Papers by Peadar R Rooney
Journal of Biomedical Materials Research Part B: Applied Biomaterials
Biomaterials, 2017
Without an appropriate disease model, the understanding of the pathophysiology of intervertebral ... more Without an appropriate disease model, the understanding of the pathophysiology of intervertebral disc degeneration and inflammation is limited. The lack of understanding limits the potential discovery of therapeutic targets as viable treatment options. Here, we report a versatile method to develop a three-dimensional intervertebral disc (IVD) model to study the response of nucleus pulposus (NP) and annulus fibrosus (AF) cells to inflammatory (IL-1β-induced) stimulation. The cell shape regulated IVD model was engineered by modulating the crosslinking of a self-assembled collagen hydrogel. The developed model has provided us with an understanding of the molecular changes that occur at genetic level which modulate the production of extracellular matrix components and key inflammatory pathways in the inflamed IVD. We have identified the role of the suppressor of cytokine proteins (SOCS) family in combating detrimental effects of pro-inflammatory cytokines in degenerated human NP tissue ...
Arthritis Research & Therapy, 2012
After the breakthrough in the treatment of rheumatoid arthritis and numerous related disorders wi... more After the breakthrough in the treatment of rheumatoid arthritis and numerous related disorders with biological therapies targeting TNFa at the Kennedy Institute in London Millions of patients have tremendously benefitted. However, we cannot cure these diseases yet and have to search for additional therapeutic targets. Since it was shown that synovial fibroblasts (SF) are not only effector cells responding to inflammatory stimuli, but appear endogenously activated and potentially involved into spreading the disease [1], we searched for the epigenetic modifications leading to the activated phenotype of these cells. Epigenetics in its scientific definition "is the study of all heritable and potentially reversible changes in genome function that do not alter the nucleotide sequence within the DNA", but might be considered in simpler terms as the regulation of gene expression. Epigenetic modifications include: Acetylation, Methylation, Phosphorylation, Sumoylation, miRs or microRNAs. Our laboratory is studying these processes and we have found that RASF reside in a hyperacetylated synovial tissue and appear hypomethylated [2]. Hypomethylation leads to the activated phenotype of RASF which is characterized by the production of matrix-degrading enzymes and of potent chemokines induced by Toll-like receptor signalling. Current strategies are designed to methylate these cells to deactivate and "normalise" them again. miRs are about 20 nucleotide long smallRNAs acting to destroy specific mRNA. In the race to identify specific miRs as novel targets we have identified for example, that interleukin-6 modulates the expression of the Bone Morphogenic Protein Receptor Type II through a novel STAT3microRNA cluster 17/92 pathway, which helps to explain the loss of the BMPR2 in the vascular cells in pulmonary hypertension [3]. Moreover, miR-203 is regulating the production of IL-6 [4]. Most interestingly, epigenetic therapy is also on the horizon [5]. References 1. Lefèvre S, et al: Synovial fibroblasts spread rheumatoid arthritis to unaffected joints.
Arthritis Research & Therapy
After the breakthrough in the treatment of rheumatoid arthritis and numerous related disorders wi... more After the breakthrough in the treatment of rheumatoid arthritis and numerous related disorders with biological therapies targeting TNFa at the Kennedy Institute in London Millions of patients have tremendously benefitted. However, we cannot cure these diseases yet and have to search for additional therapeutic targets. Since it was shown that synovial fibroblasts (SF) are not only effector cells responding to inflammatory stimuli, but appear endogenously activated and potentially involved into spreading the disease [1], we searched for the epigenetic modifications leading to the activated phenotype of these cells. Epigenetics in its scientific definition "is the study of all heritable and potentially reversible changes in genome function that do not alter the nucleotide sequence within the DNA", but might be considered in simpler terms as the regulation of gene expression. Epigenetic modifications include: Acetylation, Methylation, Phosphorylation, Sumoylation, miRs or microRNAs. Our laboratory is studying these processes and we have found that RASF reside in a hyperacetylated synovial tissue and appear hypomethylated [2]. Hypomethylation leads to the activated phenotype of RASF which is characterized by the production of matrix-degrading enzymes and of potent chemokines induced by Toll-like receptor signalling. Current strategies are designed to methylate these cells to deactivate and "normalise" them again. miRs are about 20 nucleotide long smallRNAs acting to destroy specific mRNA. In the race to identify specific miRs as novel targets we have identified for example, that interleukin-6 modulates the expression of the Bone Morphogenic Protein Receptor Type II through a novel STAT3microRNA cluster 17/92 pathway, which helps to explain the loss of the BMPR2 in the vascular cells in pulmonary hypertension [3]. Moreover, miR-203 is regulating the production of IL-6 [4]. Most interestingly, epigenetic therapy is also on the horizon [5]. References 1. Lefèvre S, et al: Synovial fibroblasts spread rheumatoid arthritis to unaffected joints.
Clinical utility of conventional oral therapies is limited by their inability to deliver therapeu... more Clinical utility of conventional oral therapies is limited by their inability to deliver therapeutic molecules at the local or targeted site, causing a variety of side effects. Transdermal delivery has made a significant contribution in the management of skin diseases with enhanced therapeutic activities over the past two decades. In the modern era, various biomimetic and biocompatible polymer−lipid hybrid systems have been used to augment the transdermal delivery of therapeutics such as dermal patches, topical gels, iontophoresis, electroporation, sonophoresis, thermal ablation, microneedles, cavitational ultrasound, and nano or microlipid vesicular systems. Nevertheless, the stratum corneum still represents the main barrier to the delivery of vesicles into the skin. Lipid based formulations applied to the skin are at the center of attention and are anticipated to be increasingly functional as the skin offers many advantages for the direction of such systems. Accordingly, this review provides an overview of the development of conventional to advanced biomimetic lipid vesicles for skin delivery of a variety of therapeutics, with special emphasis on recent developments in this field including the development of transferosomes, niosomes, aquasomes, cubosomes, and other new generation lipoidal carriers.
Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications ... more Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications in wound healing, drug delivery, vascular repair and cell and/or gene delivery. Interstitial cystitis (IC) is charac-terised by an increase in the permeability of the bladder wall urothelium due to loss of the glycosamino-glycan (GAG) layer. The degradation of the urothelium leads to chronic pain and urinary dysfunction. The aetiology of the degradation of the GAG layer in this instance is currently unknown. At a clinical level, GAG replacement therapy using a HA solution is currently utilised as a treatment for IC. However, there is a significant lack of data on the mechanism of action of HA in IC. The current study investigates the mechanistic effect of clinically relevant HA treatment on an in vitro model of IC using urothelial cells, examining cytokine secretion, GAG secretion and trans-epithelial permeability. This study demonstrates that HA can significantly decrease induced cytokine secretion (4–5 fold increase), increase sulphated GAG production (2-fold increase) and without altering tight junction expression, decrease trans-epithelial permeability, suggesting that the HA pathway is a clinical target and potential treatment vector.
Biomacromolecules, Jan 14, 2015
Inflammation plays an important role in symptomatic intervertebral disc degeneration and is assoc... more Inflammation plays an important role in symptomatic intervertebral disc degeneration and is associated with the production of neurotrophins in sensitizing innervation into the disc. The use of high molecular weight (HMw) hyaluronic acid (HA) hydrogels offers a potential therapeutic biomaterial for nucleus pulposus (NP) regeneration as it exerts an anti-inflammatory effect and provides a microenvironment that is more suitable for NP. Therefore, it was hypothesized that crosslinked HMw HA hydrogels modulate the inflammatory receptor of IL-1R1, MyD88 and neurotrophin expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in an in vitro inflammation model of NP. HA crosslinking was optimised using various concentrations of 4-arm PEG-amine by determination of free carboxyl groups of HA and unreacted free amine groups of PEG-amine. The optimally crosslinked HA hydrogels were characterised for hydrolytic stability, enzymatic degradation and cytotoxicity on NP ...
Acta biomaterialia, Jan 26, 2015
Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications ... more Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications in wound healing, drug delivery, vascular repair and cell and/or gene delivery. Interstitial cystitis (IC) is characterised by an increase in the permeability of the bladder wall urothelium due to loss of the glycosaminoglycan (GAG) layer. The degradation of the urothelium leads to chronic pain and urinary dysfunction. The aetiology of the degradation of the GAG layer in this instance is currently unknown. At a clinical level, GAG replacement therapy using a HA solution is currently utilised as a treatment for IC. However, there is a significant lack of data on the mechanism of action of HA in IC. The current study investigates the mechanistic effect of clinically relevant HA treatment on an in vitro model of IC using urothelial cells, examining cytokine secretion, GAG secretion and trans-epithelial permeability. This study demonstrates that HA can significantly decrease induced cytokine...
Arthritis & Rheumatism, 2012
To elucidate histamine receptormediated signaling pathways, transcriptional events, and target ge... more To elucidate histamine receptormediated signaling pathways, transcriptional events, and target gene expression in human cartilage.
Arthritis & Rheumatology, 2015
Giant cell arteritis (GCA) is pathologically characterised by dysfunctional angiogenesis and infl... more Giant cell arteritis (GCA) is pathologically characterised by dysfunctional angiogenesis and inflammatory cell infiltration. Acute serum amyloid-A (A-SAA) is an acute phase reactant, but is also produced at sites of inflammation and may contribute to vascular inflammation in atherosclerosis. This study examines the effect of A-SAA on pro-inflammatory pathways and angiogenesis in GCA, using a novel ex-vivo Temporal Artery (TA) tissue explant model. Serum A-SAA levels were measured by ELISA. TA explants and peripheral blood mononuclear cell (PBMCs) cultures were established. TA explant morphology, viability and spontaneous release of pro-inflammatory mediators following 24 hour culture was assessed by H&E, calcein viability staining and ELISA. TA explants and PBMC cultures were stimulated with A-SAA (10ug/ml) and IL-6, IL-8, VEGF, Ang2 and MMP2/9 quantified by ELISA and gelatin zymography. The effect of conditioned media from TA explants on angiogenesis was assessed using endothelial cell matrigel tube-formation assays. TA explants were also embedded in matrigel and myofibroblast outgrowth assessed. Serum A-SAA levels were significantly higher in GCA patients vs healthy controls (p<0.001). Intact tissue morphology, cell viability and spontaneous cytokine secretion was demonstrated in TA explants. A-SAA significantly induced IL-6 and IL-8 from TA explants (p<0.05) and PBMCs (p<0.05). Conditioned media from A-SAA treated explants significantly induced angiogenic tube formation (p<0.05). Finally, A-SAA induced myofibroblast outgrowth and MMP9 activation. This study demonstrates a functional role for A-SAA in regulating temporal artery inflammation, angiogenesis and invasion; all key processes in the pathogenesis of GCA. This article is protected by copyright. All rights reserved.
Experimental Dermatology, 2014
Notch receptor-ligand interactions are critical for cell proliferation, differentiation and survi... more Notch receptor-ligand interactions are critical for cell proliferation, differentiation and survival; however, the role of Notch signalling in psoriasis remains to be elucidated. Serum amyloid A (A-SAA) is an acute-phase protein with cytokine-like properties, regulates cell survival pathways and is implicated in many inflammatory conditions. To examine the role of Notch-1 signalling in the pathogenesis of psoriasis, Notch-1, DLL-4, Jagged-1, Hrt-1/Hrt-2, A-SAA, Factor VIII and vascular endothelial growth factor (VEGF) mRNA and/or protein expression in psoriasis skin biopsies, serum and dHMVEC were assessed by immunohistology, dual-immunofluorescence, real-time PCR, ELISA and Western blotting. A-SAA-induced angiogenesis and invasion in the presence of Notch-1 siRNA was assessed by matrigel tube formation assays and Transwell invasion assay. Increased Notch-1, its ligand DLL-4 and Hrt-1 expression were demonstrated in lesional skin compared with non-lesional skin, with greatest expression observed in the dermal vasculature (P < 0.05). Dual-immunofluorescent staining demonstrated co-localization of Notch-1 to endothelial cell marker Factor VIII. A significant increase in A-SAA levels was demonstrated in psoriasis serum compared with healthy control serum (P < 0.05), and A-SAA expression was higher in lesional skin compared with non-lesional. In dHMVEC, A-SAA significantly induced Jagged-1, Hrt-1 and VEGF mRNA expression (P < 0.05) and activated Notch-1 IC indicative of transcriptional regulation. In contrast, A-SAA significantly inhibited DLL-4 mRNA expression (P < 0.05). Finally A-SAA-induced angiogenesis and invasion were inhibited by Notch-1 siRNA…
Arthritis & Rheumatology, 2015
Giant cell arteritis (GCA) is pathologically characterised by dysfunctional angiogenesis and infl... more Giant cell arteritis (GCA) is pathologically characterised by dysfunctional angiogenesis and inflammatory cell infiltration. Acute serum amyloid-A (A-SAA) is an acute phase reactant, but is also produced at sites of inflammation and may contribute to vascular inflammation in atherosclerosis. This study examines the effect of A-SAA on pro-inflammatory pathways and angiogenesis in GCA, using a novel ex-vivo Temporal Artery (TA) tissue explant model. Serum A-SAA levels were measured by ELISA. TA explants and peripheral blood mononuclear cell (PBMCs) cultures were established. TA explant morphology, viability and spontaneous release of pro-inflammatory mediators following 24 hour culture was assessed by H&E, calcein viability staining and ELISA. TA explants and PBMC cultures were stimulated with A-SAA (10ug/ml) and IL-6, IL-8, VEGF, Ang2 and MMP2/9 quantified by ELISA and gelatin zymography. The effect of conditioned media from TA explants on angiogenesis was assessed using endothelial cell matrigel tube-formation assays. TA explants were also embedded in matrigel and myofibroblast outgrowth assessed. Serum A-SAA levels were significantly higher in GCA patients vs healthy controls (p<0.001). Intact tissue morphology, cell viability and spontaneous cytokine secretion was demonstrated in TA explants. A-SAA significantly induced IL-6 and IL-8 from TA explants (p<0.05) and PBMCs (p<0.05). Conditioned media from A-SAA treated explants significantly induced angiogenic tube formation (p<0.05). Finally, A-SAA induced myofibroblast outgrowth and MMP9 activation. This study demonstrates a functional role for A-SAA in regulating temporal artery inflammation, angiogenesis and invasion; all key processes in the pathogenesis of GCA. This article is protected by copyright. All rights reserved.
Acta biomaterialia, Jan 26, 2015
Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications ... more Hyaluronic acid (HA) has received a lot of attention recently as a biomaterial with applications in wound healing, drug delivery, vascular repair and cell and/or gene delivery. Interstitial cystitis (IC) is characterised by an increase in the permeability of the bladder wall urothelium due to loss of the glycosaminoglycan (GAG) layer. The degradation of the urothelium leads to chronic pain and urinary dysfunction. The aetiology of the degradation of the GAG layer in this instance is currently unknown. At a clinical level, GAG replacement therapy using a HA solution is currently utilised as a treatment for IC. However, there is a significant lack of data on the mechanism of action of HA in IC. The current study investigates the mechanistic effect of clinically relevant HA treatment on an in vitro model of IC using urothelial cells, examining cytokine secretion, GAG secretion and trans-epithelial permeability. This study demonstrates that HA can significantly decrease induced cytokine...
The complex pathophysiology of chronic ulceration in diabetic patients is poorly understood; diab... more The complex pathophysiology of chronic ulceration in diabetic patients is poorly understood; diabetesrelated lower limb amputation is a major health issue, which has limited effective treatment regimes in the clinic. This study attempted to understand the complex pathology of hyperglycemic wound healing by showing profound changes in gene expression profiles in wounded human keratinocytes in hyperglycemic conditions compared to normal glucose conditions. In the hyper-secretory wound microenvironment of hyperglycemia, Rab18, a secretory control molecule, was found to be significantly downregulated. Using a biomaterial platform for dual therapy targeting the two distinct pathways, this study aimed to resolve the major dysregulated pathways in hyperglycemic wound healing. To complement Rab18, and promote angiogenesis eNOS was also targeted, and this novel Rab18-eNOS therapy via a dynamically controlled 'fibrin-in-fibrin' delivery system, demonstrated enhanced wound closure, by increasing functional angiogenesis and reducing inflammation, in an alloxan-induced hyperglycemic preclinical ear ulcer model of compromised wound healing.
Biomacromolecules, Jan 14, 2015
Inflammation plays an important role in symptomatic intervertebral disc degeneration and is assoc... more Inflammation plays an important role in symptomatic intervertebral disc degeneration and is associated with the production of neurotrophins in sensitizing innervation into the disc. The use of high molecular weight (HMw) hyaluronic acid (HA) hydrogels offers a potential therapeutic biomaterial for nucleus pulposus (NP) regeneration as it exerts an anti-inflammatory effect and provides a microenvironment that is more suitable for NP. Therefore, it was hypothesized that crosslinked HMw HA hydrogels modulate the inflammatory receptor of IL-1R1, MyD88 and neurotrophin expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in an in vitro inflammation model of NP. HA crosslinking was optimised using various concentrations of 4-arm PEG-amine by determination of free carboxyl groups of HA and unreacted free amine groups of PEG-amine. The optimally crosslinked HA hydrogels were characterised for hydrolytic stability, enzymatic degradation and cytotoxicity on NP ...
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Papers by Peadar R Rooney