Nonequilibrium Thermodynamics of Cell Signaling

Abstract

Signal transduction inside and across the cells, also called cellular signaling, is key to most biological functions and is ultimately related with both life and death of the organisms. The processes giving rise to the propagation of biosignals are complex and extremely cooperative and occur in a far-from thermodynamic equilibrium regime. They are also driven by activation kinetics strongly dependent on local energetics. For these reasons, a nonequilibrium thermodynamical description, taking into account not just the activation of second messengers, but also transport processes and dissipation is desirable. Here we present a proposal for such a formalism, that considers cells as small thermodynamical systems and incorporates the role of fluctuations as intrinsic to the dynamics in a spirit guided by mesoscopic nonequilibrium thermodynamics. We present also a minimal model for cellular signaling that includes contributions from activation, transport, and intrinsic fluctuations. We finally illustrate its feasibility by considering the case of FAS signaling which is a vital signal transduction pathway that determines either cell survival or death by apoptosis.

Immotile Active Matter: Activity from Death and Reproduction

“…However, further work is necessary to ascertain if the approach employed here would work in biofilms with substantial viscoelastic extracellular matrix secretions [39]. Further, along with other recent results [40] [41] [42], the observations reported here support the idea that death and reproduction have a fluidizing effect [ [12], and suggest that a statistical description of biofilms, rooted in the extension of concepts from equilibrium statistical mechanics [43] [44] [45], may yet play a large role in explaining complex microbial communities. Finally, it is surprising that the biofilms studied here exhibit an apparent universality in surface fluctuation spectra with thermal permeable membranes, as well as nonequilibrium tissues [1], despite many differences in these systems.…”

Information in Biological Systems and the Fluctuation Theorem

“…Thermodynamic coupling [16,17,32,[44][45][46][47][48][49] materialized by certain coupling mechanisms (i.e., configurations, ATPase) has the ability to process information and hence the lower the entropy production 0…”

“…Signal transduction inside and across the cells is complex and cooperative, and occurs in a far-from thermodynamic equilibrium. It is also driven by the activation kinetics strongly dependent on the local energetics [7,20,45].…”

Gibbs Thermodynamics of the Renninger-Wilemski Problem

“…The principle of correspondence states that since we use the surface tension from the measurements with a capillary tube we have to use the Gibbs-Duhem relation for the surface of a tube. The Gibbs-Duhem relation for the surface in a tube has the following form 8 :…”

“…Thermodynamic aspects of investigations occupy an important place in this field considering not only the fundamental question of stationarity (see to clarify it, e.g., [4,5]), but also the problems of smallness of characteristic embryos and corrections appeared because of its sizes and shapes [6]. The results given by thermodynamics immediately lead to quantitative description of kinetics [7] and can be included into consideration of some rather complex aggregates with very specific properties [8]. This consideration is based mainly on thermodynamics of small embryos.…”