Neuroglial Regulation of the Haematopoietic Stem Cell Niche in Acute Myeloid Leukaemia Transformation
This is an extension of a previously approved Project (FOTS9005). The aim of this study is to test the contribution of the neural dysfunction of the bone marrow microenvironment to drive AML, and the therapeutic potential of the reversion of this damage. This project is a continuation of FOTS 7922 and FOTS 9005 to confirm preliminary data with optimized protocols. The expected harmful effect on the animals are mild to transiently severe, only in transplanted mice. The present research will provide with insights into the basic processes that underlie HSC dysfunction and pinpoint a novel therapy against AML. Haematopoiesis has been best characterized in the mouse system and the interaction of the haematopoietic stem cell with its microenvironment can only be studied in vivo, due to the insufficient knowledge of the microenvironment. Number of animals are kept to a minimum (640-500 in Tromsø and 140 in Oslo) consistent with the obtention of statistically meaningful results. Mice will be used in the most efficient way possible, attempting to obtain the maximum information from each experimental animal. When assays cannot be performed immediately, cells will be cryopreserved whenever possible. Mice will be sacrificed at time points when they will only show haematological symptoms of disease. It is not the goal of this study to analyze terminal stages of disease, but identify the role of the nervous system before severe symptoms develop aiming at uncovering early therapeutic targets against agressive AML.
Etterevaluering
We classify the severity of the procedures as severe, cf. the Regulation annex B.
The applicant points out that it is not the goal of the study to analyze terminal stages of disease, but to identify the role of the nervous system before severe symptoms develop aiming at uncovering early therapeutic targets against aggressive AML.
However, we find that the mice might experience severe symptoms in the first 1-2 weeks after whole body irradiation.
The Norwegian food safety authority must retrospectively assess all severe experiments.
The applicant points out that it is not the goal of the study to analyze terminal stages of disease, but to identify the role of the nervous system before severe symptoms develop aiming at uncovering early therapeutic targets against aggressive AML.
However, we find that the mice might experience severe symptoms in the first 1-2 weeks after whole body irradiation.
The Norwegian food safety authority must retrospectively assess all severe experiments.
Begrunnelse for etterevalueringen
The project has been a continuation of FOTS 7922 and FOTS 9005 to confirm preliminary data with optimized protocols.
The overall aim of the project has been to study the contribution of neural dysfunction of the bone marrow microenvironment in acute myeloid leukemia development and the therapeutic potential of reversion of such damage.
The responsible researcher informs that despite not having been able to perform the experiments of restoring damaged neuroglial bone marrow components in pre-leukemic mice, the researchers were able to develop an in vivo sympathectomy method and show that neuroglial damage is an early event in pre-leukemic disease, which contributes to disease progression.
The researchers observed that Mx1-Cre Nras G12D pre-leukemic mice present early neuroglial damage in the course of the disease.
The researchers have not been able to perform the experiments on the gain of sympathetic function through administration of 4-methylcatechol.
The unachieved objectives in FOTS id 21740 will be completed in FOTS id 24737.
The experiments allowed to obtain significant knowledge in the neuroglial regulation of the hematopoietic system in health and in blood malignancy. These data, together with other complementary data will be submitted to publication in a scientific journal.
The project was approved for the use of 140 mice. 92 mice were used.
The severity has been reported as moderate for 81 mice and severe for 11 mice.
Mice reported with high severity have been euthanized because they reached a humane endpoint or have been found dead.
Humane endpoints have been established using a tailored score sheet and following recommendation of the animal facility veterinarian when appropriate.
The researchers use replacement techniques as much as possible, such as replating of CFU-C assays to study long-term hematopoietic potential of hematopoietic stem cells ex vivo.
However, results must always be confirmed by the gold standard method to study long-term self-renewal of hematopoietic stem cells, i.e. transplantation.
The research group have used the lowest number of animals possible to ensure statistical relevance of the results. Outlier animals are systematically excluded from the group`s studies before starting in vivo treatment in order to limit the number of repetitions of experiments to obtain statistically meaningful data.
The impact of hematopoietic transplantation severity has been reduced as much as possible. The transplants are only performed by experienced researchers and animals are closely followed up with the use of specific score sheets.
Conditions have been kept strictly sterile before, during and after lethal irradiation, and during the time of recovery.
The overall aim of the project has been to study the contribution of neural dysfunction of the bone marrow microenvironment in acute myeloid leukemia development and the therapeutic potential of reversion of such damage.
The responsible researcher informs that despite not having been able to perform the experiments of restoring damaged neuroglial bone marrow components in pre-leukemic mice, the researchers were able to develop an in vivo sympathectomy method and show that neuroglial damage is an early event in pre-leukemic disease, which contributes to disease progression.
The researchers observed that Mx1-Cre Nras G12D pre-leukemic mice present early neuroglial damage in the course of the disease.
The researchers have not been able to perform the experiments on the gain of sympathetic function through administration of 4-methylcatechol.
The unachieved objectives in FOTS id 21740 will be completed in FOTS id 24737.
The experiments allowed to obtain significant knowledge in the neuroglial regulation of the hematopoietic system in health and in blood malignancy. These data, together with other complementary data will be submitted to publication in a scientific journal.
The project was approved for the use of 140 mice. 92 mice were used.
The severity has been reported as moderate for 81 mice and severe for 11 mice.
Mice reported with high severity have been euthanized because they reached a humane endpoint or have been found dead.
Humane endpoints have been established using a tailored score sheet and following recommendation of the animal facility veterinarian when appropriate.
The researchers use replacement techniques as much as possible, such as replating of CFU-C assays to study long-term hematopoietic potential of hematopoietic stem cells ex vivo.
However, results must always be confirmed by the gold standard method to study long-term self-renewal of hematopoietic stem cells, i.e. transplantation.
The research group have used the lowest number of animals possible to ensure statistical relevance of the results. Outlier animals are systematically excluded from the group`s studies before starting in vivo treatment in order to limit the number of repetitions of experiments to obtain statistically meaningful data.
The impact of hematopoietic transplantation severity has been reduced as much as possible. The transplants are only performed by experienced researchers and animals are closely followed up with the use of specific score sheets.
Conditions have been kept strictly sterile before, during and after lethal irradiation, and during the time of recovery.