LICAMM Differentiated response of endothelial Piezo1 channels to shear stress and hydrostatic pressure and its underlying molecular basis

Mechanical forces play important roles in physiology and pathophysiology of vascular endothelial cells such as proliferation, apoptosis, migration, permeability, and remodelling. The endothelial cells are constantly exposed to two principle mechanical forces: shear stress and hydrostatic pressure. Although both types of mechanical forces could induce considerably similar responses in endothelial cells, they also differ in evoking some important cellular activities: e.g., only shear stress can up-regulate nitric oxide synthesis in the cells while hydrostatic pressure does not affect such synthesis, which provides the evidence that shear stress and hydrostatic pressure acting on endothelial cells could regulate the cell functions through different ways.

<p>Interestingly, Piezo1 channel has been identified as the only ion channel sensing either shear stress or hydrostatic pressure in native endothelial cells. As one of the ion channels recognised by the 2021 Nobel Prize on Medicine and Physiology, Piezo1 possesses some unique characteristics. It consists of 2521 amino acids in human and 2547 amino acids in mouse with an unusual molecular weight of around 280 KD. It is only homologous to Piezo2. It can form a trimeric ion channel permeable to Na+ and Ca2+.</p> <p>Given that shear stress and hydrostatic pressure could cause different responses in endothelial cells and Piezo1 is the only channel sensing both mechanical forces, it is thus intriguing and important to understand how the Piezo1 channel activities evoked by shear stress or hydrostatic pressure differ from each other, which underlies the differentiated cellular responses to both mechanical forces.</p> <p>In this project the student will combine state-of-the-art electrophysiological recordings in native cells with cutting-edge molecular dynamic simulations to study the molecular functional kinetics of Piezo1 channel, regulation of mechanical sensing in Piezo1 by important chemical signals and the underlying molecular basis. The specific objectives include:</p> <ol> <li>To determine the molecular functional kinetics of endothelial Piezo1 channel activated by shear stress or hydrostatic pressure;</li> <li>To determine how the mechanical sensing capability in endothelial Piezo1 channel in response to shear stress or hydrostatic pressure is regulated by its surrounding chemical signals including pH, cytoplasmic Ca2+;</li> <li>To simulate the molecular conformation changes of Piezo1 channel with endothelial membrane in response to either shear stress or hydrostatic pressure and predict the molecular basis;</li> <li>To validate the simulated molecular basis in an overexpression system with the“hypothesis-check-adjust-iterate”strategy.</li> </ol> <p>The student will learn cutting-edge electrophysiological recordings in native cells with different configurations and molecular dynamics simulation in combination with molecular biology method which are all well-established at Leeds. The combination of experimental findings with computational modelling will enable the student to achieve an insightful and comprehensive understanding of molecular dynamic characteristics of endothelial Piezo1 channel, which could be further extended to its relevance to vascular physiology and pathophysiology.</p> <p>The student will be based in the Leeds Institute of Cardiovascular and Metabolic Medicine which is already reputed for conducting high-impact research that has real-world impact, improving peoples' lives and addressing the world's healthcare challenges. The existing cross-disciplinary approaches will allow the student to receive extensive trainings on all methods necessary for cardiovascular research. This opportunity would suit a student with the background of medicine, biology, biochemistry, chemistry or physics, or a combination of these. No prior research experience is required.</p> <h5>References</h5> <ol> <li>Vozzi <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Vozzi+F&cauthor_id=23959971">F</a>, Bianchi <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Bianchi+F&cauthor_id=23959971">F</a>, Ahluwalia <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Ahluwalia+A&cauthor_id=23959971">A</a>, Domenici <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Domenici+C&cauthor_id=23959971">C.</a> 2014. Hydrostatic pressure and shear stress affect endothelin-1 and nitric oxide release by endothelial cells in bioreactors. Biotechnol J.  9(1):146-54.</li> <li>Prystopiuk <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Prystopiuk+V&cauthor_id=29848657">V</a>, Fels <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Fels+B&cauthor_id=29848657">B</a>, Simon <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Simon+CS&cauthor_id=29848657">CS</a>, Liashkovich <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Liashkovich+I&cauthor_id=29848657">I</a>, Pasrednik <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Pasrednik+D&cauthor_id=29848657">D</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Kronlage+C&cauthor_id=29848657">Kronlage</a> C, <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Wedlich-S%C3%B6ldner+R&cauthor_id=29848657">Wedlich-Söldner</a> R, <a href="https://pubmed.ncbi.nlm.nih.gov/?sort=date&term=Oberleithner+H&cauthor_id=29848657">Oberleithner</a> H, Fels J. 2018. A two-phase response of endothelial cells to hydrostatic pressure. J Cell Sci. 131(12):jcs206920.</li> <li>Shi J, Hyman AJ, De Vecchis D, Chong J, Lichtenstein L, Futers TS, Rouahi M, Salvayre AN, Auge N, Kalli AC, Beech DJ. 2020. Sphingomyelinase Disables Inactivation in Endogenous PIEZO1 Channels. Cell Rep. 33.</li> <li>Rode B, Shi J, Endesh N, Drinkhill MJ, Webster PJ, Lotteau SJ, Bailey MA, Yuldasheva NY, Ludlow MJ, Cubbon RM, Li J, Futers TS, Morley L, Gaunt HJ, Marszalek K, Viswambharan H, Cuthbertson K, Baxter PD, Foster R, Sukumar P, Weightman A, Calaghan SC, Wheatcroft SB, Kearney MT, Beech DJ.  2017. Piezo1 channels sense whole body physical activity to reset cardiovascular homeostasis and enhance performance.  Nat Commun. 8(1):350. </li> <li>Chong J, De Vecchis D, Hyman AJ, Povstyan OV, Ludlow MJ, Shi J, Beech DJ, Kalli AC. 2021. Modeling of full-length Piezo1 suggests importance of the proximal N-terminus for dome structure. Biophys. J. 120: 1343–1356.2.</li> <li>De Vecchis D, Beech DJ, Kalli AC. 2021. Molecular dynamics simulations of Piezo1 channel opening by increases in membrane tension. Biophys. J. 120: 1510–1521.</li> <li>Li J, Hou B, Tumova S, Muraki K, Bruns A, Ludlow MJ, Sedo A, Hyman AJ, McKeown L, Young RS, Yuldasheva NY, Majeed Y, Wilson LA, Rode B, Bailey MA, Kim HR, Fu Z, Carter DA, Bilton J, Imrie H, Ajuh P, Dear TN, Cubbon RM, Kearney MT, Prasad RK, Evans PC, Ainscough JF, Beech DJ. 2014. Piezo1 integration of vascular architecture with physiological force. Nature. 515: 279–282. </li> </ol>

<p>Please note these are not standalone projects and applicants must apply to the PhD academy directly.</p> <p>Applications can be made at any time. You should complete an <a href="https://medicinehealth.leeds.ac.uk/faculty-graduate-school/doc/apply-2">online application form</a> and attach the following documentation to support your application. </p> <ul> <li>a full academic CV</li> <li>degree certificate and transcripts of marks (or marks so far if still studying)</li> <li>Evidence that you meet the programme’s minimum English language requirements (if applicable, see requirement below)</li> <li>Evidence of funding to support your studies</li> </ul> <p>To help us identify that you are applying for this project please ensure you provide the following information on your application form;</p> <ul> <li>Select PhD in Medicine, Health & Human Disease as your planned programme of study</li> <li>Give the full project title and name the supervisors listed in this advert</li> </ul>

A degree in biological sciences, dentistry, medicine, midwifery, nursing, psychology or a good honours degree in a subject relevant to the research topic. A Masters degree in a relevant subject area is desirable but not essential.

Applicants whose first language is not English must provide evidence that their English language is sufficient to meet the specific demands of their study. The minimum requirements for this programme in IELTS and TOEFL tests are: • British Council IELTS - score of 7.0 overall, with no element less than 6.5 • TOEFL iBT - overall score of 100 with the listening and reading element no less than 22, writing element no less than 23 and the speaking element no less than 24.

<p>For further information please contact the Faculty Graduate School<br /> e:<a href="mailto:fmhpgradmissions@leeds.ac.uk">fmhpgradmissions@leeds.ac.uk</a></p>