Mural cells from saphenous vein could have long-term benefits in heart attacks

Stem cell therapies promise to regenerate the infarcted heart through the replacement of dead cardiac cells and stimulation of the growth of new vessels. New research has found the transplantation of stem cells that reside in human veins can help in the recovery of a heart attack. The findings could lead, in the next few years, to the first human clinical trial.

The study, led by Professor Paolo Madeddu, Chair of Experimental in the School of Clinical Sciences at the University of Bristol and colleagues in the Bristol Institute, is published online in : Journal of the .

The study, funded by the British Heart Foundation (BHF) and a National Institute for Health Research (NIHR) grant, looked at whether human mural cells, known to scientists as pericytes, cells that stay around, can stabilise blood vessels after a heart attack.

The researchers, using a mouse model, have demonstrated for the first time that pericytes expanded from redundant human leg veins are able to stimulate new blood vessels (neovascularization) and help with the recovery after a heart attack.

The study found that upon transplantation pericytes relocate around the vessels of the peri-infarct zone and establish with them physical contacts allowing the transfer of genetic material, microRNA-132 (miR-132). MicroRNAs are small non-coding that modulate the expression of genes by binding to messenger-RNA and inhibiting it. One microRNA can inhibit many genes simultaneously. The study shows that the transfer of miR-132 from pericytes to inhibits a gene that acts as a negative regulator of cell growth. This unlashes endothelial cell proliferation and the formation of new vessels.

Professor Madeddu said: "Although bone marrow cell therapies dominate today, continued research on other types of stem cells is mandatory to achieve optimal treatment of cardiovascular disease.

"Human pericytes could be an invaluable source for future applications of cardiovascular regenerative medicine."

The researchers demonstrated that transplanted pericytes relocate around and support the growth of blood vessels in the heart, suggesting an unusual growth of these cells is instrumental to therapeutic benefit. The physical contact between pericytes and resident endothelial cells may strengthen the nascent vascularization, thus reducing micro-vascular permeability and myocardial oedema, which are acknowledged to have a negative impact on cardiac function.

The discovery that pericytes use microRNAs to communicate with neighbouring cells reveals a new mechanism used by these cells to influence vascular function. Likewise, pericytes can sense signals from the endothelium and communicate biochemical information to surrounding tissue.

Dr Helene Wilson, Research Advisor at the BHF, which co-funded the study, said: "This exciting discovery is one more step towards mending broken hearts. It shows that 'one man's trash could be another's treasure' – using from leftover vein normally binned after heart bypass surgery, to try to repair heart damage in mice.

"While it's early days, the study shows that pericytes may have potential to help repair the heart after a heart attack. This is a vital goal for preventing heart failure, which currently affects more than 750,000 people in the UK and has a worse prognosis than many cancers."

Related Stories

Stem cells to repair damaged heart muscle

Jun 22, 2007

In the first trial of its kind in the world, 60 patients who have recently suffered a major heart attack will be injected with selected stem cells from their own bone marrow during routine coronary bypass surgery.

Unexpected cell repairs injured spinal cord

Jul 07, 2011

Lesions to the brain or spinal cord rarely heal fully, which leads to permanent functional impairment. After injury to the central nervous system (CNS), neurons are lost and largely replaced by a scar often referred to as ...

Recommended for you

Gene variant raises risk for aortic tear and rupture

Apr 17, 2014

Researchers from Yale School of Medicine and Celera Diagnostics have confirmed the significance of a genetic variant that substantially increases the risk of a frequently fatal thoracic aortic dissection or full rupture. ...

Considerable variation in CT use in ischemic stroke

Apr 17, 2014

(HealthDay)—For patients with ischemic stroke there is considerable variation in the rates of high-intensity computed tomography (CT) use, according to a study published online April 8 in Circulation: Ca ...

Beating the clock for ischemic stroke sufferers

Apr 17, 2014

A ground-breaking computer technology raises hope for people struck by ischemic stroke, which is a very common kind of stroke accounting for over 80 per cent of overall stroke cases. Developed by research experts at The Hong ...

User comments