Estimate of entropy generation rate can spatiotemporally resolve the active nature of cell flickering

Manikandan, Sreekanth K; Ghosh, Tanmoy; Mandal, Tithi; Biswas, Arikta; Sinha, Bidisha; Mitra, Dhrubaditya

doi:10.48550/arxiv.2205.12849

Cited by 4 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have evidenced that membrane fluctuations assayed at such small patches (0.75 µm 2 ) have overall weak activity (Manikandan et al, 2022) as inferred from measurements of the lower-bound of the entropy generation rate. Using the same algorithm (Manikandan et al, 2022), change in activity is clear when endocytic activity is blocked by Dynasore (Fig. S7g) indicating that the technique is capable of resolving small changes.…”

Section: Discussionmentioning

confidence: 65%

“…It should be noted that deriving tension required the use of a model that doesn't account for the frequency-dependent activity factor. We have evidenced that membrane fluctuations assayed at such small patches (0.75 µm 2 ) have overall weak activity (Manikandan et al, 2022) as inferred from measurements of the lower-bound of the entropy generation rate. Using the same algorithm (Manikandan et al, 2022), change in activity is clear when endocytic activity is blocked by Dynasore (Fig.…”

Section: Discussionmentioning

confidence: 65%

“…For obtaining the entropy generation rate, data pooled from all pixels of the FBR were taken through dimensional reduction using principal component analysis. The time series (2048 frames) of one of the principal components were built and analyzed as described recently (Manikandan et al, 2022) using the short-time inference scheme reported earlier (Manikandan et al, 2020).…”

Section: Analysis Of Irm Imagesmentioning

confidence: 99%

“…Fluctuations reported by IRM are mainly thermal in nature but can have contributions from active (ATP dependent, non-thermal) processes in cells (Turlier and Betz, 2019). A recently developed algorithm (Manikandan et al, 2022(Manikandan et al, , 2020, using a model-free method quantified the effect of active forces on membrane fluctuations (termed activity) and revealed local membrane fluctuations to be weakly active.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Formation of clathrin-pits and ATP-independent cholesterol-dependent tubules initiates mechano-regulation on de-adhesion

Biswas

Ghosh

Manikandan

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Adherent cells ensure membrane homeostasis during de-adhesion by various mechanisms including endocytosis. Although mechano-chemical feedbacks involved in this process have been studied, the step-by-step build-up and resolution of the mechanical changes by endocytosis is not well understood. To investigate this, we studied the de-adhesion of HeLa cells using a combination of interference reflection microscopy, optical-trapping and fluorescence experiments. We found that de-adhesion enhanced membrane height fluctuations of the basal membrane in the presence of an intact cortex. A reduction in the tether-force was also noted at the apical side. However, membrane fluctuations reveal phases of an initial drop in effective tension followed by a saturation. The area fractions of early (Rab5-labelled) and recycling (Rab4-labelled) endosomes as well as transferrin-labelled pits close to the basal plasma membrane also transiently increased. On blocking dynamin-dependent scission of endocytic pits, the regulation of fluctuations was not blocked but proceeded uncontrolled. Interestingly, the regulation could not be suppressed by ATP or cholesterol depletion individually but was arrested on depleting both. The data strongly supports pit-formation to be central to the reduction in fluctuations whether in normal or ATP depleted condition. Furthermore, while in normal conditions the contribution of clathrin-mediated endocytosis is clear, under ATP-depleted conditions we propose that cholesterol-dependent pits spontaneously regulate tension.

show abstract

Section: Discussionmentioning

confidence: 65%

Section: Discussionmentioning

confidence: 65%

Section: Analysis Of Irm Imagesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Formation of clathrin-pits and ATP-independent cholesterol-dependent tubules initiates mechano-regulation on de-adhesion

Biswas

Ghosh

Manikandan

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Equation (11) and the more general form (9) with their second-order time derivative term at time zero bear resemblance with the short-time thermodynamic uncertainty relation derived by Manikandan and collaborators [47,79,108]. In this case, currents must be optimised to find good estimates; however, in most cases, σ values are too small [13,109]. Previously, a relation between activity and the displacement variance was proposed by Bohec et al [110], which connects the correlations between activity and position to the first time derivative of the displacement's variance.…”

Section: Discussionmentioning

confidence: 66%

Variance sum rule: proofs and solvable models

Di Terlizzi,

Baiesi,

Ritort

2024

New J. Phys.

View full text Add to dashboard Cite

We derive, in more general conditions, a recently introduced variance sum rule (VSR) [I. Di Terlizzi et al., 2024 Science 383, 971] involving variances of displacement and force impulse for overdamped Langevin systems in a nonequilibrium steady state (NESS). This formula allows visualising the effect of nonequilibrium as a deviation of the sum of variances from normal diffusion 2Dt, with D the diffusion constant and t the time. From the VSR, we also derive formulas for the entropy production rate σ that, differently from previous results, involve second-order time derivatives of position correlation functions. This novel feature gives a criterion for discriminating strong nonequilibrium regimes without measuring forces. We then apply and discuss our results to three analytically solved models: a stochastic switching trap, a Brownian vortex, and a Brownian gyrator. Finally, we compare the advantages and limitations of known and novel formulas for σ in an overdamped NESS.

show abstract

Mechano-regulation by clathrin pit-formation and passive cholesterol-dependent tubules during de-adhesion

Mandal,

Biswas,

Ghosh

et al. 2024

Cell. Mol. Life Sci.

Self Cite

View full text Add to dashboard Cite

Adherent cells ensure membrane homeostasis during de-adhesion by various mechanisms, including endocytosis. Although mechano-chemical feedbacks involved in this process have been studied, the step-by-step build-up and resolution of the mechanical changes by endocytosis are poorly understood. To investigate this, we studied the de-adhesion of HeLa cells using a combination of interference reflection microscopy, optical trapping and fluorescence experiments. We found that de-adhesion enhanced membrane height fluctuations of the basal membrane in the presence of an intact cortex. A reduction in the tether force was also noted at the apical side. However, membrane fluctuations reveal phases of an initial drop in effective tension followed by saturation. The area fractions of early (Rab5-labelled) and recycling (Rab4-labelled) endosomes, as well as transferrin-labelled pits close to the basal plasma membrane, also transiently increased. On blocking dynamin-dependent scission of endocytic pits, the regulation of fluctuations was not blocked, but knocking down AP2-dependent pit formation stopped the tension recovery. Interestingly, the regulation could not be suppressed by ATP or cholesterol depletion individually but was arrested by depleting both. The data strongly supports Clathrin and AP2-dependent pit-formation to be central to the reduction in fluctuations confirmed by super-resolution microscopy. Furthermore, we propose that cholesterol-dependent pits spontaneously regulate tension under ATP-depleted conditions.

show abstract

Estimate of entropy generation rate can spatiotemporally resolve the active nature of cell flickering

Cited by 4 publications

References 0 publications

Formation of clathrin-pits and ATP-independent cholesterol-dependent tubules initiates mechano-regulation on de-adhesion

Formation of clathrin-pits and ATP-independent cholesterol-dependent tubules initiates mechano-regulation on de-adhesion

Variance sum rule: proofs and solvable models

Mechano-regulation by clathrin pit-formation and passive cholesterol-dependent tubules during de-adhesion

Contact Info

Product

Resources

About