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Cell Communication: Alopecia
Transcript of Cell Communication: Alopecia
Stages of Signaling Transduction Pathway
Cell Communication: Alopecia
By: Safia Bashir
Local: In animals, local signaling can occur through direct contact through cell junctions, or when two cells are close to each other using local regulators.
Local & Long-Distance Signaling
The signal triggers a specific cellular response.
When the signaling molecule binds to the receptor it changes the shape of the proteins. This conformational change initiates the process of transduction. Signal transduction usually occurs in multiple steps.
Alopecia is the sudden hair loss that starts with one or more circular bald patches that may overlap.
What Causes Alopecia?
Patchy hair loss
Wide-spread hair loss
Nail problems -> dents in nails
Thinning of hair
Alopecia has no age limits, it can develop at any age. Alopecia is an autoimmune disease. Autoimmune means that the body's immune system attacks the body. When alopecia develops, the body attacks its own hair follicles. A person's genetic makeup, combined with other factors, triggers this form of hair loss.
Causes of Alopecia
Animal cells secrete hormones that are dispersed through the body into the circulatory system to the target cell.
Cell Response to Signal Reception
Regulates protein synthesis
Signals growth factors such as mRNA
Regulates the activity of proteins
Affects overall shape
A ligand is a molecule that binds to another, often it is larger, in order to create a chain reaction. A ligand often alters the shape of the larger molecule (receptor protein) which allows it to interact with various other molecules that allows for further molecular events to occur.
A protein kinase is a general name for an enzyme that transfers phosphate groups from ATP to protein. Protein kinase cascade works when the signal is transmitted by a cascade of protein phosphorylations. Each shape change in the signal results from added phosphate groups changing the protein from being inactive to active.
Cyclic AMP is a second messenger that transmits the signal from the plasma membrane to the metabolic machinery in the cytoplasm. cAMP will broadcast the message from the plasma membrane through the cytoplasm to allow the transduction to occur to the target molecular reaction.
Top: Male Pattern
Bottom: Female Pattern
DHT blocks the action of beta Catenin in the hair follicle ("Mouse Pattern Baldness")
There is a change in the affect of DHT and it acts on the hair follicle causing it to undergo a shortened growing phase ("Hair Loss Information")
Increased activity of androgen receptors in hair follicle ("Androgenic Alopecia")
The enzyme 5 alpha reductase converts testosterone to DHT in the hair follicle ("Androgenic Alopecia")
5 alpha reductase binds to receptors in DHT which then binds to the androgen receptor forming an androgen-receptor complex (AR).
The complex binds to DNA and regulates androgen responsive genes such as hair growth.
Androgen Receptor Pathway
Studying similar conditions found in mice
This medicine suppresses the immune system. It can be given as shots, with the dermatologist injecting the medicine into the places with hair loss. Sometimes a patient gets a topical (applied to the skin) form of this medicine. It may be a cream, lotion, or ointment. The patient applies the medicine to the bare spots. Less often, patients take corticosteroid pills.
A hair re-growth medicine, minoxidil 5%, may help some patients re-grow their hair. Both children and adults can use it. Patients apply it twice a day to the scalp, brows, or beard. New hair may start to grow in about 3 months. Patients most often use this medicine with another treatment.
This medicine alters the skin’s immune function. The patient applies a tar-like substance to the skin and leaves it on for 20 to 60 minutes. A dermatologist may call this short-contact therapy. After 20 to 60 minutes, the anthralin is washed off to avoid the skin from becoming irritated.
Outcome of Treatment
When a person has alopecia, the hair will start to re-grow when the body gets the right signals. Sometimes this happens without treatment. Even with treatment, new hair loss can occur. Everything depends on how the immune system reacts.
What is alopecia?