BASIC SCIENCE TIP SHEET

November 13, 2016 Categories: Heart News, Scientific Conferences & Meetings

Tip Headlines:

  • Ultrasound-targeted microbubble may help deliver novel drug to the heart
  • Cardiovascular health linked to cellular aging 
  • Patient’s own connective tissues may serve as future dialysis access tubes
  • microRNA 128 may restore hearts self-healing ability

All tips listed below are embargoed for 3 p.m. CT/4 p.m. ET, Sunday, Nov. 13, 2016

Poster: S4217 – Session: IM.APS.P20

Ultrasound-targeted microbubble may help deliver novel drug to the heart

Ultrasound-targeted microbubbles may be the best way of delivering a novel class of drug targeting molecules called microRNAs (miRs) to the diseased heart, according to a preliminary study presented at the American Heart Association’s Scientific Sessions 2016.

Previous studies have observed blocking the actions of a particular miR called mir-23a prevents the thickening of the heart walls. However, moving the drug towards patient use has been limited because of the challenges of delivering the drug only to the heart.

In this new study, researchers from the University of Pittsburgh demonstrate in mice a possible solution: encapsulating anti-miR23a drug in microbubbles that break open with ultrasound. The hearts of hypertensive mice treated with this strategy had significantly less cardiac hypertrophy (wall thickening) than untreated hypertensive mice and their hearts performed the same as the healthy mice. This is one of the first studies to support microbubbles as a viable way of delivering miR-blocking drugs for heart therapies,” researchers said.

Jonathan Kopechek, Ph.D., University of Louisville, Louisville, Kentucky.

Note: scientific presentation is 3:45 p.m. CT, Sunday, Nov. 13 in the Science and Technology Hall, Basic Science Section.

 

Presentation: 251 – Session: EP.AOS.486.N

Cardiovascular health linked to cellular aging 

The age of a person’s immune cells may predict risk of cardiovascular disease, according to a preliminary study presented at the American Heart Association’s Scientific Sessions 2016.

DNA is packed into structures called chromosomes, and when cells copy themselves to replace old, damaged or dead cells, the tips of the chromosomes, called telomeres, shorten. Shorter telomere length is a sign of aging in a cell and has been associated with a number of diseases, including heart disease.

Researchers examined the relationship between telomere length of leukocytes, the body’s immune cells, and overall cardiovascular health — defined using the American Heart Association’s Life Simple 7 metrics (smoking, physical activity, diet, body mass index, blood pressure, total cholesterol and fasting blood glucose).

Using data from the 1999-2002 National Health and Nutrition Examination Survey, researchers measured telomere length and overall cardiovascular health in 5,194 subjects, researchers found:

  • Participants with shorter leukocyte telomere length tended to have poorer cardiovascular health.
  • Leukocyte telomere length reflected cardiovascular health more accurately in women and white people.

The findings support the link between cardiovascular health and cell aging even though it can vary by gender and race. More research is needed to explain the gender and race differences, researchers said.

Samson Gebreab, Ph.D., National Human Genome Research Institute, Bethesda, Maryland.

Note: scientific presentation is 2:00 p.m. CT, Monday, Nov. 14 in room 346-347.

 

Poster: M4141 - Session: VA.APS.P73

Patient’s own connective tissues may serve as future dialysis access tubes

Access tubes made from a patient’s own connective tissue may be an alternative to plastic tubes used to prepare the patient’s vein for dialysis treatment, according to a preliminary study presented at the American Heart Association’s Scientific Sessions 2016.

A patient’s vein is prepared to withstand the repeated needle insertions from the dialysis procedure by connecting it with the artery. While the preferred approach is to join a section of the vein directly to the artery, it is not appropriate for all patients. As an alternative, the vein can be bridged to the artery with a plastic tube. However, plastic is prone to clotting and infections so Japanese researchers proposed forming a tube made from a patient’s own connective tissue — a material that occurs naturally in the body.

The researchers selected two female patients with end stage kidney disease who were at high risk for dialysis treatment failure. Connective tissue tubes, called Biotubes, were formed by embedding small stainless steel tubes underneath patient’s skin for two months.

After the tubes were surgically bypassed for the treatment of venous stenosis in an AV shunt, they showed no changes in shape, normal blood flow patterns or damage in the first three months. Repeated punctures could be performed without damage to the grafts.

Researchers said this is the first in-human study to successfully use tubes made from the patient’s connective tissue in dialysis.

Yasuhide Nakayama, Ph.D., National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan.

Note: scientific presentation is 10:45 a.m. CT, Monday, Nov. 14 in the Science and Technology Hall, Clinical Science Section.

 

Poster S1000 - Session: AT.APS.P88

microRNA 128 may restore hearts self-healing ability

Blocking the activity of a specific microRNA — molecules that turn genes on and off — may help the heart recover after a heart attack, according to a preliminary study presented at the American Heart Association’s Scientific Sessions 2016.

The ability of cardiomyocytes to copy and replace damaged heart tissue is lost in adulthood. However, enabling this ability would be a promising therapy for helping hearts recover after injury, such as a heart attack. Researchers from the University of Cincinnati studied the role of micro RNA and the loss of the heart’s self-healing capacity.

They found the level of one miR called miR128 increased as the cell’s capacity to replicate itself decreased. Also, mice with elevated levels of miR128 had less cardiomyocyte replication. But, mice with miR128 deletion had more cardiomyocyte replication and recovered better after heart attack.

Researchers said these results show that miR128 controls the ability of cardiomyocytes to replicate themselves and may be a promising therapeutic option for heart repair after injury.

Wei Huang, M.D., Ph.D., University of Cincinnati, Cincinnati, Ohio.

Note: scientific presentation is 4:45 p.m. C.T., Sunday, Nov. 13 in the Science and Technology Hall, Basic Science Section.

Additional Resources:

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Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at www.heart.org/corporatefunding.

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