Prednisone and prednisolone effects on development, blood, biochemical and histopathological markers of Aquarana catesbeianus tadpoles.

Synthetic glucocorticoids are often found in surface waters and can cause harmful effects to aquatic organisms such as amphibians. In this work we evaluated the effects of the drugs prednisone (PD) and prednisolone (PL) on developmental, molecular, blood, biochemical and histological markers. Aquarana catesbeianus tadpoles were exposed for 16 days to environmentally relevant concentrations of 0, 0.1, 1 and 10 µg/L of both drugs. PD increased the transcript levels of the enzyme deiodinase III (Dio3), the hormones cortisol and T4 and delayed development. Changes in the thyroid gland occurred after tadpoles were exposed to both drugs, with a reduction in the diameter and number of follicles and an increase/or decrease in area. Also, both drugs caused a decrease in lymphocytes (L) and an increase in neutrophils (N), thrombocytes, the N:L ratio and lobed and notched erythrocytes. Increased activity of the enzymes superoxide dismutase, glutathione S-transferase and glucose 6-phosphate dehydrogenase was observed after exposure to PD. Furthermore, both drugs caused an increase in the activity of the enzymes catalase and glutathione peroxidase. However, only PD caused oxidative stress in exposed tadpoles, evidenced by increased levels of malondialdehyde and carbonyl proteins. Both drugs caused an increase in inflammatory infiltrates, blood cells and melanomacrophages in the liver. Our results indicate that PD was more toxic than PL, affecting development and causing oxidative stress.

Prednisolone and rapamycin reduce the plasma cell gene signature and may improve AAV gene therapy in cynomolgus macaques.

Adeno-associated virus (AAV) vector gene therapy is a promising approach to treat rare genetic diseases; however, an ongoing challenge is how to best modulate host immunity to improve transduction efficiency and therapeutic outcomes. This report presents two studies characterizing multiple prophylactic immunosuppression regimens in male cynomolgus macaques receiving an AAVrh10 gene therapy vector expressing human coagulation factor VIII (hFVIII). In study 1, no immunosuppression was compared with prednisolone, rapamycin (or sirolimus), rapamycin and cyclosporin A in combination, and cyclosporin A and azathioprine in combination. Prednisolone alone demonstrated higher mean peripheral blood hFVIII expression; however, this was not sustained upon taper. Anti-capsid and anti-hFVIII antibody responses were robust, and vector genomes and transgene mRNA levels were similar to no immunosuppression at necropsy. Study 2 compared no immunosuppression with prednisolone alone or in combination with rapamycin or methotrexate. The prednisolone/rapamycin group demonstrated an increase in mean hFVIII expression and a mean delay in anti-capsid IgG development until after rapamycin taper. Additionally, a significant reduction in the plasma cell gene signature was observed with prednisolone/rapamycin, suggesting that rapamycin's tolerogenic effects may include plasma cell differentiation blockade. Immunosuppression with prednisolone and rapamycin in combination could improve therapeutic outcomes in AAV vector gene therapy.

Prednisolone Accelerates Embryonic Development of Zebrafish via Glucocorticoid Receptor Signaling at Low Concentrations.

Synthetic glucocorticoids have been widely detected in aquatic ecosystems and may pose a toxicological risk to fish. In the present study, we described multiple end point responses of zebrafish to a commonly prescribed glucocorticoid, prednisolone (PREL), at concentrations between 0.001 and 9.26 µg/L. Of 23 end points monitored, 7 were affected significantly. Significant increases in the frequency of yolk extension formation, spontaneous contraction, heart rate, and ocular melanin density and significant decreases of ear-eye distance at PREL concentrations of 0.001 µg/L and above clearly pointed to the acceleration of embryonic development of zebrafish by PREL. Further confirmation came from the alterations in somite numbers, head-trunk angle, and yolk sac size, as well as outcomes obtained via RNA sequencing, in which signaling pathways involved in tissue/organ growth and development were highly enriched in embryos upon PREL exposure. In addition, the crucial role of glucocorticoid receptor (GR) for PREL-induced effects was confirmed by both, the coexposure to antagonist mifepristone (RU486) and GR-/- mutant zebrafish experiments. We further demonstrated similar accelerations of embryonic development of zebrafish upon exposure to 11 additional glucocorticoids, indicating generic adverse effect characteristics. Overall, our results revealed developmental alterations of PREL in fish embryos at low concentrations and thus provided novel insights into the understanding of the potential environmental risks of glucocorticoids.

Mineralocorticoid receptor antagonists and glucocorticoids differentially affect skeletal muscle inflammation and pathology in muscular dystrophy.

Mineralocorticoid receptor antagonists (MRAs) slow cardiomyopathy in patients with Duchenne muscular dystrophy (DMD) and improve skeletal muscle pathology and function in dystrophic mice. However, glucocorticoids, known antiinflammatory drugs, remain a standard of care for DMD, despite substantial side effects. Exact mechanisms underlying mineralocorticoid receptor (MR) signaling contribution to dystrophy are unknown. Whether MRAs affect inflammation in dystrophic muscles and how they compare with glucocorticoids is unclear. The MRA spironolactone and glucocorticoid prednisolone were each administered for 1 week to dystrophic mdx mice during peak skeletal muscle necrosis to compare effects on inflammation. Both drugs reduced cytokine levels in mdx quadriceps, but prednisolone elevated diaphragm cytokines. Spironolactone did not alter myeloid populations in mdx quadriceps or diaphragms, but prednisolone increased F4/80hi macrophages. Both spironolactone and prednisolone reduced inflammatory gene expression in myeloid cells sorted from mdx quadriceps, while prednisolone additionally perturbed cell cycle genes. Spironolactone also repressed myeloid expression of the gene encoding fibronectin, while prednisolone increased its expression. Overall, spironolactone exhibits antiinflammatory properties without altering leukocyte distribution within skeletal muscles, while prednisolone suppresses quadriceps cytokines but increases diaphragm cytokines and pathology. Antiinflammatory properties of MRAs and different limb and respiratory muscle responses to glucocorticoids should be considered when optimizing treatments for patients with DMD.

Single-Dose Intrathecal Dorsal Root Ganglia Toxicity of Onasemnogene Abeparvovec in Cynomolgus Monkeys.

Intravenous onasemnogene abeparvovec is approved for the treatment of spinal muscular atrophy in children < 2 years. For later-onset patients, intrathecal onasemnogene abeparvovec may be advantageous over intravenous administration. Recently, microscopic dorsal root ganglion (DRG) changes were observed in nonhuman primates (NHPs) following intrathecal onasemnogene abeparvovec administration. To characterize these DRG findings, two NHP studies evaluating intrathecal onasemnogene abeparvovec administration were conducted: a 12-month study with a 6-week interim cohort and a 13-week study with a 2-week interim cohort. The latter investigated the potential impact of prednisolone or rituximab plus everolimus on DRG toxicity. An additional 6-month, single-dose, intravenous NHP study conducted in parallel evaluated onasemnogene abeparvovec safety (including DRG toxicity) with or without prednisolone coadministration. Intrathecal onasemnogene abeparvovec administration was well tolerated and not associated with clinical observations. Microscopic onasemnogene abeparvovec-related changes were observed in the DRG and trigeminal ganglion (TG) and included mononuclear cell inflammation and/or neuronal degeneration, which was colocalized with high vector transcript expression at 6 weeks postdose. Incidence and severity of DRG changes were generally decreased after 52 weeks compared with 6 weeks postdose. Other onasemnogene abeparvovec-related microscopic findings of axonal degeneration, mononuclear cell infiltrates and/or gliosis in the spinal cord, dorsal spinal nerve root/spinal nerves, and/or peripheral nerves were absent or found at decreased incidences and/or severities after 52 weeks. DRG and/or TG microscopic findings following intravenous onasemnogene abeparvovec dosing included minimal to slight neuronal degeneration and mononuclear cell inflammation at 6 weeks and 6 months postdose. Nervous system microscopic findings following intrathecal onasemnogene abeparvovec (≥1.2 × 1013 vg/animal) trended toward resolution after 52 weeks, supporting nonprogression of changes, including in the DRG. Onasemnogene abeparvovec-related DRG findings were not associated with electrophysiology changes and were not ameliorated by prednisolone or rituximab plus everolimus coadministration. The pathogenesis is possibly a consequence of increased vector genome transduction and/or transgene expression.

Early developmental stage glucocorticoid exposure causes DNA methylation and behavioral defects in adult zebrafish.

Post-traumatic stress disorder (PTSD) is a psychiatric disorder caused by genetic and environmental factors. It is closely related to a dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, in which the epigenetic modification of the nr3c1 plays an important role. It is well known that nr3c1 methylation in offspring is reportedly related to early adverse life experiences, prenatal stress response, and early nursing conditions; however, the methylation location and extent of the nr3c1 are not sufficiently elucidated. In order to study the internal mechanism of PTSD caused by early adverse life experience, we used zebrafish to construct a psychopathological model. We found that early developmental stage prednisolone exposure caused HPA axis negative feedback dysfunction and hormone secretion disorder in adult male zebrafish. By analyzing nr3c1 promoter, we found that cytosine-guanine island (CpGI) 2 was highly methylated in adult male zebrafish, which affected the expression of glucocorticoid receptor, resulting in abnormal behavior and anxiety like phenotype of adult male zebrafish. Therefore, we believed that an early exposure of zebrafish larvae to prednisolone may be recorded through a change of CpGI 2 methylation in the nr3c1 promoter region, causing abnormal adult male zebrafish behavior. Moreover, the establishment of the zebrafish psychopathological model may facilitate the study of the clinical management of patients with PTSD.

In vitro assessments predict that CYP3A4 contributes to a greater extent than CYP3A5 to prednisolone clearance.

Because several steroid hormones are metabolized to their respective 6ß-hydroxy forms by CYP3A4 and CYP3A5, these isoenzymes have been assumed to metabolize the immunosuppressive drug prednisolone, with conflicting results in the literature with respect to their relative importance. A direct study of the metabolism of prednisolone by microsomal CYP3A4 and CYP3A5 is missing. The aim of this in vitro study was to investigate the relative importance of recombinant CYP3A4 and recombinant CYP3A5 in the metabolism of prednisolone and to compare the extent of formation of 6ß-OH-prednisolone by the two enzymes. Through in vitro incubations using rCYP3A4 and rCYP3A5 enzymes, intrinsic clearance (CLint ) of prednisolone was determined by the substrate depletion approach. Formation of the metabolite 6ß-OH-prednisolone by rCYP3A4 and rCYP3A5, respectively, was compared. Prednisolone concentrations were measured, and its metabolite 6ß-OH-prednisolone was identified using a HPLC-MS/MS in-house method. CLint for prednisolone by rCYP3A5 was less than 26% relative to rCYP3A4. Formation of 6ß-OH-prednisolone by rCYP3A5 was less than 11% relative to rCYP3A4. The study indicates that 6ß-hydroxylation of prednisolone assessed in vitro in recombinant CYP enzymes depends on rCYP3A4 rather than rCYP3A5 and that CYP3A5 may be responsible for the formation of other prednisolone metabolite(s) in addition to 6ß-OH-prednisolone.

Biomimetic-Coated Nanoplatform with Lipid-Specific Imaging and ROS Responsiveness for Atherosclerosis-Targeted Theranostics.

Atherosclerosis is one of the leading causes of cardiovascular diseases and is triggered by endothelial damage, local lipid cumulation, and inflammation. Despite the conventional medication treatment, nanosized drug carriers have become promising candidates for efficient drug delivery with lower side effects. However, the development of problems in nanocarriers such as drug leakage, accumulating efficiency, and accurate drug release, as well as the specific recognition of atherosclerotic plaques, still needs to be checked. In this study, a lipid-specific fluorophore (LFP) has been designed, which is further packaged with a reactive oxygen species (ROS)-responsive prednisolone (Pred) prodrug copolymer [PMPC-P(MEMA-co-PDMA)] to self-assemble into LFP@PMMP micelles. LFP@PMMP can be further coated with red blood cell (RBC) membrane to obtain surface-biomimetic nanoparticles (RBC/LFP@PMMP), demonstrating prolonged circulation, minimal drug leakage, and better accumulation at the plaques. With ROS responsiveness, RBC/LFP@PMMP can be interrupted at inflammatory atherosclerotic tissue with overexpressed ROS, followed by the dissociation of Pred from the polymer backbone and the release of LFP to combine with the rich lipid in the plaques. An accurate anti-inflammation and lipid-specific fluorescent imaging of atherosclerotic lesions was performed and further proven on ApoE-/- mice; this holds prospective potential for atherosclerosis theranostics.

γ­irradiated prednisolone promotes apoptosis of liver cancer cells via activation of intrinsic apoptosis signaling pathway.

Prednisolone is an anti­inflammatory drug used to treat a number of conditions, including liver disease and cancer. Numerous studies have demonstrated that glucocorticoids such as prednisolone modified by ionizing radiation can promote anticancer activity in cancer cells. To the best of our knowledge, however, the effect of ionizing radiation on prednisolone structure and cancer cells has not yet been identified. The present study created a novel prednisolone derivative using γ­irradiation, and its anticancer properties were investigated in liver cancer cells. The present study confirmed the structure of the new prednisolone derivative using liquid chromatogram­mass spectrometry. MTT assays determined the cytotoxic effects of γ­irradiated (IR)­prednisolone in liver cancer cells. Flow cytometry analysis evaluated apoptosis, mitochondrial membrane potential and cell cycle distribution. Western blotting was used to analyze the proteins associated with apoptosis. The chromatogram profile revealed that IR­prednisolone produced a number of peaks compared with the single peak of the original prednisolone. In contrast to prednisolone, the MTT results showed that IR­prednisolone significantly prevented the growth of liver cancer cells. IR­prednisolone promoted apoptosis and arrested the cell cycle at the G0/G1 stage in Huh7 cells. IR­prednisolone also altered the mitochondrial membrane potential and activated caspase­associated proteins, which activated the intrinsic apoptotic signaling pathway. In conclusion, IR­prednisolone promoted anticancer effects in liver cancer cells via apoptosis activation. The present study demonstrated that IR­prednisolone may be a potential anticancer agent against liver cancer, although specific molecules have yet to be identified.

Elimination profiles of prednisone and prednisolone after different administration routes: Evaluation of the reporting level and washout periods to ensure safe therapeutic administrations.

Prednisolone (PRED) and prednisone (PSONE) are prohibited in sports competitions when administered by systemic routes, and they are allowed by other routes for therapeutic purposes. There is no restriction of use in out-of-competition periods. The present study aimed to evaluate the urinary excretion of PRED, PSONE, and their most important metabolites after systemic and nonsystemic treatments in order to verify the suitability of the current reporting level of 30 ng/ml used to distinguish allowed and prohibited administrations and to establish washout periods for oral treatments performed in out-of-competition periods. PRED was studied after dermatological administration (5 mg/day for 5 days, n = 6 males) and oral administration (5 mg, n = 6 males; 10 mg, n = 2 males). PSONE was studied after oral administration (10 mg, n = 2 males; 30 mg, n = 1 male and 1 female). Concentrations in urine were measured using an LC-MS/MS method. Concentrations after dermatological treatment were low for all metabolites. After oral administration, concentrations were very high during the first 24 h after administration ranging from 1.6 to 2261 ng/ml and from 4.6 to 908 ng/ml for PRED and PSONE, respectively. Concentrations of most of the metabolites measured were lower than 30 ng/ml from 24 h after all oral administrations. New reporting levels are proposed for PRED and PSONE considering data of our study and other information published after nonsystemic administrations of the compounds. Washout periods of at least 24 h are recommended to ensure no false positives when oral treatments need to be performed in out-of-competition periods.

Biotechnological Transformation of Hydrocortisone into 16α-Hydroxyprednisolone by Coupling Arthrobacter simplex and Streptomyces roseochromogenes.

16α-Hydroxyprednisolone, an anti-inflammatory drug, could be potentially obtained from hydrocortisone bioconversion by combining a 1,2-dehydrogenation reaction performed by Arthrobacter simplexATCC31652 with a 16α-hydroxylation reaction by Streptomyces roseochromogenes ATCC13400. In this study we tested, for the first time, potential approaches to couple the two reactions using similar pH and temperature conditions for hydrocortisone bioconversion by the two strains. The A. simplex capability to 1,2-dehydrogenate the 16α-hydroxyhydrocortisone, the product of S. roseochromogenes transformation of hydrocortisone, and vice versa the capability of S. roseochromogenes to 16α-hydroxylate the prednisolone were assessed. Bioconversions were studied in shake flasks and strain morphology changes were observed by SEM. Whole cell experiments were set up to perform the two reactions in a sequential mode in alternate order or contemporarily at diverse temperature conditions. A. simplex catalyzed either the dehydrogenation of hydrocortisone into prednisolone efficiently or of 16α-hydroxyhydrocortisone into 16α-hydroxyprednisolone in 24 h (up to 93.9%). Surprisingly S. roseochromogenes partially converted prednisolone back to hydrocortisone. A 68.8% maximum of 16α-hydroxyprednisolone was obtained in 120-h bioconversion by coupling whole cells of the two strains at pH 6.0 and 26 °C. High bioconversion of hydrocortisone into 16α-hydroxyprednisolone was obtained for the first time by coupling A. simplex and S. roseochromogenes.

Δ1-Dehydrogenation and C20 Reduction of Cortisone and Hydrocortisone Catalyzed by Rhodococcus Strains.

Prednisone and prednisolone are steroids widely used as anti-inflammatory drugs. Development of the pharmaceutical industry is currently aimed at introducing biotechnological processes and replacing multiple-stage chemical syntheses. In this work we evaluated the ability of bacteria belonging to the Rhodococcus genus to biotransform substrates, such as cortisone and hydrocortisone, to obtain prednisone and prednisolone, respectively. These products are of great interest from a pharmaceutical point of view as they have higher anti-inflammatory activity than the starting substrates. After an initial lab-scale screening of 13 Rhodococcus strains, to select the highest producers of prednisone and prednisolone, we reported the 200 ml-batch scale-up to test the process efficiency and productivity of the most promising Rhodococcus strains. R. ruber, R. globerulus and R. coprophilus gave the Δ1-dehydrogenation products of cortisone and hydrocortisone (prednisone and prednisolone) in variable amounts. In these biotransformations, the formation of products with the reduced carbonyl group in position C20 of the lateral chain of the steroid nucleus was also observed (i.e., 20ß-hydroxy-prednisone and 20ß-hydroxy-prednisolone). The yields, the absence of collateral products, and in some cases the absence of starting products allow us to say that cortisone and hydrocortisone are partly degraded.

Sex-specific epigenetic gene activation profiles are differentially modulated in human placentas affected by intrauterine growth restriction.

BACKGROUND: The purpose of this study was to investigate the sex specific expression of histone protein modifications responsible for rapid gene expression in IUGR placentas. PATIENTS AND METHODS: We screened for fetal sex-specific expression of the histone proteins H3K4me3 and H3K9ac in 23 IUGR and 40 control placentas via immunohistochemistry. The trophoblast-like cell line BeWo was used in order to analyze a potential effect of stimulation with prednisolone on H3K4me3 and H3K9ac in vitro. Calculating regression models with additional adjustment for potential confounders were used. RESULTS: A significantly decreased level of H3K4me3 was detectable in female syncytiotrophoblasts, whereas H3K9ac was reduced predominantly in male extravillous throphoblast (EVT). No association to the gestational age existed. CONCLUSION: Our data showed a reduced expression of the histone proteins H3K4me3 (female) and H3K9ac (male) in IUGR, furthermore elevated cortisol levels may lead to a sex-specific down-regulation of histone proteins in IUGR placentas.

Primary Human Hepatocytes, but Not HepG2 or Balb/c 3T3 Cells, Efficiently Metabolize Salinomycin and Are Resistant to Its Cytotoxicity.

Salinomycin is a polyether antibiotic showing anticancer activity. There are many reports of its toxicity to animals but little is known about the potential adverse effects in humans. The action of the drug may be connected to its metabolism. That is why we investigated the cytotoxicity of salinomycin and pathways of its biotransformation using human primary hepatocytes, human hepatoma cells (HepG2), and the mouse fibroblast cell line (Balb/c 3T3). The cytotoxicity of salinomycin was time-dependent, concentration-dependent, and cell-dependent with primary hepatocytes being the most resistant. Among the studied models, primary hepatocytes were the only ones to efficiently metabolize salinomycin but even they were saturated at higher concentrations. The main route of biotransformation was monooxygenation leading to the formation of monohydroxysalinomycin, dihydroxysalinomycin, and trihydroxysalinomycin. Tiamulin, which is a known inhibitor of CYP450 izoenzymes, synergistically induced cytotoxicity of salinomycin in all cell types, including non-metabolising fibroblasts. Therefore, the pharmacokinetic interaction cannot fully explain tiamulin impact on salinomycin toxicity.

Liposomal Delivery Improves the Efficacy of Prednisolone to Attenuate Renal Inflammation in a Mouse Model of Acute Renal Allograft Rejection.

BACKGROUND: Systemic exposure to high-dose corticosteroids effectively combats acute rejection after kidney transplantation, but at the cost of substantial side effects. In this study, a murine acute renal allograft rejection model was used to investigate whether liposomal-encapsulated prednisolone (LP) facilitates local exposure to enhance its therapeutic effect. METHODS: Male BalbC recipients received renal allografts from male C57BL/6J donors. Recipients were injected daily with 5 mg/kg cyclosporine A and received either 10 mg/kg prednisolone (P), or LP intravenously on day 0, 3, and 6, or no additional treatment. Functional magnetic resonance imaging (fMRI) was performed on day 6 to study allograft perfusion and organs were retrieved on day 7 for further analysis. RESULTS: Staining of polyethylene-glycol-labeled liposomes and high performance liquid chromatography analysis revealed accumulation in the LP treated allograft. LP treatment induced the expression of glucocorticoid responsive gene Fkbp5 in the allograft. Flow-cytometry of allografts revealed liposome presence in CD45 cells, and reduced numbers of F4/80 macrophages, and CD3 T-lymphocytes upon LP treatment. Banff scoring showed reduced interstitial inflammation and tubulitis and fMRI analysis revealed improved allograft perfusion in LP versus NA mice. CONCLUSIONS: Liposomal delivery of prednisolone improved renal bio-availability, increased perfusion and reduced cellular infiltrate in the allograft, when compared with conventional prednisolone. Clinical studies should reveal if treatment with LP results in improved efficacy and reduced side effects in patients with renal allograft rejection.

Bacterial steroid-17,20-desmolase is a taxonomically rare enzymatic pathway that converts prednisone to 1,4-androstanediene-3,11,17-trione, a metabolite that causes proliferation of prostate cancer cells.

The adrenal gland has traditionally been viewed as a source of "weak androgens"; however, emerging evidence indicates 11-oxy-androgens of adrenal origin are metabolized in peripheral tissues to potent androgens. Also emerging is the role of gut bacteria in the conversion of C21 glucocorticoids to 11-oxygenated C19 androgens. Clostridium scindens ATCC 35,704 is a gut microbe capable of converting cortisol into 11-oxy-androgens by cleaving the side-chain. The desA and desB genes encode steroid-17,20-desmolase. Our prior study indicated that the urinary tract bacterium, Propionimicrobium lymphophilum ACS-093-V-SCH5 encodes desAB and converts cortisol to 11ß-hydroxyandrostenedione. We wanted to determine how widespread this function occurs in the human microbiome. Phylogenetic and sequence similarity network analyses indicated that the steroid-17,20-desmolase pathway is taxonomically rare and located in gut and urogenital microbiomes. Two microbes from each of these niches, C. scindens and Propionimicrobium lymphophilum, respectively, were screened for activity against endogenous (cortisol, cortisone, and allotetrahydrocortisol) and exogenous (prednisone, prednisolone, dexamethasone, and 9-fluorocortisol) glucocorticoids. LC/MS analysis showed that both microbes were able to side-chain cleave all glucocorticoids, forming 11-oxy-androgens. Pure recombinant DesAB from C. scindens showed the highest activity against prednisone, a commonly prescribed glucocorticoid. In addition, 0.1 nM 1,4-androstadiene-3,11,17-trione, bacterial side-chain cleavage product of prednisone, showed significant proliferation relative to vehicle in androgen-dependent growth LNCaP prostate cancer cells after 24 h (2.3 fold; P <  0.01) and 72 h (1.6 fold; P < 0.01). Taken together, DesAB-expressing microbes may be an overlooked source of androgens in the body, potentially contributing to various disease states, such as prostate cancer.

The ergogenic impact of the glucocorticoid prednisolone does not translate into increased running motivation in mice.

Glucocorticoids, such as prednisolone, are considered sport doping agents owing to their ergogenic properties. These are accounted for by peripheral mechanisms associated with energetic and anti-inflammatory processes. However, because glucocorticoids target brain tissues, it is likely that these ergogenic impacts are associated with central effects. One of these might be reward motivation, which relies on glucocorticoid receptor-expressing mesocorticolimbic dopaminergic neurons. In keeping with this possibility, this study has explored in mice whether repeated prednisolone administration (5 or 15 µg/ml of drinking water for 10 days) affected intrinsic motivation for running, a strong reinforcer in rodents. Running motivation was assessed by means of a cued-reward motivated instrumental task wherein wheel-running was conditioned by prior nose poke responses under fixed (FR), and then progressive (PR), ratio reinforcement schedules. Sub-chronic ingestion of prednisolone decreased the running distance covered during each rewarded sequence under FR schedules. This finding did not extend to wheel-running performances in mice provided free (i.e. unconditioned) wheel-running opportunities. Running motivation, as estimated under a PR reinforcement schedule, was found to be decreased (lowest concentration) or to remain unaffected (highest concentration) by prednisolone concentration. Lastly, an inter-individual analysis of the respective effects of prednisolone on muscular endurance (as assessed in the wire grid-hanging test) and on running motivation indicated that the former was not predictive of the latter. This observation suggests that prednisolone ergogenic impacts might occur without any concomitant increase in intrinsic exercise motivation.

Effects of truck transportation and slaughtering on the occurrence of prednisolone and its metabolites in cow urine, liver, and adrenal glands.

BACKGROUND: The recognition of illegal administration of synthetic corticosteroids in animal husbandry has been recently challenged by the case of prednisolone, whose occasional presence in the urine of bovines under strong stressful conditions was attributed to endogenous biosynthesis, not to exogenous administration. The study of the natural stress sources possibly inducing endogenous prednisolone production represents a stimulating investigation subject. The biochemical effects of transportation and slaughtering were verified in untreated cows by studying the possible occurrence of prednisolone and its metabolites in urine, liver and adrenal glands, and the cortisol/cortisone quantification. RESULTS: Cortisol, cortisone, prednisolone and its metabolites were measured in urine, collected at farm under natural micturition and then at the slaughterhouse. The study was performed on 15 untreated cows reared in different farms at the end of their productive cycle. 2-3 days after the first urine collection, the animals were transported by trucks to the abattoir, slaughtered, and subjected to a second urine sampling from the bladder. Specimens of liver and adrenal gland were also collected and analysed by means of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) validated method. The stressful conditions of transportation and slaughtering proved to increase considerably the urinary levels of cortisol and cortisone as compared to those collected at farm. Prednisolone was detected in the urine collected at the slaughterhouse of two cows only, at a concentration level (≈0.6 µg L- 1) largely below the official cut off (5.0 µg L- 1) established to avoid false non-compliances. These two animals exhibited the highest urinary cortisol levels of the series. Prednisolone and prednisone were also detected in the adrenal glands of a different cow. Prednisolone metabolites were not detected in any urine, liver, and adrenal gland sample. CONCLUSION: Within the constraints of the condition adopted, this study confirms the sporadic presence of prednisolone traces (2 samples out of 15) and the consistently increased concentration of cortisone and cortisol in the urines collected from cows subjected to truck transportation and subsequent slaughtering. No prednisolone metabolites were detected in any liver and adrenal gland samples, nor in urine specimens, unlike what was previously reported for cows artificially stressed by pharmacological treatment.

Striatal spreading depolarization: Possible implication in levodopa-induced dyskinetic-like behavior.

OBJECTIVE: Spreading depolarization (SD) is a transient self-propagating wave of neuronal and glial depolarization coupled with large membrane ionic changes and a subsequent depression of neuronal activity. Spreading depolarization in the cortex is implicated in migraine, stroke, and epilepsy. Conversely, spreading depolarization in the striatum, a brain structure deeply involved in motor control and in Parkinson's disease (PD) pathophysiology, has been poorly investigated. METHODS: We characterized the participation of glutamatergic and dopaminergic transmission in the induction of striatal spreading depolarization by using a novel approach combining optical imaging, measurements of endogenous DA levels, and pharmacological and molecular analyses. RESULTS: We found that striatal spreading depolarization requires the concomitant activation of D1-like DA and N-methyl-d-aspartate receptors, and it is reduced in experimental PD. Chronic l-dopa treatment, inducing dyskinesia in the parkinsonian condition, increases the occurrence and speed of propagation of striatal spreading depolarization, which has a direct impact on one of the signaling pathways downstream from the activation of D1 receptors. CONCLUSION: Striatal spreading depolarization might contribute to abnormal basal ganglia activity in the dyskinetic condition and represents a possible therapeutic target. © 2019 International Parkinson and Movement Disorder Society.

The corticosteroid prednisolone increases amygdala and insula reactivity to food approach signals in healthy young men.

Short- and long-term treatment with glucocorticoids is widely used in clinical practice and frequently induces features of iatrogenic Cushing syndrome, such as abdominally centered weight gain. Despite decades of glucocorticoids usage, the mechanisms underlying these side effects are still only partly understood. One possibility is that glucocorticoids impact subcortical (hypothalamus, amygdala, insula) and cortical (orbitofrontal and cingulate cortex) brain regions involved in appetite regulation and reward processing. In the present study, we used functional magnetic resonance imaging (fMRI) to study the acute effects of a prednisolone infusion on reactivity of brain reward systems to food stimuli. Twenty healthy normal-weight men were tested in a randomized, double-blind, cross-over study. After an overnight fast and infusion of either 250 mg prednisolone or placebo (always administered between 8 and 9 A M), fMRI scans were taken while presenting food and object pictures in a Go/NoGo (GNG) task. At home, participants were asked to register what they had eaten. On the following morning they came back to the lab and had a supervised ad libitum breakfast at a standardized buffet. Food-Go in contrast to Object-Go pictures yielded increased blood oxygen level dependent (BOLD) activity in hippocampus, amygdala, orbitofrontal cortex, insula and anterior cingulate cortex. Prednisolone increased activation in the bilateral amygdala and right insula for approach-associated food pictures. The buffet test did not reveal significant differences in calorie consumption or preferences of different macronutrients. However, prednisolone-induced insula reactivity to Food-Go images was associated with greater caloric intake, both at home and in the standardized buffet. In sum, we observed a specific effect of prednisolone on the BOLD response of the amygdala and insula to approach-associated food stimuli. As these brain areas have previously been implicated in hedonic eating, the present pattern of results may reflect an increased anticipated reward value of food modulated by glucocorticoids. These effects might potentially drive increased food intake and weight gain under prolonged glucocorticoid treatment.