The Effect of Melatonin of Mast Cell Activation
Sasenick, Jonathan B.
- Mast cells are a heterogeneous population of inflammatory cells derived from hematopoietic stem cells. Located in nearly all tissues of the body, mast cells have been implicated in allergic disorders, tissue remodeling, wound healing, and immune modulation. Upon activation, mast cells release a variety of both preformed and de novo synthesized chemical mediators through a process known as degranul... read moreation. These mediators have been found to have both positive and negative regulatory effects on the immune system, often benefiting the body, but sometimes causing damage. Melatonin is a hormone synthesized primarily in the pineal gland in the brain. It is best known for the regulation of circadian rhythm and its light-dependent synthesis. Melatonin has also been implicated in many of the same diseases as mast cells, including Alzheimer's Disease and many types of cancer, and has shown to be an effective immune regulator in certain systems. Rat mast cells have been shown to express both isotypes (MT1 and MT2) of the melatonin receptor on their cell surfaces. I hypothesized that HMC-1 human mast cells expressed these same receptors on their cell surface. In addition, I hypothesized that melatonin would interact with these mast cells, causing some change in the degree of mast cell activation. Results from this study not only showed that HMC-1 human mast cells express mRNA messages for MT1 and MT2, but also showed that HMC-1 and rat mast cell activation seem to be partially inhibited by incubation with melatonin. Better understanding of this modulation in mast cell activity could have an impact on the way mast cell interactions are understood and how melatonin is used as a clinical intervention in patients suffering from chronic inflammation.read less