Tag Archives: heart failure

Heart Health: Slowing the Progression of Heart Failure
Amal Altaf
Junior
Biological sciences (BS) and global health (BA)
Barrett at Arizona State University

My Research Project

Cardiac fibroblasts are cells in the heart that are involved in producing proteins such as collagen. An accumulation of these proteins leads to a medical diagnosis termed fibrosis, which plays a major role in the progression of heart failure. Proteins such as angiotensin II are known to activate fibroblasts and promote fibrosis. Reactive oxygen species (ROS) are unstable molecules in the cell that have been suspected to play a role in angiotensin-II-induced inflammation and, consequently, fibrosis. An imbalance of ROS in the cells is called oxidative stress. While no treatment is known to reverse fibrosis, a class of drugs known as angiotensin converting enzyme inhibitors (ACEI) are able to slow its progression, even after ACEI treatment has been stopped. However, it is unknown how ACEI treatment is able to protect against fibrosis.

In this experiment, I was tasked with investigating whether the protection against fibrosis was a consequence of a more favorable oxidative stress profile in response to angiotensin II treatment. Using heart tissue from the left ventricle of rats my lab was able to test our hypotheses. The rats were divided into three treatment groups, each treated for a total of six weeks, The treatment proposed on the rat models is depicted by the table below.

Because ACEI has been previously shown to protect against fibrosis, we hypothesized that hearts from hypertensive rats previously treated with ACEI would show decreased protein expression of pro- and anti-oxidant enzymes in response to angiotensin II, which corresponds to Group 3 in the table above. Understanding whether oxidative stress is altered due to prior ACEI treatment will allow for a better understanding of the mechanisms through which the heart can become more resistant to fibrosis. This may contribute to a better understanding of cardiac fibrosis and the development of novel treatments that may slow or prevent heart failure.

Realities of Research

Loading of Western Blot gel.

It surprised me, but I quickly learned that research involved a great deal of trial and error. I learned that while every step in the research plan is well thought out, there is still a lot of uncertainty. However, that was not a bad thing, because that uncertainty is exactly what we are targeting through our research. We sought to understand things we did not already know. My experience this summer forced me to learn new techniques, such as those of western blotting, imaging via film, and technology and analysis. I was also been fortunate enough to shadow others in the lab and gain better understanding of several other procedures such as surgeries, cell culture and immunohistochemistry.

More often than not, the results I received were different from what I expected, which led to several discussions with my research host about possible explanations and potential next steps, very often being revised. It almost reminded me of the game “Chutes and Ladders.” We would make progress in the direction we expected, then come across unexpected results which sometimes brought us back to square one or took us in a new direction. I’m not entirely sure how many times we had to start over, but we certainly had to go back and change our plan several times. We actually just revised our research question a few weeks prior to wrapping up the summer research!

Life as a Scientist

The daily life of a scientist is much more than mixing chemicals and making graphs. My life as a scientist this summer provided me with insight into the reality of working in a research lab. Beyond the trial and error, the uncertainty and the constant learning that all made each day in this field so intriguing, there was also a great amount of collaboration involved. Working as part of a team was one of my favorite parts of being a scientist. I worked towards a common goal with my lab team, but also worked with people outside of my lab, even those whose research had a different focus. My least favorite part of working in the lab was how writing-intensive it was.

When picturing a scientist, a person in a lab coat working at a lab bench usually comes to mind. In reality, the life of a scientist involves a considerable amount of writing in order to obtain grants to fund the research and to communicate the research. While this hasn’t been completely applicable to my case (since I’m not writing grants—yet!), I would still consider it to be the “worst” part about the day-to-day life of a scientist. All in all, my time in the lab this summer allowed me to gain an invaluable understanding not only of the research project I worked on, but also the realities of research and the life of a scientist.

Amal Altaf is a junior double majoring in biological sciences and global health at Barrett, The Honors College at Arizona State University in Tempe, Ariz. She is a 2019 Undergraduate Summer Research Fellow (UGSRF) working in Dr. Taben Hale’s lab at the University of Arizona College of Medicine in Phoenix. Amal’s fellowship is funded by the American Physiological Society. Upon graduating, Amal hopes to pursue medical school to eventually practice as a physician

A Summer of Fibrosis

This summer I have had the unique opportunity to work on a project that involves human heart tissue, an opportunity provided to me by the American Physiological Society and the Campbell Muscle Lab at The University of Kentucky.  My project focused on heart failure, a topic that is vital to many Americans, in fact, the American Heart Association showed that approximately 5.7 million adults in the United States suffer from heart failure. My study looked specifically at the varying amounts of collagen based on sex and heart failure status. It has been researched and shown that there is an increase in fibrosis when a patient has heart failure. Fibrosis is a term that describes tough fibers that replace damaged cardiac tissue in a process known as cardiac remodeling; an example of fibrosis is collagen, the protein that we stained for. The unique part to this study is the comparison of men and women, regarding the amount of collagen present in the heart tissue. This idea stems from a previous experiment conducted in the lab that used a process called Nanostring to determine the expression of genes related to heart disease and failure in both failing and non-failing human hearts. This study showed that there were genes related to collagen that had sex specific differences. Although the experiment might not be revolutionary, it will aid in bridging the gap that currently exists in research regarding the physiological difference between men and women. Although, we do not have enough data to draw conclusions yet, we are already thinking about future directions for our project!

The Realities of Research

Research is an imperfect process to say the least, and in my opinion that is what makes it wonderful. Things do not always go as anticipated when conducting research. It might not always yield the expected results, but it was at the very least a learning experience. One of the largest realities I had to face was that just because a protocol is well established does not mean that it is easy to learn, or unalterable. The protocol for my experiment is one that is well established and has been for many years. That would ideally make the project simple, right? Wrong. At the beginning, there were numerous problems, most associated with a steep learning curve. Part of my job is to cut tissue, and there were many rat heart samples that had to be cut before I could begin working with human tissue. Once the cutting was mastered, there was still a problem with the staining aspect of the protocol.  The protocol written seemed clear, but the results of the stains were not up to par. So, we worked to adjust the protocol in order to obtain samples that were suitable enough to analyze. This steep learning curve was rough, but it made for a great application of problem solving skills.

The Daily Life of a Scientist

The daily life of a scientist is quite interesting, especially in my lab. Sometimes the day to day life of a scientist can be a little monotonous. I would come in and cut the tissue, stain the tissue, and image the samples, but just when things were getting a little boring, we would get a call on what we call the bat phone. The bat phone rings whenever there is a heart transplant or an organ donor, who is unable to donate his or her heart. We are then able to take the heart and store it for future research for our lab or any other that wants to use human samples. We are on call 24/7 and there are times where I must leave an experiment to collect a heart. Although this seemed inconvenient at times, such as 2 AM, it was great to have such a unique opportunity. The daily life of a scientist in the Campbell Muscle Lab is exciting, challenging, and unique to say the least.

References

  1. Mozaffarian, Benjamin, Go, Arnett, Blaha, Cushman, . . . Turner. (2016). Heart Disease and Stroke Statistics—2016 Update: A Report From the American Heart Association. Circulation, 133(4), E38-E360.
Autumn Conger attends the University of Kentucky in Lexington, KY. She is a 2017 Undergraduate Summer Research Fellow (UGSRF) and worked in Dr. Kenneth Campbell’s lab at the University of Kentucky. Autumn plans to go to medical school and become a physician scientist. She hopes to help in bridging the gap between the fields of medicine and research.
Making Networks of Many Kinds

A heart attack, or myocardial infarction, results from blockage of arteries that deliver oxygen-carrying blood to heart tissue (NIH). Once the cells of the affected region die, the heart’s wall may grow so thin that it ruptures, or the heart’s force of contraction can decrease to the point that it is nonfunctional. Heart failure is a major medical problem for both patients and physicians. In the United States alone, approximately 5.7 million people 20 years or older had heart failure, according to data collected between 2009 and 2012. Moreover, there is approximately a fifty percent probability of death within 5 years of diagnosis (Mozaffarian et al., 2016). Angiogenesis, the formation of new blood vessels from preexisting ones (Robich, Chu, Oyamada, Sodha, & Sellke, 2011), is a key process to delaying the progression of heart failure. Angiogenesis helps heal damaged heart tissue by restoring blood flow, and scientists have worked to investigate and stimulate this process because of its beneficial potential. My research project explores angiogenesis throughout the full timeline of heart failure pathology—up to 56 days after myocardial infarction in mice models, or 10 years after myocardial infarction in humans. I also want to determine if there is a relationship between angiogenesis and lipoxygenase 12/15, an enzyme that forms metabolites which can aggravate or inhibit disease, depending on the context (Conrad, 1999). Mice are lipoxygenase 12/15-deficient heal better and have a higher survival rate after myocardial infarction than wild type mice, but the reason for this is unknown. My project is important because previous studies have primarily focused on angiogenesis during a single stage after myocardial infarction, but to fully understand this healing process, we must look at its entire duration. Also, some humans express lipoxygenase 12/15, whereas others do not; if we can understand the role of this enzyme in heart failure pathology, then we can offer more exacting prognostics to patients.

Life in the Lab

To put it simply, my summer research experience has been a continual learning process. Although all of the projects are related, there are so many different types going on simultaneously within the lab. I have gotten the opportunity to observe or help with various types of procedures, such as mice surgeries, exosome measurements, gene expression, and multiple stainings. I have also practiced patience, perseverance, and adaptability, as we have encountered numerous technical difficulties. The histology staining for my slides was not strong enough after my first two attempts, and it was difficult to pinpoint exactly which part of the process or handling was at fault. We had to troubleshoot multiple steps of the protocol and encountered problems with back-ordered supplies before we realized that an antibody used in the staining was getting older and therefore losing its potency. I also tried changing a step of the protocol based on new information, and that seems to have worked better than the original instructions due to the changed circumstances. Because of these issues, we have had to start over multiple times.

There is always work to do in the lab, and I have had to strike a balance between multitasking to get things done, but not taking on too much lest I make a mistake. I like that there are multiple projects going on within the lab, so although they are all related to the cardiovascular system, there is still a decent amount of variety. However, a good many of the protocols require repetitious procedures or long waiting periods, and those are far from my favorite parts. As for working with a lab team, that has been extremely enjoyable. I have made several good friends within my lab, and we learn from and support each other. We are always willing to help each other and therefore work well together, which not only makes for a better working environment, but also makes completing the work itself more efficient.

References

  1. Conrad DJ. The arachidonate 12/15 lipoxygenases: a review of tissue expression and biologic function. Clinical Reviews in Allergy and Immunology 17: 71-89, 1999.
  2. Mozzafarian DM, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, . . .Sandeep RD. Heart disease and stroke statistics—2016 update: a report from the American Heart Association. Circulation: e308-309, 2016.
  3. NIH – National Heart, Lung, and Blood Institute. Myocardial Infarction. (n.d.). In PubMed Health Glossary. Retrieved from https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0021982/.
  4. Robich MP, Chu LM, Oyamada S, Sodha NR, Sellke FW. Myocardial therapeutic angiogenesis: a review of the state of developmental and future obstacles. Expert Rev Cardiovasc Ther. 9(11): 1469-79, 2011.
Carolee (MeMe) Collier is a rising senior majoring in English, pre-med at Auburn University in Auburn, AL. She is a 2017 Short-Term Research Education Program to Increase Diversity in Health-Related Research (STRIDE) Fellow working in Dr. Ganesh Halade’s lab at the University of Alabama at Birmingham in Birmingham, AL. MeMe’s fellowship is funded by the APS and a grant from the National Heart, Lung and Blood Institute (Grant #1 R25 HL115473-01). After graduation, MeMe plans to attend medical school and later use her undergraduate and professional degrees to become both a physician and an author. She also hopes to utilize her research experience by getting involved in clinical research during her career.