Characterization of pancreatic beta cell fate in murine models of MODY3 (breeding application)
Purpose: to characterise the cellular and molecular basis of the gradual failure of insulin-producing â-cells in monogenic diabetes. To achieve this, we are generating two mouse models of human HNF1a mutation, direct counterparts of MODY3 (Maturity Onset Diabetes of the Young) patients. These murine models will express both the wild type and mutant allele at endogenous levels under the control of the endogenous regulatory elements, thus excluding unexpected manifestations due to transgene overexpression. Importantly, the mutation is activated only upon conditional induction (mice will be normal and healthy before induction), allowing a tight selection of timing and organ affected.
Expected distress for the animals: This application regards breeding animals to create the experimental stock animals required in application #10785: "Characterization of pancreatic beta cell fate in murine models of MODY3". We do not foresee additional distress to these animals, except for what is occasionally associated with normal breeding. We will monitor all our breeding pairs to ensure animal well-being.
Expected scientific or societal benefit: Similar with application 10785. As the prevalent forms of diabetes are complex disorders, it remains largely unknown what are the cellular and molecular basis of insulin-producing â-cell decay. Identifying these processes is a requirement for understanding diabetes onset. The study of other complex disorders, such as Parkinson, strongly benefited from researching their monogenic variants. Our projects aim at characterizing the unknown mechanisms governing the decay of â-cells in monogenic diabetes. This study will provide the first comprehensive cellular and molecular timeline of â-cell decay as well as systematically define the beta-cell niche in diabetes. As only a limited number of scenarios can be considered for stress-related cell-fate changes, the revealed process of beta-cell failure will be relevant for the complex forms of diabetes. Moreover, our transcriptomic analyses will reveal new potential therapeutic targets. Our findings will allow a much more efficient clinical intervention with a greater gain in terms of functionality and health span for patients.
Animals to be used: transgenic mice.
Replacement, reduction and improvement
All experiments that do not require a living organism (metabolism; systemic organ interactions) will be performed in vitro by using patient-derived hiPSC. However, as diabetes is a systemic disease involving several organs, certain in vivo studies are unavoidable. Nevertheless, we will optimise the number of mice necessary for our 2 projects by using common experimental groups, where the same set of collected samples will be processed separately for replying distinct questions, hence halving the number of required animals. Our breeding strategy takes into the consideration the reduction of unwanted transgenic genotypes by optimizing the breeding pairing and, when possible, using intermediary genotypes in order to create the new transgenic lines (thus reducing the number of generations required for obtaining the necessary transgenes combination). Moreover, wherever possible, we will maintain the transgenic lines as homozygous, hence assuring the chance for mice with the desired genotype thus reducing to 0 the number of mice sacrificed due to unwanted genotype.
Expected distress for the animals: This application regards breeding animals to create the experimental stock animals required in application #10785: "Characterization of pancreatic beta cell fate in murine models of MODY3". We do not foresee additional distress to these animals, except for what is occasionally associated with normal breeding. We will monitor all our breeding pairs to ensure animal well-being.
Expected scientific or societal benefit: Similar with application 10785. As the prevalent forms of diabetes are complex disorders, it remains largely unknown what are the cellular and molecular basis of insulin-producing â-cell decay. Identifying these processes is a requirement for understanding diabetes onset. The study of other complex disorders, such as Parkinson, strongly benefited from researching their monogenic variants. Our projects aim at characterizing the unknown mechanisms governing the decay of â-cells in monogenic diabetes. This study will provide the first comprehensive cellular and molecular timeline of â-cell decay as well as systematically define the beta-cell niche in diabetes. As only a limited number of scenarios can be considered for stress-related cell-fate changes, the revealed process of beta-cell failure will be relevant for the complex forms of diabetes. Moreover, our transcriptomic analyses will reveal new potential therapeutic targets. Our findings will allow a much more efficient clinical intervention with a greater gain in terms of functionality and health span for patients.
Animals to be used: transgenic mice.
Replacement, reduction and improvement
All experiments that do not require a living organism (metabolism; systemic organ interactions) will be performed in vitro by using patient-derived hiPSC. However, as diabetes is a systemic disease involving several organs, certain in vivo studies are unavoidable. Nevertheless, we will optimise the number of mice necessary for our 2 projects by using common experimental groups, where the same set of collected samples will be processed separately for replying distinct questions, hence halving the number of required animals. Our breeding strategy takes into the consideration the reduction of unwanted transgenic genotypes by optimizing the breeding pairing and, when possible, using intermediary genotypes in order to create the new transgenic lines (thus reducing the number of generations required for obtaining the necessary transgenes combination). Moreover, wherever possible, we will maintain the transgenic lines as homozygous, hence assuring the chance for mice with the desired genotype thus reducing to 0 the number of mice sacrificed due to unwanted genotype.