Date: [July 29, 2018]
Yesterday I wrote about H. Pylori and discussed inflammatory cytokines mentioned in Nasrat et al.’s 2016 paper. But what exactly are they? How could they be important to PSSD?
First, we need to understand how cells signal to themselves and to other cells. We can break this down into three categories:
- Autocrine Signaling
- Paracrine Signaling
- Endocrine Signaling
Autocrine signaling occurs when a cell secretes a hormone or chemical messenger that binds to receptors on that same cell, leading to changes in the cell releasing the chemical or hormone.
Paracrine signaling also involves a cell releasing a chemical or hormone, but the agent is intended for receptors on a nearby cell.
Endocrine signaling often uses the bloodstream to disperse chemicals released from a cell to receptors on a far away cell.
Signaling in the body
Cytokines use all three types of signaling in the body, making them important on a system-wide scale on physiology.
Cytokines are produced by various types of cells (immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells). Different cell types may in some cases produce the same cytokines.
You might have picked up on the strong connection to the immune system, as cytokines are very important in the immune response. In our case, we’re concerned with their role in inflammation.
Inflammatory cytokines are, as the name suggests, cytokines that promote inflammation. They include interleukin-1 (IL-1), IL-12, and IL-18, tumor necrosis factor (TNF), interferon gamma (IFN-gamma), and granulocyte-macrophage colony stimulating factor. Balancing pro vs anti inflammatory cytokines is important, as dysfunction of these systems is strongly correlated with depression and other mental illnesses.
For today, I’ll focus on the pro-inflammatory cytokines mentioned in the other paper cited in yesterday’s log as being relevant to H. Pylori.
H. pylori infection is associated with the up-regulation of toll-like receptors and cytokine overproduction, especially tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6, and IL-8
IL-1
The Interleukin-1 (IL-1) family is a group of 11 pro-inflammatory (mostly) cytokines. IL-1 is produced widely in tissue macrophages, monocytes, fibroblasts, and dendritic cells, but is also expressed by B lymphocytes, NK cells, microglia, and epithelial cells. IL-1 cytokines are very important in the infection response. They affect the activity of the hypothalamus, the thermoregulatory center, leading to a rise in body temperature (fever). However, IL-1 has several other roles – causing hyperalgesia (increased pain sensitivity), vasodilation and hypotension.
IL-6
Interleukin-6 (IL-6) acts as a pro-inflammatory cytokine and is also involved in temperature control (among other things throughout the body). It’s interesting to note that cortisol spikes can increase the release of IL-6.
IL-8
IL-8 induces a series of physiological responses required for migration and phagocytosis in target cells, such as increases in intracellular Ca2+, exocytosis (e.g. histamine release), and the respiratory burst. (Again, I’m really simplifying here. These cytokines have MANY roles in the body and there actions are still not fully understood).
TNF-Alpha
The primary role of TNF is in the regulation of immune cells. It is able to produce apoptotic cell death, cachexia, and inflammation. TNF dysfunction is implicated in a myriad of disorders including Alzheimer’s disease, cancer, depression, and inflammatory bowel disease.
With a basic introduction to inflammatory cytokines under our belt, we can dig deeper into their connection to sexual, mental, and emotional health in later logs. Of special interest to me is how they may influence penile health and function. I’m curious about their role in H. Pylori and what the existing literature has to offer.
Ghost
