Allergy, Asthma, Autoimmunity Start the Same Way

Inflammation is the current medical buzzword. Name the disease and inflammation is there.

Reproduction Requires Controlled Inflammation
Aspirin blocks many of the steps in triggering inflammation and thus, aspirin administration can be used to reveal a role of inflammation in many unexpected places. Aspirin is effective in blocking some forms of infertility, inhibiting miscarriages and ameliorating postpartum depression. So inflammation is a critical part of reproduction. But, also notice that depression is a symptom of chronic inflammation.

Cancer Requires Inflammation
High dose (IV) aspirin has been successfully used to treat cancer. Inflammation is required for cancer growth, because both use the same transcription factor, NFkB. The aberrant signaling of cancer cells would normally lead to programed cell death, apoptosis, but inflammation blocks apoptosis. Aspirin can in turn block NFkB and in the absence of inflammation, cancer cells die by apoptosis.

Inflammation is Self-Limiting
Aspirin also transforms the COX/lipoxidase system to produce anti-inflammatory prostaglandins/eicosinoids. Inflammation normally progresses into anti-inflammation. Blocking this progression leads to chronic inflammation and a shift from local to systemic inflammation with the rise of inflammatory interleukins in the blood stream.

Immune Response Requires Inflammation
The signal molecules (IL-1, IL-6, TNF) and transcription factor, NFkB, associated with inflammation were all initially identified in the development of lymphocytes. Hence, IL stands for interleukin, a hormone that triggers leukocyte (literally white blood cells or cells associated with the lymphatic immune system, i.e. lymphocytes) development. The nuclear factor, i.e. transcription factor, involved in expression of the large chain, kappa, of immunoglobulins in B cells, was called NFkB.

Genes Expressed by NFkB Cause Symptoms of Inflammation
About five dozen genes are under control of NFkB. Among these are COX-2, the enzyme that converts omega-6 arachidonic acid to inflammatory prostaglandins; iNOS, the enzyme that produces nitric oxide that dilates blood vessels to produce hot, red skin; and the inflammatory interleukins, IL-1, IL-6 and TNF, associated with autoimmune disease, fatigue and cachexia (wasting).

Autoimmunity and Allergy Start with Inflammation
Medical treatments focus on symptom abatement and ignore cause. What causes obesity, allergy or autoimmune disease? The answer appears to be chronic systemic inflammation plus exposure to unusual proteins. The unusual proteins are immunogenic, i.e. interact with the immune system to produce antibodies or reactive T-cell receptors, and are subsequently recognized as autoantigens or allergens, that are the targets for immune attack. Inspection of these autoantigens and allergens shows that they all have one thing in common, they bind to heparin via a strong heparin-binding protein domain that is typically a triplet of adjacent basic amino acids.

Heparin is a Short, Highly Sulfated Fragment of Heparan Sulfate
Commercial heparin is purified from the intestines of hogs and cattle. Heparin is released from mast cells (made fluorescent for microscopy using berberine) along with histamine and is released into the intestines to block pathogens from binding to the heparan sulfate that is part of the intestine surface. The heparin is anti-inflammatory and it contributes to minimizing the inflammatory response of the intestines to food.

Inflammation Reduces Heparan Sulfate Production
Pathogen-generated inflammation of the intestines reduces heparan sulfate production and increases immune response to food antigens. NFkB activation by inflammation turns off the production of some genes needed for heparan sulfate proteoglycan (HSPG) synthesis. Since HSPG is a major component of the basement membrane that holds tissues together, the reduction of HSPG results in protein loss (proteinuria) from kidneys, leaking of intestines, and disruption of the blood/brain barrier.

Reduction of HSPG Results in Immunological Presentation of Autoantigens/Allergens
Proteins are brought into cells by specific binding to protein receptors. In many cases, particularly involving signaling or growth factors, both the signal molecules and the receptors bind to heparin. In addition, there is a robust circulation of HSPG, which is secreted and internalized with a half-life of approximately six hours. The sweep of the HSPGs take heparin-binding proteins with them for internalization, e.g. HIV-TAT, heparanase, tissue transglutaminase. I think that this HSPG sweep under inflammatory conditions also internalizes basic autoantigens and allergens with strong heparin-binding domains. This internalization is the first step toward immunological presentation and the immune response to autoantigens and allergens.

Autoantigen/autoantibody/HSPG Complexes Kill Cells
Antibodies against self-antigens, autoantigens form antigen/antibody complexes that also bind to and cross-link HSPGs, because of the heparin-binding domains of the autoantigens. The large complexes may disrupt HSPG circulation and trigger apoptosis or abnormal physiology. There are many other examples of heparin-based complexes that are toxic, e.g. Alzheimer’s amyloid plaque, diabetic beta cell antibody complexes, celiac gluten/tRG antibody complexes, multiple sclerosis myelin antibody complexes, atherosclerotic plaque.

Anti-Inflammatory Diet and Lifestyle Protects
Dietary and lifestyle adjustments that minimize inflammation, e.g. low starch, no HFCS, low vegetable oil (except olive) and supplements of vitamins D & C, fish oil (omega-3) and glucosamine, reduce the risk of allergies/asthma, degenerative diseases and cancers. Simple, high level supplements with fish oil reduce numerous mental disorders, e.g. depression, ADHD; infertility, pre-eclampsia and postpartum depression; allergies, asthma; arthritis, atherosclerosis; burn recovery, septicemia and head injury.

Reducing Inflammation is a Panacea for Modern Diseases
Most modern diseases have an inflammatory component, because modern diets are rich in inflammatory components, e.g. starch/sugar, corn/soy oil, HFCS, trans fats, and exercise is minimal. The medical industry has not successfully promoted healthy eating and exercise; and in fact has promoted the devastating replacement of saturated fats with inflammatory polyunsaturated vegetable oils. Meat production has moved away from grazing on omega-3-rich plant vegetation to omega-6-rich corn and soy. Replacement of the corn/soy based agricultural economy would have predictably immense beneficial impact in reducing inflammation-based degenerative autoimmune diseases and cancers.

Where’s the Aspirin?

Aspirin is the traditional anti-inflammatory agent. Many of us grew up with the quintessential doctoring phrase, “Take two aspirin and call me in the morning.” Aspirin stops inflammation in several ways. Like all drugs, it interacts with many different proteins/enzymes. In fact it interacts so intimately with the inflammatory system that it suggests that the process of inflammation may require an aspirin-like molecule to function normally.

Aspirin Binds to Multiple Enzymes of Inflammation

Aspirin is observed to reduce inflammation. That means that ingested aspirin tablet dissolve in the stomach and pass through the intestines into the blood stream and subsequently bath cells of the blood and the endothelium that lines the blood vessels. In order to reach the blood stream, the aspirin must pass through the intestinal cells. That passage requires binding to a protein transport molecule.

Cells responding to an inflammatory signal (NFkB, transcription factor is activated) synthesize enzymes that release unsaturated fatty acids (ARA, EPA, DHA) from membrane phospholipids (PLA2, phospholipase A2), form a cyclic epoxide from the fatty acid (prostaglandin H2 synthase 2, also called cyclooxygenase 2, COX-2).

Aspirin binds to the inhibitor that normally inactivates NFkB and prevents NFkB activation that is required for inflammation. Aspirin also binds to PLA2 and prevents fatty acid release and thereby blocks activation of inflammation. Aspirin also binds to COX-2 and blocks the production of inflammatory prostaglandins from ARA. But that is not all that aspirin does.

Inflammation Resolution Uses Aspirin-COX-2 Interaction

The strange interaction that makes aspirin suspicious is that aspirin doesn’t just interfere with the action of enzymes, it subtly changes their specificity. Thus aspirin chemically transfers its acetyl group (CH3-COOH-) to an amino acid in the active site of COX-2 to produce a new group of anti-inflammatory lipoxins from ARA, EPA and DHA.

This raises the question of whether aspirin is a natural dietary modulator of inflammation. Recall that aspirin was initially obtained from willow (Salix) bark. Unfortunately, the data are conflicting. Initial research indicated that grains (naturally inflammatory) lacked aspirin, but many herbs, spices and leafy vegetables (naturally anti-inflammatory) contained aspirin. Subsequent tests refuted this work. It would be consistent with observations that some dietary components are anti-inflammatory, but candidate acetyl donors have not been identified.

Speculative acetyl candidates may include the menthol relatives, such as menthyl acetate (figure). Peppermint oil, which contains mostly menthol with some menthyl acetate, is more effective in the treatment of inflammatory bowel disease than most pharmaceuticals prescribed to treat the condition. This anti-inflammatory activity may be due in part to the aspirin-like chemical structure and function of the menthyl acetate. Also note that acetic acid/vinegar is sometimes suggested as a cure-all. This activity may be a consequence of its formation of ester linkages with alcohols that have structures similar to menthol.

Large Dose Aspirin as Cancer Treatment

The potent anti-inflammatory effects of aspirin have been compromised, because inflammation is an essential developmental activity. Thus, the integrity of the gut, for example, requires modest production of inflammatory prostaglandins and a pill of aspirin can disrupt gut tissue. Large doses of aspirin cannot be given orally. Intravenous administration of large doses of aspirin, however, is possible and the impact on process that require inflammation is dramatic.

Anecdotal evidence indicates that large dose aspirin is able to disrupt cancers, because proliferation of cancer cells requires NFkB activation and other inflammatory responses. High doses of aspirin also cause other potentially dangerous complications, such as short-circuiting oxidative phosphorylation of mitochondria and increasing nitric oxide free radical production. Still, the impact of high dose aspirin on some diseases is so amazing that it is being actively and carefully pursued.

What’s the Opposite of Inflammation?

I want to commemorate the writing of my 100th article on Blogspot by discussing a new insight into inflammation.

I have been searching the last several years for an anti-inflammatory system to balance inflammation. Now I realize that there is no opposite to inflammation. There is only completion of inflammation to return to the original state. Inflammation is a process that includes resolution or recovery from the defensive, destructive state of immunological activity.

Inflammation is the martialling of resources for battle by offloading lymphocytes from the blood stream, engaging the enemy by triggering the release of toxic secretory vesicles from leukocytes, and cleaning up the carnage by macrophages engulfing cellular fragments. Each step in the inflammatory process induces the next step until there is a return to the origin. Inflammation is not balanced by anti-inflammatory processes.

Inflammation is triggered by molecules characteristic of viruses, bacteria or fungi binding to membrane receptors (TLRs). The result is activation of the inflammatory transcription factor, NFkB (illustrated holding DNA), that turns on the expression of dozens of genes that code for cytokines (IL-1, IL-6, TNF) and enzymes (COX-2) that produce signal compounds. Among the signal compounds are the inflammatory eicosanoids (PGE2) produced from the omega-6 fatty acid arachidonic acid (ARA).

The complex signaling pathways that lead to PGE2 synthesis subsequently initiate transcription of genes that code for the enzymes that make lipoxins (resolvins and protectins) from eicosapentanaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are the two omega-3 fatty acid components of fish oil and a shortage of these dietary components blocks the next step, resolution of inflammation.

The lipoxins reduce the permeability of blood vessels, stop the offloading of lymphocytes, reduce responsiveness to inflammatory cytokines, recruit phagocytic macrophages to clean up debris and orchestrate a return to quiescence of the inflammatory system. Without adequate lipoxins, inflammation continues.

An interesting footnote to this discussion is the impact of aspirin on inflammation. Aspirin binds to the enzyme (COX-2) that converts ARA to inflammatory prostaglandins and leukotrienes. Acetylation of COX-2 by aspirin stops inflammatory eicosanoid synthesis and shifts the synthesis to anti-inflammatory lipoxins. Even ARA is used to make anti-inflammatory lipoxins in the presence of aspirin. This shift to anti-inflammatory signaling may occur naturally in the small intestines in response to aspirin-like compounds in vegetables. This would be a transitory response similar to taking aspirin with a meal. More constant use of aspirin would disrupt the normal and necessary actions of the inflammatory signaling to maintain the integrity of the gut.

Excess of dietary omega-6 oils and deficiency in omega-3 fatty acids corrupts inflammatory signaling by eliminating recovery and produces chronic inflammation. Another name for chronic inflammation is obesity/metabolic syndrome. Chronic inflammation is the foundation for the degenerative, autoimmune and cancer diseases that are so prevalent today.

Fortunately a shift to an anti-inflammatory diet and lifestyle provides a simple solution to chronic inflammation.

[Note added: Perhaps the opposite of anti-inflammatory is immunosuppressed, as in high use of omega-3 oils can increase the risk of tuberculosis of influenza.]

Topoisomerase Inhibitors

Inhibiting enzymes involved in DNA synthesis should stop cancer cells, because cancer is uncontrolled cell division. Topoisomerases are enzymes that help to relieve the twists on double helical DNA as it unwinds preparatory to replication. It appears logical that topoisomerase inhibitors should be cancer inhibitors. Unfortunately targeting DNA-binding proteins also targets most of the signal receptors that are the targets for the evolution of plant alkaloids.

Drugs are designed to be specific in their interactions with a particular target protein, but they are too small to be specific and end up binding to many other related proteins. Hence, drugs have side reactions that are to some extent unpredictable, because the interacting proteins are not known.

Aspirin, for example, is supposed to bind to and inhibit COX-2, the enzyme that converts omega-3 and omega-6, long-chain fatty acids into corresponding anti-inflammatory and inflammatory prostaglandins, resp. Aspirin also binds to proteins that inhibit NFkB, the transcription factor that controls expression of inflammatory genes. Aspirin binds to dozens of other proteins. Aspirin does lots of other things than just blunt inflammation, but those side reactions are usually not significant enough to get our attention.

Heparin is one of the most commonly used drugs. It binds to and activates an inhibitor of thrombin, an enzyme that activates fibrin and mediates clotting. Heparin also binds to other components of the clotting system, as well as a dozen components of the complement system, and most of the cytokines that control communications throughout the body. When patients are given heparin injections, heparin binds continually to all of these components and must be constantly supplemented and monitored. Inflammation depletes the heparin components throughout the body, so it is not known prior to injection, how much heparin will be needed to saturate other serum proteins before the desired level of clotting inhibition is achieved. This illustrates rather dramatically that most drugs have only limited specificity.

One of my students provided another example of the minimal specificity of small molecules, especially the alkaloids and phenolics produced by plants. He brought to me a research article espousing the use of phenolics from yerba mate, which serves as a coffee-like stimulant in Argentina, as a topoisomerase inhibitor and potential anti-tumor treatment. Sure enough, phenolics extracted from this plant inhibit topoisomerase, and they may well be able to inhibit the growth of tumors, but it is doubtful that the binding of the phenolics to topoisomerase in the tumor nuclei has anything to do with inhibition of tumor growth.

Topoisomerase binds to nuclear DNA as the DNA unwinds during replication to produce two new double helical DNA molecules. Topoisomerase is a DNA-binding protein, i.e. a protein that binds to a negatively charged polymer of small deoxyribose sugars and flat purine and pyrimidine bases. Proteins bind to DNA in two ways. Amino acids of the protein either bind along the edges of the hydrophobic stack of base pairs, e.g. sequence-specific transcription factors, or they provide hydrophobic, flat surfaces that bind to the hydrophobic faces of the separated bases. Topoisomerase does both, because it deals with single-stranded regions of DNA and therefore binds to both the phosphates, as well as the bases. The important point here is that both aromatic amino acids, with flat hydrophobic rings, and the hydrophobic tails of basic amino acids, i.e. lysine and arginine, bind to the hydrophobic faces of nucleic acid bases.

I have illustrated the binding of a “topoisomerase inhibitor” to show the arginine (blue) in the active site cleft of the topoisomerase that binds across the hydrophobic face of the inhibitor (grey and red). Many plant phenolics and alkaloids would be expected to similarly bind and act as inhibitors of topoisomerase. This observation and the ease by which alkaloids enter cells (attached to circulating heparan sulfate?) suggests that a major function of the nuclear envelope may be to minimize access of alkaloid and related molecules to the nucleic acid binding proteins of the nucleus.

The binding promiscuity of secondary plant products is further exemplified by berberine. Berberine is an alkaloid found in goldenseal and is an herbal remedy used to treat a variety of inflammatory diseases. It also binds to heparin (and nucleic acids) to produce a fluorescent complex. Thus, mast cells that store and secrete histamine and heparin to produce the symptoms of allergy, can be vividly stained with berberine.

I could not resist the temptation to check to see if berberine also binds to topoisomerase. A quick search of the research literature showed that berberine is in fact a topoisomerase inhibitor.

The numerous cross reactions of drugs are further illustrated by metformin, the common drug used in the treatment of type II diabetes. Metformin is approximately planar and provides a surface that cannot hydrogen bond, i.e. it is hydrophobic. I expected that metformin would bind to tryptophans that I observed as common substrate-binding amino acids in the active sites of proteins that bound to polysaccharides, e.g. lectins, glycosidases and glycanases. To test this, I had students in one of my courses examine the inhibitory activity of metformin on E. coli beta-galactosidase. They found measurable inhibition and support for competitive binding to the active site that contains a pair of the predicted tryptophans.

My protein modeling and structural studies show the basis for numerous interactions between plant secondary compounds, drugs, nucleic acids, polysaccharides (glycosaminoglycans, e.g. heparin) and proteins. Unpredicted cross reactions abound and every drug can be expected to interact with multiple proteins. This provides a note of caution to the use of any drug and encourages minimal exposure, since many unobserved and unanticipated side effects are occurring. These observations also question routine ingestion of herbal remedies, after all, plants use their secondary products as potent defenses against being eaten. Alkaloids disrupt nervous systems and cellular signaling. Plants are not naturally safe.

Thalidomide Waste

Thalidomide suppresses TNF production and alleviates cachexia and anorexia of terminal cancer. Suppression of TNF is also effective in the control of numerous inflammatory diseases.

I have often wondered how cancer actually kills. By infiltrating and displacing cells of essential organs, a metastasizing cancer can kill by starvation, suffocation, etc. Brain cancers can build up pressure in the skull and cut off neural function needed to sustain life. But what about the loss of appetite and general wasting, anorexia and cachexia, associated with the terminal stages of cancer? As more people live longer with cancer, it seems to me that avoiding the wasting of the last stage is becoming more important. So what is wasting?

It seems to me that wasting is high level chronic inflammation. Inflammatory cytokines, particularly TNF (tumor necrosis factor) reach high levels and are characteristic of acute inflammation. TNF was initially called “cachexin” based on its association with wasting. Cytokine signaling is usually balanced and local, so chronic high level TNF marks a system out of control.

Inflammation suffers from stereotyping. We spend so much time trying to block inflammation that we sometimes lose sight of the essential requirement for inflammatory processes in normal immune function, wound repair and development. We notice this need for example in the disruption of the gut by aspirin, since inflammatory prostaglandins are needed for ongoing maintenance of the gastric and intestinal epithelium. Aspirin blocks COX2, the enzyme that produces inflammatory prostaglandins from omega-6 fatty acids, and that is how it leads to problems with causing bleeding.

A potent inhibitor of TNF, thalidomide, was initially banned, because it caused horrible birth defects when taken by pregnant women. We must be vigilant when using potent drugs to selectively eliminate problematic protein functions, because proteins always have multiple functions and multiple proteins have similar structures. Thus testing for the effectiveness of a drug, does not protect us from numerous underlying unintended consequences. All drugs interact and alter numerous, and in most cases unknown, functions within a cell.

Thalidomide was found to reduce TNF and was effective in the treatment of nausea and sleeping problems of pregnancy. Its teratogenicity gave it a terrible reputation for many years, so it was a long time before its potential was appreciated. Suppression of high chronic inflammation is very useful in extreme cases of arthritis, leprosy, multiple myeloma and many other diseases currently being examined. So, thalidomide is now being vindicated.

Upon seeing these observations of the effectiveness of thalidomide, I immediately thought about the possibility of alleviating cancer cachexia and perhaps even the physiological reinforcement of anorexia nervosa. A quick check of the biomedical literature confirmed that thalidomide is a very useful new tool in the treatment of terminal cancer. Thalidomide that can be tragic to embryos can provide comfort and improve the quality of life in its final stage.