Ferulic Acid Induces Bone Marrow Mesenchymal Stem Cells to Alleviate the Activation of Hepatic Stellate Cells and Liver Fibrosis via Cytoskeletal Rearrangement Inhibition and Mir-19b-3p Transfer

Background: Bone marrow mesenchymal stem cells (BMSCs) are effective for treating fibrotic liver. BMSCs contain a variety of proteins and RNAs, which have functions similar to their derived cells, but the specific mechanism is unclear. In a recent study, ferulic acid (FA) was highly effective in treating liver fibrosis. Therefore, we combined BMSCs and FA to treat CCl4-induced fibrosis models. Methods: First, we used BMSCs and FA to treat CCl4-induced fibrosis models and observed their therapeutic effect, investigated the specific mechanism of this combination therapy in liver fibrosis. Second, we created a BMSC/hepatic stellate cell (HSC) co-culture system and used FA to treat activated HSCs. We next used cytochalasin D and angiotensin II to investigate whether BMSCs and FA inactivate HSCs through cytoskeletal rearrangement. MiR-19b-3p was enriched in BMSCs and targeted TGF-β receptor II (TGF-βR2). We transfected miR-19b-3p into HSCs and BMSCs separately and detected whether BMSCs transferred miR-19b-3p to HSCs or inactivated HSCs. Results: We used BMSCs and FA to treat CCl4-induced fibrosis models and found that the combination therapy had better effects than FA or BMSCs alone. The expression of the profibrotic markers α-SMA and COL1-A1 was significantly decreased in HSCs co-cultured with BMSCs and FA treatment. Cytoskeletal rearrangement in HSCs was inhibited, and RhoA/ROCK pathway gene expression was decreased. With angiotensin II treatment, COL1-A1 and a-SMA expression increased, while with cytochalasin D treatment, profibrotic gene expression decreased in HSCs. COL1-A1, α-SMA and RhoA/ROCK pathway genes were decreased in activated HSCs treated with a miR-19b-3p mimic, indicating that miR-19b-3p inactivated HSCs by suppressing RhoA/ROCK signalling. In contrast, profibrotic genes were significantly decreased in BMSCs treated with the miR-19b-3p mimic or a miR-19b-3p inhibitor and FA compared with BMSCs treated with the miR-19b-3p mimic alone.Conclusion: BMSCs attenuated HSC activation and liver fibrosis by inhibiting cytoskeletal rearrangement and delivering miR-19b-3p to activated HSCs, inactivating RhoA/ROCK signaling. FA-based combination therapy showed better inhibitory effects on HSC activation, suggesting that BMSCs and their miRNAs combined with FA are novel antifibrotic therapeutics for treating chronic liver disease.

YAP Translocation Precedes Cytoskeletal Rearrangement in Podocyte Stress Response: A Podometric Investigation of Diabetic Nephropathy

Podocyte loss plays a pivotal role in the pathogenesis of glomerular disease. However, the mechanisms underlying podocyte damage and loss remain poorly understood. Although detachment of viable cells has been documented in experimental Diabetic Nephropathy, correlations between reduced podocyte density and disease severity have not yet been established. YAP, a mechanosensing protein, has recently been shown to correlate with glomerular disease progression, however, the underlying mechanism has yet to be fully elucidated. In this study, we sought to document podocyte density in Diabetic Nephropathy using an amended podometric methodology, and to investigate the interplay between YAP and cytoskeletal integrity during podocyte injury. Podocyte density was quantified using TLE4 and GLEPP1 multiplexed immunofluorescence. Fourteen Diabetic Nephropathy cases were analyzed for both podocyte density and cytoplasmic translocation of YAP via automated image analysis. We demonstrate a significant decrease in podocyte density in Grade III/IV cases (124.5 per 106 μm3) relative to Grade I/II cases (226 per 106 μm3) (Student’s t-test, p < 0.001), and further show that YAP translocation precedes cytoskeletal rearrangement following injury. Based on these findings we hypothesize that a significant decrease in podocyte density in late grade Diabetic Nephropathy may be explained by early cytoplasmic translocation of YAP.

Thermal stress induces dysfunction and facilitates senescence via disruption of cytoskeletal rearrangement and stimulation of the inflammatory response in primary endothelial cells

BackgroundThermal injury occurs when energy is transferred from a heat source to the body, causing local tissues to heat up. It has been demonstrated that the tissue temperature exceeds a certain threshold by exposure to external heat (thermal stress, TS), irreversible cell damage occurs, resulting in a delayed neovascularization. In recent years, warm paste is a popular item for people to keep warm in winter. Although the average temperature from the hot paste is only 54 ± 3°C, numerous cases of contact burns, that induced an increased capillary permeability in damaged tissue, by body warm paste were reported in our hospital.MethodsHerein, we evaluated the damage to primary microvascular endothelial cells (ECs) at 45°C with various times and demonstrated that exposure to TS at 45°C only for 10 minutes induced irreversible damage in ECs via suppressed proliferation and promoted apoptosis.ResultsTS significantly delayed the cell cycle and facilitated senescence in primary ECs. ECs exposed to TS lost their motility, and cytoskeletal rearrangement resulted in impaired angiogenic function. Furthermore, the result from mRNA array revealed that TS induced not only a negative regulation of migration and branching structures, but also revealed that TS exposure promoted apoptotic processes and TNF signalling resulting in increased expression of pro-inflammatory factors, such as IL-1β and IL-6.ConclusionTaken together, our results indicate that burn injury may initiate systemic injury of the vascular system even at 45°C only for 10 minutes, which might be one of the mechanisms of delayed damaged tissue repair.Trial registrationNot applicable.

p21-Activated Kinases in Thyroid Cancer

The family of p21-activated kinases (PAKs) are oncogenic proteins that regulate critical cellular functions. PAKs play central signaling roles in the integrin/CDC42/Rho, ERK/MAPK, PI3K/AKT, NF-κB, and Wnt/β-catenin pathways, functioning both as kinases and scaffolds to regulate cell motility, mitosis and proliferation, cytoskeletal rearrangement, and other cellular activities. PAKs have been implicated in both the development and progression of a wide range of cancers, including breast cancer, pancreatic melanoma, thyroid cancer, and others. Here we will discuss the current knowledge on the structure and biological functions of both group I and group II PAKs, as well as the roles that PAKs play in oncogenesis and progression, with a focus on thyroid cancer and emerging data regarding BRAF/PAK signaling.