1
|
Elliott J, Bailey SR. A review of cellular and molecular mechanisms in endocrinopathic, sepsis-related and supporting limb equine laminitis. Equine Vet J 2023; 55:350-375. [PMID: 36847165 DOI: 10.1111/evj.13933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 02/23/2023] [Indexed: 03/01/2023]
Abstract
Equine laminitis has both fascinated and frustrated veterinary researchers and clinicians for many years. The recognition that many ponies suffering from pasture-associated laminitis have an insulin-dysregulated phenotype (endocrinopathic laminitis, EL) and that prolonged insulin and glucose infusions can experimentally induce laminar pathology and functional failure are seminal discoveries in this field. Researchers have studied the molecular basis for disease pathogenesis in models of EL, sepsis-related laminitis and supporting limb laminitis and generated much data over the last 15 years. This review attempts to synthesise those data, drawing comparisons between models and naturally occurring laminitis. A hypothesis is proposed that the basal epithelial cell stress is a central event in each category of laminitis. Furthermore, in naturally occurring pasture-associated laminitis, pathways that predominate in each type of laminitis contribute to laminar lamellar pathology to varying extents. Based on the molecular mechanisms determined in experimental models, interactions between these pathways are identified.
Collapse
Affiliation(s)
- Jonathan Elliott
- Department of Comparative Biomedical Sciences, The Royal Veterinary College University of London, London, UK
| | - Simon R Bailey
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
2
|
Galantino-Homer H, Brooks SA. Genetics and Signaling Pathways of Laminitis. Vet Clin North Am Equine Pract 2020; 36:379-394. [PMID: 32654786 DOI: 10.1016/j.cveq.2020.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Laminitis is a devastating disease with diverse etiologies and few, if any, effective treatments. Gene expression and hypothesis-generating genomic studies have provided a fresh look at the key molecular players at crucial timepoints in diverse experimental and naturally affected tissues. We summarize findings to date, and propose a unifying model of the laminitis disease process that includes several pathogenesis concepts shared with other diseases of epidermal and epithelial tissues. The value of these new pathways as potential therapeutic targets is exciting but will require careful future work to validate new methods and launch systematic clinical trials.
Collapse
Affiliation(s)
- Hannah Galantino-Homer
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, USA
| | - Samantha A Brooks
- Department of Animal Sciences, UF Genetics Institute, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
3
|
Yaqoob A, Ali Shahid A, Salisu IB, Shakoor S, Usmaan M, Shad M, Rao AQ. Comparative analysis of Constitutive and fiber-specific promoters under the expression pattern of Expansin gene in transgenic Cotton. PLoS One 2020; 15:e0230519. [PMID: 32187234 PMCID: PMC7080281 DOI: 10.1371/journal.pone.0230519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/02/2020] [Indexed: 11/18/2022] Open
Abstract
Promoters are specified segments of DNA that lead to the initiation of transcription of a specific gene. The designing of a gene cassette for plant transformation is significantly dependent upon the specificity of a promoter. Constitutive Cauliflower mosaic virus promoter, CaMV35S, due to its developmental role, is the most commonly used promoter in plant transformation. While Gossypium hirsutum (Gh) being fiber-specific promoter (GhSCFP) specifically activates transcription in seed coat and fiber associated genes. The Expansin genes are renowned for their versatile roles in plant growth. The overexpression of Expansin genes has been reported to enhance fiber length and fineness. Thus, in this study, a local Cotton variety was transformed with Expansin (CpEXPA1) gene, in the form of two separate cassettes, each with a different promoter, named as 35SEXPA1 and FSEXPA1 expressed under CaMV35S and GhSCFP promoters respectively. Integration and Spatiotemporal relative expression of the transgene were studied in an advanced generation. GhSCFP bearing transgene expression was significantly higher in Cotton fiber than other plant parts. While transgene with CaMV35S promoter was found to be continually expressing in all tissues but the expression was lower in fiber than that expressed under GhSCFP. The temporal expression profile was quite interesting with a gradual increasing pattern of both constructs from 1DPA (days post anthesis) to 18DPA and decreased expression from 24 to 30 DPA. Besides the relative expression of promoters, fiber cellulose quantification and fluorescence intensity were also observed. The study significantly compared the two most commonly used promoters and it is deduced from the results that the GhSCFP promoter could be used more efficiently in fiber when compared with CaMV35S which being constitutive in nature preferred for expression in all parts of the plant.
Collapse
Affiliation(s)
- Amina Yaqoob
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Ahmad Ali Shahid
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
- * E-mail:
| | - Ibrahim Bala Salisu
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sana Shakoor
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Muhammad Usmaan
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Mohsin Shad
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Abdul Qayyum Rao
- Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| |
Collapse
|
4
|
Holl HM, Gao S, Fei Z, Andrews C, Brooks SA. Generation of a de novo transcriptome from equine lamellar tissue. BMC Genomics 2015; 16:739. [PMID: 26432030 PMCID: PMC4592545 DOI: 10.1186/s12864-015-1948-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 09/22/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Laminitis, the structural failure of interdigitated tissue that suspends the distal skeleton within the hoof capsule, is a devastating disease that is the second leading cause of both lameness and euthanasia in the horse. Current transcriptomic research focuses on the expression of known genes. However, as this tissue is quite unique and equine gene annotation is largely derived from computational predictions, there are likely yet uncharacterized transcripts that may be involved in the etiology of laminitis. In order to create a novel annotation resource, we performed whole transcriptome sequencing of sagittal lamellar sections from one control and two laminitis affected horses. RESULTS Whole transcriptome sequencing of the three samples resulted in 113 million reads. Overall, 88 % of the reads mapped to the equCab2 reference genome, allowing for the identification of 119,430 SNPs. The de novo assembly generated around 75,000 transcripts, of which 36,000 corresponded to known annotations. Annotated transcript models are hosted in a public data repository and thus can be easily accessed or loaded into genome browsers. RT-PCR of 12 selected assemblies confirmed structure and expression in lamellar tissue. CONCLUSIONS Transcriptome sequencing represents a powerful tool to expand on equine annotation and identify novel targets for further laminitis research.
Collapse
Affiliation(s)
- Heather M Holl
- Department of Animal Sciences, University of Florida, Gainesville, FL, 32611, USA.
| | - Shan Gao
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, 14853, USA.
| | - Zhangjun Fei
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, 14853, USA.
| | - Caroline Andrews
- Laboratory of Molecular Immunoregulation, National Cancer Institute, Bethesda, MD, 20892, USA.
| | - Samantha A Brooks
- Department of Animal Sciences, University of Florida, Gainesville, FL, 32611, USA.
| |
Collapse
|
5
|
Leise BS, Watts MR, Roy S, Yilmaz AS, Alder H, Belknap JK. Use of laser capture microdissection for the assessment of equine lamellar basal epithelial cell signalling in the early stages of laminitis. Equine Vet J 2014; 47:478-88. [PMID: 24750316 DOI: 10.1111/evj.12283] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 04/04/2014] [Indexed: 12/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Dysadhesion of laminar basal epithelial cells (LBECs) from the underlying dermis is the central event leading to structural failure in equine laminitis. Although many studies of sepsis-related laminitis have reported multiple events occurring throughout the lamellar tissue, there is minimal information regarding signalling events occurring specifically in LBECs. OBJECTIVES To determine signalling events in the LBECs during the early stages of carbohydrate-induced laminitis. STUDY DESIGN Experimental study. METHODS Eight horses were given an overload of carbohydrate (CHO) consisting of corn starch mixture via nasogastric tube. Prior to administration of CHO, lamellar biopsies were taken from the left forefoot (control [CON]). Biopsies were taken from the left hind foot at the onset of fever (developmental [DEV]) and from the right forefoot at the onset of Obel grade 1 lameness (OG1). Laminar basal epithelial cells were isolated from cryosections using a laser capture microdissection (LCM) microscope. Next generation sequencing (RNA-seq) was used to identify transcripts expressed in the LBECs for each time point and bioinformatic analysis was performed with thresholds for between group comparisons set at a greater than 2-fold change and P value ≤0.05. RESULTS Forty genes (22 increased/18 decreased) were significantly different from DEV time vs. CON and 107 genes (57 increased/50 decreased) were significantly different from OG1 time vs. CON. Significant increases in inflammatory genes were present in addition to significantly altered expression of genes related to extracellular matrix composition, stability and turnover. CONCLUSIONS Signalling related to inflammatory response and extracellular matrix regulation was strongly represented at the DEV and OG1 times. These results indicate that the LBEC is not only a casualty but also an active participant in lamellar events leading to structural failure of the digital lamellae in equine laminitis.
Collapse
Affiliation(s)
- B S Leise
- Department of Clinical Sciences, College of Veterinary and Biomedical Sciences, Colorado State University, Fort Collins, USA
| | - M R Watts
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, USA
| | - S Roy
- Department of Surgery, College of Medicine, Ohio State University, Columbus, USA
| | - A S Yilmaz
- Biomedical Informatics Shared Resource, Ohio State University Comprehensive Cancer Center, Columbus, USA
| | - H Alder
- Biomedical Informatics Shared Resource, Ohio State University Comprehensive Cancer Center, Columbus, USA
| | - J K Belknap
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ohio State University, Columbus, USA
| |
Collapse
|
6
|
Characterization of genes for beef marbling based on applying gene coexpression network. Int J Genomics 2014; 2014:708562. [PMID: 24624372 PMCID: PMC3929194 DOI: 10.1155/2014/708562] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/19/2013] [Accepted: 12/07/2013] [Indexed: 12/29/2022] Open
Abstract
Marbling is an important trait in characterization beef quality and a major factor for determining the price of beef in the Korean beef market. In particular, marbling is a complex trait and needs a system-level approach for identifying candidate genes related to the trait. To find the candidate gene associated with marbling, we used a weighted gene coexpression network analysis from the expression value of bovine genes. Hub genes were identified; they were topologically centered with large degree and BC values in the global network. We performed gene expression analysis to detect candidate genes in M. longissimus with divergent marbling phenotype (marbling scores 2 to 7) using qRT-PCR. The results demonstrate that transmembrane protein 60 (TMEM60) and dihydropyrimidine dehydrogenase (DPYD) are associated with increasing marbling fat. We suggest that the network-based approach in livestock may be an important method for analyzing the complex effects of candidate genes associated with complex traits like marbling or tenderness.
Collapse
|
7
|
Swalve H, Floren C, Wensch-Dorendorf M, Schöpke K, Pijl R, Wimmers K, Brenig B. A study based on records taken at time of hoof trimming reveals a strong association between the IQ motif-containing GTPase-activating protein 1 (IQGAP1) gene and sole hemorrhage in Holstein cattle. J Dairy Sci 2014; 97:507-19. [DOI: 10.3168/jds.2013-6997] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 09/16/2013] [Indexed: 11/19/2022]
|
8
|
de Laat MA, Clement CK, McGowan CM, Sillence MN, Pollitt CC, Lacombe VA. Toll-like receptor and pro-inflammatory cytokine expression during prolonged hyperinsulinaemia in horses: implications for laminitis. Vet Immunol Immunopathol 2013; 157:78-86. [PMID: 24246153 DOI: 10.1016/j.vetimm.2013.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/12/2013] [Accepted: 10/18/2013] [Indexed: 12/31/2022]
Abstract
Equine laminitis, a disease of the lamellar structure of the horse's hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Toll-like receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-inflammatory cytokine production is increased in lamellae and skeletal muscle during equine hyperinsulinaemia. Standardbred horses were treated with either a prolonged, euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged, glucose infusion (p-GI), which induced marked and moderate hyperinsulinaemia, respectively. Age-matched control horses were treated simultaneously with a balanced electrolyte solution. Treated horses developed clinical (p-EHC) or subclinical (p-GI) laminitis, whereas controls did not. Skeletal muscle and lamellar protein extracts were analysed by Western blotting for TLR4, IL-6, TNF-α and suppressor of cytokine signalling 3 (SOCS3) expression. Lamellar protein expression of TLR4 and TNF-α, but not IL-6, was increased by the p-EHC, compared to control horses. A significant positive correlation was found between lamellar TLR4 and SOCS3. Skeletal muscle protein expression of TLR4 signalling parameters did not differ between control and p-EHC-treated horses. Similarly, the p-GI did not result in up-regulation of lamellar protein expression of any parameter. The results suggest that insulin-sensitive tissues may not accurately reflect lamellar pathology during hyperinsulinaemia. While TLR4 is present in the lamellae, its activation appears unlikely to contribute significantly to the developmental pathogenesis of hyperinsulinaemic laminitis. However, inflammation may have a role to play in the later stages (e.g., repair or remodelling) of the disease.
Collapse
Affiliation(s)
- M A de Laat
- Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - C K Clement
- Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - C M McGowan
- Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Neston, CH64 7TE, UK
| | - M N Sillence
- Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, 4001, Australia
| | - C C Pollitt
- Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Gatton, Queensland, 4343, Australia
| | - V A Lacombe
- Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| |
Collapse
|
9
|
Cellular and humoral immunity in chronic equine laminitis. Vet Immunol Immunopathol 2013; 153:217-26. [PMID: 23521925 DOI: 10.1016/j.vetimm.2013.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 12/12/2022]
Abstract
Chronic equine laminitis causes persistent pain and lameness in affected animals and often necessitates euthanasia when pain management strategies become ineffective. Published studies as well as anecdotal reports suggest that this chronic inflammatory disease is associated with systemic alterations in immune responsiveness, perhaps involving an autoimmune component. We investigated this broad hypothesis by measuring a variety of immune indicators in healthy control horses (CON) and horses with chronic laminitis (LMN). We found that white blood cells from LMN horses produced more IFNγ than did cells from CON horses when stimulated in vitro with polyinosinic-polycytidylic acid [poly(I:C)], possibly due to an elevated number of circulating monocytes. No differences between groups were observed in plasma concentrations of IgG, IgA, IgM, IgE, or rheumatoid factor. Laminar tissue from LMN horses expressed elevated levels of keratinocyte damage-related genes as well as inflammatory cytokines and chemokines, which corresponded with a modest amount of neutrophil infiltration as shown by histological staining of fixed tissue and accumulation of neutrophil elastase protein. Taken together, our results do not support the hypothesis of an autoimmune component in chronic laminitis, although the strong induction of neutrophil chemokines and the presence of tissue neutrophils suggests that this cell type is likely involved in perpetuating the inflammation and tissue damage associated with this disease.
Collapse
|
10
|
Tadros EM, Frank N. Effects of continuous or intermittent lipopolysaccharide administration for 48 hours on the systemic inflammatory response in horses. Am J Vet Res 2013; 73:1394-402. [PMID: 22924721 DOI: 10.2460/ajvr.73.9.1394] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether the method of lipopolysaccharide (LPS) administration (intermittent vs continuous) affects the magnitude and duration of the systemic inflammatory response in horses and whether prolonged (48 hours) endotoxemia induces laminitis. ANIMALS 12 healthy adult horses (10 mares and 2 geldings). PROCEDURES Horses were randomly assigned to receive LPS (total dose, 80 μg; n = 4) or saline (0.9% NaCl) solution (80 mL/h; 4) via constant rate infusion or 8 bolus IV injections of LPS (10 μg, q 6 h;4) during a 48-hour period. Physical examinations were performed every 4 hours, inflammatory cytokine gene expression was determined for blood samples obtained every 8 hours, and IV glucose tolerance tests were performed. RESULTS All LPS-treated horses had signs of depression and mild colic; those signs abated as the study progressed. Administration of LPS increased expression of interleukin-1β, interleukin-6, and interleukin-8, but results were not significantly different between LPS treatment groups. Cytokine expression was significantly higher on the first day versus the second day of LPS treatment. Interleukin-1β expression was positively correlated with rectal temperature and expression of other cytokines. Glucose and insulin dynamics for both LPS groups combined did not differ significantly from those of the saline solution group. Signs of laminitis were not detected in any of the horses. CONCLUSIONS AND CLINICAL RELEVANCE Horses developed LPS tolerance within approximately 24 hours after administration was started, and the method of LPS administration did not affect the magnitude or duration of systemic inflammation. Laminitis was not induced in horses.
Collapse
Affiliation(s)
- Elizabeth M Tadros
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA
| | | |
Collapse
|
11
|
Suagee JK, Corl BA, Geor RJ. A Potential Role for Pro-Inflammatory Cytokines in the Development of Insulin Resistance in Horses. Animals (Basel) 2012; 2:243-60. [PMID: 26486919 PMCID: PMC4494330 DOI: 10.3390/ani2020243] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/16/2012] [Accepted: 04/26/2012] [Indexed: 02/07/2023] Open
Abstract
Insulin resistance is a metabolic condition involving reduced sensitivity of insulin-sensitive tissues to insulin-induced glucose disposal, including adipose tissue, skeletal muscle, and liver. Insulin resistance occurs in overweight and obese horses, and may increase risk for the development of laminitis. The development of insulin resistance is thought to occur in response to increased production of pro-inflammatory cytokines by adipose tissue in obesity, that then have an inhibitory effect on insulin signaling pathways in multiple tissues. This article reviews current knowledge of the involvement of pro-inflammatory cytokines in the development of insulin resistance in horses and uses data from other species to provide context. Understanding the mechanisms involved in the development of insulin resistance in horses should enable development of effective treatment and prevention strategies. Current knowledge of these mechanisms is based upon research in obese humans and rodents, in which there is evidence that the increased production of pro-inflammatory cytokines by adipose tissue negatively influences insulin signaling in insulin-responsive tissues. In horses, plasma concentrations of the cytokine, tumor necrosis factor-α, have been positively correlated with body fatness and insulin resistance, leading to the hypothesis that inflammation may reduce insulin sensitivity in horses. However, little evidence has documented a tissue site of production and a direct link between inflammation and induction of insulin resistance has not been established. Several mechanisms are reviewed in this article, including the potential for macrophage infiltration, hyperinsulinemia, hypoxia, and lipopolysaccharide to increase pro-inflammatory cytokine production by adipose tissue of obese horses. Clearly defining the role of cytokines in reduced insulin sensitivity of horses will be a very important step in determining how obesity and insulin resistance are related.
Collapse
Affiliation(s)
- Jessica K Suagee
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24071, USA.
| | - Benjamin A Corl
- Department of Dairy Science, Virginia Tech, Blacksburg, VA 24071, USA.
| | - Raymond J Geor
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
12
|
Faleiros RR, Leise BS, Watts M, Johnson PJ, Black SJ, Belknap JK. Laminar chemokine mRNA concentrations in horses with carbohydrate overload-induced laminitis. Vet Immunol Immunopathol 2011; 144:45-51. [DOI: 10.1016/j.vetimm.2011.07.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/13/2011] [Accepted: 07/08/2011] [Indexed: 01/14/2023]
|
13
|
Visser MB, Pollitt CC. The timeline of lamellar basement membrane changes during equine laminitis development. Equine Vet J 2011; 43:471-7. [PMID: 21496071 DOI: 10.1111/j.2042-3306.2010.00292.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
REASONS FOR PERFORMING STUDY The timing of lamellar basement membrane (BM) changes occurring during laminitis development is incompletely understood. OBJECTIVES To determine the temporal progression of lamellar BM changes and whether laminin-332 (Ln-332) γ2 cleavage products are generated during laminitis development. METHODS Eight clinically normal Standardbred horses were allocated into treatment (n = 5) or sham (n = 3) groups. The treatment group received, via nasogastric intubation, an oligofructose (OF) bolus (10 g/kg bwt) while the sham group was given water. Laminitis induction proceeded for 48 h followed by euthanasia. Lamellar biopsies were obtained prior to dosing and at intervals during the treatment period for analysis (at 12, 18, 24, 30 and 36 h and at 48 h following euthanasia). RESULTS Changes in lamellar collagen type IV and Ln-332 were first observed at 12 h post dosing. A unique pattern of reactivity for the Ln-332 γ2 antibody D4B5 occurred, in which reactivity was observed only in lamellar tissue affected by laminitis. No bioactive Ln-332 γ2 proteolytic fragments were detected in lamellar samples. CONCLUSIONS Basement membrane changes occurred early during the laminitis process. Direct Ln-332 γ2 cleavage to release biologically active products did not appear to occur. Thus loss of stability or protein interaction of the BM is probably responsible for the γ2 specific reactivity observed. POTENTIAL RELEVANCE Basement membrane changes may a first step in lamellar failure occurring prior to detection with conventional methods. Thus, more sensitive detection methods of BM changes are required to study laminitis development.
Collapse
Affiliation(s)
- M B Visser
- The Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, St Lucia, Australia
| | | |
Collapse
|
14
|
Visser MB, Pollitt CC. The timeline of metalloprotease events during oligofructose induced equine laminitis development. Equine Vet J 2011; 44:88-93. [PMID: 21696433 DOI: 10.1111/j.2042-3306.2011.00393.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
REASON FOR PERFORMING STUDY The role of matrix metalloproteases (MMPs) and the timeline of proteolysis during laminitis development are incompletely understood. OBJECTIVES To determine the temporal progression of selected MMPs and protease regulators during laminitis development. METHODS Five clinically normal Standardbred horses received, via nasogastric intubation, an oligofructose (OF) bolus (10 g/kg bwt). Laminitis induction proceeded for 48 h followed by euthanasia. Lamellar biopsies were obtained prior to dosing and at intervals during the treatment period for analysis (12, 18, 24, 30 and 36 h and at 48 h following euthanasia). Tissue samples were analysed by real-time PCR, zymography and western blotting. RESULTS Activation of proMMP-2 occurs either simultaneously or at least 12 h following lamellar basement membrane (BM) damage, while no activation of proMMP-9 is seen during OF laminitis induction. Aggrecanase gene expression increased initially at 12-18 h post OF dosing, similar to BM changes. Gene expression of TIMP-2, a MMP regulator, decreases during laminitis development. CONCLUSIONS The MMP-2/MT1-MMP complex may not play a major role in initiating lamellar BM damage. Aggrecanase and TIMP-2 gene expression appear related to BM lamellar changes. POTENTIAL RELEVANCE MMPs, historically thought to cause laminitis, do not appear to play an initiating role in the lamellar lesion. Other host derived proteases and degradation of alternative lamellar matrix components need to be considered.
Collapse
Affiliation(s)
- M B Visser
- The Australian Equine Laminitis Research Unit, School of Veterinary Science, The University of Queensland, Australia.
| | | |
Collapse
|
15
|
Suagee JK, Corl BA, Crisman MV, Hulver MW, McCutcheon LJ, Geor RJ. Effects of acute hyperinsulinemia on inflammatory proteins in horses. Vet Immunol Immunopathol 2011; 142:141-6. [PMID: 21621276 DOI: 10.1016/j.vetimm.2011.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/05/2011] [Accepted: 05/02/2011] [Indexed: 01/28/2023]
Abstract
Laminitis is a painful, inflammatory disease of the equine hoof that often results in euthanasia. Elevated plasma insulin concentrations are a predictive factor for laminitis, and in previously healthy horses and ponies, laminitis was induced by infusion of insulin. Thus, we chose to determine if an infusion of insulin would increase plasma concentrations of inflammatory cytokines and cytokine mRNA abundance in subcutaneous adipose tissue, skeletal muscle, and white blood cells. Ten mature Thoroughbred mares received an insulin infusion that elevated plasma insulin concentrations for 6h or an equivalent volume of isotonic saline in a switchback design. Insulin infusion altered plasma concentrations of both TNF (P=0.037) and IL-6 (P=0.044), but did not result in consistent changes to either skeletal muscle or adipose tissue cytokine mRNA. Insulin may be involved in the production of inflammatory cytokines, and this could be a mechanism for insulin increasing the risk of laminitis.
Collapse
Affiliation(s)
- Jessica K Suagee
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061-0306, USA
| | | | | | | | | | | |
Collapse
|
16
|
Burns TA, Westerman T, Nuovo GJ, Watts MR, Pettigrew A, Yin C, Belknap JK. Role of oxidative tissue injury in the pathophysiology of experimentally induced equine laminitis: a comparison of 2 models. J Vet Intern Med 2011; 25:540-8. [PMID: 21418321 DOI: 10.1111/j.1939-1676.2011.0706.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Oxidative stress reportedly plays a role in sepsis-induced organ dysfunction and failure in many species. In septic horses, laminae are targeted; evidence of laminar oxidative stress has been reported experimentally in the black walnut extract (BWE) model. Carbohydrate (CHO)-induced laminitis may be more similar to clinical sepsis-related laminitis than the BWE model in that animals with CHO-induced disease commonly develop laminar failure. The role of oxidative stress in the CHO model remains unknown. HYPOTHESIS/OBJECTIVES Markers of oxidative stress will be increased in laminae from horses with BWE- and CHO-induced laminitis. ANIMALS Banked laminar tissue from various time points from animals subjected to BWE (n = 15) and CHO (n = 20) protocols. METHODS Laminar 4-hydroxynonenal (4-HNE) and protein carbonyl content were evaluated by slot blot analysis. Laminar 3-nitrotyrosine (3-NT) immunohistochemistry was performed. RESULTS The number of laminar 3-NT (+) cells was increased at developmental and Obel grade 1 (OG1) time points in the BWE model (versus control [CON]; P= .013) and lower in OG1 tissues than CON in the CHO model (P = .04). No change in 4-HNE content was observed in the CHO model, and no increase in laminar protein carbonyl content was present in either model (P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE These results do not support a prominent role for oxidative stress at examined time points in CHO-overload laminitis and support transient oxidative stress in the BWE model. Tissue oxidation does not appear to be a central early pathophysiologic event in CHO-associated laminitis.
Collapse
Affiliation(s)
- T A Burns
- Ohio State University College of Veterinary Medicine, Columbus, OH 43210, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Vascular dysfunction and inflammation in laminitis: Modifying blood flow through the equine digit. Vet J 2010; 186:8-9. [DOI: 10.1016/j.tvjl.2009.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 10/17/2009] [Indexed: 11/20/2022]
|
18
|
Abstract
In acute laminitis, the suspensory apparatus of the distal phalanx fails at the lamellar dermal/epidermal interface. A grading system for the histopathology of laminitis is based on the consistent pattern of histologic changes to the secondary epidermal lamellae, basal cells, and basement membrane that occur as carbohydrate-induced laminitis develops. The actual trigger factors of carbohydrate-induced laminitis remain unidentified.
Collapse
Affiliation(s)
- Christopher C Pollitt
- School of Veterinary Science, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
| | | |
Collapse
|
19
|
Johnson PJ, Wiedmeyer CE, LaCarrubba A, Ganjam VKS, Messer NT. Laminitis and the equine metabolic syndrome. Vet Clin North Am Equine Pract 2010; 26:239-55. [PMID: 20699172 DOI: 10.1016/j.cveq.2010.04.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although much has been written about laminitis in the context of its association with inflammatory processes, recognition is growing that most cases of laminitis examined by veterinarians in private practice are those associated with pasture grazing, obesity, and insulin resistance (IR). The term 'endocrinopathic laminitis' has been adopted to classify the instances of laminitis in which the origin seems to be more strongly associated with an underlying endocrinopathy, such as either IR or the influence of corticosteroids. Results of a recent study suggest that obesity and IR represent the most common metabolic and endocrinopathic predispositions for laminitis in horses. IR also plays an important role in the pathogenesis of laminitis that develops when some horses or ponies are allowed to graze pastures at certain times of the year. The term equine metabolic syndrome (EMS) has been proposed as a label for horses whose clinical examination results (including both physical examination and laboratory testing) suggest heightened risk for developing laminitis as a result of underlying IR.
Collapse
Affiliation(s)
- Philip J Johnson
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, 900 East Campus Drive, Columbia, MO 65211, USA.
| | | | | | | | | |
Collapse
|
20
|
|