scholarly journals A mathematical model demonstrating the role of interstitial fluid flow on the clearance and accumulation of amyloid β in the brain

2019 ◽  
Vol 317 ◽  
pp. 108258 ◽  
Author(s):  
C.Y. Chen ◽  
Y.H. Tseng ◽  
J.P. Ward
2019 ◽  
Vol 4 (2) ◽  
pp. 90-92 ◽  
Author(s):  
Li Zhang ◽  
Michael Chopp ◽  
Quan Jiang ◽  
Zhenggang Zhang

Diabetes mellitus (DM) is a common metabolic disease in the middle-aged and older population, and is associated with cognitive impairment and an increased risk of developing dementia. The glymphatic system is a recently characterised brain-wide cerebrospinal fluid and interstitial fluid drainage pathway that enables the clearance of interstitial metabolic waste from the brain parenchyma. Emerging data suggest that DM and ageing impair the glymphatic system, leading to accumulation of metabolic wastes including amyloid-β within the brain parenchyma, and consequently provoking cognitive dysfunction. In this review, we concisely discuss recent findings regarding the role of the glymphatic system in DM and ageing associated cognitive impairment.


2002 ◽  
Vol 17 (11) ◽  
pp. 2030-2037 ◽  
Author(s):  
A. E. Tami ◽  
P. Nasser ◽  
O. Verborgt ◽  
M. B. Schaffler ◽  
M. L. Knothe Tate

Author(s):  
Caleb Stine ◽  
Jennifer Munson

Fluid flow and chemokine gradients play a large part in not only regulating homeostatic processes in the brain, but also in pathologic conditions by directing cell migration. Tumor cells in particular are superior at invading into the brain resulting in tumor recurrence. One mechanism that governs cellular invasion is autologous chemotaxis, whereby pericellular chemokine gradients form due to interstitial fluid flow (IFF) leading cells to migrate up the gradient. Glioma cells have been shown to specifically use CXCL12 to increase their invasion under heightened interstitial flow. Computational modeling of this gradient offers better insight into the extent of its development around single cells, yet very few conditions have been modelled. In this paper, a computational model is developed to investigate how a CXCL12 gradient may form around a tumor cell and what conditions are necessary to affect its formation. Through finite element analysis using COMSOL and coupled convection-diffusion/mass transport equations, we show that velocity (IFF magnitude) has the largest parametric effect on gradient formation, multidirectional fluid flow causes gradient formation in the direction of the resultant which is governed by IFF magnitude, common treatments and flow patterns have a spatiotemporal effect on pericellular gradients, exogenous background concentrations can abrogate the autologous effect depending on how close the cell is to the source, that there is a minimal distance away from the tumor border required for a single cell to establish an autologous gradient, and finally that the development of a gradient formation is highly dependent on specific cell morphology.


2021 ◽  
Author(s):  
Anna M Li ◽  
Jiadi Xu

Purpose: To develop Phase Alternate LAbeling with Null recovery (PALAN) MRI methods for the quantification of interstitial to cerebrospinal fluid flow (ICF) and cerebrospinal to interstitial fluid flow (CIF) in the brain. Method: In both T1-PALAN and apparent diffusion coefficient (ADC)-PALAN MRI methods, the cerebrospinal fluid (CSF) signal was nulled, while the residual interstitial fluid (ISF) was labeled by alternating the phase of pulses. ICF was extracted from the difference between the recovery curves of CSF with and without labeling. Similarly, CIF was measured by the T2-PALAN MRI method by labeling CSF, which took advance of the significant T2 difference between CSF and parenchyma. Results: Both T1-PALAN and ADC-PALAN observed a rapid occurrence of ICF at 67±56 ms and 13±2 ms interstitial fluid transit times, respectively. ICF signal peaked at 1.5 s for both methods. ICF was 1153±270 ml/100ml/min with T1-PALAN in the third and lateral ventricles, which was higher than 891±60 ml/100ml/min obtained by ADC-PALAN. The results of the T2-PALAN suggested the ISF exchanging from ependymal layer to the parenchyma was extremely slow. Conclusion: The PALAN methods are suitable tools to study ISF and CSF flow kinetics in the brain.


Biophysica ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 16-33
Author(s):  
Caleb A. Stine ◽  
Jennifer M. Munson

Fluid flow and chemokine gradients play a large part in not only regulating homeostatic processes in the brain, but also in pathologic conditions by directing cell migration. Tumor cells in particular are superior at invading into the brain resulting in tumor recurrence. One mechanism that governs cellular invasion is autologous chemotaxis, whereby pericellular chemokine gradients form due to interstitial fluid flow (IFF) leading cells to migrate up the gradient. Glioma cells have been shown to specifically use CXCL12 to increase their invasion under heightened interstitial flow. Computational modeling of this gradient offers better insight into the extent of its development around single cells, yet very few conditions have been modelled. In this paper, a computational model is developed to investigate how a CXCL12 gradient may form around a tumor cell and what conditions are necessary to affect its formation. Through finite element analysis using COMSOL and coupled convection-diffusion/mass transport equations, we show that velocity (IFF magnitude) has the largest parametric effect on gradient formation, multidirectional fluid flow causes gradient formation in the direction of the resultant which is governed by IFF magnitude, common treatments and flow patterns have a spatiotemporal effect on pericellular gradients, exogenous background concentrations can abrogate the autologous effect depending on how close the cell is to the source, that there is a minimum distance away from the tumor border required for a single cell to establish an autologous gradient, and finally that the development of a gradient formation is highly dependent on specific cell morphology.


2020 ◽  
Author(s):  
R. C. Cornelison ◽  
J. X. Yuan ◽  
K. M. Tate ◽  
A. Petrosky ◽  
G. F. Beeghly ◽  
...  

AbstractGlioblastoma is an aggressive brain cancer characterized by diffuse infiltration. Infiltrated glioma cells persist in the brain post-resection where they interact with glial cells and experience interstitial fluid flow. We recreate this infiltrative microenvironment in vitro based on resected patient tumors and examine malignancy metrics (invasion, proliferation, and stemness) in the context of cellular and biophysical factors and therapies. Our 3D tissue-engineered model comprises patient-derived glioma stem cells, human astrocytes and microglia, and interstitial fluid flow. We found flow contributes to all outcomes across seven patient-derived lines, and glial effects are driven by CCL2 and differential glial activation. We conducted a six-drug screen using four outcomes and find expression of putative stemness marker CD71, opposed to viability IC50, significantly predicts murine xenograft survival. Our results dispute the paradigm of viability as predictive of drug efficacy. We posit this patient-centric, infiltrative tumor model is a novel advance towards translational personalized medicine.


2016 ◽  
Vol 21 (2) ◽  
pp. 28-37
Author(s):  
Oscar Solís-Salgado ◽  
José Luis López-Payares ◽  
Mauricio Ayala-González

Las vías de drenaje solutos del sistema nervioso central (SNC) participan en el recambio de liquido intersticial con el líquido cefalorraquídeo (LIT-LCR), generando un estado de homeostasis. Las alteraciones dentro de este sistema homeostático afectará la eliminación de solutos del espacio intersticial (EIT) como el péptido βa y proteína tau, los cuales son sustancias neurotóxicas para el SNC. Se han utilizado técnicas experimentales para poder analizar el intercambio LIT-LCR, las cuales revelan que este intercambio tiene una estructura bien organizada. La eliminación de solutos del SNC no tiene una estructura anatómica propiamente, se han descubierto vías de eliminación de solutos a través de marcadores florecentes en el espacio subaracnoideo, cisternas de la base y sistema ventricular que nos permiten observar una serie de vías ampliamente distribuidas en el cerebro. El LCR muestra que tiene una función linfática debido a su recambio con el LIT a lo largo de rutas paravasculares. Estos espacios que rodean la superficie arterial así como los espacios de Virchow-Robin y el pie astrocitico junto con la AQP-4, facilitan la entrada de LCR para-arterial y el aclaramiento de LIT para-venoso dentro del cerebro. El flujo y dirección que toma el LCR por estas estructuras, es conducido por la pulsación arterial. Esta función será la que finalmente llevara a la eliminación de estas sustancias neurotóxicas. En base a la dependencia de este flujo para la eliminación de sustancias se propone que el sistema sea llamado “ la Vía Glinfática”. La bibliografía así como las limitaciones que se encuentran en esta revisión están dadas por la metodología de búsqueda que ha sido realizada principalmente en PubMed utilizando los siguientes términos Mesh: Cerebral Arterial Pulsation, the brain via paravascular, drainage of amyloid-beta, bulk flow of brain interstitial fluid, radiolabeled polyethylene glycols and albumin, amyloid-β, the perivascular astroglial sheath, Brain Glymphatic Transport.


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