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T1D Biomarkers
Need for miRNA biomarkers of T1D
MicroRNAs represent a subset of non-protein-coding(nc)RNA molecules that are now identified to be stable (nuclease and freeze-thaw resistant) biomarkers of disease state. MicroRNAs play an important role in human physiology, including the development and function of insulin-producing β-cells. MicroRNAs in dead and /or dying β-cells can travel via gap-junctions or exosome-mediated transfer to surrounding tissues or can be released from damaged cells and be detected in body fluids, including in blood.
Studies from our lab and other investigators also confirm that microRNAs are resistant to freeze-thawing. Although microRNA biomarkers are now clinically used (e.g. for diagnosis of prostate cancer), such a microRNA signature is not yet identified, validated and clinically available for human islet β-cell death in T1D. So far there have been very few studies on circulating microRNAs in T1D, which are mainly in mice or in cross-sectional human studies.
Blood glucose levels are a blunt instrument and not a reliable measure of β-cell death/diabetes progression. It is now well known that most individuals with T1D have 10 to 30% viable β-cells at clinical diagnosis (See figure above and Atkinson M et al 2014 ). Thus even after 70% pancreatic β-cell death, the residual β-cells could possibly maintain “normal” glucose concentrations. Antibody titres are also not the best candidates as sero-conversion (immune-positivity to multiple auto-antibodies) does not always confirm progression to T1D. There is therefore a need to identify an assay that can be used in a clinical research laboratory and ultimately clinical lab setting to diagnose β-cell death and T1D progression at an early stage; long before the clinical onset of T1D.
Molecular biomarkers of Type 1 diabetes (T1D)
Islet cell death is a common feature of type 1 diabetes (T1D), including after islet cell transplantation, as well as in Latent Autoimmune Diabetes of Adults (LADA) (‘type 1.5 diabetes’). We currently lack tools to quantitatively detect islet cell death prior to the clinical onset of diabetes, or to predict the progression of established T1D.
Over the past several years, our lab group has focussed on understanding the potential of ncRNAs, mainly microRNAs associated with islet beta cell death and Type 1 diabetes. Research funded through the Australian Research Council Future Fellowship to Prof. Hardikar and JDRF Australia funding over the past several years has helped in development of this program. We aim to (i) validate a microRNA signature associated with T1D in ~1000 Australians without or with T1D; (ii) assess the differences in circulating (plasma) miRNAs in geogrophically distinct and ethnically diverse individuals without and with T1D; (iii) compare the potential of these miRNAs and insulin cfDNA to stratify individuals without and with T1D; (iv) use machine-learning algorithms to predict future diabetes (v) identify the potential of our molecular biomarkers to test treatment efficacies of drugs/interventions aimed to retard the death of insulin-producing cells in individuals recently diagnosed, or at risk of T1D. Our previous studies supported by the ARC and the JDRF Australia, have identified key microRNA signatures; the ARC Future Fellowship funding led to identification of human islet-enriched microRNAs, while the JDRF CRN P&F grant led to identification of circulating microRNAs that are differentially expressed in individuals with T1D relative to age, gender and smoking-matched Controls. We have generated a custom panel of microRNAs that contains a set of our key candidates, stage-specific spike-in controls, positive control, negative control, duplicate/positional control and repeat control microRNAs. Robotics workflows ensure inter-assay CVs of <5% for the isolation and ~5-7% for inter-batch repeats.
Over the past several years, our lab group has focussed on understanding the potential of ncRNAs, mainly microRNAs associated with islet beta cell death and Type 1 diabetes. Research funded through the Australian Research Council Future Fellowship to Prof. Hardikar and JDRF Australia funding over the past several years has helped in development of this program. We aim to (i) validate a microRNA signature associated with T1D in ~1000 Australians without or with T1D; (ii) assess the differences in circulating (plasma) miRNAs in geogrophically distinct and ethnically diverse individuals without and with T1D; (iii) compare the potential of these miRNAs and insulin cfDNA to stratify individuals without and with T1D; (iv) use machine-learning algorithms to predict future diabetes (v) identify the potential of our molecular biomarkers to test treatment efficacies of drugs/interventions aimed to retard the death of insulin-producing cells in individuals recently diagnosed, or at risk of T1D. Our previous studies supported by the ARC and the JDRF Australia, have identified key microRNA signatures; the ARC Future Fellowship funding led to identification of human islet-enriched microRNAs, while the JDRF CRN P&F grant led to identification of circulating microRNAs that are differentially expressed in individuals with T1D relative to age, gender and smoking-matched Controls. We have generated a custom panel of microRNAs that contains a set of our key candidates, stage-specific spike-in controls, positive control, negative control, duplicate/positional control and repeat control microRNAs. Robotics workflows ensure inter-assay CVs of <5% for the isolation and ~5-7% for inter-batch repeats.
Team members
Mugdha Joglekar (Research co-lead, WSU), Wilson Wong (WSU), Rajesh Ramanathan, Pabudi Weerathunge, Anupriya Baranwal and César Sánchez Huertas (at RMIT) and Rohan Patil, Sarang Satoor and Mahesh Karandikar (India) Past team members: Ryan Farr, Caroline Taylor, Nirupa Sachithanandan, Virginia Cotta
Collaborators (listed on grants and in alphabetical order): Vipul Bansal (Australia), Juliana Chan (Hong Kong), Maria Craig (Australia), Louise Torp Dalgaard (Denmark), Kirstie Danielson (USA), Kim Donaghue (Australia), Andrzej Januszewski (Australia), Alicia Jenkins (Australia), Tim Jones (Australia), Ronald Ma (Hong Kong), Raghu Mirmira (USA), Arnan Mitchell (Australia), Flemming Pociot (Denmark), Kristina Rother (USA), Ravi Shukla (Australia), Ranjan Yajnik (India).
Present and past funders/supporters: ARC Future Fellowship, NHMRC CCRE and JDRF Australia pilot and Feasibility grants, JDRF International Fellowship (to MVJ), JDRF Australia CDA (to AAH), NHMRC APA scholarships, Danish Diabetes Academy, Rebecca L Cooper Foundation, University of Sydney, Australian Academy of Sciences (AISRF award to MVJ) and The Helmsley Trust, USA.
