Ginsenoside Rb1 induces hepatic stellate cell ferroptosis to alleviate liver fibrosis via the BECN1/SLC7A11 axis

Liver fibrosis is primarily driven by the activation of hepatic stellate cells(HSCs),a process associated with ferroptosis.Ginsenoside Rb1(GRb1),a major active component extracted from Panax ginseng,inhibits HSC activation.However,the potential role of GRb1 in mediating HSC ferroptosis remains unclear.This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro,using CCl4-induced liver fibrosis mouse model and primary HSCs,LX-2 cells.The findings revealed that GRb1 effectively inactivated HSCs in vitro,reducing alpha-smooth muscle actin(a-SMA)and type I collagen(Col1A1)levels.Moreover,GRb1 significantly alleviated CCl4-induced liver fibrosis in vivo.From a mechanistic standpoint,the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1.Specifically,GRb1 promoted HSC ferroptosis both in vivo and in vitro,characterized by increased glutathione depletion,malondialdehyde production,iron overload,and accumulation of reactive oxygen species(ROS).Intriguingly,GRb1 increased Beclin 1(BECN1)levels and decreased the System Xc-key subunit SLC7A11.Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1.Moreover,BECN1 could directly interact with SLC7A11,initiating HSC ferroptosis.In conclusion,the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro.Overall,this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation,at least partly through its modulation of BECN1 and SLC7A11.

The Zero Mach Number Limit of the Three-Dimensional Compressible Viscous Magnetohydrodynamic Equations

This paper is concerned with the zero Mach number limit of the three-dimensional compressible viscous magnetohydrodynamic equations.More precisely,based on the local existence of the three-dimensional compressible viscous magnetohydrodynamic equations,first the convergence-stability principle is established.Then it is shown that,when the Mach number is sufficiently small,the periodic initial value problems of the equations have a unique smooth solution in the time interval,where the incompressible viscous magnetohydrodynamic equations have a smooth solution.When the latter has a global smooth solution,the maximal existence time for the former tends to infinity as the Mach number goes to zero.Moreover,the authors prove the convergence of smooth solutions of the equations towards those of the incompressible viscous magnetohydrodynamic equations with a sharp convergence rate.

The Asymptotic Behavior and the Quasineutral Limit for the Bipolar Euler-Poisson System with Boundary Efects and a Vacuum

In this paper, a one-dimensional bipolar Euler-Poisson system(a hydrodynamic model) from semiconductors or plasmas with boundary efects is considered. This system takes the form of Euler-Poisson with an electric field and frictional damping added to the momentum equations. The large-time behavior of uniformly bounded weak solutions to the initial-boundary value problem for the one-dimensional bipolar Euler-Poisson system is firstly presented. Next, two particle densities and the corresponding current momenta are verified to satisfy the porous medium equation and the classical Darcy's law time asymptotically. Finally, as a by-product, the quasineutral limit of the weak solutions to the initial-boundary value problem is investigated in the sense that the bounded L∞entropy solution to the one-dimensional bipolar Euler-Poisson system converges to that of the corresponding one-dimensional compressible Euler equations with damping exponentially fast as t → +∞. As far as we know, this is the first result about the asymptotic behavior and the quasineutral limit for the one-dimensional bipolar Euler-Poisson system with boundary efects and a vacuum.

Abnormal behavior of fluorescence quenching of gramicidin A inphase transition of lipid vesicles by hypocrellin B——Does anelectron transfer inverted region exist?

The fluorescence of gramicidin A(GA) in lipid bilayer may be quenched by Hypocre-Ilin B. When the phospholipids undergo a phase transition from gel to liquid crystalline phase, the reaction rate decreases unusually. This phenomenon has been analyzed by Marcus’ pho-toinduced electron theory, and an electron transfer inverted region hypothesis is proposed,