The spinal cord is a key component of the central nervous system, acting as a relay to convey information between the brain and the rest of the body. A number of diseases affect the spinal cord, including multiple sclerosis (MS). MS affects more than 240 Canadians per 100,000, and is suspected of shrinking the spinal cord. In fact, recent studies have shown a strong correlation between spinal cord atrophy and disability related to the advancement of the disease. Spinal cord analysis, conducted with magnetic resonance imaging (MRI), is an important tool for detecting and measuring disease progression. This requires cross-sectional segmentation of the image, where specific points that correspond to the spinal cord are identified and measured over time. Most current methods require some manual intervention by radiologists; this is time-consuming and increases variability in the measurements. Chris McIntosh creates software for accurately analyzing tubular structures in the body – such as blood vessels and airways – using MRI and computed tomography. His current focus is on employing MRI to accurately measure and analyze spinal cord atrophy in patients with MS. Building on a preliminary study on automatic spinal cord segmentation, McIntosh is fine tuning the technology through additional validation, ensuring the results correspond with clinical measurements. He will then segment larger data sets with minimal user-interaction and perform analysis to see if the findings correlate with disease progression. A fully-automatic, computerized system would reduce variability seen with manual intervention, resulting in more accurate and useful spinal cord analysis. It also has the potential to free up radiologists’ time for other clinical work.
Program: Trainee
Intravesical mucoadhesive nanoparticulate drug delivery systems for application in bladder cancer
Urinary bladder cancer is one of the most commonly diagnosed malignancies in North America. The great majority of cases are superficial carcinomas, where the tumour is confined to the inner layer of the bladder wall. The most common treatment method is known as transurethral resection, which involves the surgical removal of tumour nodules from the bladder wall. However, there is a high rate of tumour recurrence after this surgical procedure. Intravesical chemotherapy, which involves instillation of one or more chemotherapeutic agents into the bladder following resection, has become the treatment of choice for superficial carcinoma. Unfortunately, the major limitation of this treatment is the rapid and almost complete washout of the drugs from the bladder on first void of urine, and low exposure of chemotherapeutic agents to the tumour sites. This can lead to treatment failure. Although drug treatments via bladder instillation following resection have decreased tumour recurrence rates, overall mortality rates for bladder cancer have not changed in Canada over the last several years. New approaches are needed to treat this type of cancer. Clement Mugabe is working to develop formulations of drugs that are not easily flushed out of the bladder. This can be achieved by creating drugs in the form of mucoadhesive nanoparticles –so tiny and sticky. Mucoadhesive nanoparticle formulations have the potential to adhere to the bladder wall, increase drug uptake into bladder tissue and thereby increase the effectiveness of drug treatment. Mugabe’s research will lead to novel formulations, and new information about the factors that influence uptake of drugs into the bladder wall.
Examining the role of N-linked glycosylation on the maturation and cell surface trafficking of hyperpolarization-activated cyclic nucleotide-gated (HCN) pacemaker channels
Cardiovascular disease remains the number one killer in British Columbia. These diseases include cardiac arrhythmias, which cause the heart to beat too slowly, too quickly, or in an uncoordinated fashion. Arrhythmias arise from dysfunction of the heart’s natural pacemaker: the sinoatrial node. The sinoatrial node consists of a group of cells responsible for generating the electrical impulse that controls normal rhythmic contraction and relaxation of the heart. In order to generate these electrical impulses, these cells possess a group of proteins known as ion channels. These proteins allow ions to selectively cross the cell membrane barrier, generating an electrical impulse that spreads to neighbouring cells. One particularly important family of ion channels are the HCN or ‘pacemaker’ channels which are responsible for generating the spontaneous activity of the sinoatrial node. The assembly and trafficking of these channels to the cell membrane is vital for ensuring our hearts beat in a regular fashion. How the cell accomplishes this task remains an unanswered question. Hamed Nazzarisedeh’s research attempts to uncover the underlying mechanisms that help regulate or contribute to the trafficking of HCN channels in the heart. Specifically, he is examining the role in which N-linked glycosylation of these proteins may factor in this regulation. His research will contribute to further our knowledge about how various forms of cardiovascular disease associated with HCN channel disruption arise in the heart. Ultimately, this work could aid in the discovery of novel treatment strategies.
Investigating the molecular mechanisms of micrometastasis and tumour dormancy in pediatric sarcoma
Sarcomas are an aggressive type of childhood cancer arising from bone or soft tissue. Despite advances in cancer treatment, sarcomas remain a deadly disease because of their tendency to spread throughout the body (metastasis). Following cancer surgery to remove a malignancy, remnant sarcoma cells are often able to remain dormant in the body for months or years, in spite of efforts to eradicate them with chemotherapy. When such therapies are ineffective, these hibernating cells may revive and regrow as deadly metastases. Under laboratory conditions, cultured cancer cells are able to survive for long periods in the form of multi-cellular clusters called “”spheroids””. Interestingly, these spheroids also appear to enter a hibernation state, with cancer cells trading away their ability to grow rapidly in favour of the ability to survive for long periods. The cells use their “oncogenes” to suppress the expression of their growth-promoting genes, despite the fact that oncogenes are normally known for their cancer-promoting properties. It is believed that cancer cells and their oncogenes target a new set of genes to drive this hibernation. Tony Ng is screening all human genes for ones important in maintaining this hibernation. Using a technique called gene expression profiling, he will determine which genes become more active when cancer cells hibernate. He is also studying two genes, TXNIP and YB-1, which appear to be important for spheroid survival and dormancy. Laboratory results will be validated using clinical samples of dormant tumour cells from childhood cancers. Ng hopes that the genes identified in these studies will become the basis of chemotherapies to specifically kill these hibernating cells, resulting in therapies that are more effective and less toxic to patients.
Spatial characterization of brain activation in Parkinson's Disease research
Parkinson’s disease (PD) affects 100,000 Canadians, and this number is expected to increase with the aging of the population. Primary symptoms include tremor, rigidity, slowness of movement, and posture instability. These motor disabilities are believed to be associated with the premature death of dopamine-secreting cells in the brain region Substantia Nigra pars compacta. However, the cause of this premature cell death is unknown, and symptoms often do not emerge until 80 per cent of the dopaminergic cells are lost. Detecting the onset of PD thus remains a major challenge, hindering the development of a cure. It is believed that substantial compensation occurs in the brains of PD patients, obscuring the early effects of disease. Therefore, current clinical assessments that rely on symptom severity may not provide an accurate measure of disease progression. Instead, it is predicted that abnormal brain activity changes will emerge long before substantial dopaminergic cells are lost. Thus, altered brain activity may serve as a more useful marker than symptom severity for diagnosing and treating PD. In order to disentangle compensatory mechanisms from disease effects, Bernard Ng is comparing the brain activity of PD patients at similar stages of disease progression, but with varying degrees of symptom severity. Specifically, he is using functional magnetic resonance imaging (fMRI),to study diseased-induced changes in brain activity within specific brain regions as well as changes in connectivity between brain regions. To more elaborately characterize brain activity, he is employing novel statistical spatial descriptors to examine the spatial distribution of regional activity in additional to the traditionally-employed intensity measures. By incorporating spatial information in this combined approach, better distinctions between compensatory mechanisms from disease effects would be enabled. Ng’s research aims to provide more accurate diagnosis of disease progression in PD patients, better assessment of medication effectiveness, and ultimately earlier PD detection.
Biological role of IL-7Ralpha Y449-dependent and -independent signals in T cell development and function
The molecule interleukin-7 (IL-7) is an important regulator of the development and signalling function of T cells, the white blood cells involved in fighting off infection and coordinating an efficient immune response. Loss of IL-7 signalling in humans results in a complete lack of T cells, demonstrating the necessity of IL-7 in the development of these important cells. After T cells mature, they circulate through the blood, searching out invading pathogens, mounting an immune response and clearing the infection. This process generates specialized memory T cells, which are able to mount a stronger and more efficient immune response upon subsequent encounters with the same pathogen. Memory cell development is the basis of vaccination, which serves to “prime” the immune system to ward off infections. Growing evidence indicates that not only is IL-7 essential in the development of these memory T cells, but that its overproduction is also implicated in a number of immune system cancers. Lisa Osborne was previously funded by MSFHR for her early PhD research training. She is now continuing her studies of IL-7. Using a number of genetic models of IL-7 signalling, Osborne will clarify the IL-7 mediated biochemical pathways that are involved in a number of T cell processes. She aims to demonstrate which molecule or pathway is primarily involved in the de-regulated growth of T cells that leads to cancer. Ultimately, this research could guide the development of vaccines that rely on the generation of memory T cells against a particular pathogen. Her work will also provide insights into the development of immune system cancers, and potentially a novel treatment approach.
Endogenous cell replacement: progenitor characterization and promotion of oligodendrocyte differentiation and remyelination in the central nervous system by attenuating myelin inhibition
White matter is the part of the nervous system composed mainly of nerve fibres covered by a lipid-dense sheath of myelin. Myelin is produced by cells known as oligodendrocytes, and is responsible for increasing the speed of electrical impulses throughout the nervous system. White matter disorders, such as multiple sclerosis (MS) and spinal cord injury (SCI), comprise a devastating group of conditions that affect millions of people around the world. Although these disorders may have different features, they are all characterized by myelin damage that will not sufficiently repair (remyelinate). While the exact cause of this insufficient remyelination is unknown, one thing is clear: for myelin repair to occur, oligodendrocyte precursor cells (OPCs) need to proliferate and migrate to areas of demyelination, to differentiate, and to then remyelinate denuded neurons. While the transplantation of cells with the potential to myelinate is feasible, there are significant barriers for effectively translating this technology into clinical treatment. An alternative strategy is to activate precursor cells within the host tissue (endogenous cells) to mobilize and promote repair. Jason Plemel was previously funded by MSFHR for his work studying oligodendrocyte transplantation following spinal cord injury. He is now exploring the dynamics of cell-based repair via endogenous cells. He is studying the capacity of oligodendrocytes to self-renew and replicate under normal and disease conditions. He is also investigating possible inhibitory signals at the region of damage that could inhibit endogenous repair, and whether these signals could be blocked to promote remyelination. Plemel anticipates that this work could ultimately lead to new targets for drugs that promote regeneration of myelin in a number of white matter disorders.
Absence of IL-6 results in increased autoimmune myocarditis severity following coxsackievirus infection
Myocarditis is a disease that results in inflammation of heart muscle. Myocarditis and dilated cardiomyopathy (DCM), a condition in which the heart becomes weakened and enlarged, are believed to be continuing stages of an autoimmune disease of the heart. This condition can progress to a stage that requires heart transplantation. Myocarditis is often brought on by a viral infection. In humans, coxsackie B viruses (CBV) are the most frequent cause of viral-induced myocarditis. It is estimated that 30 per cent of new DCM cases in North America are the result of CBV infection. Maya Poffenberger’s research aims to determine the specific immune components that control myocarditis disease severity following viral infection. She is studying cells and molecules that control immune cells. Using mouse models that lack certain immune genes, Poffenberger will be able to identify the genes that influence the induction and severity of myocarditis from CBV infection. With knowledge of how myocarditis is induced and controlled, researchers will be able to develop better disease specific therapies that target immune genes important to disease induction and severity.
Mechanistic studies and engineering of an endo-beta-galactosidase (EABase) from C. perfringens: blood group antigen synthesis
The ABO blood groups – comprising the A, B, AB and O blood types – are vitally important in blood transfusion and organ transplantation. The four types are differentiated by the presence or absence of two sugar antigens on the surface of red blood cells: a terminal alpha-1,3-linked N-acetylgalactosamine (A-antigen) or an alpha-1,3-linked galactose (B-antigen), both of which are absent in the O-blood type. As all individuals have antibodies to the antigen(s) they lack, transfusion with an incorrect blood type results in destruction of the incompatible blood cells, which can result in death. The enzyme EABase is capable of releasing both the A and B trisaccharides from the surface of red blood cells, giving it the potential to be used to convert blood cell types by the addition or removal of their antigens. Fathima Shaikh’s studies seek to determine the mechanisms underlying EABase activity, and identify the residues that are created as a result. Knowledge of these enzyme properties is crucial for the next stage of the project: engineering EABase into a glycosynthase, which is a mutant form of the enzyme that can synthesize (form) antigens, rather than removing them. She will conduct further work to optimize the efficiency of this glycosynthase, as well as increasing its synthetic utility by broadening its ability to transfer different sugars. If Shaikh’s experiments are successful, this process would allow for the conversion between blood groups. These enzymes could be of great benefit to human health, helping to overcome shortages in donated blood, and helping in the modification of related antigens on other cell types.
Microfluidic technologies for high-throughput selection and production of monoclonal antibodies from single cells
Antibodies are proteins produced by the immune system. They work by selectively and tightly attaching themselves to infectious bacteria, viruses, and other pathogens, neutralizing their disease-causing abilities. The natural role of antibodies in clearing infections has prompted the pharmaceutical industry to invest billions of dollars in attempts to produce new antibody therapies to treat rheumatoid arthritis, cancer, cardiovascular disease, HIV/AIDS, and other diseases. As a result, antibodies have become the most rapidly growing class of therapeutic drugs over the last decade. One successful example of an antibody-based therapy is the drug Herceptin, which treats a highly-aggressive form of breast cancer. In order to produce vast quantities of antibodies required for research and therapeutic use, antibody-producing cells are currently fused to immortal cancer cells to allow them to be grown in laboratory culture. Successfully creating antibody-producing fused cells can involve hundreds to thousands of attempts, requiring many years and millions of dollars in research money. MSFHR previously funded Anupam Singhal as he used micron-sized fluid-handling devices and nanotechnology to allow the study of stem cells at the single cell level. He is now using these approaches to rapidly and inexpensively produce antibodies. He is working on a novel technology that is sensitive enough to detect antibodies produced by single cells, and determine which ones are producing the optimal antibody. Then, the genes responsible for antibody production in these cells can be isolated, cloned and inserted into cell lines for production. As a demonstration of this technology, human antibodies against the influenza virus will be developed. This technology could have far-reaching impacts on the rapid and inexpensive development of breakthrough therapeutic drugs and diagnostic agents.