Physiological relevance of epithelial geometry: New insights into the standing gradient model and the role of LI cadherin

Vereshchaga, Yana; Arnold, N.; Baumgärtner, Werner

doi:10.1371/journal.pone.0208791

Cited by 4 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been his life's work and is (in my view) a triumph of biophysics, theory and experiment. 95,179,180,182,183,[185][186][187][188][189][190][191][192][193][194][195][196][197][198][199][200][201][202] Indeed, Mathias resolved (to my satisfaction) several damaging controversies in epithelial physiology 154,[203][204][205] as he studied water flow in the lens and in a more general context. [206][207][208]…”

Section: The Lens Of the Eyementioning

confidence: 95%

Structural analysis of fluid flow in complex biological systems

Eisenberg

2023

MAIO

View full text Add to dashboard Cite

Biology is about structure. Structures within structures. Organs within animals, tissues within organs, cells within tissues, and molecules, often proteins within cells. The structures are so complex that they can only be described by numbers. No numbers are of more importance than those that describe proteins. The numbers that describe coordinates of its atoms, often determined by Patterson functions (which are inverse Fourier Transforms of intensities) of crystal diffraction. Without these numbers, structural biology would hardly exist. Without numbers, engineering would not exist. Numbers are surely needed by the engineers who produce the x-rays diffracting from atoms of protein crystals. Devices of engineering have function. They are built to implement equations. Engineering devices use structures to implement equations, when power is supplied at the right places, that produces appropriate flows. Flows are the essence of life. Equilibrium means death in most living systems. Flows in biological structures are hard to analyze because we do not know input output equations in advance. Sometimes we do not know the function of the structures. Flows, forces, and structures of life (like those of engineering) are related by field equations of conservation laws, partial differential equations, constrained by location and properties of structures. Constraints are boundary conditions located on the complicated domain of biological structure. The hierarchy of structures allows a handful of atoms (in proteins and nucleic acids) to control macroscopic function. Dealing with this complexity is simplified if one systematically analyzes structure using the most general field theory known, electricity described by the Maxwell equations, without significant known error. Currents are involved because flows of biology usually involve migration of charges, convection of water and solutes, diffusion of ions that form the plasma of life, and their interactions. Interactions can dominate function. Here I show how a few complex structures can be understood in engineering detail. This approach may be useful in dealing with biological and medical issues in many other cases. In one limited case—the clearance of a toxic waste (potassium ions) from the optic nerve—this approach seems to have succeeded.

show abstract

Section: The Lens Of the Eyementioning

confidence: 95%

Structural analysis of fluid flow in complex biological systems

Eisenberg

2023

MAIO

View full text Add to dashboard Cite

show abstract

“…It was shown that water transport was impaired under hypertonic conditions when LI-cadherin is reduced [40,41]. Therefore, LI-cadherin might be important for water reabsorption of the gut at intraluminal hypertonic conditions [40,41]. Interestingly, the expression of angulin-2 and -3 did not change after the knockout of angulin-1 as a form of compensation in both cell lines.…”

Section: Angulin-1 Knockout Alters the Expression And Localization Of Other Proteins In Mdck C7 And Ht-29/b6 Cellsmentioning

confidence: 97%

“…Lastly, the expression of LI-cadherin was increased in both KO clones, this could affect the water permeability under our experimental conditions. It was shown that water transport was impaired under hypertonic conditions when LI-cadherin is reduced [40,41]. Therefore, LI-cadherin might be important for water reabsorption of the gut at intraluminal hypertonic conditions [40,41].…”

Section: Angulin-1 Knockout Alters the Expression And Localization Of Other Proteins In Mdck C7 And Ht-29/b6 Cellsmentioning

confidence: 99%

Angulin-1 (LSR) Affects Paracellular Water Transport, However Only in Tight Epithelial Cells

Ayala‐Torres

Krug

Rosenthal

et al. 2021

IJMS

View full text Add to dashboard Cite

Water transport in epithelia occurs transcellularly (aquaporins) and paracellularly (claudin-2, claudin-15). Recently, we showed that downregulated tricellulin, a protein of the tricellular tight junction (tTJ, the site where three epithelial cells meet), increased transepithelial water flux. We now check the hypothesis that another tTJ-associated protein, angulin-1 (alias lipolysis-stimulated lipoprotein receptor, LSR) is a direct negative actuator of tTJ water permeability depending on the tightness of the epithelium. For this, a tight and an intermediate-tight epithelial cell line, MDCK C7 and HT-29/B6, were stably transfected with CRISPR/Cas9 and single-guide RNA targeting angulin-1 and morphologically and functionally characterized. Water flux induced by an osmotic gradient using 4-kDa dextran caused water flux to increase in angulin-1 KO clones in MDCK C7 cells, but not in HT-29/B6 cells. In addition, we found that water permeability in HT-29/B6 cells was not modified after either angulin-1 knockout or tricellulin knockdown, which may be related to the presence of other pathways, which reduce the impact of the tTJ pathway. In conclusion, modulation of the tTJ by knockout or knockdown of tTJ proteins affects ion and macromolecule permeability in tight and intermediate-tight epithelial cell lines, while the transepithelial water permeability was affected only in tight cell lines.

show abstract

“…(95,179,180,182,183,(185)(186)(187)(188)(189)(190)(191)(192)(193)(194)(195)(196)(197)(198)(199)(200)(201)(202). Indeed, Mathias resolved (to my satisfaction) several damaging controversies in epithelial physiology (154,(203)(204)(205) as he studied water flow in the lens and in a more general context (206)(207)(208).…”

Section: 1mentioning

confidence: 97%

Structural Analysis of Fluid Flow in Complex Biological Systems

Eisenberg¹

2022

Preprint

View full text Add to dashboard Cite

Biology is about structure. Structures within structures. Organs within animals, tissues within organs, cells within tissues, and molecules, often proteins within cells. The structures are so complex that they can only be described by numbers. No numbers are of more importance than those that describe proteins. The numbers that describe coordinates of its atoms, often determined by Patterson functions (which are inverse Fourier Transforms of intensities) of crystal diffraction. Without these numbers, structural biology would hardly exist. Without numbers, engineering would not exist. Numbers are surely needed by the engineers who produce the x-rays diffracting from atoms of protein crystals. Devices of engineering have function. They are built to implement equations. Engineering devices use structures to implement equations, when power is supplied at the right places, that produces appropriate flows. Flows are the essence of life. Equilibrium means death in most living systems. Flows in biological structures are hard to analyze because we do not know input output equations in advance. Sometimes we do not know their function. Flows, forces, and structures of life (like those of engineering) are related by field equations of conservation laws, partial differential equations, constrained by location and properties of structures. Constraints are boundary conditions located on the complicated domain of biological structure. Dealing with this complexity is simplified if one systematically analyzes structure using the most general field theory known, electricity described by the Maxwell equations, without significant known error. Currents are involved because flows of biology usually involve migration of charges, convection of water and solutes, diffusion of ions that form the plasma of life, and their interactions. Interactions can dominate function. Here I show how a few complex structures can be understood in engineering detail. This approach may be useful in dealing with biological and medical issues in many other cases. In one limited case—the clearance of a toxic waste (potassium ions) from the optic nerve—this approach seems to have succeeded.

show abstract

Physiological relevance of epithelial geometry: New insights into the standing gradient model and the role of LI cadherin

Cited by 4 publications

References 39 publications

Structural analysis of fluid flow in complex biological systems

Structural analysis of fluid flow in complex biological systems

Angulin-1 (LSR) Affects Paracellular Water Transport, However Only in Tight Epithelial Cells

Structural Analysis of Fluid Flow in Complex Biological Systems

Contact Info

Product

Resources

About