Yang Zheng,Jiahui Wang,Jiaru Wang,Haiyuan Xie,Tiejian Zhao
Objective. To study the effect of curcumol on liver sinusoidal endothelial cells (LSECs) and to analyze the mechanism of antihepatic fibrosis. Methods. The effects of drug intervention on cell proliferation rates were detected by MTT assay. The expression of NF-κB was detected by RT-PCR and WB. The NF-κB expression and entry into the nucleus were detected by immunofluorescence; scanning electron microscopy was used to observe the changes of LSECs fenestrae. Results. MTT results showed that the interference of cell proliferation in each group was small. RT-PCR showed that the expression of NF-κB in the curcumol intervention group was significantly lower than that in the positive control group (). The WB detection found that, in the curcumol intervention group, the expression of pNF-κB in the NF-κB signaling pathway was significantly lower than that in the positive control group (). Scanning electron microscopy showed that the LSEC fenestrae were significantly improved compared with the positive control group. Conclusion. Curcumol may be one of the mechanisms of antihepatic fibrosis by inhibiting the activity of the NF-κB signaling pathway and increasing the fenestrae of LSECs.
Background Liver sinusoidal endothelial cells (LSECs) display unique fenestrated morphology. Alterations in the size and number of fenestrae play a crucial role in the progression of various liver diseases. While their features have been visualized using atomic force microscopy (AFM), the in situ imaging methods and off-line analyses are further required for fenestra quantification. Methods Primary mouse LSECs were cultured on a collagen-I-coated culture dish, or a polydimethylsiloxane (PDMS) or polyacrylamide (PA) hydrogel substrate. An AFM contact mode was applied to visualize fenestrae on individual fixed LSECs. Collected images were analyzed using an in-house developed image recognition program based on fully convolutional networks (FCN). Results Key scanning parameters were first optimized for visualizing the fenestrae on LSECs on culture dish, which was also applicable for the LSECs cultured on various hydrogels. The intermediate-magnification morphology images of LSECs were used for developing the FCN-based, fenestra recognition program. This program enabled us to recognize the vast majority of fenestrae from AFM images after twice trainings at a typical accuracy of 81.6% on soft substrate and also quantify the statistics of porosity, number of fenestrae and distribution of fenestra diameter. Conclusions Combining AFM imaging with FCN training is able to quantify the morphological distributions of LSEC fenestrae on various substrates. Significance AFM images acquired and analyzed here provided the global information of surface ultramicroscopic structures over an entire cell, which is fundamental in understanding their regulatory mechanisms and pathophysiological relevance in fenestra-like evolution of individual cells on stiffness-varied substrates.
Liver sinusoidal endothelial cells (LSECs) are highly specific endothelial cells which play an essential role in the maintenance of liver homeostasis . During the progression of liver fibrosis, matrix stiffening promotes LSEC defenestration, however, the underlying mechanotransduction mechanism remains poorly understood. Here, we applied stiffness-tunable hydrogels to assess the matrix stiffening-induced phenotypic changes in primary mouse LSECs. Results indicated that increased stiffness promoted LSEC defenestration through cytoskeletal reorganization. LSECs sensed the increased matrix stiffness via focal adhesion kinase (FAK), leading to the activation of p38-mitogen activated protein kinase activated protein kinase 2 (MK2) pathway, thereby inducing actin remodeling via LIM Kinase 1 (LIMK1) and Cofilin . Interestingly, inhibition of FAK or p38-MK2 pathway was able to effectively restore the fenestrae to a certain degree in LSECs isolated from early to late stages of liver fibrosis mice. Thus, this study highlights the impact of mechanotransduction in LSEC defenestration, and provides novel insights for potential therapeutic interventions for liver fibrosis.