Function of CD 28-

Hey guys!

I remember in class there was a question regarding CD 28- and its function. I found myself digging through my brain and eventully came to the conclusion that I didn't know what it did either! Like all science nerds, I went off on a search and finally figured it out.

In the article it was paired with CD 4. We know CD 4 is expressed on dendritic cells, macrophages T helper cells etc. It is a co-receptor that assists the T cell with the antigen-presenting cell and allows the signal to be amplified, so on and so forth.
It turns out that CD 28 is also expressed on T cells! It has an intense co-stimulatory signal for producing interleukins. CD28 also happens to be the only B7 receptor expressed on naive T cells!

There is a plethora of additional information in the journal article attached :)

http://jem.rupress.org/content/190/4/487.full

Can Diet or Supplements Relieve Your Arthritis Aches and Inflammation?

Compared to the majority of lay articles discussed in this class, this article was very well written. The author did a great job of simplifying the information to a point where a person with no medical background could easily understand it. The definitions were especially easy to understand and not overly simplified. They explained how arthritis is a group of diseases and conditions that share common symptoms including pain, aches, stiffness and swelling in or around the joints. There are more than 100 types (which I definitely did not know!). The two most common are obviously osteoarthritis and rheumatoid arthritis. They then go into discussing how a lot of arthritis sufferers seek herbal supplements and diets to complement their medication. They talk about 13 double-blind, placebo-controlled studies in which about 3.3 grams of omega-3 fatty acids a day significantly reduce rheumatoid arthritis symptoms. They also mention another study where vitamins A, C and selenium were not noted to be effective in relieving symptoms. They pretty much summed it up by saying that some supplements work, some have no effects, and others can harm you. Towards the end the article started to go all over the place stating a series of "myths" that may or may not work and explaining that they have no scientific evidence behind them. They also stressed not to cut out an entire food group when dieting, which seems obvious to us but may not no others, so I really like that they threw that in there! However, at the end in "EN's Bottom Line" was not very specific. The article didn't really end up saying anything of great significant importance to arthritis. It was just kind of how to live healthy. "Eat a well balanced diet and take a multivitamin" was the overall message which is not very specific to arthritis, more just how to lead a healthy lifestyle.

Irons effect on ROS

After reading the review article “Reactive Oxygen Species and Superoxide Dismutases: Role in Joint Diseases”, I was able to grasp a better understanding of some additional ways arthritis comes to be. This of course is due to an increased production of reactive oxygen species, such as the superoxide anions. The authors explained that an over production of ROS damages the endothelial cells and the extracellular matrix of various joint tissues.

One out of the many statements that caught my eye was that more reactive and aggressive ROS exists, such as the hydroxyl radicals. These come to be when the superoxide anion interacts with free iron or copper ions. Normally, this would not be an issue for healthy adults, but with people who have Hemochromatosis, which is an over absorption of iron ions from the digestive track, arthritis and several other complications arise. Primary Hemochromatosis is due to a genetic defect that affects nearly 1 out of every 200 to 300 Americans. With the addition of an increased risk of getting arthritis, the liver absorbs much of the excess iron causing it to swell and sometimes leads to liver cancer or even failure. This is obviously the worst-case scenario, but many of the other symptoms are more easily manageable and can be fix with simple diet and life style changes.

I just found it interesting how the pathology of arthritis can be caused by so many different factors and I am curious to see what more we learn about this disease in the coming years.

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001368/

Arthritis Comes in Different Forms

As most of you know, arthritis is a disease that comes in several forms. Arthritis itself means inflammation of the joints. The most common forms of arthritis are osteoarthritis and rheumatoid arthritis, however, there are over one hundred different forms identified. Here is a brief list of some of the more common forms of arthritis. Osteoarthritis is the degradation of the joints, including the cartilage and the bone. This degradation causes the sufferer pain, stiffness and loss of mobility. While there is a hereditary factor in developing osteoarthritis, it is a fairly common disease of ageing regardless of genetics. Rheumatoid arthritis is considered a systemic autoimmune disease. It is systemic because it has the potential to affect many of the body's organs and tissues. Rheumatoid arthritis is an autoimmune disease because it mistakenly attacks the body's own healthy tissues. Rheumatoid arthritis affects the lining of the joints, the synovium. Juvenile Rheumatoid arthritis is the most common form of arthritis in children. It usually will appear between 6 months and 16 years of age. Just like adult Rheumatoid arthritis, Juvenile Rheumatoid arthritis is an autoimmune disorder. Gouty Arthritis is associated with the disorder gout which is an overload of uric acid in the body that causes the formation of small crystals of urate that deposit in tissues throughout the body. This causes inflammation of the joints which is intensified even more as the immune system reacts to the deposits of the urate crystals. Lupus arthritis is a side effect of the autoimmune disease Lupus. In this disease, inflammation of the joints is common. Sufferers of Lupus arthritis tend to have morning stiffness as well as tenderness around the area(s) of the infected joint(s). Again, these are only a few of the forms of arthritis out there. I hope this helps while you are reading the lay articles!

Th17... always our enemy?

So after reading the McInness article on Cytokines in the pathogenesis of rheumatoid arthritis I was left with the feeling Th17 cells equal a bad situation for autoimmune disease. Which typically seems to be the case in most if not all disease states, and is been looked at as a target in several diseases states from RA to MS. However, I have been doing some outside reading on type 1 diabetes (T1D), another autoimmune disease where Th17 is implicated. However, it seems that it may actually have a protective effect in NOD mice (non obese diabetes mice), one of the two typical mouse models used in studying T1D. The theory is that Th1 cells are primarily responsible for beta-cell apoptosis; thus if we can sustain Th17 cells rather than increasing proliferation of Th1 cells we see less incidence of T1D in these mice. So the authors in several papers associate at IL-6 and IL-12 as positive outcomes as these cytokines promote and sustain Th17 cells. This is obviously a new thought and slightly controversial; but brings to mind how much we really don't know about all the factors involved in different inflammatory pathways. And in blocking or diminishing a one cell type cell in a autoimmune condition my actually be detrimental in another. Food for thought....

Han et al. Interleukin-17 producing gamma+ T cells protect NOD mice from type 1 diabetes through a mechanism involving transforming growth factor-beta. Immunology. 2009;197-206

Nikoopour et al. Th17 Polarized cells from NOD mice following mycobacterial adjuvant immunotherapy delay type 1 diabetes. The Journal of Immnology. 2010;4779-88.

"CNS Can Control Arthritic Joint Inflammation and Destruction"

When Looking at the "CNS Can Control Arthritic Joint Inflammation and Destruction" article I found it very interesting that the CNS is a controlling influence for the body and can regulate peripheral inflammation and immune responses. The study showed that if p38 is blocked in a highly restricted site but not throughout the body inflammation in the joints is significantly suppressed. The researchers also showed a decrease in joint destruction in the rats paws. Through the study inhibition of TNF-a was also studied because it was thought that p38 regulates release of TNF-a but also that TNF-a can continue activating spinal p-38 causing ongoing symptoms and destruction. The article showed that an inhibition of p38 and TNF-a causes a decrease in arthritic symptoms. After reading about this I found it interesting that spinal delivery may be more effective than systemic delivery. I believe that more studies need to be conducted and looked at investigating the route of administration. After looking at this article did anyone find a good diagram to explain the different enzymes and why the spinal delivery may be more effective with these certain enzymes?

The Positive Side to Smoking

The dangers of smoking are well known, but there are several types of “Smoker’s Paradoxes” or cases where the effects of smoking appear to be beneficial. These paradoxes are over shadowed by the negative health effects of smoking that little is known about them.

One example can be seen when looking at ulcerative colitis (UC). Research shows that smoking may be beneficial in regards to UC and that individuals who smoke are at the least risk of developing it. This is because the nicotine in tobacco cigarettes has been found to have a positive influence on symptoms of UC. It is believed that nicotine affects the smooth muscle found on the inside of the colon which alters the rate at which food moves through the GI tract.

Another example is how research has shown that smoking helps lower the risk of developing Parkinson’s disease. It is believed to be a temporal relationship that may be due to nicotine having effects on dopamine. Smoking has also been found to reduce rates of uterine fibroids.

New Caucus for Crohn's Disease and Colitis

There is a new caucus for IBD started by Congressmen Ander Crenshaw and Jesse Jackson, Jr. I found this on the website of Crohn's and Colitis Foundation of America. The objectives of the caucus are to raise awareness about IBD, promote more NIH attention to research on this disease, and encourage that patients with IBD have access to insurance and disability.

There is a section for advocacy that we can participate in. There is a call for greater funding for IBD research and you can help this cause by sharing your personal experiences or have someone you know who has Crohn's Disease or Ulcerative Colitis share theirs through this link.

http://www.ccfa.org/advocacy/

Mice Models of IBD

The problem in testing any treatment is finding a good model for the disease. Here are a couple of types of mice currently being used to model IBD.

The first model is the one we saw in the Ruyssers paper we discussed in class. To replicate colitis, a mouse is anesthetized and catheterized. Through the catheter a mixture of TNBS and ethanol will be administered into the lumen of the colon. The ethanol is needed to break the intestinal epithelial barrier while the TNBS is extremely oxidative. The damage from the TNBS will induce a IL-12 driven, Th1 mediated response in the colon [1]. The problem with this model is that the mouse naturally starts to heal this damage so treatments might appear more effective than they might be.

An alternate model looks to induce IBD via excessive effector T cell function. This is done by transferring CD4+/CD45RB T cells minus T-regulatory cells into a mouse that has SCID (severe combined immunodeficiency). If I'm understanding this correctly, as this mouse does not have any T-reg cells to control the newly introduced Th1 cells, the mouse will become inflamed [2].

[1]Boirivant, M et al. (2001). Oral Administration of Recombinant Cholera Toxin Subunit. The Journal of Immunology , 3522-3532.

[2]Ding, X et al.(2005). Inducible nitric oxide synthase-dependent DNA damage in mouse model of inflammatory bowel disease. Cancer Science , 157–163.

-Vinoo

I know we already talked about stroke in class, but I found an interesting article! A study in Sweden showed a reduced risk of stroke in women who drank one or more cups of coffee a day. There was a 23-25% lower risk of stroke in women who drank coffee compared to those who did not. It was hypothesized that coffee may reduce risk by "weakening subclinical inflammation, reducing oxidative stress and improving insulin sensitivity." Here's the link:
http://www.newsroom.heart.org/index.php?s=43&item=1284

Just though I would share, since I'm a big coffee fan!

Helminthic therapy

In class we talked about how helminthic therapy showed promise in treating IBD in human trails. I was curious about just how effective this therapy is so I looked up one of the original trials. This particular paper by RW Summers was looking to see the effectiveness and safety of using Trichuris suis to treat Crohn's (CD). Summers et al. recruited 29 patients with CD and had them ingest 2500 T. suis ova every 3 weeks for 24 weeks. Out of the 29 patients, they found that 23 of the patients showed improvement in their CD activity index (a method of monitoring CD symptoms). This particular study was very rudimentary as they not only didn't even bother with a control group, but in fact many of these patients enrolled were on other medication to treat CD ... talk about complications. That being said, this study still showed that helminthic therapy could be a novel way to treat CD.

If you'd like to read up on the specifics:

http://gut.bmj.com/content/54/1/87.full.pdf

-Vinoo

Get ready for Arthritis

Since Arthritis will be our next topic of discussion, I thought we should all be on the same page about it. Though brief, I feel like this video has a good explanation of what Rheumatoid Arthritis is. It is a clinical application of a young girl named Anna, as well as a physiological explanation of what actually occurs in a body with Rheumatoid Arthritis. Some key take away points are:

http://health.discovery.com/videos/body-invaders-rheumatoid-arthritis.html

• Rheumatoid Arthritis is a systemic disease which begins with a malfunction in the immune system
• White blood cells normally attack foreign invaders, but in Rheumatoid Arthritis they begin to attack healthy ligaments, tendons, and cartilage especially in the joints
• The synovium becomes inflamed and releases enzymes which eat away at the joint causing pain

siRNA

small RNAs can regulate gene expression by mRNA degradation, inhibition of translation, or transcription

• Dicer protein attracted to double-stranded (abnormal) RNA and cuts it into small pieces
• RISC protein recognizes dsRNA and degrades one strand
• Other strand can direct RISC protein to the complementary mRNA it came from, so RISC can destroy it
• The “intrinsic/endogenous” process and the experimental process-similar to what the Emory/GT lab did : introduce siRNA through more innovative ways (viral vector-RISC will go looking for viral mRNA strand)

Overview of Thioketal article

Nature article: Orally delivered thioketal nanoparticles loaded with TNF-a-siRNA target inflammation and inhibit gene expression in the intestines

Problems: troubleshooting things

Hypotheses: actual experiments to test effects

· Problem 1:

o How to localize delivery of siRNA to diseased intestinal tissue?

· Solution 1

o Made a chemical that can target high levels of ROS produced in inflamed intestine

§ TKNs made from PPADT, which are stable in acid and base solutions, but break down in high oxygen concentration areas

· PPADT stable in gut, attracted to ROS

o Encapsulated siRNA in TKN, so it is released only in areas with high ROS (inflammation)

· Problem 2

o How specific is PPDAT for ROS?

· Solution 2

o Incubated PPADT in acid, base, or oxide solutions

o Results: figure 2a

§ Chromotograhy separation based on side of particles

§ Fewer PPADT broke down in acid/base solutions, so they showed up at a different molecular weight than the PPADT in KO2 as seen by the 2 different peaks

· Problem 3

o This is all good but, what about in physiological ROS concentrations, where ROS is produced by actual macrophages?

· Solution 3

o Induced a toll-like receptor immune response using LPS and dye-filled capsules

o Compared amount of dye released during activated macrophage response (physiological ROS concentration) with no activation (1^st two bars in figure 2b)

o Did a positive control: added TEMPOL so that they can verify that the macrophages producing ROS was actually what caused a release of the dye, not something else. TEMPOL chelates ROS, so a decrease in dye release means that it must be ROS that is making the dye be released

o Results: Figure 2b

§ This is what happened in the 2 bottom bars

· Problem 4

o What is TNF-alpha role in gut inflammation? But first how do you get the TNF-alpha-siRNA ready for delivery?

· Solution 4

o Complex siRNA with DOTAP, which increases siRNA stability, cell internalization, mucosal transport, and endosomal escape

· Hypothesis 1 (in vitro)

o Can TNF-a-siRNA TKNs deliver the active form of siRNA safely to decrease TNF-a expression in inflamed cells?

· Test 1

o Treated LPS-activated macropages with TNF-a-TKNs and controls

o Results

§ Figure 2c

§ TNF-a protein concentration significantly decreased with treatment groups: scrambled siRNA, TNF-a siRNA

· Hypothesis 2 (in vivo)

o Can orally-administered TKNs deliver siRNA to the right tissue?

· Test 2

o Induced ulcerative colitis by DSS in mice, and treated with TKNs loaded with siRNA labeled with a fluorescent probe

o Results

§ Figure 3a

§ TKNS can deliver siRNA to correct sites: proximal and distal colon

§ After 7 days, see fluorescent dye only in colon; would want to see trend over all 7 days? Did it stay in the stomach for a few days?

· Hypothesis 3

o Can orally-administered TKNs deliver siRNA, and silence TNF-a mRNA expression in the same was as it silenced TNF-a protein levels in macrophages?

· Test 3

o DSS mice treated with TNF-a siRNA or scrambled siRNA by different means as seen in fig 3b

o Results

§ Figure 3b

§ TNF-a mRNA expression significantly decreased with treatment group: TNF-a siRNA-TKN by 10 fold

§ Free TNF-a-DOTAP increased expression!

· Hypothesis 4

o Did not get the PLGA stuff

· Hypothesis 5

o What is the smallest dose possible that elicits an adequate decrease in TNF-a mRNA expression

· Test 5

o Lowered treatment dose 1-fold for DSS mice

o Results

§ Figure 3c

§ Still see significant inhibition of mRNA

· Hypothesis 6

o Did not understand why they treated with beta glucan particles

o Seemed like beta-gp cannot target disease tissue, but siRNA can still can get to colon by TNKs, but they the siRNa cannot lower mRNA levels? Why not?

· Hypothesis 7

o What are the clinical/macroscopic and physiological manifestations of DDS, and can TNF-a-TKNs treat this too?

· Test 7

o Do a histological examination, neutrophil accumulation assessment (MPO-lysozyme produced by neutophils), and weight measurement

o Results

§ Figure 4 a-f

§ D looks great: TNF-a-TKN

§ Even with lowered dose, TNF-a-TKNs reduced MPO activity, and DSS animals maintained weight with this treatment

Probiotics!

After discussing the probiotics lay article in class I decided to get a little more background information on the topic for everyone and hopefully this will help those individuals that are considering using them as a complementary and alternative medicine (CAM).

Probiotics are live microorganisms (bacteria, viruses, yeast) that can have beneficial effects on one’s health. Probiotics can be found in certain foods like yogurt, unfermented milk, juices, soy drinks, etc. They can also be found as dietary supplements. The two main groups of “friendly” bacteria are Lactobacillus and Bifidobacterium.

Probiotics are used to help treat health conditions like: diarrhea, Irritable Bowel Syndrome, Inflammatory Bowel Disease, skin and vaginal infections, tooth decay and more. Since Probiotics are already a part of our normal digestive system they are considered safe, but they are not regulated the same way as medicine is by the FDA. Side effects, if they occur, are mild like bloating.

Some popular probiotic supplements on the market are:

Align Digestive Care Probiotic Supplement 28 count

Iflora Multi Probiotic 60 Capsules

Enzymatic Therapy- Acidophilus Pearls

Fem-Dophilus (Women)

More research in the area of probiotics is being done at Tulane University School of Public Health and Tropical Medicine, at the Mayo Clinic College of Medicine, and at Tufts-New England Medical Center.

I also found this video that I thought did a good job at explaining probiotics and wanted to share with everyone for some fun.

Citations

Chrisjc2010. "YouTube - Probiotics." YouTube - Broadcast Yourself. 25 Oct. 2007. Web. 8 Mar. 2011. .

"An Introduction to Probiotics [NCCAM Health Information]." National Center for Complementary and Alternative Medicine [NCCAM] - Nccam.nih.gov Home Page. Jan. 2007. Web. 8 Mar. 2011. .

"Probiotics & Probiotic Supplements: Uses and Safety." WebMD - Better Information. Better Health. Web. 8 Mar. 2011.

Whipworm details--YUM!

While discussing whipworms in class, both pig and human, I realized that I had no idea just how someone acquired such a squirmy friend. I did a little research and found this diagram, specific to the human, which shows just how you and Mr. Trichuris Trichiura become so close.

http://img.medscape.com/pi/emed/ckb/emergency_medicine/756148-780913-788570-1678898.jpg

Fun Facts:

- They can grow up to 2 inches long while hanging out in the lumen of your intestine or colon!
- Females tend to lay about 20,000 eggs per day!
- This parasite is carried by about 1/4 of our world's population!
- Boys, when children, are much more apt to become a host than young girls due to "more soil and dirt consumption"...looks like my hypothetical children won't be playing in the sand box.

The article as a whole contains a great deal of interesting information. Here is the link if you feel like checking it out!
http://emedicine.medscape.com/article/788570-overview

Have a great spring break everyone!!

-Heidi

RNAi Discovered

Hey Everyone,
In class we were discussion siRNA and I remembered that in one of my classes we got a chance to watch a rather entertaining and informative tutorial on RNAi (interference). I figured for those of you who are not familiar with the process it may be ineresting to watch. The University of Arizona even makes a short appearance! Enjoy :)

Exogenous IL-10

At the end of the Levels of Anti-Inflammatory Cytokines and Neurological Worsening in Acute Ischemic Stroke, treatment with exogenous IL-1o as a preventative measure against stroke was mentioned. The paper said that recombinant human IL-10 was administered in healthy patients, and that it was safe. I looked up the paper that detailed the IV IL-10 administration (which was reference 37 in the paper we read for class).

The study was conducted with 84 healthy, nonsmoking men. They were split into placebo and single injection of rhIL-10 groups (the "rh" stands for recombinant human). There was a huge range in dosages, from 0.1 microgram/kg body weight up to 100.0 microgram/kg body weight. Each subject received their injection for 30 seconds through IV.

Subjects had mild-to-moderate flu like symptoms (fever, chills, myalgia, cough, nasal congestion...), but "no clinically significant adverse effects on clinical chemistry, serology, or urinalysis were observed. (Huhn et al 700)" Obviously, IL-10 levels increased. There were increased numbers of neutrophils and monocytes. There was a decrease in lymphocyte numbers.

I think it would be really interesting to see a study with IL-10 administered before a MCAO is induced, and to see if IL-10 can actually be used as a preventative measure. From the papers we've read over the past two weeks, I would guess that IV IL-1o treatment pre-stroke would decrease lesion volume and would improve behavior scores. Would IV IL-1o treatment help post-stroke? I wonder...

References:

Vila et al. "Levels of Anti-Inflammatory Cytokines and Neurological Worsening in Acute Ischemic Stroke." Stroke (2003): 671-675. Web. 22 Feb 2011.

Huhn et al . "Pharmacokinetics and Immunomodulatory Properties of Intravenously Administered Recombinant Human Interleukin-l0 in Healthy Volunteers." Blood 87.2 (1996): 699-705. Web. 2 Mar 2011. .

Nasal Vaccination Article

After discussion on Monday, I realized that I had not brought up the concept of a prenumbra, "a constrained area of blood flow with partially preserved energy metabolism...that surrounds the lethally damaged core of the ischemic infarct". Having no idea what a prenumbra looked like, I googled it, and was surprised at the extent of viable tissue surrounding the ischemic core. It got me thinking that if medical professionals could shunt the constrained flow to the most ischemic tissue, damage could be minimilized (I was thinking of it as an almost focal reprofusion). I guess the rub lies in how to reperfuse the area without subsequent reperfusion injury. I just found it interesting that this study, which investigated a T-cell mediated approach as a prophylactic therapy, would be the first (and only) of our papers to address the matter.