Arterial damage is caused by caused by excess lipids, infections and other stresses. This can manifest as loss or damage to the innermost layer of artery walls, the endothelium. This triggers an inflammatory reaction and a number of signalling cascades that converge on medial smooth muscle cells to stimulate their proliferation, leading to overexuberant repair and the development of neointimal hyperplasia. New approaches to tackle this response are needed and especially in procedures that involve coronary stenting where there are opportunities to add additional drugs to coronary stents for example to speed up the repair of endothelium or to halt excessive growth of smooth muscle cells.
We recently published a paper on another formulation of CORM https://journals.lww.com/cardiovascularpharm/Abstract/9000/Carbon_monoxide_releasing_molecule_A1_reduces.98224.aspx where minute quantities of carbon monoxide released by the specific pharmaceutical formulation improved healing of the heart after heart attacks.
Carbon monoxide (CO) is endogenously produced in the body during the degradation of haem by haem oxygenases (HO). Several studies have demonstrated that CO is not just an inconsequential by-product of haem metabolism, but may also have potent anti-inflammatory, anti-proliferative and anti-apoptotic effects on vessel walls; all of which are involved in restenosis. CO has emerged as a potential therapeutic target for preventing restenosis, although the exact mechanisms involved are not yet known. CO-releasing molecules (CORMs), capable of carrying and releasing controlled quantities of CO in cellular systems, are a promising therapeutic that overcome the limitations of CO gas.
This PhD project hypotheses that CORM-3 inhibits vascular cell repair by suppressing inflammation and/or NO/NOS crosstalk.
There are several potential mechanisms of action by which CO could inhibit excessive vascular cell growth: via an anti-inflammatory, anti-proliferative, or anti-apoptotic effect, or by affecting crosstalk with nitric oxide synthases (NOS) and nitric oxide (NO). This project aims to build on data already generated, to address the specific questions: 1) Is the expression and release of inflammatory cytokines and their signalling mechanisms affected in either VSMCs or HCEACs, when incubated with CORM-3, in culture?; 2) Is the expression of NO or NOS affected in either VSMCs or HCEACs, when incubated with CORM-3, in culture?; and 3) If inflammation and/or NO/NOS is affected in HCAECs, do these cells need to be activated to respond to CORM-3?
Both human coronary artery endothelial cells (HCAECs) and vascular smooth muscle cells (VSMCs) will be used. HCAECs will be pre-stimulated with cytokines (TNF-α and IL-1α) to activate them, or left unstimulated. VSMCs do not need prior stimulation. All cells will be incubated with CORM-3 or placebo (RuDMSO) for different timepoints in vitro. Pro-inflammatory cytokines (IL-1, IL-6, TNF-α, MCP-1), and signalling pathways (MyD88, p-AKT, p-p38 MAPK, p65 NF-κB, Nrf2) will be used to assess the affect on inflammation. NO/NOS crosstalk will also be analysed by measurement of iNOS, eNOS, NO and cGMP levels. Both supernatants and lysates will be collected, and analysed by ELISA, Western Blotting and commercial assay kits, as appropriate. We will also the effects of CORM3 on physiological mechanisms such as endothelial-mesenchymal transition in vitro and in models of cytokine release. We already have in vivo data with CORM3 which the student will be able to analyse in depth during their project.
We expect these data to confirm whether CORM-3 acts to reduce inflammatory or NO/NOS mechanisms in HCAECs and/or VSMCs, which will clarify in vivo data already collated, to help determine the mechanism by which excessive vascular cell proliferation is reduced following CORM-3 treatment.
Candidates must have a first or upper second class honors degree or significant research experience.
How to apply:
Please complete a University Postgraduate Research Application form available here: https://www.sheffield.ac.uk/postgraduate/phd/apply/applying
Please clearly state the prospective main supervisor in the respective box and select Infection, Immunity and Cardiovascular Disease as the department.