Gene therapy helps patients with damaged hearts grow new blood vessels

Washington, January 5 (ANI): A cocktail of three specific genes can reprogram cells in the scars caused by heart attacks into functioning muscle cells, and the addition of a gene that stimulates the growth of blood vessels enhances that effect, researchers say.

"The idea of reprogramming scar tissue in the heart into functioning heart muscle was exciting," Dr. Todd K. Rosengart, corresponding author of the study from Baylor College of Medicine, said.

"The theory is that if you have a big heart attack, your doctor can just inject these three genes into the scar tissue during surgery and change it back into heart muscle. However, in these animal studies, we found that even the effect is enhanced when combined with the VEGF gene," he said.

During a heart attack, blood supply is cut off to the heart, resulting in the death of heart muscle. The damage leaves behind a scar and a much weakened heart. Eventually, most people who have had serious heart attacks will develop heart failure.

Changing the scar into heart muscle would strengthen the heart. To accomplish this, during surgery, Rosengart and his colleagues from Weill Cornell Medical College and Stony Brook University Medical Center transferred three forms of the vascular endothelial growth factor (VEGF) gene that enhances blood vessel growth or an inactive material (both attached to a gene vector) into the hearts of rats.

Three weeks later, the rats received either Gata4, Mef 2c and Tbx5 (the cocktail of transcription factor genes called GMT) or an inactive material. (A transcription factor binds to specific DNA sequences and starts the process that translates the genetic information into a protein.)

The GMT genes alone reduced the amount of scar tissue by half compared to animals that did not receive the genes, and there were more heart muscle cells in the animals that were treated with GMT.

The hearts of animals that received GMT alone also worked better as defined by ejection fraction than those who had not received genes. (Ejection fraction refers to the percentage of blood that is pumped out of a filled ventricle or pumping chamber of the heart.)

The hearts of the animals that had received both the GMT and the VEGF gene transfers had an ejection fraction four times greater than that of the animals that had received only the GMT transfer.

Rosengart emphasizes that more work needs to be completed to show that the effect of the VEGF is real, but it has real promise as part of a new treatment for heart attack that would minimize heart damage.

"We have shown both that GMT can effect change that enhances the activity of the heart and that the VEGF gene is effective in improving heart function even more," Dr. Ronald G. Crystal said.

The idea started with the notion of induced pluripotent stem cells - reprogramming mature specialized cells into stem cells that are immature and can differentiate into different specific cells needed in the body.

Dr. Shinya Yamanaka and Sir John B. Gurdon received the Nobel Prize in Medicine and Physiology for their work toward this goal this year.

However, use of induced pluripotent stem cells has the potential to cause tumours. To get around that, researchers in Dallas and San Francisco used the GMT cocktail to reprogram the scar cells into cardiomyocytes (cells that become heart muscle) in the living animals.

The study has been published online in the Journal of the American Heart Association. (ANI)

Matches

MORE TOP STORIES TODAY

Rajasthan edge low-scoring thriller

Rajasthan edge low-scoring thriller

The bowlers restricted Hyderabad to 133 for 6 before Rahane and Binny took Rajasthan over the line. More »

Maxwell blitz takes Punjab home

Maxwell blitz takes Punjab home

The Kings XI batsman blasted a 43-ball 95 to help his team pull off a massive chase against Chennai Super Kings. More »

Bangalore vs Mumbai: A battle of the big-hitters

Bangalore vs Mumbai: A battle of the big-hitters

As two of the most glamorous sides in the Indian T20 league, the focus of the match between Mumbai and Bangalore will invariably be on the middle-order… More »

BCCI lacks leaders to take on Srinivasan, says Manohar

BCCI lacks leaders to take on Srinivasan, says Manohar

Two former BCCI presidents, Shashank Manohar and Jagmohan Dalmiya, have reacted strongly to the news of the BCCI calling an emergent meeting on Sunday… More »

Pietersen ridicules idea of day-night Tests

Pietersen ridicules idea of day-night Tests

Kevin Pietersen has ridiculed the idea of day-night Test cricket, saying the game would be so different to proper Test cricket that we will need a whole… More »

Beleaguered Yuvraj tees off to Sharjah's delight

Beleaguered Yuvraj tees off to Sharjah's delight

Yuvraj Singh was hardly convincing to begin with against Delhi, but a big dose of crowd support and a helping of poor bowling meant he had the opportunity… More »

Stressed Trott stands down again

Stressed Trott stands down again

The England and Wales Cricket Board (ECB) on Friday confirmed that batsman Jonathan Trott is to take another break from all cricket with immediate eff… More »

PCB starts another coach hunt

PCB starts another coach hunt

The PCB has decided to not extend the contracts of head coach Moin Khan, fielding coach Shoaib Mohammad and batting consultant Zaheer Abbas, and has invited… More »

Pakistan cricketers face probe

Pakistan cricketers face probe

Pakistani cricket authorities have launched an investigation after a number of current international stars played in exhibition matches in the United States… More »

Fiery star Stokes bids to curb his temper

Fiery star Stokes bids to curb his temper

England all-rounder Ben Stokes admits he must keep his anger under control if he is to end his international exile. More »

Bangalore's arsenal blazes to victory

Bangalore's arsenal blazes to victory

Yuvraj Singh was back to his best in his first match for Royal Challengers Bangalore. More »

BCCI to meet before next court hearing

BCCI to meet before next court hearing

The BCCI will hold an emergent working committee meeting on April 20 to discuss the future course of action with regard to the Supreme Court hearing concerning… More »

Gavaskar wants a clean IPL

Gavaskar wants a clean IPL

"Integrity is non-negotiable..." says the BCCI's interim chief ahead of Season 7 of the tainted league. More »

Time for Chennai to enter familiar cocoon

Time for Chennai to enter familiar cocoon

Chennai have an emphatic 8-3 lead in the head-to-head with Punjab, with one game tied More »

Kallis, Narine star in KKR win

Kallis, Narine star in KKR win

An all-round display saw Knight Riders thump Mumbai Indians by 41 runs in the IPL-7 opener. More »

'Yak' Kallis still on top of his game

'Yak' Kallis still on top of his game

The 38-year-old South African veteran turned it on for Kolkata Knight RIders in the opening match of IPL-7. More »

Rajasthan and Hyderabad face-off

Rajasthan and Hyderabad face-off

A quality that defines Rajasthan and Hyderabad is consistency. Rajasthan was one among two teams to enjoy complete dominance at home last season. Hyderabad… More »

Srinivasan named in fixing report: SC

Srinivasan named in fixing report: SC

The court emphasised that the tainted administrator can no longer work for the BCCI. More »

Yuvraj happy to play for RCB: Kohli

Yuvraj happy to play for RCB: Kohli

New-look RCB will play their first game of IPL-7 on Thursday. More »

IPL: News Line

IPL: News Line

A round-up of all the news from this season of the IPL. More »

Shane Watson issues moral warning

Shane Watson issues moral warning

'Everyone knows what is right and what is wrong and if you do the wrong thing it will be found out' More »

Why I'm not looking forward to the IPL

Why I'm not looking forward to the IPL

Welcome to another season of a league that many watch but few trust. More »

Johnson may quit T20s for Tests

Johnson may quit T20s for Tests

Australia's Mitchell Johnson may quit limited-overs cricket to prolong his test career with an eye on the 2015 Ashes series in England, the fast bowler… More »

Nepal players call off boycott

Nepal players call off boycott

Thaw in relations after formation of an advisory committee that would work in tandem with the Cricket Association of Nepal. More »