Peristaltic pump flow induces amyloid formation

Peristaltic pump flow induces amyloid formation

Researchers from Osaka University find that peristaltic pump action and high shear flow forces promote amyloid nucleation

Feb 25, 2025Natural Sciences
Graduate School of Engineering SciencesSpecially Appointed ResearcherGOTO Yuji

The factor that tips you over the edge from being at risk for a disease to actually developing the disease is not always clear. Now, researchers from Japan report one factor that triggers problematic proteins to start behaving badly.

In a study published recently in npj biosensing, researchers from Osaka University have revealed that high liquid flow rates could cause aggregation-prone proteins to start sticking together.

Amyloidosis is the basis of several serious diseases, such as Alzheimer disease and Parkinson disease. This process involves the formation of amyloid fibrils, crystal-like collections of misfolded proteins that clump together when the proteins are highly concentrated (supersaturated) in liquids like blood or cerebrospinal fluid.

"Amyloidosis is a serious concern in our aging society, as elderly individuals are more likely to develop these conditions," says lead author of the study Yuji Goto. "Although studies have shown that supersaturation is a necessary condition for amyloid fibril formation, the factors that actually induce protein aggregation in supersaturated fluids remain unclear."

To address this, the researchers ran a model amyloid-forming protein, hen egg white lysozyme, through a peristaltic pump similar to those used for dialysis. They then used fluorescence detection to monitor hen egg white lysozyme amyloid formation as it was propelled through the pump system.

"The results were highly intriguing," explains Hirotsugu Ogi, senior author. "Flow through the peristaltic pump system effectively triggered amyloid formation by hen egg white lysozyme."

Next, the researchers tested amyloid-forming proteins associated with human disease, including a-synuclein, amyloid b 1-40, and b2-microglobulin, and found that they also formed amyloids in the peristaltic pump system. Their calculations showed that the shear stress on the liquid caused by the pumping motion mechanically broke supersaturation to induce amyloid formation.

"Our findings suggest that shear flow forces in various fluids in our body, such as blood and cerebrospinal fluid, could trigger amyloid formation," says Goto.

Given that some medical procedures like dialysis use peristaltic pumps, it is possible that this could be another trigger of amyloidosis. Understanding the effects of shear forces on protein supersaturation could clarify how amyloid aggregates begin to form nucleation and help develop treatment strategies.

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Fig. 1

Overview of peristaltic pump-dependent amyloid inducer with the looped flow of amyloidogenic proteins.

Credit: 2025 Goto et al., Peristaltic pump-triggered amyloid formation suggests shear stresses are in vivo risks for amyloid nucleation. npj biosensing

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Fig. 2

Peristaltic pump-dependent amyloid formation of aSN and Ab40. (a-c) aSN. (d-f) Ab40. Typical profiles of amyloid formation observed at 485 nm (a, d), fluorescence microscopy images (b, e), and TEM images (c, f) are shown.

Credit: 2025 Goto et al., Peristaltic pump-triggered amyloid formation suggests shear stresses are in vivo risks for amyloid nucleation. npj biosensing

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Fig. 3

Numerical analysis of shear stress induced in liquid by movement of a contacting rotor. (a) An enlarged view near the rotor located most downstream. (b) Dependence of the maximum shear stress on the number of rotors.

Credit: 2025 Goto et al., Peristaltic pump-triggered amyloid formation suggests shear stresses are in vivo risks for amyloid nucleation. npj biosensing

The article, "Peristaltic pump-triggered amyloid formation suggests shear stresses are in vivo risks for amyloid nucleation," was published in npj biosensing at DOI: https://doi.org/10.1038/s44328-025-00027-0.

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