Showing posts with label obesity. Show all posts
Showing posts with label obesity. Show all posts

Thursday, September 2, 2010

Gulf War Syndrome, Chemical Sensitivity and Why Benefits of CPAP!

It has only been in the not-to-distant past that officials and medical experts have come out and admitted that Gulf War Syndrome is an actual disease and while many that have tried to find the cause the "true cause" is not yet known. In previous blogs, I have discussed how Gulf War Syndrome shares many of the same symptoms as other environmental conditions and are often co-morbid and include chronic fatigue syndrome, fibromyalgia and multiple chemical sensitivity and other environmental factors may contribute to fascilitate the condition that is commonly regarded as Gulf War Syndrome. One well-respected research blogger, Dr. Art Ayers, explains that CFS, MCS and fibromyalgia "can be induced by organophosphate pesticide exposure. In GWS, two insults seem to be needed: acetylcholine signal disruption and inflammation. He says that in the effected individuals the acetylcholine mimetics (pesticides, pyridostigmine) disrupted the nervous system and numerous immunological, infectious, chemical and emotional stresses generated a high level of chronic inflammation. The vaccine against anthrax and exposure to burning oil wells may have contributed to inflammation." Without a clear understanding of what causes GWS, physicians and health experts are mostly at a loss on how to treat it and clearly, most of the research is now focused on providing effective therapies until a cure is found for it.

In recent weeks, two interesting studies have been released that show CPAP (continuous positive airway pressure) may be beneficial in treating symptoms of Gulf War Syndrome with sleep disordered breathing. In the pilot study, findings demonstrated improvements in many symptoms including pain, fatigue, cognitive function, sleep quality, physical and mental health. The researchers' concluded from this experiment that CPAP can greatly improve overall health in GW patients with sleep disordered breathing which may be a distinguishing factor in veterans with GWI compared to veterans without Gulf War Illness. (Amin)  While this research is preliminary it provides interesting insight into GWS. Admittedly, there are reported side-effects associated with CPAP use and the pros and cons of it should be addressed fully with a qualified physician even if CPAP is taken out of the research lab and used as therapy for GWS.

To date, even with these published findings, the reader is left with the question why CPAP may be effective for treating some symptoms of GWS. The author only makes the comment that GWS experience a "frequency of arousals related to apneas, hypopneas, and mild inspiratory airflow limitation."  Taking a more holistic systematic approach to understanding the nature of GWS ; one can draw some conclusions that provide at least a reasonable explanation of what may be occurring in GW patients with sleep apneas and why CPAP may provide at least "some" relief. CPAP has been used for quite some time to  treat sleep apneas and more recently has been used for a variety of other medical respiratory conditions. Budhiraja explains that sleep disordered breathing is often associated with hypertension and that "sleep apnea, hypocapneas and hypoxemia contribute to alterations in sympathetic activity, changes in the renin-angiotensin pathway, impede xanthine oxireductase production, cause endothelial dysfunction and lower levels of eNOS."  If you are a consistent reader of my feeds, chronic low-level inflammation contributes to endothelial dysfunction and higher risk for cardiovascular disease in many environmentally-induced health conditions.

Recently, it has been suggested that sickness syndrome contributes to symptoms in GWS and may explain  fatigue, pain and other behavioral changes as well. Sickness syndrome is in associated with elevated levels of cytokines including Il-1b and Il-6 and these inflammatory cytokines may also be associated with PTSD and CFS and are activated during the general response to stress which can lead to changes in genetic expression. Two researchers, Burioka and Steiropoulis found significant changes in Il-6 and Tnf-a, uric acid and immune complexes after CPAP. These findings suggest intermittent hypoxia contibutes significantly to inflammation and noted positive changes in patients that use regularly CPAP .  We have suggested that insulin resistance may be a critical factor in environmental illness and obesity and dietary influences may influence the severity of many environmental diseases including sickness syndrome, PTSD, MCS, CFS and fibromyalgia. To some extent, this can be explained by the fact that inflammatory cytokines and adipokines such as leptin and adiponectin can produce systemic changes. Patients with OSA have a higher prevalence of insulin resistance both in the obese and non-obese. (Lam)

In severa studies, agents such as pesticides, particulates and compounds emitted from fires and other environmental conditions that GW veterans may have been exposed too, exert an inhibitory and/or negative influence on cell function. (Gulati) For example, the metabolites of many toxic chemicals consistent with these types of exposures bio-accumulate in adipose tissue and contribute to inflammation and insulin resistance. (Nov) More specifically, it is proposed immune-mediate macrophages in adipose tissue contribute to insulin resistance and Tregs dampen this response and their reduction may contribute to insulin resistance. (Winer) Also, smaller particulates that bind to metals and hydrocarbons and contain endotoxin may infiltrate deeply into body tissues and through a complex process, end up in vessels and contribute to inflammation that leads to vascular disease.  (Li) An August 2010 study of Gulf War patients demonstrate high prevalence of problems with hypercoagulation which are also common in sleep apnea patients and can potentially be reversed by use of CPAP in some individuals. (Guardiola, Nichols)

Sleep apnea often accompanies obesity and for years, it has been assumed that inflammation is an important consequence of obesity. However, many experts now believe endothelial inflammation probably precedes obesity. Whatever the case may be, CPAP has demonstrated therapeutic effects on inflammation in obesity and this inflammatory process is similar in other environmentally-induced diseases. This leads one to assume its benefits may be achieved in the same way for GWS patients. Budhiraja and others have shown,  "CPAP therapy improves endothelial function, decreases the abnormally increased levels of circulating apoptotic endothelial cells, attenuates free radical production from neutrophils and monocytes, reduces the levels of C-reactive protein (CRP), a marker of vascular inflammation, increases vasodilator levels and mediates a decline in vasoconstrictor levels  in patients with sleep apnea altering blood flow. In the future, more studies may demonstrate CPAP may be of benefit for other "somatic" environmental illnesses as well.  (Gold, El Soth) In CPAP studies in obese patients, CPAP therapy has shown to reduce oxidative stress as well as, raise levels of SOD and alter nitrate and nitrite levels. Other changes that are reflected during CPAP adjustments also may have positive influences on physiology in a so-far unknown way. (Calero)

I have agreed with a few health experts and proposed due to my own experiences with several environmental diseases, severe reactions of MCS may be caused by the "lack of tolerance" to environmental conditions. Reactions develops to conditions that were considered normal and therefore, is more like an autoimmune disease and inflammatory cytokines and epigenetic changes in gene expression are contributory to this disruption. This "loss of tolerance" could explain why MCS patients develop extreme sensitivity to very low levels of pollutants such as those found in perfumes and detergents. Chemical sensitivity is also common in Gulf War veterans but the research disagrees with the Treg theory at least in part. Interestingly, a recent study demonstrated that post-natal exposure to flame retardents in animals leads to inhibitory functions on the AhR and a reduction of Tregs (Wahl)  and supports that the AhR modulates Treg production (Mezrich) and they may  be a factor at least in some types of reactions to certain toxins.  It would be interesting to examine different Treg ratios and to compare them with patients with MCS that are not GW patients and also compare this to other factors. Specifically, one example would be extenuating circumstances that dramatically effect stress response regulation. From my own experience, I would suggest actual stress and anxiety levels may alter certain markers because my own reactions are significantly different in different environments.

As far as chemical sensitivity, the idea of "loss of tolerance" is relatively new and may involve a better understanding of a "bridge" that links the immune system and metabolic homeostasis.  Because glucose and metabolic dysregulation seems to be concurrent with many environmental illnesses, one must consider metabolic syndrome as a risk factor for any environmental illness and there is little doubt some may contribute to GWS.  Hersoug hypothesizes that diseases like atopy, asthma and autoimmune diseases which are more common with obesity are the result of changes in adipokines including leptin, adiponectin, Il-6 and tumor necrosis factor (Tnf-a) secreted by white adipose tissue.  He adds that body weight contributes to an increase of these inflammatory mediators which in turn down-regulate regulatory T cells which in turn results in a reduction of the anti-inflammatory Il-10. He proposes that this process forms the basis of the idea of "loss of tolerance" and this author believes the loss of "Tregs" contributes significantly to chemical and environmental pollutant sensitivity. Other factors such as endotoxin and loss by genetics or environmental depression of Nrf2 and aberrant AhR signalling may augment the inflammation and allergic and non-allergic reactions and responses and may explain some of the sensitivity to "oil fires".  This may partially be explained by the fact that crude oil and coal dust contain significant amounts of polyaromatic hydrocarbons (PAH) and are ligands for the AhR. (Neff)  They are present in high amounts in diesel exhaust and disruption of the Nrf2 raises allergic airway inflammatory reactions to oxidative stress at much lower levels of diesel exhaust exposure. This may be true and does not dismis some reactions may be a consequence of diesel hydrocarbon content. (Li) Quinatana concludes the AhR, depending on the ligand, is able to modulate both Tregs and Il-17 which is often upregulated in inflammatory autoimmune diseases. It is easy to gather from all of this, that there is probably no simple answer to resolution of environmental disease except to prevent and limit exposures to the "activating" agents.

Of course, one needs to consider the initial "trigger" and the resulting inflammatory immune response may be different through time and be altered through interaction with other other chronic environmental and behavioral factors such as exercise, diet and other noxious "agents" of exposure in one's environment.  The AhR may provide a clue or two because of its role in activation from dioxins and its aberrant signals could be enough to initiate inflammatory responses that may be important in GWS and chemical sensitivity. I have proposed that some of this is due to the communication channel between the Nrf2 and the AhR. Jensen explains that exposure to PAH AhR ligands suppress B cell production and suppress Il-6 and makes an important comment that any alteration in Il-6 can lead to assorted pathologies including autoimmune disease, vitiligo, lupus and multple sclerosis.  Under normal conditions, elevations in Il-6 increase significantly through time in response to endotoxin but when cells are exposed to dioxin or another AhR ligand, cells presented with much lower levels of Il-6. Jensen concludes, "Any environmental chemical capable of compromising this response has the potential to disrupt the regulation of many important stromal cell functions, including generation of inflammatory responses in general and the elaboration of several cytokines, including IL-6, to regulate blood cell development in particular."  In addition, Jensen's research shows that exposures of different AhR ligands including PAH which are prevalent both in indoor and outdoor environments may be different depending on the tissue and may lead to elevations in other inflammatory cytokines such as Tnf-a. Considering that these influences are common in the environment, they can serve to augment responses in GWS or any environmental disease for that matter. (Jensen) One potential consideration is that if alterations in cytokines contribute to blood abnormalities that contribute to hypoxic conditions,
improvements observed with CPAP may reflect improvements in blood parameters of one sort or another. (Incidentally, after my last chemical injury obvious symptoms could have been explained by blood abnormalities like these. Unfortunately, they were not diagnosed because of improper medical care by a licensed practitioner and brings up concerns about access to properly trained practioners for environmental disease which I have discussed at length in other blogs.)

Foster shows that impaired regulation to hypoxic condition in sleep apnea patients and CPAP increases blood flow to normal levels. Another study demonstrates "hypoxia and dioxin response pathways can compete for limiting cellular factor(s) and cross-talk that occur between the hypoxia and dioxin signal transduction pathways and identify Epo as an AHR-regulated gene." (Chan)  This suggests signal dysfunction may influence a battery of physiological and toxicological responses. Most recently in fish, there is evidence that hypoxia reduces the response of the AhR. (Matson) This brings to light two important concerns in light of the discussion here. One is that there is direct interaction between the AhR and the Nrf2 antioxidant system and two, the AhR is an activator of Tregs regulation. In this context, dysfunction could certainly lead to apneas and chronic inflammation. It also may lead to other impairments in the antioxidant system and possibly to chemical sensitivities with a lower Treg production and a "loss of tolerance". It is also worth pondering the extent of effects of blood cell production in relation to circadian rhythm and influence on the positive effects of CPAP (Burioka).

An alternative example of aberrant levels of Il-6 demonstrates the complexity of environmental disease in relation to inflammatory mediators. Curiously, a recent report shows how different factors may be instrumental and  suggest that stress and the effect of pyridostigmine bromide (PB) may be a plausible cause of GWS. Mauck says that his research shows that while stress normally upregulates muscarinic receptor density, the application of  pyridostigmine bromide or physostigmine reduces them. One of the muscarinic targets is the Nrf2 and may suggest a reduction in these receptors may also reduce or prevent the activation of Nrf2. In addition, GSK-3b inhibition also augments muscarinic signals and Treg expression. Thus, conditions where GSK-3b is upregulated may have a negative influence on both chemical sensitivity in GWS and also other types of chemical sensitivity.  The other part of the puzzle in these conditions may be explained and supported by evidence that shows pesticides may contribute to insulin resistance and diabetes and may negatively influence how the body reacts to infection. This could alter inflammatory mediator production and in turn, contribute to the neuroinflammatory process as shown through reductions of Il-6 by GSk-3b inhibition.(Beurel) Dioxins on the other hand, seem to contribute to insulin resistance independant of the AhR. (Hsu)

I have often said in other blogs that environmental illnesses seem more like a failure to adapt and the concept of down-regulation of Tregs provides a viable mechanism for "maladaptation" at least in multiple chemical sensitivity. It may end up that taking genetic expression and immune regulators into account could be what differentiates the forms of chemical sensitivity in autism and MCS from GWS. If Amin is correct and the presence of apneas can be a predictor of  GW syndrome, then one can presume dysregulation of glucose metabolism similar to that that would occur with obesity and the development of chronic inflammation even though GW patients may not be overweight may contribute to GWS. Obesity is a problem in all age groups and classes and is associated with Western diets and GSK-3b may also play its part. It is worth considering that Gulf War veterans that are overweight and eat a typical Western diet will be more at risk for more severe GWI symptoms and those with conditions that depress Nrf2 (which are often diet, exposure and epigenetic influences related) will be even more so!  One may suggest that a lifestyle that promotes healthy eating and low-inflammatory menu like a Mediterranean diet may provide some healthy benefits.





Amin, M. M., Belisova, Z., Hossain, S., Gold, M. S., Broderick, J. E., and Gold, A. R. (2010). Inspiratory airflow dynamics during sleep in veterans with gulf war illness: a controlled study. Sleep & breathing = Schlaf & Atmung. http://www.citeulike.org/user/HEIRS/article/7756111
Gold, A. R., Dipalo, F., Gold, M. S., and Broderick, J. (2004). Inspiratory airflow dynamics during sleep in women with fibromyalgia. Sleep, 27(3):459-466. http://www.citeulike.org/user/HEIRS/article/7756324
Omurtag, G. Z., Tozan, A., Sehirli, A. O. O., and Sener, G. (2008). Melatonin protects against endosulfan-induced oxidative tissue damage in rats. Journal of pineal research, 44(4):432-438.  http://www.citeulike.org/user/HEIRS/article/2674835
Gulati, K., Banerjee, B., Lall, S. B., and Ray, A. (2010). Effects of diesel exhaust, heavy metals , and pesticides on various organ systems: Possible mechanisms and strategies for prevention and treatment. Indian Journal of Experimental Biology, 48:710-721. http://www.citeulike.org/user/HEIRS/article/7753532
Calero, G., Farre, R., Ballester, E., Hernandez, L., Daniel, N., and Montserrat Canal, J. M. (2006). Physiological consequences of prolonged periods of flow limitation in patients with sleep apnea hypopnea syndrome. Respiratory medicine, 100(5):813-817. http://www.citeulike.org/user/HEIRS/article/7756347
Singh, A. K. and Jiang, Y. Lipopolysaccharide (lps) induced activation of the immune system in control rats and rats chronically exposed to a low level of the organothiophosphate insecticide, acephate. Toxicology and Industrial Health, 19(2-6):93-108. http://www.citeulike.org/user/HEIRS/article/7796
Li, R., Ning, Z., Cui, J., Yu, F., Sioutas, C., and Hsiai, T. (2010). Diesel exhaust particles modulate vascular endothelial cell permeability: implication of zo-1 expression. Toxicology letters, 197(3):163-168.  http://www.citeulike.org/user/HEIRS/article/7284279
Nov, O., Kohl, A., Lewis, E. C., Bashan, N., Dvir, I., Ben-Shlomo, S., Fishman, S., Wueest, S., Konrad, D., and Rudich, A. (2010). Interleukin-1beta may mediate insulin resistance in liver-derived cells in response to adipocyte inflammation. Endocrinology, 151(9):4247-4256. http://www.citeulike.org/user/HEIRS/article/7752881
Budhiraja, R. and Quan, S. F. (2009). When is cpap an antihypertensive in sleep apnea patients? Journal of clinical sleep medicine : JCSM, 5(2):108-109. http://www.citeulike.org/user/HEIRS/article/7752952
Amin, M. M., Gold, M. S., Broderick, J. E., and Gold, A. R. (2010). The effect of nasal continuous positive airway pressure on the symptoms of gulf war illness. Sleep & breathing = Schlaf & Atmung. http://www.citeulike.org/user/HEIRS/article/7756404
Hersoug, L.-G. G., Husemoen, L. L., Sigsgaard, T., Madsen, F., and Linneberg, A. (2010). Indoor exposure to environmental cigarette smoke, but not other inhaled particulates associates with respiratory symptoms and diminished lung function in adults. Respirology (Carlton, Vic.), 15(6):993-1000.  http://www.citeulike.org/user/HEIRS/article/7582695
Hersoug, L.-G. G. and Linneberg, A. (2007). The link between the epidemics of obesity and allergic diseases: does obesity induce decreased immune tolerance? Allergy, 62(10):1205-1213. http://www.citeulike.org/user/HEIRS/article/1640991
Winer, S., Chan, Y., Paltser, G., Truong, D., Tsui, H., Bahrami, J., Dorfman, R., Wang, Y., Zielenski, J., Mastronardi, F., Maezawa, Y., Drucker, D. J., Engleman, E., Winer, D., and Dosch, H.-M. M. (2009). Normalization of obesity-associated insulin resistance through immunotherapy. Nature medicine, 15(8):921-929. http://www.citeulike.org/user/HEIRS/article/5398151
El Solh, A. A., Akinnusi, M. E., Baddoura, F. H., and Mankowski, C. R. (2007). Endothelial cell apoptosis in obstructive sleep apnea: a link to endothelial dysfunction. American journal of respiratory and critical care medicine, 175(11):1186-1191.  http://www.citeulike.org/user/HEIRS/article/7756664
Burioka, N., Miyata, M., Fukuoka, Y., Endo, M., and Shimizu, E. (2008). Day-night variations of serum interleukin-6 in patients with severe obstructive sleep apnea syndrome before and after continuous positive airway pressure (cpap). Chronobiology international, 25(5):827-834. http://www.citeulike.org/user/HEIRS/article/7748469
Steiropoulos, P., Kotsianidis, I., Nena, E., Tsara, V., Gounari, E., Hatzizisi, O., Kyriazis, G., Christaki, P., Froudarakis, M., and Bouros, D. (2009). Long-term effect of continuous positive airway pressure therapy on inflammation markers of patients with obstructive sleep apnea syndrome. Sleep, 32(4):537-543. http://www.citeulike.org/user/HEIRS/article/7756944
Lam, J. C. M. and Ip, M. S. M. Obstructive sleep apnea and the metabolic syndrome: Osa and insulin resistance. Medscape Today. http://www.citeulike.org/user/HEIRS/article/7765845
Gaurdiola, J., Matheson, P., Cavijo, L., Wilson, M., and Fletcher, E. (2001). Hypercoagulability in patients with obstructive sleep apnea. Sleep Medicine, 2(6):517-523. http://www.citeulike.org/user/HEIRS/article/7790684
Nichols, Denise. Original Hypercoagulation Study on Gulf War Veterans. (August 20, 2010) Veterans Today. http://www.veteranstoday.com/2010/08/20/original-hypercoagulation-study-on-gulf-war-veterans/
Salvador, Lourdes. CPAP Machine Improves Gulf War Illness Symptoms for Some. American Chronicle. http://www.americanchronicle.com/articles/view/180225
Espada, S., Rojo, A. I., Salinas, M., and Cuadrado, A. (2009). The muscarinic m1 receptor activates nrf2 through a signaling cascade that involves protein kinase c and inhibition of gsk-3beta: connecting neurotransmission with neuroprotection. Journal of Neural Chemistry, 110(3):1107-1119. http://www.citeulike.org/user/HEIRS/article/7791380
Mauck, B., Lucot, J. B., Paton, S., and Grubbs, R. D. (2010). Cholinesterase inhibitors and stress: Effects on brain muscarinic receptor density in mice. Neurotoxicology. http://www.citeulike.org/user/HEIRS/article/7395495
Beurel, E. and Jope, R. S. (2010). Glycogen synthase kinase-3 regulates inflammatory tolerance in astrocytes. Neuroscience. http://www.citeulike.org/user/HEIRS/article/7264009
Jensen, B., Leeman, R., Schlezinger, J., and Sherr, D. (2003). Aryl hydrocarbon receptor (ahr) agonists suppress interleukin-6 expression by bone marrow stromal cells: an immunotoxicology study. Environmental Health: A Global Access Science Source, 2(1):16+. http://www.citeulike.org/user/HEIRS/article/3802484?show_msg=already_posted
Chan, W. K., Yao, G., Gu, Y.-Z., and Bradfiel, C. A. (1999). Cross-talk between the aryl hydrocarbon receptor and hypoxia inducible factor signaling pathways. The Journal of Biological Chemistry, 274(17). http://www.citeulike.org/user/HEIRS/article/7795717
Foster, G. E., Hanly, P. J., Ostrowski, M., and Poulin, M. J. (2007). Effects of cpap on cerebral vascular response to hypoxia in obstructive sleep apnea patients. Respiratory and Critical Care Medicine, 175(7):720-725. http://www.citeulike.org/user/HEIRS/article/7795723
Matson, C. W., Timme-Laragy, A. R., and Di Giulio, R. T. (2008). Fluoranthene, but not benzo[a]pyrene, interacts with hypoxia resulting in pericardial effusion and lordosis in developing zebrafish. Chemosphere, 74(1):149-154. http://www.citeulike.org/user/HEIRS/article/7795748
Neff, Jerry. Bioaccumulation in marine organisms: effect of contaminants from oil well produced water. 2004. Pg 241. http://books.google.com/books?id=ABIQ_FGKOZcC&lpg=PA241&ots=v-kRmNZQY5&dq=polyaromatic%20hydrocarbons%2Bhypoxia&pg=PA241#v=onepage&q&f=false
Li, Y. J. J., Takizawa, H., Azuma, A., Kohyama, T., Yamauchi, Y., Takahashi, S., Yamamoto, M., Kawada, T., Kudoh, S., and Sugawara, I. (2010). Nrf2 is closely related to allergic airway inflammatory responses induced by low-dose diesel exhaust particles in mice. Clinical immunology (Orlando, Fla.). http://www.citeulike.org/user/HEIRS/article/7730119?show_msg=already_posted
Hsu, H.-F. F., Tsou, T.-C. C., Chao, H.-R. R., Kuo, Y.-T. T., Tsai, F.-Y. Y., and Yeh, S.-C. C. (2010). Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on adipogenic differentiation and insulin-induced glucose uptake in 3t3-l1 cells. Journal of hazardous materials, 182(1-3):649-655. http://www.citeulike.org/user/HEIRS/article/7383158?show_msg=already_posted
Wahl, M., Guenther, R., Yang, L., Bergman, A., Straehle, U., Strack, S., and Weiss, C. (2010). Polybrominated diphenyl ethers and arylhydrocarbon receptor agonists: Different toxicity and target gene expression. Toxicology letters, 198(2):119-126. http://www.citeulike.org/user/HEIRS/article/7408849
Mezrich, J. D., Fechner, J. H., Zhang, X., Johnson, B. P., Burlingham, W. J., and Bradfield, C. A. (2010). An interaction between kynurenine and the aryl hydrocarbon receptor can generate regulatory t cells. Journal of immunology (Baltimore, Md. : 1950), 185(6):3190-3198. http://www.citeulike.org/user/HEIRS/article/7795863
Ho, P. P. and Steinman, L. (2008). The aryl hydrocarbon receptor: a regulator of th17 and treg cell development in disease. Cell Research, 18(6):605-608. http://www.citeulike.org/user/HEIRS/article/3709745

Saturday, June 12, 2010

Leptin and hunger levels in young healthy adults after one night of sleep loss. SLOBODANKA PEJOVIC. 2010; Journal of Sleep Research - Wiley InterScience

sleep loss associated with activation of the stress system but not sleep loss per se may lead to increased hunger and appetite and hormonal changes, which ultimately may lead to increased consumption of 'comfort' food and obesity.



Leptin and hunger levels in young healthy adults after one night of sleep loss. SLOBODANKA PEJOVIC. 2010; Journal of Sleep Research - Wiley InterScience

Thursday, June 3, 2010

PROPENSITY TO HIGH FAT DIET-INDUCED OBESITY IN RATS IS ASSOCIATED WITH CHANGES IN THE GUT MICROBIOTA AND GUT INFLAMMATION.

Consumption of a high fat diet induces changes in the gut microbiota, but it is the development of inflammation that is associated with the appearance of hyperphagia and an obese phenotype.


"De La Serre, C. B. B., Ellis, C. L., Lee, J., Hartman, A. L., Rutledge, J. C., and Raybould, H. E. (2010). Propensity to high fat diet-induced obesity in rats is associated with changes in the gut microbiota and gut inflammation. American journal of physiology. Gastrointestinal and liver physiology."CiteULike: PROPENSITY TO HIGH FAT DIET-INDUCED OBESITY IN RATS IS ASSOCIATED WITH CHANGES IN THE GUT MICROBIOTA AND GUT INFLAMMATION.:




Monday, May 10, 2010

Reduced NO-cGMP Signaling Contributes to Vascular Inflammation and Insulin Resistance Induced by High-Fat Feeding

Reduced signaling via the NO-cGMP pathway is a mediator of vascular inflammation and insulin resistance during overnutrition induced by high-fat feeding. Therefore, phosphodiesterase-5, soluble guanylyl cyclase, and other molecules in the NO-cGMP pathway (eg, protein kinase G) constitute potential targets for the treatment of vascular dysfunction in the setting of obesity.


CiteULike: Reduced NO-cGMP Signaling Contributes to Vascular Inflammation and Insulin Resistance Induced by High-Fat Feeding: "Rizzo, N. O., Maloney, E., Pham, M., Luttrell, I., Wessells, H., Tateya, S., Daum, G., Handa, P., Schwartz, M. W., and Kim, F. (2010). Reduced no-cgmp signaling contributes to vascular inflammation and insulin resistance induced by high-fat feeding. Arterioscler Thromb Vasc Biol, 30(4):758-765."

Tuesday, March 9, 2010

Obesity as protection against metabolic syndrome, not its cause

Obesity as protection against metabolic syndrome, not its cause

ScienceDaily (2010-03-09) -- The collection of symptoms that is the metabolic syndrome -- insulin resistance, high cholesterol, fatty liver, and a greater risk for diabetes, heart disease, and stroke -- are all related to obesity, but, according to a new review not in the way you probably think they are. ... > read full article

Friday, March 5, 2010

Intestinal bacteria drive obesity and metabolic disease in immune-altered mice

"Mice lacking a gene called TLR5 have an altered ability to recognize and control bacteria in their intestines, leading them to develop obesity and insulin resistance, which is often referred to as "pre-diabetes." The bacteria appear to influence appetite and metabolism rather than how well calories are absorbed. Obesity and insulin resistance can be transferred from TLR5-deficient mice via intestinal bacteria."
Intestinal bacteria drive obesity and metabolic disease in immune-altered mice

Notes:
  • GSK-3b regulates TLR production including TLR5. Studies have demonstrated that TLR signaling increases IL-10 which has an anti-inflammatory effect and inhibition of GSK-3b may be protective against endotoxic shock.
  • Changes in inflammatory cytokines may influence TLR functioning in mesenchymal stromal cells.

Martin, M., Rehani, K., Jope, R. S., and Michalek, S. M. (2005). Toll-like receptor-mediated cytokine production is differentially regulated by glycogen synthase kinase 3. Nature immunology, 6(8):777-784. http://www.citeulike.org/user/HEIRS/article/260512
Abreu, M. T. (2010). Toll-like receptor signalling in the intestinal epithelium: how bacterial recognition shapes intestinal function. Nature Reviews Immunology, 10(2):131-144. http://www.citeulike.org/user/HEIRS/article/6589668
Palmer, Eric. Innate immune defense against intestinal bacteria. Videocast. National Institutes of Health. Retrieved on Monday March 1, 2010. http://videocast.nih.gov/ram/iig102109.ram

Wednesday, March 3, 2010

Effects of green tea compound (EGCG) on Treg number and function in obese v. lean volunteers.

EGCG enhances the functionality of Tregs, i.e. IL-10 production and number by suppressing the NF-kappaB signalling pathway via inducing epigenetic changes


CiteULike: Effects of epigallocatechin gallate on regulatory T cell number and function in obese v. lean volunteers.: "Yun, J.-M. M., Jialal, I., and Devaraj, S. (2010). Effects of epigallocatechin gallate on regulatory t cell number and function in obese v. lean volunteers. The British journal of nutrition, pages 1-7."

Monday, November 23, 2009

Environmental endocrine disruptors promote adipogenesis in the 3t3-l1 cell line through glucocorticoid receptor activation.

Summary: EDCs are able to promote adipogenesis through the activation of the GR, further implicating these compounds in the rising rates of obesity and diabetes.

Sargis, R. M., Johnson, D. N., Choudhury, R. A., and Brady, M. J. (2009). Environmental endocrine disruptors promote adipogenesis in the 3t3-l1 cell line through glucocorticoid receptor activation. Obesity. http://www.citeulike.org/user/HEIRS/article/6198203

Tuesday, November 17, 2009

Obesity is the major contributor to vascular dysfunction and inflammation in high-fat diet hypertensive rats

Obesity and hypertension are the two major risk factors that contribute to the progression of end-stage renal disease. To examine whether hypertension further exacerbates oxidative stress and vascular dysfunction and inflammation in obese rats, four groups of male Sprague–Dawley rats were fed either a normal (7% fat) or high-fat (36% fat) diet for 6 weeks and osmotic pumps were implanted to deliver ANG (angiotensin II) or vehicle for an additional 4 weeks.

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Sunday, November 1, 2009

Vitamin E Improves NASH

ALEXANDRIA, Va. and BOSTON, Oct. 31 /- In a randomized, double-blind, placebo-controlled trial of 247 patients who had NASH but not diabetes, pioglitazone improved key histological features and liver enzymes; however, vitamin E was more successful for the treatment of NASH in these patients. NASH is associated with fatty liver disease, insulin resistance, and obesity, an... Click here.

Tuesday, October 27, 2009

Pgc-1β: A regulator of mitochondrial function with subtle roles in energy metabolism

"As expected from PGC-1β’s ability to stimulate mitochondrial function, the loss of PGC-1β decreased the transcription of genes encoding many of the mitochondrial proteins that generate ATP and heat. Yet the mutant mice appeared essentially healthy under normal conditions. Still, a slight impairment of mitochondrial function might lead to some metabolic imbalance, for instance obesity, since mitochondria burn energy that would otherwise be stored as fat."

Chanut, F. (2006). Pgc-1β: A regulator of mitochondrial function with subtle roles in energy metabolism. PLoS Biol, 4(11):e402+. http://www.citeulike.org/user/HEIRS/article/6016816

Friday, October 23, 2009

PON-1 dysregulation in obesity linked to reduced cellular repair, protection

Title: PON-1 dysregulation in obesity linked to reduced cellular repair, protection.

Summary: "evaluation of PON1 activity in obesity and in other diseases associated with alterations of lipid metabolism could therefore represent a useful approach to study the effect of drugs used in the therapy and to determine whether weight reduction, diet, and nutritional approaches affect endogenous antioxidant capabilities."


Citation: Lyford, J. (2009). Pon-1 dysregulation in obesity linked to reduced cellular repair, protection. http://www.citeulike.org/user/HEIRS/article/5998953

Inflammation and Alterations in Fat Cells By Pesticide Alterations of Anti-inflammatory Protein Genes!

Background: Some experts believe that changes in gene expression may be a consequence of certain chemical exposures. Researchers are now focusing a lot of attention on the effects of these exposures on adipocytes which can produce inflammatory chemokines which may generate inflammation.  It has been observed that some types of exposures are associated with obesity which is a risk factor for diabetes while, others can lead to weight reduction.   Arsenescu demonstrated toxic exposures can stimulate and increase expansion of adipose tissue and other studies show alterations in the process of differentiation of preadipoctyes into adipocytes. In 2008, a preliminary study suggested endothelial dysfunction contributes to fat cell development because adipose stromal cells are in close contact with endothelial cells of capillaries and small blood vessels. (ScienceDaily) Long-term high serum levels of dioxin has been shown to contribute to endothelial dysfunction which provides a possible mechanism for the association of certain exposures to endothelial dysfunction, obesity and a higher risk for diabetes. (Peclova)

In the past, obesity has been characterized by differentiation of preadipocytes to adipocytes and involves the coordinated responses of a number of proteins with fatty acids that leads to increases of the size of fat cells.(Uto-Kondo) However, a recent study suggests that in in the case of abdominal obesity which may have more severe long-term health effects, there is impairment of the ability for preadipocytes to differentiate into adipocytes. Irakson says that "inhibition of this type can lead to a proinflammatory state and macrophage-like phenotype and as Hou explains "elevated levels of TNF-a or Il-1b in inflammatory tissues prolongs the survival of these immune cells and lengthens the durations they remain in an inflammatory state." 

 In one study, eldrin causes inhibition of a binding protein and interfered with expression of the anti-inflammatory protein PPAR-gamma and altered the expression of NF-kappaB which usually decreases as adipocytes differentiate. (Moreno-Aliego) We have suggested that the aberrant signaling from the AhR, which normally is important for cellular homeostasis and contributes to detoxification of PAHs and HAHS, may be an important factor in MCS. Hanlon et el notes that activation of the AhR by dioxin blocks hormone-induced adipocyte differentiation through the suppression of PPAR-gamma. The presence of inflammatory mediators are also associated with insulin resistance which can further impair normal cell function and reductions in the expression of Nrf2 may further complicate it. Chronic inflammation have been suggested as a causal factor in environmental illnesses including obesity and diabetes. One study shows proteins associated with cell death are less efficient in diffentiated adipocytes than in undifferentiated cells when introduced to a reactive species stimulus. Kojima confirmed an increase in antioxidants including MnSOD, catalase, Cu/ZnSOD as well as, FOXO with the the progression of adipocyte differentiation.  From this study, it has been concluded that ROS-generated apoptosis is associated with the expression of FOXO3a in undifferentiated adipocytes and FOXO expression suppresses ROS-apoptosis through activation of scavenging enzymes in differentiated ones. With this study in mind and considering that uncontrolled production of ROS contribute to cellular processes that cause inflammation, preventing differentiation of adipocytes may have negative consequences in certain cases.

Kojima, T., Norose, T., Tsuchiya, K., and Sakamoto, K. Mouse 3t3-l1 cells acquire resistance against oxidative stress as the adipocytes differentiate via the transcription factor foxo. Apoptosis. http://www.citeulike.org/user/HEIRS/article/5998696
Isakson, P., Hammarstedt, A., Gustafson, B., and Smith, U. (2009). Impaired preadipocyte differentiation in human abdominal obesity. Diabetes, 58(7):1550-1557. http://www.citeulike.org/user/HEIRS/article/5017576
Hou, F. F., Boyce, J., Zhang, Y., and Owen, W. F. (2000). Phenotypic and functional characteristics of macrophage-like cells differentiated in pro-inflammatory cytokine-containing cultures. Immunology and cell biology, 78(3):205-213. http://www.citeulike.org/user/HEIRS/article/5998701
Hanlon, P. (2003). Ahr- and erk-dependent pathways function synergistically to mediate 2,3,7,8-tetrachlorodibenzo-p-dioxin suppression of peroxisome proliferator-activated receptor-γ1 expression and subsequent adipocyte differentiation. Toxicology and Applied Pharmacology, 189(1):11-27. http://www.citeulike.org/user/HEIRS/article/5778106
Moreno-Aliaga, M. J. and Matsumura, F. (1999). Endrin inhibits adipocyte differentiation by selectively altering expression pattern of ccaat/enhancer binding protein-alpha in 3t3-l1 cells. Mol Pharmacol, 56(1):91-101. http://www.citeulike.org/user/HEIRS/article/5998840
Uto-Kondo, H., Ohmori, R., Kiyose, C., Kishimoto, Y., Saito, H., Igarashi, O., and Kondo, K. (2009). Tocotrienol suppresses adipocyte differentiation and akt phosphorylation in 3t3-l1 preadipocytes. J. Nutr., 139(1):51-57. http://www.citeulike.org/user/HEIRS/article/5998926
Healthy Blood Vessels May Prevent Fat Growth. ScienceDaily. September 23, 2008.
PelclovƔ, D., PrƔzny, M., Skrha, J., FenclovƔ, Z., KalousovƔ, M., Urban, P., NavrƔtil, T., SenholdovƔ, Z., and Smerhovsky, Z. (2007). 2,3,7,8-tcdd exposure, endothelial dysfunction and impaired microvascular reactivity. Human & experimental toxicology, 26(9):705-713. http://www.citeulike.org/group/7254/article/6000451

Friday, October 9, 2009

Phthalates Regulates Hepatic Energy Metabolism Through PPAR-alpha!

Title: The pollutant di-ethyl-hexyl-phthalate regulates hepatic energy metabolism via species-specific pparα-dependent mechanisms.

Summary: "DEHP slightly promotes weight gain in PPARα-humanized mice. Consistent with this
observation, the urinary concentrations of phthalates metabolites have been recently positively
correlated with obesity and insulin resistance in humans.  Our results clearly demonstrate that these effects are most likely not linked to activation of PPARγ and adipogenesis in the adipose tissue but potentially to low hepatic oxidative metabolism." Note in this study, the effect of phthalates in this study is different in mice that are wild-type vs. mice that are altered to be human-type models. It is also important to mention that PPAR-alpha is an important protein that is associated with mitochondrial function.

Citation: Feige, J. N., Gerber, A., Casals-Casas, C., Yang, Q., Winkler, C., Bedu, E., Bueno, M., Gelman, L., Auwerx, J., and Frank (2009). The pollutant di-ethyl-hexyl-phthalate regulates hepatic energy metabolism via species-specific pparα-dependent mechanisms. Environmental Health Perspectives. http://www.citeulike.org/group/7833/article/5916157

Tuesday, October 6, 2009

Inflammatory Proteins and IL-10 in Obesity and Pathogenic Exposure: Implications for Sickness Syndrome and Fatigue!

Background: Sickness syndrome is a response to infection and inflammation and has been associated with production of Il-1b. Fatigue is a common symptom in environmental illness and may be a factor in sickness syndrome and recent studies provide evidence that activation of the Il-1 system may be a factor in causing the fatigue. Other studies demonstrate that Il-10 can modulate the severity of sickness syndrome through its interactions with HO-1 and other proteins such as BDNF.(Richwine) Richwine has also demonstrated that inflammatory processes increase in aged mice compared to adults. Meador has explained that IL-10 is associated with lower levels of inflammatory cytokines including Tnf-a, Il-1 and Il-6 in muscle and non-muscle.  The effects of aging on the expression of Il-10 would suggest alteration in SIRT1 or Nrf2/HO-1 and/or changes in expression of another gene that is effected by the aging process and high-fat diets.

New Research:
Title: Environmental and genetic factors influence the relationship between circulating Il-10 and obesity phenotypes.

Summary: "circulating IL-10 levels were associated not only with obesity status but also with genetic factors and with the exposure to environmental pathogens."

Citation: Bassols, J., Botas, P., Moreno-Navarrete, J. M., Delgado, E., Ortega, F., Ricart, W., and Fernandez-Real, J. M. (2009). Environmental and genetic factors influence the relationship between circulating il-10 and obesity phenotypes. Obesity (Silver Spring, Md.). http://www.citeulike.org/group/7167/article/5898650

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Additional References:
Richwine, A. F., Sparkman, N. L., Dilger, R. N., Buchanan, J. B., and Johnson, R. W. (2009). Cognitive deficits in interleukin-10-deficient mice after peripheral injection of lipopolysaccharide. Brain, behavior, and immunity, 23(6):794-802. http://www.citeulike.org/user/HEIRS/article/4710107
Godbout, J. P., Chen, J., Abraham, J., Richwine, A. F., Berg, B. M., Kelley, K. W., and Johnson, R. W. (2005). Exaggerated neuroinflammation and sickness behavior in aged mice following activation of the peripheral innate immune system. The FASEB Journal, 19. http://www.citeulike.org/user/HEIRS/article/4745254
Meador, B. M., Krzyszton, C. P., Johnson, R. W., and Huey, K. A. (2008). Effects of il-10 and age on il-6, il-1beta, and tnf-alpha responses in mouse skeletal and cardiac muscle to an acute inflammatory insult. Journal of applied physiology (Bethesda, Md. : 1985), 104(4):991-997. http://www.citeulike.org/user/HEIRS/article/5488212

Sunday, October 4, 2009

Nrf2 Potent Inhibitor of Obesity, Says New Study!

Title: Role of nrf2 in prevention of high-fat diet-induced obesity by synthetic triterpenoid cddo-imidazolide.

Summary: "CDDO-Im is an exceedingly potent agent for preventing obesity, and identify the Nrf2 pathway as a novel target for management of obesogenesis."

Shin, S., Wakabayashi, J., Yates, M. S., Wakabayashi, N., Dolan, P. M., Aja, S., Liby, K. T., Sporn, M. B., Yamamoto, M., and Kensler, T. W. (2009). Role of nrf2 in prevention of high-fat diet-induced obesity by synthetic triterpenoid cddo-imidazolide. European journal of pharmacology, 620(1-3):138-144. http://www.citeulike.org/user/HEIRS/article/5624234

Saturday, September 26, 2009

Association between oxidized LDL, obesity and type 2 diabetes in a population-based cohort, the Health, Aging and Body Composition Study

Title: Association between oxidized ldl, obesity and type 2 diabetes in a population-based cohort, the health, aging and body composition study.

Comments: "No significant association was found between oxLDL and incident T2D. Interestingly, oxLDL was significantly associated with % change in T2D- and obesity-related traits in whites but not in blacks.Our data suggest that systemic oxidative stress may be a novel risk factor for T2D and obesity."

Njajou, O. T., Kanaya, A. M., Holvoet, P., Connelly, S., Strotmeyer, E. S., Harris, T. B., Cummings, S. R., and Hsueh, W.-C. (2009). Association between oxidized ldl, obesity and type 2 diabetes in a population-based cohort, the health, aging and body composition study. Diabetes/Metabolism Research and Reviews, 9999(9999):n/a+. http://www.citeulike.org/user/HEIRS/article/5843201