Problems with the mouth may plant the seeds of Alzheimer's disease

▎Editor of WuXi AppTec content team

Alzheimer's disease is the most common type of dementia, and the patient's cognitive and memory function will gradually decline, and it will also cause communication skills
.
At present, many related studies have focused on amyloid accumulation and tau tangles, but the occurrence of Alzheimer's disease is still very complex, and it is still extremely challenging to prevent and treat it
.

Other studies have found that problems in the mouth are also likely to be related to Alzheimer's disease, such as the detection of porphyrin gingivum and the gingivin
it produced in the brain tissue of patients.
This is also very surprising, how exactly do oral disease factors affect the brain?

Porphyrin gingivum (Credit: University of Central Lancashire)
Recently, two studies have partly explained why
.
A paper in the Journal of Alzheimer's Disease points out that tau proteins are originally present inside nerve cells, but when they encounter gingivin, they are released from nerve cells into the surrounding environment
.

These free tau proteins are suddenly more dangerous, and their physical properties change to become coil-like or other shapes
.
The scary thing is that these tau proteins will reconnect with healthy neurons, causing neurofibrillary tangles, which will overwhelm nerve cells and eventually die
.

Image source: 123RF
And this process is like the domino effect, the affected dead nerve cells will release the tau protein into the brain, the above process will be repeated again, and more neurons will die
.

Meanwhile, another study in the Journal of Alzheimer's Disease Reports found that porphyrin monas gums also cause elevated levels of many pro-inflammatory factors in the brain, including interleukin-1 and interleukin-6
.
These inflammations are associated with β-amyloid plaque buildup, which is also an important risk factor
associated with the development of Alzheimer's disease.

Studies have speculated that gingivin can also promote the breakdown of amyloid precursors, allowing more mature amyloid proteins to be produced
.
"Based on these results, we can confirm that oral health is important and that gum disease occurs with the potential for increased Alzheimer's disease risk," said
study leader Dr.
Shalini Kanagasingam.

[1] Shalini Kanagasingam et al, Antimicrobial, Polarizing Light, and Paired Helical Filament Properties of Fragmented Tau Peptides of Selected Putative Gingipains, Journal of Alzheimer's Disease (2022).
DOI: 10.
3233/JAD-220486[2]Shalini Kanagasingam et al, Porphyromonas gingivalis Conditioned Medium Induces Amyloidogenic Processing of the Amyloid-β Protein Precursor upon in vitro Infection of SH-SY5Y Cells, Journal of Alzheimer's Disease Reports (2022).
DOI: 10.
3233/ADR-220029[3] Academics make stronger connections between gum disease and Alzheimer's disease.
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