Tamer M.A. Mohamed – UofL News Wed, 22 Apr 2026 16:55:01 +0000 en-US hourly 1 UofL research extending usable life of heart tissue could help speed medical innovation /section/science-and-tech/uofl-research-extending-usable-life-of-heart-tissue-could-help-speed-medical-innovation/ Wed, 21 Sep 2022 16:20:59 +0000 /?p=57321 University of Louisville research could help spur new medicines by extending the usable life of test heart tissue from one day to 12. The findings were published in the journal .
Biomedical researchers use slices of heart tissue to test the effectiveness and toxicity of new drugs, drug candidates and gene therapies. Until recently, the limited, 24-hour usable life of those slices created a major barrier to drug discovery, slowing down the development of new, potentially life-saving medications.
UofL methods, developed by a multidisciplinary team from the School of Medicine and J.B. Speed School of Engineering, extended the tissue’s usable life with a discovery in 2019, and now to 12 days, by mimicking the conditions experienced by a living heart. The tissue ‘lives’ in a pneumatic chamber, receivingelectrical stimulation and nutrition and pumping air instead of blood.
“We’ve created a complete cardiac cycle within the chamber, so the heart tissue stays pumping and viable for longer,” said Tamer M. A. Mohamed, an associate professor of medicine who led the research. “This system will save time and costs of clinical trials during Phase 1 research, which includes testing for toxicity and proof of efficacy.”
Because of the short shelf-life of human heart tissue, he said, many drug candidates today are tested in ways that don’t perfectly emulate living heart tissue or use tests that otherwise don’t show the full range of potential side effects related to cardiotoxicity.This could be a reason some . The UofL team believes giving researchers a bigger window in which to test could lead to better, safer medications.
“A longer shelf-life gives them more time for proper testing and access to the right materials,” said Jessica Miller, a graduate student researcher and an author on the paper. “That could lead to faster advancements in how we treat heart-related conditions.”
The through the university’s . The researchers also have been working with the entrepreneurs in residence team — part of the office’s entrepreneurial arm, UofL New Ventures — to explore potential paths to market.
]]> New gene therapy for heart failure developed by UofL researchers /section/science-and-tech/new-gene-therapy-for-heart-failure-developed-by-uofl-researchers/ Mon, 24 Jan 2022 15:30:42 +0000 /?p=55504 A UofL research team has refined a process in which specific genes administered to heart muscle cells stimulate the cells to divide, with the goal of restoring heart function following a heart attack. Tamer M.A. Mohamed, assistant professor of cardiology, along with colleagues in UofL’s and elsewhere, have completed preclinical testing that will allow this therapy to be tested in humans as a treatment for certain types of heart failure.

“By inducing proliferation in cardiac heart muscle cells, we hope to be able to treat this deadly disease.” Mohamed said. “In this study, we have demonstrated preliminary efficacy of the transient gene therapy we call 4F in the treatment of ischemic heart failure.”

The most common form of heart disease, ischemic heart disease affects about 18.2 million adults in the United States and caused 360,900 deaths in 2019. Also called coronary heart disease, it is characterized by reduced blood and oxygen flow to the heart due to narrowed arteries, usually caused by a buildup of plaque. When the blood flow to the heart muscle is completely blocked, the patient experiences a heart attack and millions of heart muscle cells die.

Since heart muscle cells do not reproduce readily and limited medical options exist to repair heart muscle, a heart attack often leads to progressive heart failure.

The therapy developed by Mohamed’s team involves a combination of four cell-cycle regulator genes, cyclin-dependent kinase 1 (CDK1), CDK4, cyclin B1, and cyclin D1, known collectively as 4F, or four factors. Using 4F, the UofL-led team was able to stimulate the proliferation of heart muscle cells in the lab, leading to improved heart function in animal models for up to four months.

In addition, the proliferation was limited to onecycle, avoiding adverse effects resulting from uncontrolled proliferation, thereby increasing clinical feasibility of the process.

Mohamed Lab researchers in the UofL Institute of Molecular Cardiology, (l. to r.) Qinghui Ou, Xian-Liang Tang, Tamer Mohamed, AbouBakr Salama and Riham Abouleisa
Mohamed Lab researchers in the UofL Institute of Molecular Cardiology, (l. to r.) Qinghui Ou, Xian-Liang Tang, Tamer Mohamed, AbouBakr Salama and Riham Abouleisa

Mohamed was part of a team that first identified the potential of the of heart muscle cells in 2018. In this most recent work, he and his team further refined the process to use these genes, bringing the technology to treat ischemic heart disease closer to testing in humans. was published Jan. 21 in the journal Circulation.

In October, Mohamed and Bradford Hill, professor in the Division of Environmental Medicine, led a team that showing that two common food supplements, Nicotinamide (Vitamin B3) and N-acetyl glucosamine (GlcNAc), are essential for heart cell division and improve cardiomyocyte proliferation when included as part of treatment with 4F.

“This discovery will facilitate new avenues to use metabolites which are naturally in our food to regenerate the diseased heart and treat heart failure,” Mohamed said.

The study utilized adeveloped at UofL by Mohamed that keeps slices of human hearts alive for a longer period of time for research. The system mimics the environment of a living organ through continuous electrical stimulation and oxygenation, maintaining viability and functionality of the heart segments for six days, allowing more extensive testing. Thefor use by researchers outside UofL.

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