Transglutaminase, Gluten, Celiac, Inflammation, Autoimmunity

The point of this post is that the intestines produce an enzyme, transglutaminase (TG) that normally protects the gut from toxic plant proteins, such as grain gluten, but modern food processing and antibiotics corrupt digestion of gluten to produce intestinal inflammation and a series of related autoimmune diseases including celiac, thyroiditis, diabetes, baldness and atherosclerosis. 

Transglutaminase Links Proteins Enzymatically

Transglutaminase is a ubiquitous enzyme produced in the intestines, thyroid, heart, skin, hair follicles, etc.  This enzyme attaches to a protein (TG + ProA ~~> TG-ProA) via amino groups extending from some of the protein's amino acids, e.g. lysine or glutamine, and then the enzyme replaces itself by another protein leaving the two proteins crosslinked (TG-ProA + ProB ~~> TG + ProA-ProB).  Another alternative reaction is to leave the original glutamine without its amino group to yield glutamic acid residues.

Linking Proteins Makes Connective Tissue Tough

Transglutaminase is useful to crosslink the proteins in connective tissue.  Proteins in basement membranes form a matrix by binding to the heparan sulfate sidechains of another basement protein, perlecan.  The heparin-binding domains consist of basic amino acids that TG can react with to crosslink the proteins.

Linking Pathogen Proteins

Transglutaminase is also produced to crosslink the DNA/heparin/matrix polysaccharide-binding domains of pathogenic bacteria leading to aggregation, localization and death of the bacteria.  Inflammation resulting from activation of the inflammatory transcription factor, NFkB, stimulates production of TG.

Gluten is a Plant's Way of Saying "Don't Eat Me!"

Gliadin is a protein component of gluten that contains long stretches of glutamine residues, i.e. it is a polyglutamine protein similar to the protein that causes Huntington's disease.  Gliadin is an advantage as a storage protein for grain, because it is aggregated by the TG that protects the lining of the intestines of herbivores, such as humans, makes the animal sick and thereby discourages eating the grain.  Aggregation of gliadin/gluten inhibits digestion of the grain protein and can leave TG bound to gliadin.  Conversion of the polyglutamine stretches to polyglutamic acid stretches that are negatively charged, produces proteins that will bind to the positively charged heparan sulfates that circulate along the surface of intestinal cells leading to damage and inflammation.

Basic Triplet Leads to Antibody Production

Transglutaminase is also transported into cells, because it contains a region with a triplet of basic amino acids (...EPKQKRKLVA...).  This internalization probably contributes to enhanced presentation of TG to the immune system for subsequent antibody production.

Transglutaminase is Inflammatory

Transglutaminase interaction on the surface of cells also activates, NFkB, the transcription factor responsible for inflammation. Thus, TG turns on inflammation and part of inflammation is the activation of the innate immune system that includes production of TG.  This circular activation may produce autoinflammation that is associated with various forms of inflammatory bowel diseases.

Gluten Sensitivity is Normally Controlled By Gut Flora

Gluten sensitivity expressed by most people, is the intestinal response to the toxicity of gluten as it interacts with TG and causes inflammation.  This inflammation will also result in immune presentation of both gliadin and TG, and production of antibodies to both. Antibody production will normally be controlled by regulatory T cells of the immune system, unless spreading inflammation in the gut and/or antibiotics destabilizes the gut flora and compromises regulatory T cell development in the intestines.  

Anti-Glutaminase Antibodies Attack the Gut

Celiac results from uncontrolled production of antibodies to gliadin and TG with attack by the immune system on the aggregated gliadin/TG on the surface of the intestinal epithelium.  Celiac flare ups in response to eating even small quantities of gluten lead to further inflammation of the gut and further disruption and simplification of gut flora.

Celiac Leads to Thyroiditis and Much More

Transglutaminase is also produced by the thyroid and celiac will develop into a more generalized autoimmune disease that results in Hashimoto's thyroiditis.   TG production in the skin can result in skin rashes and may contribute to rosacea.  The base of hair follicles contains TG involved in hair production, and may contribute to some forms of hair loss.  Another substantial worry about the sequelae of celiac and gluten intolerance is the presence of TG in coronary arteries.

Antibiotics are Part of the Gluten Problem

Celiac and gluten sensitivity seem to be increasing with modern processing of grains and increased use of antibiotics.  Wheat has been gradually changed by traditional breeding, but genetic engineering has not yet been developed for wheat.  So, at least in this case, GM wheat cannot be part of the problem.  Many recent studies show that antibiotics profoundly and permanently alter gut flora.  As a result, the immune system, which is dependent on gut flora diversity is compromised, and various forms of autoimmunity and allergies develop.

Super Fine Flour Damages Gut Flora

Germ and bran are removed from all wheat before it is ground.  This is true even for whole grain flours, which have some of the germ and bran added back after milling.  Modern milling may be part of the gluten problem, because the flour is ground so fine that the grains of starch are broken.  Broken starch grains are digested by pancreatic amylases in the upper intestines, whereas some of the starch from intact grains is digested by gut flora in the colon.  Thus, modern wheat flour fails to feed gut flora like soluble fiber to produce short chain fatty acids, e.g. proprionic acid that supports Treg development; modern superfine flour supports autoimmune diseases and allergies.

Cultural Practices Make Gluten Safe

Wheat has been bred to produce bread as fast as possible from superfine flour.  This rapid bread production eliminates the exposure of gluten to enzymes from both germinating wheat seed and fermenting bacteria, which are part of traditional bread making.  Coarsely milled, traditional flour responds to soaking in water by activating enzymes that partially digest gluten, since gluten is a storage form of amino acids destined for the seedling.  Sour dough starter, a mixture of bacteria that can ferment the starch and gluten into short chain fatty acids and bubbles of carbon dioxide, has been used traditionally to provide leavening and flavor to bread.  Both flour and bacterial enzymes modify the structure of gluten to render it less toxic to the intestines.  Cultural traditions insured that gluten would be systematically detoxified by enzymes during hydration and fermentation of dough prior to baking.  Modern processing leaves wheat gluten in bread unmodified and toxic.

Prevention and Cure:  Eliminate or Detoxify Wheat and Add Bacteria

Preventing and curing diseases associated with gluten and transglutaminase is simple.  Eliminating wheat would do the trick.  Unfortunately, wheat is the mainstay in many parts of the world.  Fortunately, gluten intolerance is not uniformly observed where wheat is eaten.  This indicates that there are potentially safe ways to eat wheat and bread.  I gained insight into how to eat wheat safely from two books that were recently published:  Cooked by Michael Pollan and Artisan Bread in Five Minutes a Day by Jeff Hertzberg, MD and Zoë François.

Michael Pollan has recently become interested in gut flora and his book revealed how he built up a healthy gut flora eating homemade fermented food and compromised his work with antibiotics.  The major breakthrough that I made by reading Cooked was based on his experiments in baking whole wheat bread.  He hydrated the flour first and then used sour dough starter for lengthy fermentation.  This was the same process that I had used to make great loaves of bread (photo above) using Jeff Hertzberg’s directions in Artizan Bread in Five Minutes a Day.

The answer to gluten intolerance and most autoimmune diseases amounts to eliminating wheat or treating wheat in a safe, traditional process that inactivates the toxic properties of gluten; and maintaining a healthy gut flora (probiotics are not enough) with hundreds of different species of bacteria that promote the development of the suppressive immune system mediated by regulatory T cells:

Safe Traditional Bread 

• Remove bran and discard as toxic insoluble fiber.
• Grind wheat to retain starch grain structure.
• Soak flour to hydrate and activate wheat enzymes to start digestion/detox of gluten.
• Ferment dough with bacteria (sour dough starter) to continue digestion/detox of gluten.
• Bake.

Develop Healthy Gut Flora and Suppressive Immune System

• Avoid antibiotics that kill bacteria.
• Avoid hygiene practices, e.g. antibacterial soaps, bleaching surfaces, closing toilet covers, etc. that eliminate sources of healthy bacteria.
• Kiss your loved ones and pets, and encourage everyone to garden/play in the soil (an excellent source of thousands of different species of bacteria.)
• Recruit healthy gut bacteria by eating a variety of homemade fermented vegetables. My most highly recommended source is my friends at: http://www.fermentista.us
• Remember that cooked or pasteurized foods do not contain useful bacteria.
• Remember that dairy probiotic bacteria cannot live in the human gut and can only provide a temporary help to the immune system.
• Limit the variety of foods that are consumed and gradually change with the seasons to avoid rapid changes in nutrients to which gut flora cannot adapt.  Food intolerances indicate maladapted gut flora.
• Constipation indicates dysfunctional gut flora and a compromised immune system.

Antibiotics, Gluten, Hashimoto's Thyroiditis and Baldness

My impression is that Hashimoto's is caused by a combination of an initial immune attack on the thyroid and incompetent regulatory T cells.  In most cases the immune attack on the thyroid is a secondary consequence of celiac/gluten intolerance, in which anti-transglutaminase antibodies attack transglutaminase bound to gluten in the intestines.  Transglutaminase  is an enzyme that is also produced by the thyroid (and hair follicles) and attack by celiac antibodies can enhance or inhibit thyroid hormone production (or baldness.)  Both Hashimoto's and celiac do not occur if the suppressive part of the immune system, i.e. regulatory T cells, is functioning.  

Antibiotics Compromise the Immune System

The major point here is that antibiotics disrupt normal bacterial biofilms that line the intestines and these healthy gut bacteria are required for development of regulatory T cells.  Compromise of Tregs leads to autoimmune diseases, e.g. celiac, Hashimoto’s and baldness, and also allergies.

Antigens/Allergens Have Basic Amino Acid Triplets

The antigens targeted in autoimmune diseases, e.g. tTG, anti-nuclear, TPO, and allergies form an obvious pattern.  All of these antigens and allergens have simple amino acid sequences (rare patches of three basic/positively charged amino acids) that enhance their presentation to the immune system to produce antibodies.  Nuclear proteins, for example, are frequent autoantigens and most of these proteins interact with nucleic acids (negatively charged) and have predictable patches of positively charged amino acids (arginine and lysine).  Other common autoantigens have basic amino acid (arg/lys) patches, because they interact with phospholipids (also negatively charged.)  Proteins with basic patches, e.g. HIV-TAT or heparanase, are also readily transported into cells and nuclei.  Peptides with these sequences are produced by action of stomach enzymes on proteins, e.g. milk lactoferrin, and are antimicrobial.

Allergies / Autoimmune Diseases Are a Predictable Consequence of Antibiotics

Doctors treat with antibiotics, but they fail to repair damage that they cause to gut flora.  The gut flora of most patients treated with antibiotics, especially those who are most fastidiously hygienic, never fully recover.  Constipation is a common symptom of severe dysbiosis and related immunoincompetence.  Probiotics are gut flora bandaids and do not survive as components of gut flora.

Gut bacteria are also needed for development of the aggressive part of the immune system.  Thus, autoimmune diseases can be treated with even more intense use of antibiotics, that will eliminate the rest of the immune system.  Since all vitamins are produced by gut flora as quorum sensing signals, antibiotics can also produce the exotic symptoms of vitamin deficiencies.

Antibiotics are essential to many therapeutic approaches, e.g. surgical procedures or therapy for chronic Lyme disease, but they must be used responsibly and treated patients must be subsequently tested to ensure a repaired gut flora and a functional immune system have been reestablished after antibiotics.  Long term antibiotic use needs special attention, e.g. deliberate Repair of Gut Flora or a fecal transplant.

Thus, I think that it is most likely that ever increasing antibiotic exposure and processed foods, coupled with obsessive hygiene have led to crippled gut flora (as observed in the simplified gut microbiomes of Americans), a net decline in suppressive Tregs and the observed increase of autoimmunity and allergies.  The competence of the immune system may be a major determinant in the course of infection with a pathogen that can produce chronic infections.

Baldness/Prostatitis Treatment, Impotence, Inflammation

Male pattern baldness appears to result from the interaction between enzyme-modified male sex hormones (DHT) and receptors in some hair follicles of the scalp.  Inhibition of the enzyme by topical (Rogaine) or oral administration (Propecia) of an inhibitor, e.g Finasteride, can stop hair loss.  One of the significant side effects of oral use of Finasteride is loss of all sexual functions, which can be temporary and reversible after the drug is stopped, or permanent.  I think that inflammation may play a critical role in both hair loss (and prostatitis) and loss of sexual functions in response to Finasteride and an anti-inflammatory approach my be helpful.

Testosterone is Converted to  Dihydrotestosterone (DHT) by 5-Alpha Reductase

The male hormone, testosterone, is produced in the testes and travels to hair follicle or to other parts of the body via the blood in either a free state, or bound to a carrier protein.  Only the free form interacts with the 5-alpha reductase enzyme in the scalp to produce the DHT that diminishes hair follicles.  Application of the Reductase inhibitor, Finasteride, directly to the scalp stops the production of DHT in the scalp.  Taking oral Finasteride blocks DHT production throughout the body, and unlike topical application, can also result in apparent changes in the brain, which can explain loss of sexual behavior.

DHT Role in Hair Loss and Brain-Based Sexual Behavior is Poorly Understood

Surprisingly, the molecular biology of male pattern baldness (MPB) is not known, even though this is one of the classic examples of a dominant, sex-associated phenotype, i.e. a single copy of the baldness allele in males produces baldness.  Of course, this is not a sex linked gene, since baldness is not inherited from mothers with their X chromosome, and in some cases as many as 80% of the males in a single family exhibit male pattern baldness.  It appears to me that baldness is also likely to have an environmental, e.g. gut flora, heritability similar to obesity.  In fact, metabolic syndrome and type 2 diabetes are substantial risk factors for male pattern baldness.

There is also an association between MPB and polycystic ovary syndrome (PCOS) in females of the same family.  I would also expect that MPB is related to prostatitis, since the prostate is a major processor of testosterone to DHT via 5-alpha reductase and prostatitis can be treated with Finasteride.  PCOS is also treated with Finasteride.  PCOS is also associated with obesity and metabolic syndrome.  Prostatitis, PCOS, obesity and metabolic syndrome can all be treated as inflammatory diseases with significant contribution of dysfunction of gut flora.

  

PMB, Testosterone, 5-Alpha Reductase and Aromatase

In PMB, testosterone levels are lower and 5-alpha reductase is higher.  This suggests that testosterone has been converted into DHT in scalp hair follicles.  In order for DHT levels to make a difference, the hair follicles have to have specific receptors for DHT.  Testosterone/DHT receptors, like all steroid hormone receptors, are proteins in the cytoplasm of cells, which bind the hormone and become activated as transcription factors that migrate to the nucleus and control the expression of particular genes.

Testosterone can also be converted by another enzyme, aromatase, into estrogen.  DHT cannot be converted enzymatically into estrogen.  Estrogen has a separate receptor and controls a different set of genes.  Thus, enhanced conversion of testosterone into DHT in MPB follicles, may shift the balance away from estrogenic in favor of androgenic effects.  Women exposed to aromatase inhibitors, stop converting their limited testosterone into estrogen and more is converted into DHT, resulting in rapid signs of baldness.   All brain estrogen is produced from testosterone via aromatase in the brain and aromatase inhibitors can reduce libido in women.

DHT Activates Inflammatory NFkB (and Block Nerve Apoptosis?)

Prolonged exposure of cerebral blood vessels to DHT has been shown to activate the inflammatory transcription factor NFkB.  Conversion of testosterone to DHT by 5-alpha reductase may amplify the inflammatory impact of testosterone by virtue of the stronger activation of the androgen receptor by DHT.  Activation of NFkB also suppresses apoptosis and may be necessary to maintain some neural cells.  Reducing DHT production by 5-alpha reductase inhibitors, may reduce NFkB activation in the brain and expose androgen-sensitive parts of the brain to apoptosis.  This loss of brain cells may result in loss of sexual behavior.

Vitamin D is also Steroid Hormone/Co-Transcription Factor

It should be remembered that vitamin D also has a cytoplasmic receptor that acts as a transcription factor and that vitamin D deficiency can result in hair loss.  If fact, vitamin D is required for the normal hair growth cycle, as well as intestinal villi development (defensin production).   The vitamin D receptor can also inhibit the inflammatory transcription factor NFkB.

Thus, multiple steroid hormone receptors are involved in hair development, prostate function and brain sexual behavior.  Modification of the conversion of testosterone into DHT or estrogen can have diverse consequences directly or indirectly by modification of inflammation/development signaling.  This is also true of fertility/menstrual cycles, mammary tissue and perhaps intestinal epithelial villi or skin/follicle development in the case of rosacea.  All of these processes are affected by enzymatic interconversion of steroid hormones and interaction of hormone/receptor and NFkB transcription factors.

Questions

The questions that I have about hair loss (or prostatitis), treatment with 5-alpha reductase inhibitors, and subsequent loss of sexual function are:

1. Why are the genetics of MPB so unusual/non-Mendelian?  There are too many males with MPB in the same family.  This points to some hereditary predisposition, but with a major environmental component, e.g. “inherited gut flora.”
2. Why are only a few of the people treated with 5-alpha reductase inhibitors rendered permanently impotent?
3. There is anecdotal evidence that dexamethasone (or prostate message and antibiotics) can reverse some impotence.  Does this indicate that inflammation is involved in hair loss and/or impotence?  Where do the antibiotics act and is their action to kill bacteria?

Treatment for Finasteride-Induced Impotence

Impotence is a severe side effect of a few men using Finasteride to treat baldness or prostatitis.  I doubt that those with induced impotence are genetically predisposed, but rather these individuals probably had an altered immune system.  I suspect two types of alterations:  a compromised blood/brain barrier and a compromised suppressive immune system.  Diet-based chronic inflammation is a typical path to a leaky blood/brain barrier that facilitates the penetration of Finasteride into the brain to alter 5-alpha reductase in the DHT-responsive regions responsible for sexual function.  I presume that the subsequent reduction of DHT also results in inflammation that contributes to loss of function.  Dexamethasone and some antibiotics could attenuate the inflammation and return normal function.

Suppression of attack of normal tissues by the immune system is mediated by development of the suppressive immune system in the gut in response to specific bacteria of the gut flora.  A history of antibiotic treatment can yield a dysfunctional gut flora and a compromised immune system that results in allergies and autoimmunity.  Prostatitis may have an autoimmune component and may result from compromised gut flora.

All of the symptoms discussed from hair loss to prostatitis to impotence should be improved by normal function of the gut and immune system by my anti-inflammatory diet and normal gut flora.  Use of antibiotics will always lead to further side effects by perturbing and limiting the function of gut flora and the immune system that is dependent on the gut flora.

I particularly suspect that vitamin D deficiency is a significant contributor.  Most “anti-inflammatory diets” will lead to chronic inflammation, because they are just high carb diets with a few vegetables.  All of the complex phytochemicals produced by plants will be “antioxidants”.  Adding these antioxidants to an inflammatory diet has no impact.  Look at my anti-inflammatory diet and note that it requires attention to serum vitamin D levels, gets most calories from saturated fat and not carbs (low carb/high saturated fat), no vegetable oils and high omega-3 (EPA, DHA) to 6 ratio.  That means meat/fish/eggs/dairy and lots of fresh vegetables for new gut bacteria.