Here is the relevant info for Susan's seminar this coming Friday, April 3rd.
Title: Proteomic and targeted gene expresson profile in differentiating myoblasts
Links to papers:
http://cshperspectives.cshlp.org/content/4/2/a008342.full
http://www.hindawi.com/journals/isrn/2014/713631/
See all of you in seminar.
Susan, you did a great job with your presentation and explaining everything. Your project is really interesting.
ReplyDeleteSusan studies the proteomics involved in the processes of myogenesis. She tested whether increasing concentrations of growth factors like fetal bovine serum at later stages of in-vitro development will alter differentiation of myoblasts. Adding FBH represents in-vivo conditions better than the current methods. The results did not show altered differentiation, but did show an unusual decrease in titan expression overtime. Based on this and additional research, Susan developed a new hypothesis that adding growth factors may activate negative feedback loops.
Describe a negative feedback loop that you find interesting.
Negative feedback is the internal mechanism for blood glucose regulation. Depending on whether glucose levels are rising or falling, the body has a different response. As levels increase, the beta cells secrete insulin which then converts glucose to glycogen so that extra glucose can be stored restoring glucose levels to a normal level. When levels fall, the alpha cells secrete glucagon which then converts stored glycogen to glucose and increases levels back to normal.
ReplyDeleteAn example of a negative feedback loop is the detection of decreased levels of oxygen within the body. This is detected by the kidneys and causes the secretion of erythropoietin. This is a glycoprotein hormone that is responsible for the production of red blood cells, a process known erythropoiesis. The activation of erythropoietin by decreased oxygen levels is normally caused by the decrease in the number of red blood cells present within circulation. Thus, decrease in the number of red blood cells causes an increase in erythropoietin secretion and red blood cell production. This eventually leads to an increase in oxygen levels within the blood.
ReplyDeleteInflammatory response is an example of host defense against infection because it leads helps to traffic immunocompetent cells to the infected tissue and ultimately leads to the removal of antigens. However, this beneficial process can be detrimental in chronic inflammation and can cause tissue damage and also autoimmune diseases. IL-10 can act a negative feedback loop of the immune system, by suppressing the activation of effector B cells and Tcells and also suppressing the production of inflammatory cytokines that might cause tissue damage by these effector cells.
ReplyDeleteMetabolism essentially functions through a negative feedback loop. The longer you go without any source of nutrition, the more your body attempts to compensate through slowing down metabolic processes. The less metabolic demands placed on the body, the longer it can go without external energy sources.
ReplyDeleteThe baroreceptor reflex is a negative feedback loop. As cardiac output increases, the blood pressure increases in the aorta and carotid arteries, which is sensed by baroreceptors. Those afferents travel to the medulla, the Vegas nerve is activated, and it exerts parasympathetic actions by synapsing on the SA node, slowing depol rate, and decreasing output and BP to normal.
ReplyDeleteOne negative feedback loop that immediately comes to my mind is population equilibrium. Here we observe the size of one group of organisms being directly related to the size of another group of organisms. For instance, if a regions salmon population drops, so too will the regions bald eagle population. This drop in bald eagles allows for the regeneration of the salmon population, and thus the eventual return of the bald eagle population.
ReplyDeleteGreat job last Friday Susan!
Internal body temperature regulation is a good example of a negative feedback loop. If body temperature were to go above 98.6F nerve cells in the skin and brain are activated causing blood vessels to dilate and excretion of sweat through sweat glands to help the body cool down.
ReplyDeleteSusan you did a great job presenting and explained everything very well!
DeleteDendritic cells are antigen presenting cells that will activate T cells by exposing them the pathogens and providing molecular stimulation. However once activated the T cells will secrete Protein S (Pros1) which will bind to a tyrosine kinase receptor on the dendritic cells in order to inhibit its activation. Accordingly, this negative feedback will prevent improper immune response, autoimmunity, and hypersensitivity.
ReplyDeleteProduction of human red blood cells (erythropoiesis) - A decrease in oxygen is detected by the kidneys and they secrete erythropoietin. This hormone stimulates the production of red blood cells.
ReplyDelete1)Neurons would pick up the oxygen levels in the body, in this case would be decreased.
2)The information would be sent to the integrating center to compare values.
3)From there the neurons will send impulse to the kidneys, telling the kidneys to release erythropoeitin.
4)The erythropoeitin would stimulate red bone marrow to produce more red blood cells. This will increase the blood's ability to carry oxygen.
5)The neurons will monitor and repeat (steps 2-4) if the levels are not high enough.
Susan did a great job. It's very interesting seeing the different application of qPCR between our labs and her work with titin, particular having to improvise by cutting the wells out of her gels, is really fascinating stuff.
ReplyDeleteBlood pressure regulation is often performed through negative feedback. When blood pressure increases, signals are sent to the brain from blood vessesls, causing the brain to send signals that results in the heart slowing down its rate. This helps blood pressure stabilize.
Susan did a fantastic job of presenting.
ReplyDeleteCortsiol is another form of negative feedback regulation. In response to stress, the hypothalamus releases corticotrophic release hormone (CRH) and transported to the anterior pituitary gland. This interaction then cuases the release of adrenialcortcotropic hormone (ACTH) into the blood stream. The adrenal cortex recogonizes this signal and releases the corticosteroid, cortisol. Once levels have cortisol have reached there max, HPA axis (process that was previously mentioned) is shut off.