1
|
Oluoch GO, Stienstra Y, Schurer JM, Mijumbi R, Mbonigaba JB, Thomas B, Padidar S, Amuasi J, Lalloo DG. Correspondence: The African snakebite Alliance. Toxicon 2024; 237:107535. [PMID: 38040061 DOI: 10.1016/j.toxicon.2023.107535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/07/2023] [Accepted: 11/21/2023] [Indexed: 12/03/2023]
Abstract
The goal to reduce the burden of snakebite envenoming is challenged by the gaps in evidence for clinical care and public health. These evidence gaps and the absence of a strong network are illustrated by bibliometrics. The African Snakebite Alliance is a multidisciplinary group focusing on research themes which will generate evidence needed to shape policy and practice.
Collapse
Affiliation(s)
- George O Oluoch
- Kenya Snakebite Research & Intervention Centre, Kenya Institute of Primate Research, Ministry of Health, Karen, Nairobi, Kenya; Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Ymkje Stienstra
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; University of Groningen, Department of Internal Medicine/Infectious Diseases, University Medical Centre Groningen, Groningen, the Netherlands.
| | - Janna M Schurer
- Center for One Health, University of Global Health Equity, Butaro, Rwanda
| | - Rhona Mijumbi
- Malawi Liverpool Wellcome Research Programme, Queen Elizabeth Central Hospital, Blantyre Malawi; The Center for Rapid Evidence Synthesis, Makerere University, Kampala, Uganda
| | - Jean Bosco Mbonigaba
- Rwanda Neglected Tropical Diseases Programme, Rwanda Biomedical Centre, Ministry of Health Kigali, Rwanda
| | - Brent Thomas
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sara Padidar
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini, Swaziland; Eswatini Antivenom Foundation, Simunye, Eswatini, Swaziland; Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini, Swaziland
| | - John Amuasi
- Department of Global Health, School of Public Health & Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Bernhard Nocht Institute of Tropical Medicine, Hamburg, Germany
| | - David G Lalloo
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| |
Collapse
|
2
|
Stienstra Y, Aglanu LM, Schurer JM, Mijumbi R, Mbonigaba JB, Habib AG, Thomas B, Steinhorst J, Thomson R, Padidar S, Amuasi JH, Oluoch GO, Lalloo DG. Stakeholder perspectives from 15 countries in Africa on barriers in snakebite envenoming research and the potential role of research hubs. PLoS Negl Trop Dis 2023; 17:e0011838. [PMID: 38091347 PMCID: PMC10752511 DOI: 10.1371/journal.pntd.0011838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 12/27/2023] [Accepted: 12/04/2023] [Indexed: 12/28/2023] Open
Abstract
Snakebite envenoming is a debilitating neglected tropical disease disproportionately affecting the rural poor in low and middle-income countries in the tropics and sub-tropics. Critical questions and gaps in public health and policy need to be addressed if major progress is to be made towards reducing the negative impact of snakebite, particularly in the World Health Organisation (WHO) Africa region. We engaged key stakeholders to identify barriers to evidence-based snakebite decision making and to explore how development of research and policy hubs could help to overcome these barriers. We conducted an electronic survey among 73 stakeholders from ministries of health, health facilities, academia and non-governmental organizations from 15 countries in the WHO Africa region. The primary barriers to snakebite research and subsequent policy translation were limited funds, lack of relevant data, and lack of interest from policy makers. Adequate funding commitment, strong political will, building expert networks and a demand for scientific evidence were all considered potential factors that could facilitate snakebite research. Participants rated availability of antivenoms, research skills training and disease surveillance as key research priorities. All participants indicated interest in the development of research and policy hubs and 78% indicated their organization would be willing to actively participate. In conclusion, our survey affirms that relevant stakeholders in the field of snakebite perceive research and policy hubs as a promising development, which could help overcome the barriers to pursuing the WHO goals and targets for reducing the burden of snakebite.
Collapse
Affiliation(s)
- Ymkje Stienstra
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- University of Groningen, Department of Internal Medicine/Infectious Diseases, University Medical Centre Groningen, Groningen, The Netherlands
| | - Leslie Mawuli Aglanu
- University of Groningen, Department of Internal Medicine/Infectious Diseases, University Medical Centre Groningen, Groningen, The Netherlands
- Global Health and Infectious Diseases Research Group, Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana
- Bernhard Nocht Institute of Tropical Medicine, Hamburg, Germany
| | - Janna M. Schurer
- Center for One Health, University of Global Health Equity, Butaro, Rwanda
- Department of Global Health and Infectious Disease, Cummings School of Veterinary Medicine, North Grafton, United States of America
| | - Rhona Mijumbi
- Malawi-Liverpool-Wellcome Programme, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jean Bosco Mbonigaba
- Rwanda Neglected Tropical Diseases Programme, Rwanda Biomedical Centre, Ministry of Health Kigali, Rwanda
| | | | - Brent Thomas
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jonathan Steinhorst
- University of Groningen, Department of Internal Medicine/Infectious Diseases, University Medical Centre Groningen, Groningen, The Netherlands
| | - Rachael Thomson
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Sara Padidar
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
| | - John H. Amuasi
- Global Health and Infectious Diseases Research Group, Kumasi Centre for Collaborative Research in Tropical Medicine, Kumasi, Ghana
- Bernhard Nocht Institute of Tropical Medicine, Hamburg, Germany
- Department of Global Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - George O. Oluoch
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Kenya Snakebite Research & Intervention Centre, Kenya Institute of Primate Research, Ministry of Health, Karen, Nairobi, Kenya
| | - David G. Lalloo
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| |
Collapse
|
3
|
Padidar S, Monadjem A, Litschka-Koen T, Thomas B, Shongwe N, Baker C, Mmema L, Sithole T, Murray J, Casewell NR, Pons J, Lalloo DG, Harrison RA, Stienstra Y, Dlamini WM. Snakebite epidemiology, outcomes and multi-cluster risk modelling in Eswatini. PLoS Negl Trop Dis 2023; 17:e0011732. [PMID: 37948462 PMCID: PMC10664941 DOI: 10.1371/journal.pntd.0011732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 11/22/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Halving snakebite morbidity and mortality by 2030 requires countries to develop both prevention and treatment strategies. The paucity of data on the global incidence and severity of snakebite envenoming causes challenges in prioritizing and mobilising resources for snakebite prevention and treatment. In line with the World Health Organisation's 2019 Snakebite Strategy, this study sought to investigate Eswatini's snakebite epidemiology and outcomes, and identify the socio-geographical factors associated with snakebite risk. METHODOLOGY Programmatic data from the Ministry of Health, Government of Eswatini 2019-2021, was used to assess the epidemiology and outcomes of snakebite in Eswatini. We developed a snake species richness map from the occurrence data of all venomous snakes of medical importance in Eswatini that was subjected to niche modelling. We formulated four risk indices using snake species richness, various geospatial datasets and reported snakebites. A multivariate cluster modelling approach using these indices was developed to estimate risk of snakebite and the outcomes of snakebite in Eswatini. PRINCIPAL FINDINGS An average of 466 snakebites was recorded annually in Eswatini. Bites were recorded across the entire country and peaked in the evening during summer months. Two cluster risk maps indicated areas of the country with a high probability of snakebite and a high probability of poor snakebite outcomes. The areas with the highest rate of snakebite risk were primarily in the rural and agricultural regions of the country. SIGNIFICANCE These models can be used to inform better snakebite prevention and treatment measures to enable Eswatini to meet the global goal of reducing snakebite morbidity and mortality by 50% by 2030. The supply chain challenges of antivenom affecting southern Africa and the high rates of snakebite identified in our study highlight the need for improved snakebite prevention and treatment tools that can be employed by health care workers stationed at rural, community clinics.
Collapse
Affiliation(s)
- Sara Padidar
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | - Ara Monadjem
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
- Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Hatfield, Pretoria, South Africa
| | - Thea Litschka-Koen
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | - Brent Thomas
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nondusimo Shongwe
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | - Clare Baker
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lindelwa Mmema
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | | | - James Murray
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | - Nicholas R. Casewell
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jonathan Pons
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
| | - David G. Lalloo
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Robert A. Harrison
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Ymkje Stienstra
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- University of Groningen, University Medical Center Groningen, Department of Internal Medicine/Infectious Diseases, Groningen, The Netherlands
| | - Wisdom M. Dlamini
- Department of Geography, Environmental Science and Planning, University of Eswatini, Kwaluseni, Eswatini
| |
Collapse
|
4
|
Menzies SK, Litschka-Koen T, Edge RJ, Alsolaiss J, Crittenden E, Hall SR, Westhorpe A, Thomas B, Murray J, Shongwe N, Padidar S, Lalloo DG, Casewell NR, Pons J, Harrison RA. Two snakebite antivenoms have potential to reduce Eswatini’s dependency upon a single, increasingly unavailable product: Results of preclinical efficacy testing. PLoS Negl Trop Dis 2022; 16:e0010496. [PMID: 36108067 PMCID: PMC9529146 DOI: 10.1371/journal.pntd.0010496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 10/03/2022] [Accepted: 08/15/2022] [Indexed: 11/24/2022] Open
Abstract
Background Snakebite is a major public health concern in Eswatini, where treatment relies upon one antivenom—SAIMR Polyvalent. Although effective in treating snakebite, SAIMR Polyvalent is difficult to source outside its manufacturing country (South Africa) and is dauntingly expensive. We compared the preclinical venom-neutralising efficacy of two alternative antivenoms with that of SAIMR Polyvalent against the lethal and tissue-destructive effects of venoms from five species of medically important snakes using in vivo murine assays. The test antivenoms were ‘Panafrican’ manufactured by Instituto Clodomiro Picado and ‘PANAF’ manufactured by Premium Serums & Vaccines. Principal findings In vivo murine preclinical studies identified both test antivenoms were equally or more effective than SAIMR Polyvalent at neutralising lethal and tissue-destructive effects of Naja mossambica venom. Both test antivenoms were less effective than SAIMR Polyvalent at neutralising the lethal effects of Bitis arietans, Dendroaspis polylepis, Hemachatus haemachatus and Naja annulifera venoms, but similarly effective at neutralising tissue damage induced by B. arietans and H. haemachatus venoms. In vitro immunological assays identified that the titres and toxin-specificities of immunoglobulins (iGs) in the test antivenoms were comparable to that of SAIMR Polyvalent. Plasma clotting disturbances by H. haemachatus and N. mossambica were neutralised by the test antivenoms, whereas SAIMR Polyvalent failed to neutralise this bioactivity of N. mossambica venom. B. arietans SVMP activity was equally reduced by all three antivenoms, and H. haemachatus and N. mossambica PLA2 activities were neutralised by all three antivenoms. Conclusions While both Panafrican and PANAF antivenoms exhibited promising preclinical efficacies, both were less poly-specifically effective than SAIMR Polyvalent in these murine assays. The efficacy of these antivenoms against the lethal and tissue-destructive effects of N. mossambica venom, the most common biting species in Eswatini, identify that Panafrican and PANAF antivenoms offer effective alternatives to SAIMR Polyvalent for the treatment of snakebite in Eswatini, and potentially for neighbouring countries. Treatment of snakebite in Eswatini is reliant upon a single antivenom (SAIMR Polyvalent) manufactured in South Africa. This highly effective product is increasingly difficult to source and is expensive—alternative/additional antivenoms are urgently required to improve patient outcomes following snake envenoming. Using murine preclinical venom toxicity and antivenom efficacy assays, we identified two alternative antivenoms whose venom-neutralising characteristics, while less poly-specifically effective than SAIMR Polyvalent, were as effective against the lethal and tissue-destructive effects of the most common biting snake in Eswatini—Naja mossambica. These murine data, already shared and discussed with the Eswatini Ministry of Health and the World Health Organisation, supports and justifies human testing of these two antivenoms in Eswatini because increasing the availability of effective and affordable treatments could resolve the current medical dependency of Eswatini snakebite patients upon a single, rarely available and expensive product.
Collapse
Affiliation(s)
- Stefanie K. Menzies
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - Thea Litschka-Koen
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
| | - Rebecca J. Edge
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jaffer Alsolaiss
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Edouard Crittenden
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Steven R. Hall
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Adam Westhorpe
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Brent Thomas
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - James Murray
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
| | - Nondusimo Shongwe
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
| | - Sara Padidar
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
- Department of Biological Sciences, University of Eswatini, Kwaluseni, Eswatini
| | - David G. Lalloo
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nicholas R. Casewell
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Jonathan Pons
- Eswatini Snakebite Research and Intervention Centre, Simunye, Eswatini
- Eswatini Antivenom Foundation, Simunye, Eswatini
| | - Robert A. Harrison
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| |
Collapse
|
5
|
Malinzi J, Basita KB, Padidar S, Adeola HA. Prospect for application of mathematical models in combination cancer treatments. Informatics in Medicine Unlocked 2021. [DOI: 10.1016/j.imu.2021.100534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
|
6
|
Padidar S, Farquharson AJ, Williams LM, Kearney R, Arthur JR, Drew JE. High-fat diet alters gene expression in the liver and colon: links to increased development of aberrant crypt foci. Dig Dis Sci 2012; 57:1866-74. [PMID: 22373862 DOI: 10.1007/s10620-012-2092-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/07/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND Obesity is associated with an increased risk of colon cancer. High-fat diets that lead to obesity may be a contributing factor, but the mechanisms are unknown. AIMS This study examines susceptibility to azoxymethane (AOM)-induced precancerous lesions in mice in response to consumption of either a low or a high-fat diet and associated molecular changes in the liver and colon. METHODS Gene markers of xenobiotic metabolism, leptin-regulated inflammatory cytokines and proliferation were assessed in liver and colon in response to high-fat feeding to determine links with increased sensitivity to AOM. RESULTS High-fat feeding increased development of AOM-induced precancerous lesions and was associated with increased CYP2E1 gene expression in the liver, but not the colon. Leptin receptors and the colon stem cell marker (Lgr5) were down-regulated in the proximal colon, with a corresponding up-regulation of the inflammatory cytokine (IL6) in response to high-fat feeding. Notably in the distal colon, where aberrant crypt foci develop in response to AOM, the proliferative stem cell marker, Lgr5, was significantly up-regulated with high-fat feeding. CONCLUSIONS The current study provides evidence that high-fat diets can alter regulation of molecular markers of xenobiotic metabolism that may expose the colon to carcinogens, in parallel with activation of β-catenin-regulated targets regulating colon epithelial cells. High-fat diets associated with obesity may alter multiple molecular factors that act synergistically to increase the risk of colon cancer associated with obesity.
Collapse
Affiliation(s)
- Sara Padidar
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, Scotland, UK
| | | | | | | | | | | |
Collapse
|
7
|
Padidar S, Farquharson AJ, Williams LM, Kelaiditi E, Hoggard N, Arthur JR, Drew JE. Leptin up-regulates pro-inflammatory cytokines in discrete cells within mouse colon. J Cell Physiol 2011; 226:2123-30. [PMID: 21520064 DOI: 10.1002/jcp.22546] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dysregulation of leptin associated with obesity is implicated in obesity-related colon cancer, but mechanisms are elusive. Increased adiposity and elevated plasma leptin are associated with perturbed metabolism in colon and leptin receptors are expressed on colon epithelium. We hypothesise that obesity increases the sensitivity of the colon to cancer by disrupting leptin-regulated gene targets within colon tissues. PCR arrays were used to firstly identify leptin responsive genes and secondly to identify responses to leptin challenge in wild-type mice, or those lacking leptin (ob/ob). Leptin-regulated genes were localised in the colon using in situ hybridisation. IL6, IL1β and CXCL1 were up-regulated by leptin and localised to discrete cells in gut epithelium, lamina propria, muscularis and at the peritoneal serosal surface. Leptin regulates pro-inflammatory genes such as IL6, IL1β and CXCL1, and might increase the risk of colon cancer among obese individuals.
Collapse
Affiliation(s)
- Sara Padidar
- Molecular Nutrition, Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, Scotland, UK
| | | | | | | | | | | | | |
Collapse
|
8
|
Padidar S, Farquharson AJ, Williams LM, Hoggard N, Reid MD, Duncan GJ, Drew JE. Impact of obesity and leptin on protein expression profiles in mouse colon. Dig Dis Sci 2011; 56:1028-36. [PMID: 20824498 DOI: 10.1007/s10620-010-1394-z] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 08/11/2010] [Indexed: 01/04/2023]
Abstract
BACKGROUND Elevated leptin levels in obesity are associated with increased risk of colon pathology, implicating leptin signaling in colon disease. However, leptin-regulated processes in the colon are currently uncharacterized. Previously, we demonstrated that leptin receptors are expressed on colon epithelium and that increased adiposity and elevated plasma leptin in rats are associated with perturbed metabolism in colon tissue. Thus, we hypothesize that obesity disrupts expression of proteins regulated by leptin in the colon. METHODS A proteomic analysis was conducted to investigate firstly, differences in the colon of mice lacking leptin and leptin signaling (ob/ob and db/db, respectively) by comparing protein expression profiles with wild-type mice. Secondly, responses to leptin challenge in wild-type mice and ob/ob mice were compared to identify leptin-regulated proteins and associated cellular processes. RESULTS Forty proteins were identified with significantly altered expression patterns associated with differences in leptin status in comparisons between all groups of mice. These proteins are associated with calcium binding, cell cycle, cell proliferation, electron transport chain, energy metabolism, protein folding and transport, redox regulation, structural proteins, and proteins involved in transport and regulation of mucus production. CONCLUSIONS This study provides evidence that obesity and leptin significantly alter protein profiles of a number of proteins linked to cellular processes in colon tissues that may be linked to the increased risk of colon pathology associated with obesity.
Collapse
Affiliation(s)
- Sara Padidar
- Molecular Nutrition Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Greenburn Road, Bucksburn, Aberdeen, AB21 9SB, Scotland, UK
| | | | | | | | | | | | | |
Collapse
|
9
|
Padidar S, Bestwick CS, King TP, Rucklidge GJ, Duncan GJ, Reid MD, Drew JE. Profiling of mitochondrial associated proteins from rat colon. J Cell Biochem 2008; 103:78-97. [PMID: 17497683 DOI: 10.1002/jcb.21391] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondrial dysfunction, damage and mutations of mitochondrial proteins give rise to a range of ill understood patterns of disease. Although there is significant general knowledge of the proteins and the functional processes of the mitochondria, there is little knowledge of difference about how mitochondria respond and how they are regulated in different organs and tissues. Proteomic profiling of mitochondria and associated proteins involved in mitochondrial regulation and trafficking within cells and tissues has the potential to provide insights into mitochondrial dysfunction associated with many human diseases. The rat colon mitoproteome analysis presented here provides a useful tool to assist in identification and interpretation of mitochondrial dysfunction implicated in colon pathogenesis. 2DPAGE followed by LC/MS/MS was used to identify 430 proteins from mitochondrial enriched fractions prepared from rat colon, resulting in 195 different proteins or approximately 50% of the resolved proteins being identified as multiple protein expression forms. Proteins associated with the colon mitoproteome were involved in calcium binding, cell cycle, energy metabolism and electron transport chain, protein folding, protein synthesis and degradation, redox regulation, structural proteins, signalling and transporter and channel proteins. The mitochondrial associated proteins identified in this study of colon tissue complement and are compared with other recently published mitoproteome analyses from other organ tissues, and will assist in revealing potentially organ specific roles of the mitochondria and organ specific disease associated with mitochondrial dysfunction.
Collapse
Affiliation(s)
- Sara Padidar
- Gut Health Division, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
| | | | | | | | | | | | | |
Collapse
|
10
|
Drew JE, Farquharson AJ, Padidar S, Duthie GG, Mercer JG, Arthur JR, Morrice PC, Barrera LN. Insulin, leptin, and adiponectin receptors in colon: regulation relative to differing body adiposity independent of diet and in response to dimethylhydrazine. Am J Physiol Gastrointest Liver Physiol 2007; 293:G682-91. [PMID: 17656443 DOI: 10.1152/ajpgi.00231.2007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Obesity has recently become a focus of research to elucidate diet and lifestyle factors as important risk factors for colon cancer. Altered levels of insulin, leptin, and adiponectin have been identified as potential candidates increasing colon cancer risk within the prevailing obesogenic environment. There has been considerable research to characterize signaling via these hormones in the brain, liver, and adipose tissue; however, very little is known of their emerging role in peripheral signaling, particularly in epithelial tissues. This study profiles insulin, leptin, and adipokine receptors in the rat colon, revealing novel microanatomical location of these receptors and thereby supporting a potential role in regulating colonic tissue. Potential involvement of insulin, leptin, and adiponectin receptors in increased risk of colon cancer was investigated using Sprague-Dawley rats, either resistant or susceptible to diet-induced obesity. Regulation of insulin, leptin, and adiponectin receptors as a consequence of differing levels of adiposity was assessed regionally in the colon in response to treatment with the chemical carcinogen 1,2-dimethylhydrazine (DMH). However, significantly increased fat mass, increased levels of plasma insulin, leptin, and triglycerides, previously associated with an increased risk of colon cancer, were not associated with promotion of precancerous lesions in the experimental rats or deregulation of insulin, leptin, or adiponectin receptors. These findings do not support a direct link between the deregulation of insulin and adipokine levels observed in obese rats and an increased risk of colon carcinogenesis.
Collapse
Affiliation(s)
- Janice E Drew
- Gut Health Division, Rowett Research Institute, Greenburn Rd., Bucksburn, Aberdeen, AB21 9SB, Scotland, UK.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Drew JE, Padidar S, Horgan G, Duthie GG, Russell WR, Reid M, Duncan G, Rucklidge GJ. Salicylate modulates oxidative stress in the rat colon: a proteomic approach. Biochem Pharmacol 2006; 72:204-16. [PMID: 16730665 DOI: 10.1016/j.bcp.2006.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Accepted: 04/06/2006] [Indexed: 02/08/2023]
Abstract
The dietary phenolic compound, salicylic acid, decreases oxidative stress and pro-inflammatory and potentially neo-plastic prostaglandins with a concomitant increase in glutathione peroxidase activity. Salicylic acid, a dietary plant-based phenolic compound and also the main metabolite of aspirin, may contribute to the colon protective effects of plant-based diets. Oxidative stress is a characteristic of pre-cancerous and cancerous colon and inflammatory bowel diseases (IBD) that increase colon cancer risk. The mechanism(s) whereby salicylic acid modulates potentially pro-cancerous activity associated with oxidative stress is further investigated here using a proteomic approach. A rat model of oxidative stress was supplemented with salicylic acid (1 mg/kg diet, mean plasma levels 310+/-32 micromol/l). Soluble colon protein extracts were subjected to 2D PAGE. Salicylic acid modulated proteins, identified using MALDI-TOF and LC/MS/MS, are involved in protein folding, transport, redox, energy metabolism and cytoskeletal regulation. A partial least squares (PLS) analysis approach was used to assist biological interpretation of the altered protein profiles via their associations between previously published biochemical measurements of oxidative stress, prostaglandin levels and increased glutathione peroxidase activity. Early detection of altered homeostasis in colon may assist in identifying pre-pathological features preceding colon tumorigenesis and contribute to an understanding of epidemiological evidence supporting a protective effect of plant-based diets.
Collapse
Affiliation(s)
- Janice E Drew
- Gut Health Division, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen, AB21 9SB Scotland, UK.
| | | | | | | | | | | | | | | |
Collapse
|