Why Macrophages Promote Heterotopic Ossifications Following Spinal Cord Injuries
Funder
National Health and Medical Research Council
Funding Amount
$586,950.00
Summary
A frequent complications of brain and spine injuries is the formation of bones outside of the skeleton called "heterotopic ossifications", particularly around joints such as the knee, hip, elbow or shoulder. They grow over a few months to become so large (up to 2 kg) that they block muscles and joints, increasing pain, morbidity and dependance. This project is to understand why heterotopic ossifications form in patients with spine injuries aiming to discover effecttive treatments.
Molecular Determinants Of Bone Remodelling In The Bone Microenvironment
Funder
National Health and Medical Research Council
Funding Amount
$317,640.00
Summary
There is little information regarding the expression of specific molecules in human bone tissue or their role in skeletal disease. The process of bone remodelling is fundamental for the maintenance of skeletal integrity. Our understanding of the molecular signalling involved in activating bone remodelling is principally derived from tissue culture and animal experiments. We will study human cancellous bone samples donated by patients undergoing surgery, and with the consent of the next-of-kin, t ....There is little information regarding the expression of specific molecules in human bone tissue or their role in skeletal disease. The process of bone remodelling is fundamental for the maintenance of skeletal integrity. Our understanding of the molecular signalling involved in activating bone remodelling is principally derived from tissue culture and animal experiments. We will study human cancellous bone samples donated by patients undergoing surgery, and with the consent of the next-of-kin, taken at autopsy. These molecular and histomorphometric studies will determine whether the understanding derived from tissue culture and animal experiments is consistent with associations demonstrable in the human cancellous bone microenvironment. The elucidation of the molecular signalling in the human bone microenvironment is essential for the effective diagnosis and treatment of bone disease. Recently reported studies have shown very persuasively that fatigue microdamage accumulates in the skeleton and is targeted for repair by remodelling. Our preliminary data shows that microcrack length is positively correlated with IL-11 mRNA gene expression. We will further investigate mRNA gene expression of a number of cytokines involved in bone cell signalling and their association with the level of microdamage in the bone. Using a animal model of controlled bone microdamage induction we will seek to determine the bone remodelling causal relationship between microdamage and cytokine signalling. Furthermore, the cellular and molecular mechanisms that lead to trabecular structures are not well understood. These studies will provide new insight into the processes that determine trabecular structures. This project will investigate these mechanisms and increase our understanding of bone cell function, essential for diagnosis and design of rational treatment for bone diseases.Read moreRead less
Roles Of Injury-induced Inflammatory Response In Regulating Bony Repair At Injured Growth Plate Cartilage
Funder
National Health and Medical Research Council
Funding Amount
$366,301.00
Summary
Children's growth plate cartilage is responsible for bone lengthening. Due to popularity of sports and play, trauma-induced growth plate damage and subsequently bone growth defects are common in children, with up to 30% of growth plate injury cases resulting in growth abnormality, for which the present surgical correction is highly invasive and not fully effective. Although we know that the growth plate injury-induced bone growth defects result from bony repair of the injured growth cartilage, w ....Children's growth plate cartilage is responsible for bone lengthening. Due to popularity of sports and play, trauma-induced growth plate damage and subsequently bone growth defects are common in children, with up to 30% of growth plate injury cases resulting in growth abnormality, for which the present surgical correction is highly invasive and not fully effective. Although we know that the growth plate injury-induced bone growth defects result from bony repair of the injured growth cartilage, we largely don't understand why and how this bony repair occurs. Understanding mechanisms for this faulty bony repair of injured growth plate will be critical prior to effective biological treatments can be developed. Recently, using an injury model in young rats, we found that bony tissue formation at injured growth plate is preceded sequentially by inflammatory, fibrogenic, chondrogenic and osteogenic responses. The inflammatory response is an initial event and our recent studies suggest that inflammatory response recruits inflammatory cells and produces important molecules that could significantly influence subsequent fibrogenic, chondrogenic and osteogenic events leading to the bony repair of the injured growth plate cartilage. The current proposal further addresses roles of the inflammatory response and the molecular pathways of this response in regulating downstream bony repair events. This project will generate novel understanding on the faulty bony repair of injured growth plate, and will provide valuable information for developing cost-effective and simple therapeutic intervention that aims to prevent bony repair and to enhance cartilage regeneration of the injured growth plate in children.Read moreRead less
We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately exp ....We will seek to address an important clinical problem in orthpaedics, namely the bone loss that commonly occurs around joint replacement prostheses. Termed peri-prosthetic osteolysis (PO), this bone loss can result in the loosening and ultimate failure and need for revision of the artificial joint components. PO is thought to be caused by the body's reaction to wear particles generated from the articulating surface of the prosthesis. However, it has not previously been possible to accurately explore the relationship between prothesis wear and PO, or the progression of PO, because of a lack of techniques to image and measure the volume of PO around metal prosthesis components. We have developed a means to accurately and reproducibly measure the volume of bone loss, using CT, and will do so longitudinally in joint replacement patients to obtain the first information about the progression of PO. New computer based methods will be used concurrently to relate prosthesis wear and migration parameters to PO. Patients who come to surgery for replacement of failed prostheses will be investigated further by analysis of the tissues involved in the bone loss around prostheses. Basic science experiments will seek to understand the underlying causes of PO and the findings will be important in interpreting the clinical results. An animal model will be used to seek approaches to inhibiting the pathological response to wear particles. The significance of these studies is that they will lead to improved outcomes for joint replacement patients, increasing the interval to revision surgery, which is both extremely costly and brings an attendant morbidity and mortality.Read moreRead less