Stem Cells–Life, Muscles, and Acne Scars

Dearest Readers and fellow gym bros,

Did you know you started life as a ball of cells? Though not just any cells–embryonic stem cells to be precise–but are those the only type of stem cells that make up our bodies? If you don’t believe me, ask you parents to have “the talk” with you. Tell them to explain how two cells become one and how one becomes billions. What’s more, did you see the blemish on your face this morning or were you too in a rush to notice?

Today’s article will be a quick introduction, catered to a general audience, where I will share with you what stem cells are and why they are interesting within the context of tissue regeneration.?

Stem cells are a peculiar type of cells in that they are: (1) undifferentiated and (2) self-renewing. Essentially, what this means is stem cells have the capacity to differentiate to other cell types if stimulated to do so, and depending on the type of stimulus, they can transform to a particular cell type. Depending where they are located in the body (niche), they will already have a predetermined path for differentiation. What’s more, stem cells are self renewing in that they continue to proliferate and they maintain their numbers so that an ever present population of stem cells are available for wound healing, growth, etc.?

Are all stem cells the same? Despite stem cells having the characteristics of undifferentiated and self renewing, there exist differences in the degree of their differentiation capacities which in turn renders categorization of stems into particularly 3 different categories:?

• Totipotent stem cells (morula)–Are interesting because these are the type of cells that have the capacity of becoming every type of cells of the body including creating placental tissue.?
• Pluripotent stem cells (Blastula-ICM)–these are slightly different to the ones above in that they are capable of differentiating into all cell types of the body except placental tissue.?
• Multi-potent/Mesenchymal stem cells–these are the type of cells that have the capacity of following multiple different cell lineages but not all.?

There is one other stem cell type that has been at the center of the scientific community: induced-pluripotent cell or also known as iPSCs. These are particularly interesting because they retain the characteristic of embryonic stem cells and have the function of allowing us to study embryogenesis without breaking any ethic codes that the US government and society has in place. Essentially, we have in place these regulations so that no scientist dares make a human in a petridish. In-Vitro Fertilization is a different things and should not be confused with actually making a whole human in a petridish.

Within the context of healing, have you ever wondered why is it that after we sustain an injury or a wound, it tends to close and heal? What are the mechanisms involved in wound healing? How does the body know, from simply enduring a cut or a wound that orders are received to heal itself?

To go into the details of the cell-to-cell tight junctions and the signaling molecules or the clotting factors that all play a role in wound healing, is beyond the purpose of this article. Here, we will focus on stem cell primarily and their role in wound healing and tissue regeneration.?

Muscle Generation

For my gym bros out there, ever wonder why and how does the body gain muscle? Why do you get the “pump”? Is soreness good??

Of course we’ve all experience the feeling of soreness after a good workout. If we stay consistent, the feeling of soreness goes away and our body acclimate to our particular exercise regimen. We increase the weight or the reps, we get sore again, but we might start noticing more toning or even large muscles.?

At its core, weight lifting places stress on the body and this results in damage to the muscle fibers. Damage or sustained injury to muscles or to any part of the body will render an inflammatory response and this will promote the migration immune cells and stem cells to the affected area. As it pertains to muscles, the cells involved in the regeneration of muscle fibers are called “muscle satellite cells” and these are located at the periphery of the muscle and will migrate to the affected area.?

Muscle satellite cells (MsSC) are a type of cell derived from a progenitor cell meaning that the stem cell was predetermined to follow a particular lineage. Essentially, you can think that at the periphery of your muscles, you have a population of available stem cells that are present and ready to heal in the event you damage your muscle (weightlifting). When damage occurs, these MsSC are activated, MyoD is expressed, and they are then coined “myogenic precursor” or a “myoblast” that will migrate and developed into a myocyte and form part of a myotube and then a myofiber. Crazy, isn’t it, how many steps and how complicated it is to gain muscle? It’s more than simply exercising and eating an excess of calories. Although the latter is important, they overshadow the complicated mechanisms of muscle generation. Nevertheless, gym is life, liberty, and gains. Funny that I didn’t write “happiness” because it is certainly a drag to wake up early to hit the gym or even worse, hit the gym right after work, and sugarcoating the truth isn’t helping anyone.?

To briefly bring in an anecdote about the topic of stem cells and muscles, I once got into a heated talk with a fitness trainer while at a social gathering when I had recently graduate from UC Davis. I was a recent college grad and I was brimming (still am) with a passion for the topic of stem cell biology. One particular thing I learned about stem cells, but of cells in general, is that differentiated cells have a particular function and do not differentiate into another cell type: i.e., a liver cell (Hepatocyte) can’t become a heart cell (Cardio-myocyte). So essentially fat cells, like any other cell, cannot convert into a muscle cells, or vice versa. Hence, if you ever hear a trainer or health coach say that fat turns into muscle, which is what the fitness trainer said whom I had the heated debate with, my advice is to run and don’t spend your money on them. A fitness trainer should be knowledgeable on this topic, at least superficially, and the client should also read about the subject before trusting anything that comes out of a trainer's mouth. ?

Acne & Cosmetics

Now let’s talk about acne. Acne is something most of us have had to endure when we were adolescents and I would argue most of us dreaded that phase of our life. Occasionally we might get one here and there. Some women get a breakout during their time of the month. No less, I am sure most of us (men and women) have a blemish on our face right now. Makes you want to check the mirror, huh? I bet you are tempted to use your cellphone camera right now to see if you have blemishes. I’m evil, aren’t I??

My dad tells me he never had acne growing up, and my mom also said she didn’t have pimples or acne on her face. Unfortunately my sister, brother, and I were not so fortunate as our parents were. The acne gods did not smile upon us.?

We commonly hear acne is resultant from genetics, diet, hormones, etc. My mom would tell me that chocolate and junk food was the reason I was breaking out. Perhaps they all play a role, but at its core, acne arises from pores that are clogged with sebum (skin oils) and the bacteria that naturally live on your skin, enter these clogged pores and start to consume the oils. The accumulation of bacteria renders the migration of immune cells to the infected pore, and the immune cells now present in these pores release signaling molecules to attract more immune cells and macrophages to the affected area. This is an immunological or inflammatory response, hence the redness and warm bumps appear: acne. In my humble opinion, there is something even more dreadful than acne, it is acne scars.

As dreadful and tempting it is to pop a pimple, breaking skin will likely lead to more infections and possible formation of acne scars. Similarly as a normal scar on a different part of the body almost never goes away but rather fades away slowly, similarly acne scars may never go away. Scars are formed because of fibroblast which are the cells responsible for the production of collagen, an essential precursor and protein necessary for wound healing. As you will notice, scar lack flexibility and stretchiness as normal skin, wherein this rigidity functions to prevent the wound from opening again, and you will at times notice scars tend to be a bit elevated–giving an unattractive texture to the skin’s appearance. Similarly, acne scars on the skin will render uneven skin tone that may or may not heal, and often require more medical intervention such as the use of CO2 laser for acne scar treatment or even chemical face peels. Please speak with your dermatologist for more information on treatment options for acne scars.?

If you, however, have a great skin routine, and you have glowing skin, please let me and the audience know. My goal is to look 30 by the time I’m 50 so you must tell me your secret.?

Tissue Regeneration

Stem cells have great plasticity, meaning that they can differentiate into different cells types and because of this, we hope that contemporary research will one day allow us to regenerate entire organs in a Petri dish. Today, when patients present with organ failure and are in need of an organ transplant, the patient is placed on a wait-list and must wait until there is a match. What do I mean by this? If an organ is available, that’s one thing but if there isn’t a match, then the patient can’t receive the organ–another patient will. The science behind what makes organs compatible with prospective recipients is beyond the scope of this article, though generally, the patient is matched with an organ, and after the transplant surgery, the patient is placed on immunosuppressants which has its own secondary effects and complications. This, however, would not be the case if we could create an entire organ using the cells from the same patient. To get the patient’s stem cells, cultivate them, differentiate them, and form them into a full functioning organ would potentially save lives and would remove the need to wait for a surgery at the cost of another persons’s health or even life.?

Dearest reader, you might be tired of reading by now. I know I would be, but note that of the three topics above: muscle, acne scars, and organ transplant, these topics touch very closely to our lives but no less, it is my hope that most of us will live healthy lives and have no need for a transplant in the future. It is my personal and professional belief that stem cells are the future of science and medicine. I am confident that we will reach a point where we will have the capacity to transform medicine and save even more patients.?

Now I feel a little self-conscious about my skin and may make an appointment with my dermatologist. I’m a little annoyed having written that portion of the article but too late now.

I hope you, my dear readers, found this article instructive.?To my gym bros, did you hit the gym today?

Please like, comment, share, and subscribe.?

Best regards,

The Professor?