Mitochondria are small dynamic organelles that play major roles in cellular function. They are central to metabolic pathways that convert nutrients into energy and serve as a hub that manages stress responses related to cellular and organ health.
This field has rapidly matured over the last decade, with new and significant links of mitochondrial function with human disease. Mitobridge is leveraging the latest biological findings that have revealed new insights into complex mechanisms that regulate mitochondrial activities.
To aid our drug discovery efforts, Mitobridge is developing an integrated platform of assays to systematically interrogate changes in mitochondrial activity seen in health and disease conditions. These assays help capture alterations in various aspects of mitochondrial biology, including but not limited to, bioenergetics, dynamics, signaling and nutrient utilization. The composite data sets for compounds will reveal activity patterns that we refer to as a “MitosignatureTM”. The MitosignaturesTM for our proprietary molecules will be compared to the profiles produced by known tool compounds, clinical candidates and marketed products to help guide our target programs. The platform will be used to screen for novel compounds that improve mitochondrial function. Breakthrough molecules will be evident by comparing the newly produced MitosignaturesTM to our reference datasets.
Given the myriad of roles that mitochondria play in cellular homeostasis, it is no surprise that defects in mitochondrial function can lead to a broad spectrum of diseases. These functional defects are most apparent in tissues that have a high energy demand such as skeletal muscle, kidney, liver, heart and central nervous system (CNS).
Mitochondrial genetic diseases are caused by defects in either nuclear or mitochondrial genes. This group of disorders, which includes Leigh’s Syndrome, Leber's hereditary optic neuropathy, and MELAS can be associated with a variety of symptoms and could clinically benefit from treatments that improve mitochondrial function.
Diseases associated with mitochondrial dysfunction are common yet diverse and can manifest as kidney disease, liver disease, and heart disease, hearing loss, muscular dystrophies and myopathies. Mitochondrial dysfunction is also associated with aging, and has been shown to play a role in neurodegenerative diseases. The etiology of certain “emerging” indications such as Chronic Fatigue Syndrome and Sarcopenia is not well understood, but recent studies have indicated that targeting mitochondria to enhance their function may hold promise for attenuating those conditions.
Mitochondrial-directed therapies may have the ability to address multiple molecular abnormalities simultaneously and may prove to be more efficacious than compounds that target an isolated protein. Mitobridge has the opportunity to develop drug candidates that could be therapeutically beneficial in a multitude of disease indications. Our strategy is to quickly establish proof of concept in rare diseases with high unmet medical need and then expand into the more prevalent diseases.
Gene regulation – One of the mechanisms cells use to manage protein requirements is gene regulation. Exercise, a type of cellular stress, induces gene regulation as a response to increased energy demand. Mitobridge scientists have identified molecules that can regulate the gene sets controlled by exercise – these compounds are called “exercise mimetics”.
NAD+ enhancement –NAD+ plays many important roles within cells, including serving as an oxidizing agent in oxidative phosphorylation which generates ATP from ADP. Increasing cellular concentrations of NAD+ will enhance the oxidative capacity within mitochondria, thereby increasing nutrient oxidation and boost energy supply, which is a primary role of mitochondria.
Mitochondrial dynamics – Mitochondrial health depends on several complex processes that help cells function under normal and stress conditions. Mitochondrial dysfunction can lead to mitochondrial clearance (mitophagy) or cell death (apoptosis). Mitochondria are dynamic organelles, able to change their morphology by undergoing fusion or fission. Many diseases stress mitochondria, which can disrupt the normal dynamics processes.
Exercise provides multi-factorial benefits to patients with many disease types. Pioneering work from Mitobridge co-founder, Professor Ronald Evans, demonstrates that the PPARδ nuclear hormone receptor regulates a cascade of genes involved in muscle adaptation to exercise. This includes a change critical to improving muscle endurance and increasing mitochondrial fatty acid utilization. With this foundation of understanding, we generated a library of targeted PPARδ modulators that activate the transcription factor’s gene cascade and improve mitochondrial function. This series was developed to maximize selectivity, providing the potential for our compounds to have a safer drug-profile, yet similar effectiveness to first-generation PPARδ compounds.