Alzheimer's Disease (AD)

Introduction to Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurological disease that affects people's ability to think and live independently. Today, more than 50 million people worldwide suffer from this disease or related dementia, including 6 million in the United States alone. And the number of cases is increasing rapidly. Moreover, it is the third leading cause of death for people over 65, only after cancer and heart disease. Clinically, it is characterized by memory impairment, aphasia, apraxia, agnosia, impairment of visuospatial skills, executive dysfunction, and personality or behavior changes.

Fig.1 The physiological structure of the brain and neurons in healthy brain and Alzheimer’s disease (AD) brain. (Breijyeh, 2020)

Key Risk Factors for AD

AD may be a heterogeneous group of diseases that develop under the influence of multiple factors, such as biological and psychosocial factors. According to current studies, there are more than 35 possible factors and hypotheses for this disease. It mainly includes the following factors:

• Genetic factors

Most epidemiological studies have demonstrated that family history is a key risk factor for this disease. Family members of patients are significantly more likely to develop the disease than the general population. Furthermore, several genetic studies have confirmed that AD may be caused by some autosomal dominant genes. For example, a gene mapping study has revealed that the pathological gene of amyloid protein in the brain is located on chromosome 21.

• Physical diseases

Some diseases, such as thyroid disease, depression, immune system disease, and epilepsy, have become risk factors for AD. Meanwhile, traumatic brain injury (TBI) also significantly increases the risk of AD. Numerous data have indicated that hyperphosphorylated Tau and associated synaptic dysfunction provide a mechanical link between these two diseases.

• Chemicals

Also, a recent case-control study of chemicals like heavy metal salts, organic solvents, pesticides, and drugs, has shown these compounds can accelerate the aging process by the accumulation of neurotoxins and causing dementia in AD patients.

AD Diagnosis

Currently, no single test can be used for AD diagnosis. Existing diagnostic methods need to match symptom patterns to AD. This examination may include a thorough disease history tracking, blood tests, brain scans (MRI or PET), as well as extensive neurological or neuropsychological evaluations. In addition, dementia assessment should include interviews with relevant personnel, either family members or other people who have a close relationship.

Fig.2 Schematic representation of the pathology of Alzheimer’s disease depicting the multifactorial perplexing feature of AD disease. (Marei, 2016)

Research on AD

• Biomarkers

Biomarker discovery and identification have been considered as the focus of AD research. Biomarkers have shown promising clinical significance in AD, especially in the early diagnosis. Up to now, a wide variety of proteins, such as CSFAβ, Tau protein, and amyloid protein have been found and broadly used as diagnostic markers of AD. Normally, effective biomarkers require good sensitivity specificity that can aid in clinical diagnosis, guide treatment, or determine disease progression and prognosis. In addition to the core markers that have been extensively studied, potential markers including blood, urine, saliva, and retina are being continuously developed, which is expected to improve the accuracy of early diagnosis of patients.

• Drug treatment

Nowadays, the drugs used in the treatment of AD are mainly non-competitive N-methyl-D-Aspartic acid (NMDA) receptor antagonists and cholinesterase inhibitors. Besides, studies have proved that abnormal accumulation of amyloid-beta and hyperphosphorylation of Tau protein are the main reasons for the development of AD. As a result, many kinds of AD research products specific for these proteins, including but not limited to, Neural Proteins & Peptides and Neural Antibodies have been generated and evaluated for treating AD.

Creative Biolabs is a leader in the field of AD studies and has focused on providing products and solutions to neuroscience studies for years. We have experienced experts and advanced platforms that can provide excellent services. If you are interested in our services, please contact us for more details.

References

1. Breijyeh, Z.; et al. Comprehensive review on Alzheimer’s disease: Causes and treatment. Molecules. 2020, 25(24): 5789.
2. Marei, H. E.; et al. Recent Perspective About the Amyloid Cascade Hypothesis and Stem Cell-Based Therapy in the Treatment of Alzheimer's Disease. Frontiers in Clinical Drug Research-Alzheimer Disorder. 2016.