Hydroxybenzyl)thiocarbamic acid showed hepatotoxicity, while Chelerythrine depicted hERG inhibition, which can lead to QT syndrome, so we recommend ZINC13507461 for further testing in lab. Pharmacological based pharmacokinetic modeling revealed that it has low bioavailability and hence, absorption in healthy state. In cirrhosis and renal impairment, absorption and plasma accumulation increased so we recommend further investigation into this occurrence and recommend high dosage in further tests to increase bioavailability.

Excessive dietary linoleic acid promotes plasma accumulation of pronociceptive fatty acyl lipid mediators

Various fatty acyl lipid mediators are derived from dietary polyunsaturated fatty acids (PUFAs) and modulate nociception. The modern diet is rich in linoleic acid, which is associated with nociceptive hypersensitivities and may present a risk factor for developing pain conditions. Although recommendations about fatty acid intake exist for some diseases (e.g. cardiovascular disease), the role of dietary fatty acids in promoting pain disorders is not completely understood. To determine how dietary linoleic acid content influences the accumulation of pro- and anti-nociceptive fatty acyl lipid mediators, we created novel rodent diets using custom triglyceride blends rich in either linoleic acid or oleic acid. We quantified the fatty acyl lipidome in plasma of male and female rats fed these custom diets from the time of weaning through nine weeks of age. Dietary fatty acid composition determined circulating plasma fatty acyl lipidome content. Exposure to a diet rich in linoleic acid was associated with accumulation of linoleic and arachidonic acid-derived pro-nociceptive lipid mediators and reduction of anti-nociceptive lipid mediators derived from the omega-3 PUFAs. Our findings provide mechanistic insights into exaggerated nociceptive hypersensitivity associated with excessive dietary linoleic acid intake and highlight potential biomarkers for pain risk stratification.

Hyperglycaemia-induced degeneration of bioprosthetic valve tissue and the pivotal role of the extracellular matrix molecule biglycan

Abstract Background/Introduction Bioprosthetic valve degeneration is a growing clinical challenge in our aging society. Especially type 2 diabetes mellitus represents a risk factor for bioprosthetic valve deterioration with likewise worldwide rising prevalence. The proteoglycan biglycan has been shown to be associated with degenerative changes of the valve in diabetic patients even though underlying mechanisms are yet unknown. Purpose The impact of hyperglycaemia on bioprosthetic valve tissue was analysed in an established mouse model of ectopic calcification. Thereby, the role of biglycan in bioprosthetic valve degeneration was assessed in biglycan-deficient mice (Bgn-/0) in comparison to wild type littermates (WT). Methods Hyperglycaemia was induced in six weeks old mice by intraperitoneal injection of streptozotocin (STZ; 55 mg/kg body weight) on five consecutive days. Blood glucose concentration was verified two weeks after treatment and bioprosthetic valve material was implanted subcutaneously. After eight weeks, phenotype of invading cells and extracellular matrix remodelling of implants were analysed with histochemical and immunohistological staining. Furthermore, gene expression of invading cells, circulating cytokines in blood plasma and calcium accumulation in the tissue were quantified. Results STZ treatment significantly increased blood glucose levels in both genotype groups (WT-STZ: 156 mg/dl; WT+STZ: 353 mg/dl; Bgn-/0-STZ: 142 mg/dl; Bgn-/0+STZ: 396 mg/dl). Immunohistological staining identified most of cells invading the bioprosthetic tissue and the surrounded capsule as Mac2-positive and partly positive for vimentin, whereas alpha smooth muscle actin and von Willebrand factor were only detectable sporadically. Movat pentachrome staining exhibited an altered extracellular matrix composition of collagen and proteoglycans due to hyperglycaemia, while the elastin amount remained stable. Gene expression analysis showed an increased expression of the proteoglycan decorin in hyperglycaemic mice (WT-STZ: 0.55; WT+STZ: 1.13; Bgn-/0-STZ: 0.51; Bgn-/0+STZ: 1.70). Circulating cytokines (IL-1β, IL-2, IL-5, IL-10, INF-γ, TNF-α, GM-CSF) were influenced neither by hyperglycaemia nor by the genotype of the mice. Alizarin and von Kossa staining exhibited small to moderate calcium deposits in the bioprosthetic valve tissue. A colorimetric assay showed a significantly increased calcium accumulation in WT with hyperglycaemia versus normoglycemic WT (WT-STZ: 8.96 μg/mg; WT+STZ: 18.54 μg/mg), an observation that was lost in Bgn-/0 (Bgn-/0-STZ: 9.84 μg/mg; Bgn-/0+STZ: 12.97 μg/mg). Conclusion Hyperglycaemia significantly promotes destructive remodelling in bioprosthetic valve material. Biglycan-deficiency limits degenerative processes associated with diabetes, suggesting that biglycan as a component of the extracellular matrix has an adverse effect in diabetes-associated bioprosthetic valve deterioration. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Dr. Rusche grant of the German Heart Foundation and the German Society for Thoracic and Cardiovascular Surgery

Chronic dietary exposure to a glyphosate-based herbicide results in total or partial reversibility of plasma oxidative stress, cecal microbiota abundance and short-chain fatty acid composition in broiler hens.

Glyphosate-based herbicides (GBHs) are massively used in agriculture. However, few studies have investigated the effects of glyphosate-based herbicides on avian species although they are largely exposed via their food. Here, we investigated the potential reversibility of the effects of chronic dietary exposure to glyphosate-based herbicides in broiler hens. For 42 days, we exposed 32-week-old hens to glyphosate-based herbicides via their food (47 mg/kg/day glyphosate equivalent, glyphosate-based herbicides, n = 75) corresponding to half glyphosate’s no-observed-adverse-effect-level in birds. We compared their performance to that of 75 control animals (CT). Both groups (glyphosate-based herbicides and control animals) were then fed for 28 additional days without glyphosate-based herbicides exposure (Ex-glyphosate-based herbicides and Ex-control animals). Glyphosate-based herbicides temporarily increased the plasma glyphosate and AMPA (aminomethylphosphonic acid) concentrations. Glyphosate and aminomethylphosphonic acid mostly accumulated in the liver and to a lesser extent in the leg muscle and abdominal adipose tissue. Glyphosate-based herbicides also temporarily increased the gizzard weight and plasma oxidative stress monitored by TBARS (thiobarbituric acid reactive substances). Glyphosate-based herbicides temporarily decreased the cecal concentrations of propionate, isobutyrate and propionate but acetate and valerate were durably reduced. The cecal microbiome was also durably affected since glyphosate-based herbicides inhibited Barnesiella and favored Alloprevotella. Body weight, fattening, food intake and feeding behavior as well as plasma lipid and uric acid were unaffected by glyphosate-based herbicides. Taken together, our results show possible disturbances of the cecal microbiota associated with plasma oxidative stress and accumulation of glyphosate in metabolic tissues in response to dietary glyphosate-based herbicides exposure in broiler hens. Luckily, glyphosate-based herbicides at this concentration does not hamper growth and most of the effects on the phenotypes are reversible.

Maternal programming by high-energy diets primes ghrelin sensitivity in the offspring of rats exposed to chronic immobilization stress

Maternal overnutrition during pregnancy leads to metabolic and immune alterations, including obesity, hyperphagia, and central and peripheral inflammation in offspring. Exposure to high-energy diets during pregnancy primes ghrelin sensitivity to overfeeding in the offspring at early stages of life. Overfeeding has also been partially related to the early stages of chronic stress. We hypothesized that maternal programming sensitizes ghrelin-induced overfeeding following a chronic stress schedule in the offspring. We used a nutritional programming model exposing female Wistar rats to a cafeteria (CAF) or control diet from prepregnancy to weaning. Male offspring were injected with ghrelin and then subjected to a chronic immobilization stress (CIS) schedule, after which food intake was determined. Hypothalamic and plasma accumulation of cytokines and cortisol were evaluated using BioPlex analysis and enzyme-linked immunosorbent assay, respectively. We found that rats exposed to the CAF diet exhibited overfeeding after fasting and peripheral ghrelin administration, which was exacerbated in rats exposed to chronic stress. Offspring exposed to the CAF diet accumulated pro-inflammatory interleukin-6 (IL-6), interferon-γ, and monocyte chemoattractant protein-1 cytokines in plasma, and IL-6 cytokine in the hypothalamus. Ghrelin-sensitive overfeeding in rats exposed to CAF diet + CIS display increased cortisol levels and decreased IL-6 accumulation in plasma. Together, our results suggest that maternal nutritional programming primes susceptibility to ghrelin response for overfeeding after a CIS schedule that mirrors plasma cortisol accumulation in male offspring.

Acute Methylglyoxal-Induced Damage in Blood-Brain Barrier and Hippocampal Tissue.

Methylglyoxal (MG) is a reactive dicarbonyl compound formed mostly via the glycolytic pathway. Elevated blood glucose levels can cause MG accumulation in plasma and cerebrospinal fluid in patients with diabetes mellitus and Alzheimer's disease. Under these disease conditions, the high reactivity of MG leads to modification of proteins and other biomolecules, generating advanced glycation end products (AGEs), which are considered mediators in neurodegenerative diseases. We investigated the integrity of the blood-brain barrier (BBB) and astrocyte response in the hippocampus to acute insult induced by MG when it was intracerebroventricularly administered to rats. Seventy-two hours later, BBB integrity was lost, as assessed by the entry of Evans dye into the brain tissue and albumin in the cerebrospinal fluid, and a decrease in aquaporin-4 and connexin-43 in the hippocampal tissue. MG did not induce changes in the hippocampal contents of RAGE in this short interval, but decreased the expression of S100B, an astrocyte-secreted protein that binds RAGE. The expression of two important transcription factors of the antioxidant response, NF-κB and Nrf2, was unchanged. However, hemeoxigenase-1 was upregulated in the MG-treated group. These data corroborate the idea that hippocampal cells are targets of MG toxicity and that BBB dysfunction and specific glial alterations induced by this compound may contribute to the behavioral and cognitive alterations observed in these animals.

Plasma atropine concentrations associated with decreased intestinal motility in horses.

IntroductionAtropine is an essential part of the treatment protocol for equine uveitis. Topical atropine administration has been associated with decreased intestinal motility and abdominal pain in horses. Experimental studies have indicated that frequent dosing is associated with a higher risk than dosing every 6 h. Unfortunately, no quantitative pharmacodynamic data for inhibition of the equine gut are published.Materials and methodsEight standardbred horses were assigned to receive either atropine or saline (control) to be infused over 30 min in a two-treatment cross-over design. Atropine concentrations in plasma were measured using ultra-high-performance liquid chromatography–tandem mass spectrometry. Intestinal motility was measured using borborygmi frequency and electrointestinography (EIG). Experimental data were analyzed using a non-linear mixed effects model. The model was then used to simulate different dosing regimens.ResultsAtropine significantly decreased borborygmi response and EIG response. Six horses developed clinical signs of abdominal pain. The pharmacokinetic typical values were 0.31, 1.38, 0.69, and 1.95 L/kg·h for the volumes of the central, the highly perfused, the scarcely perfused compartments, and the total body clearance, respectively. The pharmacodynamic typical values were 0.31 μg/L and 0.6 and 207 nV27 cpm for the plasma concentration at 50% of the maximum response and the maximum response and the baseline of cecal EIG response, respectively. Six different dosing regimens of topical atropine sulfate to the eye (0.4 and 1 mg every hour, every 3 h, and every 6 h) were simulated.ConclusionThe IV PK/PD data coupled with simulations predict that administration of 1 mg of topical atropine sulfate administered to the eye every hour or every 3 h will lead to atropine accumulation in plasma and decreased intestinal myoelectric activity. Administration every 6 h predicted a safe dosing regimen in full-sized horses. Clinical studies would be valuable to confirm the conclusions. For smaller equids and horses put at risk for colic due to othercauses, droplet bottles that deliver 40 μl of 1% atropine sulfate per drop or less may be used to lower the risk further.

Influence of homoarginine on creatine accumulation and biosynthesis in the mouse.

Organisms obtain creatine from their diet or by de novo synthesis via AGAT (L-arginine:glycine amidinotransferase) and GAMT (Guanidinoacetate N-methyltrasferase) in kidney and liver, respectively. AGAT also synthesizes homoarginine (hArg), low levels of which predict poor outcomes in human cardiovascular disease, while supplementation maintains contractility in murine heart failure. However, the expression pattern of AGAT has not been systematically studied in mouse tissues and nothing is known about potential feedback interactions between creatine and hArg. Herein, we show that C57BL/6J mice express AGAT and GAMT in kidney and liver respectively, whereas pancreas was the only organ to express appreciable levels of both enzymes, but no detectable transmembrane creatine transporter (Slc6A8). In contrast, kidney, left ventricle (LV), skeletal muscle and brown adipose tissue must rely on creatine transporter for uptake, since biosynthetic enzymes are not expressed. The effects of creatine and hArg supplementation were then tested in wild-type and AGAT knockout mice. Homoarginine did not alter creatine accumulation in plasma, LV or kidney, whereas in pancreas from AGAT KO, the addition of hArg resulted in higher levels of tissue creatine than creatine-supplementation alone (P < 0.05). AGAT protein expression in kidney was downregulated by creatine supplementation (P < 0.05), consistent with previous reports of end-product repression. For the first time, we show that hArg supplementation causes a similar down-regulation of AGAT protein (P < 0.05). These effects on AGAT were absent in the pancreas, suggesting organ specific mechanisms of regulation. These findings highlight the potential for interactions between creatine and hArg that may have implications for the use of dietary supplements and other therapeutic interventions.

The major urinary protein gene cluster knockout mouse as a novel model for translational metabolism research

Scientific evidence suggests that not only murine scent communication is regulated by major urinary proteins, but that their expression may also vary in response to metabolism via a yet unknown mechanism. Major urinary proteins are expressed mainly in the liver, showing a sexually dimorphic pattern with substantially higher expression in males. Here, we investigate the metabolic implications of a major urinary protein knockout in twelve-week-old male and female C57BL/6N mice during ad libitum feeding. Despite both sexes of major urinary protein knockout mice displayed numerically increased body weight and visceral adipose tissue proportions compared to sex-matched wildtype mice, the main genotype-specific metabolic differences were observed exclusively in males. Male major urinary protein knockout mice exhibited plasma and hepatic lipid accumulation accompanied by a hepatic transcriptome indicating an activation of lipogenesis. These findings match the higher major urinary protein expression in male compared to female wildtype mice, suggesting a more distinct reduction in energy requirements in male compared to female major urinary protein knockout mice. The observed sex-specific anabolic phenotype confirms a role of major urinary protein in metabolism and, since major urinary proteins are not expressed in humans, suggests the major urinary protein knockout mouse as a potential alternative model for translational metabolism research which needs to be further elucidated.