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Khan S, Marquez-Martinez S, Erkens T, de Wilde A, Costes LMM, Vinken P, De Jonghe S, Roosen W, Talia C, Chamanza R, Serroyen J, Tolboom J, Zahn RC, Wegmann F. Intravenous Administration of Ad26.COV2.S Does Not Induce Thrombocytopenia or Thrombotic Events or Affect SARS-CoV-2 Spike Protein Bioavailability in Blood Compared with Intramuscular Vaccination in Rabbits. Vaccines (Basel) 2023; 11:1792. [PMID: 38140195 PMCID: PMC10747520 DOI: 10.3390/vaccines11121792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/25/2023] [Indexed: 12/24/2023] Open
Abstract
Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a very rare but serious adverse reaction that can occur after Ad26.COV2.S vaccination in humans, leading to thrombosis at unusual anatomic sites. One hypothesis is that accidental intravenous (IV) administration of Ad26.COV2.S or drainage of the vaccine from the muscle into the circulatory system may result in interaction of the vaccine with blood factors associated with platelet activation, leading to VITT. Here, we demonstrate that, similar to intramuscular (IM) administration of Ad26.COV2.S in rabbits, IV dosing was well tolerated, with no significant differences between dosing routes for the assessed hematologic, coagulation time, innate immune, or clinical chemistry parameters and no histopathologic indication of thrombotic events. For both routes, all other non-adverse findings observed were consistent with a normal vaccine response and comparable to those observed for unrelated or other Ad26-based control vaccines. However, Ad26.COV2.S induced significantly higher levels of C-reactive protein on day 1 after IM vaccination compared with an Ad26-based control vaccine encoding a different transgene, suggesting an inflammatory effect of the vaccine-encoded spike protein. Although based on a limited number of animals, these data indicate that an accidental IV injection of Ad26.COV2.S may not represent an increased risk for VITT.
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Affiliation(s)
- Selina Khan
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Sonia Marquez-Martinez
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Tim Erkens
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Adriaan de Wilde
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Lea M. M. Costes
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Petra Vinken
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Sandra De Jonghe
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Wendy Roosen
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Chiara Talia
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Ronnie Chamanza
- Janssen Research & Development—A Division of Janssen Pharmaceutica NV, 2340 Beerse, Belgium; (T.E.); (S.D.J.); (W.R.); (C.T.)
| | - Jan Serroyen
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Jeroen Tolboom
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Roland C. Zahn
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
| | - Frank Wegmann
- Janssen Vaccines & Prevention, 2333 CN Leiden, The Netherlands; (S.M.-M.); (A.d.W.); (L.M.M.C.); (J.S.); (J.T.); (F.W.)
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Erkens T, Boonen J, Goeminne N, Kegels A, Van den Sande L, Marien D, van Heerden M, Vinken P. Analytical and biological evaluation of cardiotoxicity safety biomarkers in the rat. Toxicol Lett 2018. [DOI: 10.1016/j.toxlet.2018.06.556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Erkens T, Bueters R, van Heerden M, Cuyckens F, Vreeken R, Goeminne N, Lammens L. Translational safety biomarkers of colonic barrier integrity in the rat. J Appl Toxicol 2018; 38:1282-1292. [DOI: 10.1002/jat.3639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Tim Erkens
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Ruud Bueters
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Marjolein van Heerden
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Filip Cuyckens
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Rob Vreeken
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Nick Goeminne
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
| | - Lieve Lammens
- Preclinical Development & Safety, Janssen Research & Development, a division of Janssen Pharmaceutica NV; Turnhoutseweg 30 2340 Beerse Belgium
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Borghys H, Van Broeck B, Dhuyvetter D, Jacobs T, de Waepenaert K, Erkens T, Brooks M, Thevarkunnel S, Araujo JA. Young to Middle-Aged Dogs with High Amyloid-β Levels in Cerebrospinal Fluid are Impaired on Learning in Standard Cognition tests. J Alzheimers Dis 2018; 56:763-774. [PMID: 28035921 PMCID: PMC5271428 DOI: 10.3233/jad-160434] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Understanding differences in Alzheimer’s disease biomarkers before the pathology becomes evident can contribute to an improved understanding of disease pathogenesis and treatment. A decrease in amyloid-β (Aβ)42 in cerebrospinal fluid (CSF) is suggested to be a biomarker for Aβ deposition in brain. However, the relevance of CSF Aβ levels prior to deposition is not entirely known. Dogs are similar to man with respect to amyloid-β protein precursor (AβPP)-processing, age-related amyloid plaque deposition, and cognitive dysfunction. In the current study, we evaluated the relation between CSF Aβ42 levels and cognitive performance in young to middle-aged dogs (1.5–7 years old). Additionally, CSF sAβPPα and sAβPPβ were measured to evaluate AβPP processing, and CSF cytokines were measured to determine the immune status of the brain. We identified two groups of dogs showing consistently low or high CSF Aβ42 levels. Based on prior studies, it was assumed that at this age no cerebral amyloid plaques were likely to be present. The cognitive performance was evaluated in standard cognition tests. Low or high Aβ concentrations coincided with low or high sAβPPα, sAβPPβ, and CXCL-1 levels, respectively. Dogs with high Aβ concentrations showed significant learning impairments on delayed non-match to position (DNMP), object discrimination, and reversal learning compared to dogs with low Aβ concentrations. Our data support the hypothesis that high levels of CSF Aβ in dogs coincide with lower cognitive performance prior to amyloid deposition. Further experiments are needed to investigate this link, as well as the relevance with respect to Alzheimer’s disease pathology progression.
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Affiliation(s)
- Herman Borghys
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Bianca Van Broeck
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Deborah Dhuyvetter
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Tom Jacobs
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Katja de Waepenaert
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
| | - Tim Erkens
- Janssen Research & Development, a division of Janssen Pharmaceutica N.V., Beerse, Belgium
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Erkens T, Goeminne N, Kegels A, Byloos M, Vinken P. Analytical performance of a commercial multiplex Luminex-based cytokine panel in the rat. J Pharmacol Toxicol Methods 2018; 91:43-49. [PMID: 29371052 DOI: 10.1016/j.vascn.2018.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/20/2017] [Accepted: 01/17/2018] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Multiplex immunoassays are an important tool in biomarker research during preclinical drug development. However, information regarding analytical performance of commercial multiplex assays for animal species is often limited. To be able to correctly interpret study results, a fit-for-purpose validation approach is recommended. The objective of our study was to provide a realistic example of what level of validation can be expected from this type of assay, using a rat cytokine panel. METHODS The analytical performance of a commercial Luminex-based multiplex assay comprising IFN-γ, IL-6, IL-10, IL-12p70, IP-10 and TNF-α was evaluated in Sprague-Dawley rat plasma and serum. Calibration curve, working range, precision, accuracy, selectivity, parallelism, dilutional linearity, prozone effect and sample stability were assessed. RESULTS Analytical performance in plasma and serum was comparable. Precision and accuracy results for all analytes were acceptable with coefficient of variation (CV) and relative error (RE) often below 15%, except for serum IL-6. Selectivity results varied per analyte with several cytokines showing CV>30% and no single minimum required dilution (MRD) could be identified. In addition, some striking differences between recombinant and endogenous protein results were observed. A pronounced prozone effect was detected for IP-10. Analytes in samples stored at -70°C were stable (RE<30%) from 1 up to 6months depending on the analyte. DISCUSSION The results illustrate the challenges encountered during validation of commercial animal Luminex-based multiplex assays, revealing analytical limitations such as matrix and prozone effects. The Milliplex rat cytokine panel under investigation was deemed suitable for relative quantification of exploratory type biomarkers.
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Affiliation(s)
- Tim Erkens
- Mechanistic and Investigative Toxicology, Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, Belgium.
| | - Nick Goeminne
- Mechanistic and Investigative Toxicology, Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, Belgium
| | - Ann Kegels
- Mechanistic and Investigative Toxicology, Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, Belgium
| | - Martine Byloos
- Mechanistic and Investigative Toxicology, Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, Belgium
| | - Petra Vinken
- Mechanistic and Investigative Toxicology, Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, Belgium
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Erkens T, Van den Sande L, Witters J, Verbraeken F, Looszova A, Feyen B. Effect of time and temperature on anticoagulant-dependent pseudothrombocytopenia in Göttingen minipigs. Vet Clin Pathol 2017; 46:416-421. [PMID: 28582600 DOI: 10.1111/vcp.12509] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND A marked decrease in thrombocyte count was observed between subsequent measurements of the same EDTA blood sample in several minipigs, but little information was available explaining this finding. OBJECTIVES The objective was to evaluate the impact of several preanalytic variables on thrombocyte counts in minipigs, in order to improve understanding of the in vitro thrombocyte decrease observed. MATERIALS AND METHODS Hematology blood samples from male and female Göttingen minipigs were collected using EDTA or citrate as an anticoagulant. Samples were stored under different conditions (room temperature, 4°C, or 37-38°C) and were analyzed approximately 0.5 to one h, 3.5-4 h, 7-7.5 h, and 28-29 h after collection. RESULTS In EDTA blood samples from male minipigs stored at room temperature, there was a progressive thrombocyte decrease over time up to -71% after 29 h, caused by in vitro aggregation. In females, no consistent change was seen up to 7.5 h, but there was a decrease up to -47% after 29 h. Thrombocyte count was most stable during storage at 4°C. No consistent marked decrease in thrombocyte counts was seen for citrated blood at room temperature, although such a decrease was present in a few individual animals. CONCLUSIONS Study results provide evidence for an anticoagulant-dependent pseudothrombocytopenia in minipigs progressing over time and depending on the storage temperature of the blood sample. It is therefore recommended to perform thrombocyte counts as soon as possible after blood collection, and in case of low counts, investigate for the presence of artifactual platelet clumping.
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Affiliation(s)
- Tim Erkens
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Liesbeth Van den Sande
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Jill Witters
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Filip Verbraeken
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Adriana Looszova
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Bianca Feyen
- Preclinical Development & Safety, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Beerse, Belgium
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Darville N, van Heerden M, Erkens T, De Jonghe S, Vynckier A, De Meulder M, Vermeulen A, Sterkens P, Annaert P, Van den Mooter G. Modeling the Time Course of the Tissue Responses to Intramuscular Long-acting Paliperidone Palmitate Nano-/Microcrystals and Polystyrene Microspheres in the Rat. Toxicol Pathol 2015; 44:189-210. [DOI: 10.1177/0192623315618291] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-acting injectable (LAI) drug suspensions consist of drug nano-/microcrystals suspended in an aqueous vehicle and enable prolonged therapeutic drug exposure up to several months. The examination of injection site reactions (ISRs) to the intramuscular (IM) injection of LAI suspensions is relevant not only from a safety perspective but also for the understanding of the pharmacokinetics. The aim of this study was to perform a multilevel temporal characterization of the local and lymphatic histopathological/immunological alterations triggered by the IM injection of an LAI paliperidone palmitate suspension and an analog polystyrene suspension in rats and identify critical time points and parameters with regard to the host response. The ISRs showed a moderate to marked chronic granulomatous inflammation, which was mediated by multiple cyto-/chemokines, including interleukin-1β, monocyte Chemoattractant Protein-1, and vascular endothelial growth factor. Lymphatic uptake and lymph node retention of nano-/microparticles were observed, but the contribution to the drug absorption was negligible. A simple image analysis procedure and empirical model were proposed for the accurate evaluation of the depot geometry, cell infiltration, and vascularization. This study was designed as a reference for the evaluation and comparison of future LAIs and to support the mechanistic modeling of the formulation–physiology interplay regulating the drug absorption from LAIs.
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Affiliation(s)
- Nicolas Darville
- Drug Delivery and Disposition, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven—University of Leuven, Leuven, Belgium
- Model Based Drug Development, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
- These authors contributed equally
| | - Marjolein van Heerden
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
- These authors contributed equally
| | - Tim Erkens
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Sandra De Jonghe
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - An Vynckier
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Marc De Meulder
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - An Vermeulen
- Model Based Drug Development, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Patrick Sterkens
- Preclinical Development and Safety, Janssen Research & Development, a Division of Janssen Pharmaceutica NV, Beerse, Belgium
| | - Pieter Annaert
- Drug Delivery and Disposition, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven—University of Leuven, Leuven, Belgium
| | - Guy Van den Mooter
- Drug Delivery and Disposition, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven—University of Leuven, Leuven, Belgium
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Bruynsteen L, Erkens T, Peelman LJ, Ducatelle R, Janssens GPJ, Harris PA, Hesta M. Expression of inflammation-related genes is associated with adipose tissue location in horses. BMC Vet Res 2013; 9:240. [PMID: 24295090 PMCID: PMC4220830 DOI: 10.1186/1746-6148-9-240] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 11/27/2013] [Indexed: 12/13/2022] Open
Abstract
Background In humans, adipose tissue (AT) originating from different depots shows varying gene expression profiles. In horses, the risk of certain metabolic disorders may also be influenced by the impact of specific AT depots. Macrophage infiltration in human and rat AT is considered to be a source of inflammatory changes. In horses, this relationship has not been extensively studied yet. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), a useful method to evaluate differences in mRNA expression across different tissues, can be used to evaluate differences between equine AT depots. For a correct interpretation of the RT-qPCR results, expression data have to be normalized by the use of validated reference genes. The main objectives of this study were to compare mRNA expression of inflammation-related genes, as well as adipocyte morphology and number between different equine AT depots; and in addition, to investigate the presence of antigen presenting cells in equine AT and any potential relationship with adipokine mRNA expression. Results In this study, the mRNA expression of inflammation-related genes (leptin, chemokine ligand 5, interleukin 1β, interleukin 6, interleukin 10, adiponectin, matrix metalloproteinase 2, and superoxide dismutase 2) and candidate reference gene stability was investigated in 8 different AT depots collected from the nuchal, abdominal (mesenteric, retroperitoneal, and peri-renal) and subcutaneous (tail head and loin) AT region. By using GeNorm analysis, HPRT1, RPL32, and GAPDH were found to be the most stable genes in equine AT. The mRNA expression of leptin, chemokine ligand 5, interleukin 10, interleukin 1β, adiponectin, and matrix metalloproteinase 2 significantly differed across AT depots (P < 0.05). No significant AT depot effect was found for interleukin 6 and superoxide dismutase 2 (P > 0.05). Adipocyte area and number of antigen presenting cells per adipocyte significantly differed between AT depots (P < 0.05). Conclusions Adipose tissue location was associated with differences in mRNA expression of inflammation-related genes. This depot-specific difference in mRNA expression suggests that the overall inflammatory status of horses could be partially determined by the relative proportion of the different AT depots.
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Affiliation(s)
- Lien Bruynsteen
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, Merelbeke 9820, Belgium.
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De Spiegelaere W, Cornillie P, Erkens T, Van Loo D, Casteleyn C, Van Poucke M, Burvenich C, Van Hoorebeke L, Van Ginneken C, Peelman L, Van den Broeck W. Expression and localization of angiogenic growth factors in developing porcine mesonephric glomeruli. J Histochem Cytochem 2010; 58:1045-56. [PMID: 20713984 DOI: 10.1369/jhc.2010.956557] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The development and growth of renal glomeruli is regulated by specific angiogenic growth factors, including vascular endothelial growth factor (VEGF) and the angiopoietins (ANGPT1 and ANGPT2). The expression of these factors has already been studied during metanephric glomerulogenesis, but it remains to be elucidated during the development of the embryonic mesonephros, which can function as an interesting model for glomerular development and senescence. In this study, the presence of the angiogenic growth factors was studied in developing porcine mesonephroi, using IHC and real-time RT-qPCR on laser capture microdissected glomeruli. In addition, mesonephric glomerular growth was measured by using stereological methods. ANGPT2 remained upregulated during maturation of glomeruli, which may be explained by the continuous growth of the glomeruli, as observed by stereological examination. The mRNA for VEGFA was expressed in early developing and in maturing glomeruli. The VEGF receptor VEGFR1 was stably expressed during the whole lifespan of mesonephric glomeruli, whereas VEGFR2 mRNA was only upregulated in early glomerulogenesis, suggesting that VEGFR2 is important for the vascular growth but that VEGFR1 is important for the maintenance of endothelial fenestrations.
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Affiliation(s)
- Ward De Spiegelaere
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
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Erkens T, Vandesompele J, Van Zeveren A, Peelman LJ. Correlation between porcine PPARGC1A mRNA expression and its downstream target genes in backfat and longissimus dorsi muscle. J Appl Genet 2010; 50:361-9. [PMID: 19875886 DOI: 10.1007/bf03195694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Knowledge of in vivo relationship between the coactivator PPARGC1A and its target genes is very limited, especially in the pig. In this study, a real-time PCR experiment was performed on longissimus dorsi muscle (MLD) and backfat with 10 presumed PPARGC1A downstream target genes, involved in energy and fat metabolism, to identify possible relationships with PPARGC1A mRNA expression in vivo in the pig (n = 20). Except for UCP3 and LPL, a very significant difference in expression was found between MLD and backfat for all genes (P < 0.01). Hierarchical cluster analysis and the significant pairing of mRNA expression data between sampling locations suggested a genetic regulation of the expression of several target genes. A positive correlation with PPARGC1A was found for CPT1B, GLUT4, PDK4, and TFAM (P < 0.0001). A negative correlation was found for UCP2, FABP4, LEP (P < 0.0001), and TNF (P = 0.0071). No significant correlation was detected for UCP3 and LPL. This study provides evidence for a clear difference in mRNA expression of crucial genes in fat and energy metabolism between 2 important tissues. Our data suggest a clear impact of PPARGC1A on energy and lipid metabolism in vivo in the pig, through several of these downstream target genes.
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Affiliation(s)
- T Erkens
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Belgium.
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Rempel LA, Nonneman DJ, Wise TH, Erkens T, Peelman LJ, Rohrer GA. Association analyses of candidate single nucleotide polymorphisms on reproductive traits in swine1,2. J Anim Sci 2010; 88:1-15. [DOI: 10.2527/jas.2009-1985] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Lampo E, Duchateau L, Schepens B, Van Poucke M, Saelens X, Erkens T, Van Zeveren A, Peelman LJ. Identification of polymorphisms in the ovine Shadow of prion protein (SPRN) gene and assessment of their effect on promoter activity and susceptibility for classical scrapie. Anim Genet 2009; 41:169-78. [PMID: 19917049 DOI: 10.1111/j.1365-2052.2009.01984.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Shadow of prion protein (SPRN) is an interesting candidate gene thought to be involved in prion pathogenesis. In humans, an association has already been discovered between mutations in SPRN and the incidence of variant and sporadic Creutzfeldt-Jakob disease. However, in sheep, the effect of mutations in SPRN is largely unknown. Therefore, we analysed the presence of mutations in the entire ovine SPRN gene, their association with scrapie susceptibility and their effect on SPRN promoter activity. In total, 26 mutations were found: seven in the promoter region, four in intron 1, seven in the coding sequence and eight in the 3' untranslated region. The mutations detected in the coding sequence and the promoter region were subsequently analysed in more detail. In the coding sequence, a polymorphism causing a deletion of two alanines was found to be associated with susceptibility for classical scrapie in sheep. Furthermore, a functional analysis of deletion constructs of the ovine SPRN promoter revealed that the region 464 to 230 bp upstream of exon 1 (containing a putative AP-2 and putative Sp1 binding sites) is of functional importance for SPRN transcription. Six mutations in the SPRN promoter were also found to alter the promoter activity in vitro. However, no association between any of these promoter mutations and susceptibility for classical scrapie was found.
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Affiliation(s)
- E Lampo
- Department of Nutrition, Genetics and Ethology, Ghent University, Merelbeke, Belgium
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Van Poucke M, Melkebeek V, Erkens T, Van Zeveren A, Cox E, Peelman LJ. Molecular cloning and characterization of the porcine prostaglandin transporter (SLCO2A1): evaluation of its role in F4 mediated neonatal diarrhoea. BMC Genet 2009; 10:64. [PMID: 19807916 PMCID: PMC2763009 DOI: 10.1186/1471-2156-10-64] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 10/06/2009] [Indexed: 01/22/2023] Open
Abstract
Background Because prostaglandins are involved in many (patho)physiological processes, SLCO2A1 was already characterized in several species in an attempt to unravel specific processes/deficiencies. Here, we describe the molecular cloning and characterization of the porcine ortholog in order to evaluate its possible involvement in F4 enterotoxigenic E. coli mediated neonatal diarrhoea, based on a positional candidate gene approach study. Results Porcine SLCO2A1 is organized in 14 exons, containing an open reading frame of 1935 bp, encoding a 12-transmembrane organic anion cell surface transporter of 644 aa. The -388 to -5 upstream region comprises a (CpG)48 island containing a number of conserved promoter elements, including a TATA box. A potential alternative promoter region was found in the conserved -973 to -700 upstream region. No consensus polyadenylation signal was discovered in the 3' UTR. Repeat sequences were found in 15% of all the non coding sequences. As expected for a multifunctional protein, a wide tissue distribution was observed. mRNA expression was found in the adrenal gland, bladder, caecum, colon (centripetal coil/centrifugal coil), diaphragm, duodenum, gallbladder, heart, ileum, jejunum, kidney, liver, longissimus dorsi muscle, lung, lymph node, mesenterium, rectum, spleen, stomach, tongue and ureter, but not in the aorta, oesophagus and pancreas. The promoter region and the exons (including the splice sites) of SLCO2A1 were resequenced in 5 F4ab/ac receptor positive and 5 F4ab/ac receptor negative pigs. Two silent and 2 missense (both S → L at position 360 and 633) mutations were found, but none was associated with the F4ab/ac receptor phenotype. In addition, no phenotype associated differential mRNA expression or alternative/abberant splicing/polyadenylation was found in the jejunum. Conclusion The molecular cloning and characterization of porcine SLCO2A1 not only contributes to the already existing knowledge about the transporter in general, but enables studies on porcine prostaglandin related processes/deficiencies as patient and/or model. Here we examined its possible involvement as receptor in F4 enterotoxigenic E. coli mediated neonatal diarrhoea. Because no phenotype associated differences could be found in the gene sequence nor in its jejunal transcription profile of F4ab/ac receptor positive/negative pigs, SLCO2A1 can most likely be excluded as receptor for F4 bacteria.
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Affiliation(s)
- Mario Van Poucke
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium.
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Abstract
Background Peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A) is a coactivator with a vital and central role in fat and energy metabolism. It is considered to be a candidate gene for meat quality in pigs and is involved in the development of obesity and diabetes in humans. How its many functions are regulated, is however still largely unclear. Therefore a transcription profile of PPARGC1A in 32 tissues and 4 embryonic developmental stages in the pig was constructed by screening its cDNA for possible splice variants with exon-spanning primers. Findings This led to the discovery of 2 new splice variants in the pig, which were subsequently also detected in human tissues. In these variants, exon 8 was either completely or partly (the last 66 bp were conserved) spliced out, potentially coding for a much shorter protein of respectively 337 and 359 amino acids (aa), of which the first 291 aa would be the same compared to the complete protein (796 aa). Conclusion Considering the functional domains of the PPARGC1A protein, it is very likely these splice variants considerably affect the function of the protein and alternative splicing could be one of the mechanisms by which the diverse functions of PPARGC1A are regulated.
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Affiliation(s)
- Tim Erkens
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium.
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Lampo E, Van Poucke M, Vandesompele J, Erkens T, Van Zeveren A, Peelman LJ. Positive correlation between relative mRNA expression of PRNP and SPRN in cerebral and cerebellar cortex of sheep. Mol Cell Probes 2008; 23:60-4. [PMID: 19059475 DOI: 10.1016/j.mcp.2008.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Revised: 11/12/2008] [Accepted: 11/13/2008] [Indexed: 10/21/2022]
Abstract
SPRN is an interesting new member of the PRNP family because of its sequence homology with the hydrophobic region of PRNP, its expression in brain tissue and its PrP-like properties in functional experiments on Prnp(0/0) mice. In this study, we investigated by quantitative real-time PCR the relative mRNA expression levels of SPRN and PRNP in sheep cerebrum and cerebellum and the mutual relationship between these expression levels. Analysis of PRNP and SPRN mRNA expression levels in 45 cerebral cortex and 47 cerebellar cortex samples showed that the PRNP expression level was significantly higher (p<0.05) in cerebellum than in cerebrum, while no significant difference was detected for SPRN between these tissues. The expression level varied clearly more in cerebrum than in cerebellum for both genes tested, and the variation was larger for SPRN than for PRNP in both types of brain tissue. Remarkably, the mRNA expression levels of PRNP and SPRN showed a highly significant positive correlation in both cerebrum (p<0.0001) and cerebellum (p<0.001). This positive correlation might indicate co-regulation between these genes. Further investigation on the causal nature of this correlation may provide new insights into prion pathogenesis.
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Affiliation(s)
- Evelyne Lampo
- Department of Nutrition, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, B-9820 Merelbeke, Belgium.
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De Spiegelaere W, Erkens T, De Craene J, Burvenich C, Peelman L, Van den Broeck W. Elimination of amplification artifacts in real-time reverse transcription PCR using laser capture microdissected samples. Anal Biochem 2008; 382:72-4. [PMID: 18652799 DOI: 10.1016/j.ab.2008.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 07/08/2008] [Accepted: 07/08/2008] [Indexed: 10/21/2022]
Abstract
Gene expression analysis on laser capture microdissected samples can be hampered because of the small sample size. The interference of PCR inhibitors increases with smaller sample size. Real-time reverse transcription PCR (RT-PCR) is usually performed directly after the reverse transcription step, enabling PCR inhibitors to remain in the complementary DNA (cDNA). A protocol was optimized for real-time RT-PCR with SYBR Green I. The introduction of an additional cDNA purification step after reverse transcription removed PCR inhibitors, making the reaction more efficient.
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Affiliation(s)
- Ward De Spiegelaere
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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Erkens T, Van Poucke M, Vandesompele J, Goossens K, Van Zeveren A, Peelman LJ. Development of a new set of reference genes for normalization of real-time RT-PCR data of porcine backfat and longissimus dorsi muscle, and evaluation with PPARGC1A. BMC Biotechnol 2006; 6:41. [PMID: 17026777 PMCID: PMC1609116 DOI: 10.1186/1472-6750-6-41] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 10/09/2006] [Indexed: 11/13/2022] Open
Abstract
Background An essential part of using real-time RT-PCR is that expression results have to be normalized before any conclusions can be drawn. This can be done by using one or multiple, validated reference genes, depending on the desired accuracy of the results. In the pig however, very little information is available on the expression stability of reference genes. The aim of this study was therefore to develop a new set of reference genes which can be used for normalization of mRNA expression data of genes expressed in porcine backfat and longissimus dorsi muscle, both representing an economically important part of a pig's carcass. Because of its multiple functions in fat metabolism and muscle fibre type composition, peroxisome proliferative activated receptor γ coactivator 1α (PPARGC1A) is a very interesting candidate gene for meat quality, and was an ideal gene to evaluate our developed set of reference genes for normalization of mRNA expression data of both tissue types. Results The mRNA expression stability of 10 reference genes was determined. The expression of RPL13A and SDHA appeared to be highly unstable. After normalization to the geometric mean of the three most stably expressed reference genes (ACTB, TBP and TOP2B), the results not only showed that the mRNA expression of PPARGC1A was significantly higher in each of the longissimus dorsi muscle samples than in backfat (P < 0.05), but also that the expression was significantly higher in the most cranial of the three muscle samples (P < 0.05). Conclusion This study provides a new set of reference genes (ACTB, TBP and TOP2B) suitable for normalization of real-time RT-PCR data of backfat and longissimus dorsi muscle in the pig. The obtained PPARGC1A expression results, after application of this set of reference genes, are a first step in unravelling the PPARGC1A expression pattern in the pig and provide a basis for possible selection towards improved meat quality while maintaining a lean carcass.
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Affiliation(s)
- Tim Erkens
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium
| | - Mario Van Poucke
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium
| | - Jo Vandesompele
- Centre for Medical Genetics, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Karen Goossens
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium
| | - Alex Van Zeveren
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium
| | - Luc J Peelman
- Department of Nutrition, Genetics and Ethology, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, 9820 Merelbeke, Belgium
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Abstract
Confluent education is presented as a method to bridge the gap between cognitive and affective learning. Attention is focused on three main characteristics of confluent education: (a) the integration of four overlapping domains in a learning process (readiness, the cognitive domain, the affective domain and responsibility); (b) the promotion of personal growth and interpersonal relationships by the development of awareness, and (c) the identification and dis-identification of teacher and participants. How confluent education can take place in practice is illustrated by presenting the way in which this method is applied in a nursing continuing education programme entitled 'Pain assessment and management in surgical-oncological patients'.
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Affiliation(s)
- A L Francke
- Helen Dowling Institute for Biopsychosocial Medicine, Rotterdam, The Netherlands
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