#2 Pemphigus is a rare autoimmune disease that causes watery blisters to form al
ID: 62564 • Letter: #
Question
#2 Pemphigus is a rare autoimmune disease that causes watery blisters to form all over the skin, including and especially the mucous membranes of the mouth and nose. These blisters are extremely itchy and easily pop or fall off, developing into deep sores that are prone to nasty infections. It was found that pemphigus is caused by the production of autoantibodies to a family of proteins called desmogleins, which is within the superfamily of proteins known as cadherins.
A.) What are cadherins and what structures do they help form?
B.) What cellular structures specifically have the desmoglein proteins and where are these found in the human body?
C.) Explain the symptoms of pemphigus, given the underlying cause.
D.) It turns out that pemphigus is actually a family of related conditions, with each version of the disease caused by autoimmune attack against a different member of the desmoglein family. Describe two specific types of pemphigus, which demiglein is being attacked, and why it has the specific features that it does.
#3 Recently, a possible explanation has been found for a strange kidney syndrome called “Renal Magnesium Wasting:” a mutation in the gene for claudin-16 or claudin-19.
A.) What are the symptoms of renal magnesium wasting?
B.) Where in the body are these two genes expressed?
C.) Assuming the mutations in the claudin genes impair their function (rather than enhancing function), how would this explain the symptoms of the disease?
Explanation / Answer
2. a). Cadherins (calcium-dependent adhesion) are the type 1 transmembrane proteins, which form adherens junctions and play a key role in cell adhesion.
b). Desmogleins (belong to the class of cadherins) are located in the cell to cell junctions. They are mostly expressed in epithelial cells. Desmoglein is highly expressed in the cardiomyocytes.
c). Pemphigus is an autoimmune disease caused by the production of autoantibodies to a family of proteins called desmogleins. Affected individuals suffer from watery, itchy blisters that are formed all over the skin, especially the on mucous membranes of the mouth and nose. Falling off of these blisters develop into deep sores, which allow the further infections to occur.
3.
A). Symptoms of renal magnesium wasting include the following.
1. High urine levels of magnesium
2. Low plasma levels of magnesium
3. Muscle cramps
4. Disorientation
5. Arrhythmias
B). Both the genes claudin-16 and claudin-19 are expressed in the thick ascending limb of nephron.
C). Expression of these genes regulate the reabsorption of magnesium ions. Mutations decrease the expression of these genes, so impaired functioning of claudins causes the excessive excretion of magnesium and symptoms associated with low magnesium levels.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.