Author: n/a
Date: 21 April 2014
APP, which stands for amyloid precursor protein, is a protein that is linked to Alzheimer's disease. In patients with Alzheimer's, APP clumps abnormally in the brain. Recently, a team of researchers at the National Neuroscience Institute have discovered a new function of APP. They found that APP affects a microRNA molecule known as microRNA-574-5p, which regulate the maturation of newborn neurons, by affecting the expression of genes. Newborn neurons are newly generated neurons in adults. Without APP, brain activities are disrupted due to the absence of control of these newborn neurons. This research could help create more targeted medicines for Alzheimer's disease. In addition, because microRNAs affect brain development, this research has implications for other diseases such as autism and schizophrenia.
This article is directly related to our study of the human body systems. One of these systems is the nervous system, which is comprised mainly of the brain, spinal cord, and nerves. Alzheimer's disease is a neurological disorder, and therefore is a disease which impacts the nervous system. As we learned, the functional unit of the nervous system is neurons. Alzheimer's is a progressive degenerative disorder, which means that the neurons continuously die in the brain. This article builds upon the information we learned about nervous system disorders in our class presentations. It relates to a cause of Alzheimer's disease that was briefly discussed, which is APP. It also is relevant to our entire biology curriculum, as it discusses molecular and genetic topics such as microRNA and the protein APP.
Sarah Bluhm
According to http://www.alz.org/alzheimers_disease_causes_risk_factors.asp, "The greatest known risk factor for Alzheimer’s is advancing age." However, you wrote
ReplyDelete"microRNAs affect[s] brain development." Can a person in their late seventies still have a developing brain, and if so, then does diseases like autism and schizophrenia similar to Alzheimer?
Adults do in fact produce new neurons with age, especially in the hippocampus, a region of the brain strongly associated with memory. This area is also affected greatly by Alzheimer’s.
DeleteWhile Alzheimer’s is associated with the elderly, spectrum disorders like Autism and Schizophrenia can occur earlier in life, and are associated with brain development problems.
MiRNAs are important in many functions. Some miRNAs are especially active in adults. Their main functions include:
regulating gene expression/protein expression
dendrite remodeling/synaptic plasticity important to long term memory
experience-dependent neural changes postnatally
cell differentiation of many stem cells
maintaining neurons
modulation of all aspects of brain maturation
In respects to Alzheimer’s, one study observed miRNAs in brain development in vitro, and saw a correlation between Alzheimer’s, miRNAs, and APP levels. This may suggest that during development, miRNAs are already affecting neurons, as well as during disease.
In respects to spectrum disorders, miRNAs’ effects on development and neuronal differentiation, and also maturation and plasticity are believed to influence these diseases. In these diseases, physical abnormalities stemming from improper brain development and maturation can be observed, such as in Schizophrenia and Autism where low dendrite density is often seen.
This means that it is highly likely that miRNAs are involved in Alzheimer’s, Autism, and Schizophrenia, and therefore research about one of them may be related to the other diseases.
See these links for more details:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3336189/
http://www.ncbi.nlm.nih.gov/pubmed/19846291
http://www.ncbi.nlm.nih.gov/pubmed/19110058
http://learnmem.cshlp.org/content/19/9/359.full
http://psychology.about.com/od/biopsychology/f/adult-neurogenesis.htm