Restoring the axis: The interplay of C peptide Na K ATPase and the renin angiotensin system in the pathogenesis of diabetic complications

Despite rigorous glycemic control, patients with Type 1 Diabetes (T1D) remain at significantly elevated risk for microvascular complications, cardiovascular disease, and neuropathy. Current therapeutic standards, which rely solely on insulin monotherapy, fail to replicate the physiological state where insulin and C-peptide are co-secreted in equimolar amounts. This presentation introduces a novel, integrated endocrine network model demonstrating that the omission of C-peptide disrupts the Renin-Angiotensin System (RAS) through a specific dysregulation of the Cortisol-Vitamin D axis, ultimately leading to Na,K-ATPase failure and systemic cellular dysfunction. We present evidence that C-peptide acts as a necessary "off-switch" for pro-metabolic signals. In the absence of C-peptide, unopposed insulin stimulation of the G-protein coupled receptor GPR146 leads to constitutive activation of Sterol Regulatory Element-Binding Protein 2 (SREBP2). This dysregulation drives a state of chronic hypercortisolemia. We demonstrate that this elevated cortisol induces a functional Vitamin D deficiency by disrupting its bioactivation. Critically, because active Vitamin D is a physiological suppressor of the renin gene, this deficiency removes the "brake" on the RAS, leading to the pathological overactivation of the ACE/Angiotensin II/AT1R axis.

This cascade has profound downstream effects on Na,K-ATPase activity. The overactive RAS promotes vasoconstriction, inflammation, and oxidative stress, which directly impairs the function of the Na,K-ATPase pump. Furthermore, we highlight that C-peptide is required to induce S-nitrosylation of the Na,K-ATPase pump, a modification that hinders the binding of inhibitory endogenous ouabain. Without this protection, and under the stress of RAS overactivation, cellular electrochemical gradients are lost, driving the pathology of diabetic neuropathy and nephropathy. Finally, we present data on a novel therapeutic co-formulation of insulin and C-peptide. Molecular docking simulations and pharmacological modeling reveal that this coformulation acts on a trio of receptors—the Insulin Receptor, GPR146, and RXFP1—to restore physiological coordination. By re-engaging GPR146 internalization (the "off-switch"), the therapy normalizes cortisol levels, restores Vitamin D-mediated suppression of Renin, and reactivates Na,K-ATPase. This mechanism offers a comprehensive strategy to arrest the "triple-hit" of hormonal dysregulation, fibrosis, and biophysical stress driving diabetic complications.

David Petch brings over 30 years of biotechnology expertise as founder and CEO/CSO of utR Biotech Ltd. With extensive experience in mammalian cell culture, fermentation processes, industrial scale-up, and cellular metabolism,  he holds an M.Sc. and B.Sc. Honours in Microbiology from the University of Manitoba, plus certificates in IP/Technology Commercialization and Project Management. Since founding utR Biotech in 2016, David has pioneered integrating C-peptide into insulin formulations—a breakthrough approach addressing severe diabetic complications including cardiovascular disease, neuropathy, and Alzheimer's. His company recently partnered with Innoplexus to leverage AI in determining novel binding sites of C-peptide and insulin, opening new biological pathways for diabetes treatment. utR Biotech focuses on developing affordable diabetes therapeutics for underserved populations worldwide, combining scientific innovation with global health equity. David's published research includes peer-reviewed work on continuous cell culture metabolism in Biotechnology and Bioengineering.