[To explore mechanism of Scabiosa comosa against liver fibrosis based on pharmacodynamics and network pharmacology].

This study aims to systematically elucidate the pharmacodynamics and network pharmacological mechanism of Mongolian medicinal plants Scabiosa comosa, explore their key targets and related pathways, and further clarify the mechanism of the plants in treating liver fibrosis. Wistar rats were assigned into the blank group, carbon tetrachloride-induced liver fibrosis model group, and low-, medium-, and high-dose S. comosa groups. HE staining and Masson staining were performed for the observation of liver tissue under a microscope. Further, Wistar rats were assigned into a control group and a S. comosa group for administration. Seven days later, blood was collected from the abdominal aorta, and different doses of drug-containing serum samples were used to treat hepatic stellate cell-T6(HSC-T6). Flow cytometry was adopted to detect the apoptosis of HSC-T6 cells. Ultra-high performance liquid chromatography-time of flight-mass spectrometry(UHPLC-TOF-MS) was employed to determine the components in Scabiosa comosa. The target of S. comosa and liver fibrosis were obtained from SwissTargetPrediction and GeneCards, respectively, and the common targets were selected as the anti-liver fibrosis targets. Protein-protein interaction was analyzed via STRING. Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment were carried out via Metascape. Phosphatidylinosital 3-kinase(PI3 K), protein kinase B(AKT), p-AKT, p38, and p-p38 targets which are involved in the top-ranked PI3 K/AKT and mitogen activated kinase-like protein(MAPK) signaling pathways were selected for validation via Western blot. The HE and Masson staining results showed that Scabiosa alleviated the hyperplasia of connective tissue and the fibrosis. The serum containing Scabiosa significantly promoted the apoptosis of HSC-T6 in a concentration-dependent manner. A total of 76 chemical components were identified by UHPLC-TOF-MS, among which flavonoids, alkaloids, terpenoids, phenols, and fatty acids were the main components. According to the prediction, there were 63 anti-liver fibrosis targets in Scabiosa comosa, the annotated GO terms of which involved biological processes, cell components, and molecular functions. The KEGG pathway enrichment showed that the targets were mainly involved in PI3 K/AKT, epidermal growth factor receptor(EGFR), RAS-associated protein 1(Rap1), hypoxia-inducible factor 1(HIF-1), resistance to audiogenic seizures(Ras), and MAPK signaling pathways. Western blot results showed that compared with the model group, S. comosa down-regulated the protein levels of α-smooth muscle actin(α-SMA), collagen Ⅰ, PI3 K, AKT, p-AKT, p38, and p-p38 in liver tissue. Compared with the control group, the low-, medium-, and high-dose S. comosa significantly down-regulated the protein levels of α-SMA, collagen Ⅰ, PI3 K, AKT, p-AKT, p38, and p-p38 in HSC-T6. The evidence of pharmacodynamics, network pharmacology, and molecular biology indicated that the plants of S. comosa had significant activity against liver fibrosis, the mechanism of which may involve the regulation of the key targets PI3 K, AKT, and MAPK14 p38 in the PI3 K/AKT and MAPK signaling pathways.

Ablation of Plasma Prekallikrein Decreases Low-Density Lipoprotein Cholesterol by Stabilizing Low-Density Lipoprotein Receptor and Protects Against Atherosclerosis.

BACKGROUND: High blood cholesterol accelerates the progression of atherosclerosis, which is an asymptomatic process lasting for decades. Rupture of atherosclerotic plaques induces thrombosis, which results in myocardial infarction or stroke. Lowering cholesterol levels is beneficial for preventing atherosclerotic cardiovascular disease. METHODS: Low-density lipoprotein (LDL) receptor (LDLR) was used as bait to identify its binding proteins in the plasma, and the coagulation factor prekallikrein (PK; encoded by the KLKB1 gene) was revealed. The correlation between serum PK protein content and lipid levels in young Chinese Han people was then analyzed. To investigate the effects of PK ablation on LDLR and lipid levels in vivo, we genetically deleted Klkb1 in hamsters and heterozygous Ldlr knockout mice and knocked down Klkb1 using adeno-associated virus-mediated shRNA in rats. The additive effect of PK and proprotein convertase subtilisin/kexin 9 inhibition also was evaluated. In addition, we applied the anti-PK neutralizing antibody that blocked the PK and LDLR interaction in mice. Mice lacking both PK and apolipoprotein e (Klkb1-/-Apoe-/-) were generated to assess the role of PK in atherosclerosis. RESULTS: PK directly bound LDLR and induced its lysosomal degradation. The serum PK concentrations positively correlated with LDL cholesterol levels in 198 young Chinese Han adults. Genetic depletion of Klkb1 increased hepatic LDLR and decreased circulating cholesterol in multiple rodent models. Inhibition of proprotein convertase subtilisin/kexin 9 with evolocumab further decreased plasma LDL cholesterol levels in Klkb1-deficient hamsters. The anti-PK neutralizing antibody could similarly lower plasma lipids through upregulating hepatic LDLR. Ablation of Klkb1 slowed the progression of atherosclerosis in mice on Apoe-deficient background. CONCLUSIONS: PK regulates circulating cholesterol levels through binding to LDLR and inducing its lysosomal degradation. Ablation of PK stabilizes LDLR, decreases LDL cholesterol, and prevents atherosclerotic plaque development. This study suggests that PK is a promising therapeutic target to treat atherosclerotic cardiovascular disease.

The hyper-activation of transcriptional enhancers in breast cancer.

BACKGROUND: Activation of transcription enhancers, especially super-enhancers, is one of the critical epigenetic features of tumorigenesis. However, very few studies have systematically identified the enhancers specific in cancer tissues. METHODS: Here, we studied the change of histone modifications in MMTV-PyVT breast cancer model, combining mass spectrometry-based proteomics and ChIP-seq-based epigenomics approaches. Some of the proteomic results were confirmed with western blotting and IHC staining. An inhibitor of H3K27ac was applied to study its effect on cancer development. RESULTS: H3K27ac and H4K8ac are elevated in cancer, which was confirmed in patient tissue chips. ChIP-seq revealed that H4K8ac is co-localized with H3K27ac on chromatin, especially on distal enhancers. Epigenomic studies further identified a subgroup of super-enhancers marked by H3K4me3 peaks in the intergenic regions. The H3K4me3-enriched regions enhancers are associated with higher level of H3K27ac and H4K8ac compared with the average level of conventional super-enhancers and are associated with higher transcription level of their adjacent genes. We identified 148 H3K4me3-enriched super-enhancers with higher gene expression in tumor, which may be critical for breast cancer. One inhibitor for p300 and H3K27ac, C646, repressed tumor formation probably through inhibiting Vegfa and other genes. CONCLUSIONS: Taken together, our work identifies novel regulators and provides important resource to the genome-wide enhancer studies in breast cancer and raises the possibility of cancer treatment through modulating enhancer activity.

Blockage of the lysosome-dependent autophagic pathway contributes to complement membrane attack complex-induced podocyte injury in idiopathic membranous nephropathy.

Dysregulation of autophagy-mediated podocyte homeostasis is proposed to play a role in idiopathic membranous nephropathy (IMN). In the present study, autophagic activity and lysosomal alterations were investigated in podocytes of IMN patients and in cultured podocytes exposed to sublytic terminal complement complex, C5b-9. C5b-9 upregulated the number of LC3 positive puncta and the expression of p62 in patient podocytes and in C5b-9 injuried podocyte model. The lysosomal turnover of LC3-II was not influenced, although the BECN1 expression level was upregulated after exposure of podocytes to C5b-9. C5b-9 also caused a significant increase in the number of autophagosomes but not autolysosomes, suggesting that C5b-9 impairs the lysosomal degration of autophagosomes. Moreover, C5b-9 exacerbated the apoptosis of podocytes, which could be mimicked by chloroquine treatment, indicating that C5b-9 triggered podocyte injury, at least partially through inhibiting autophagy. Subsequent studies revealed that C5b-9 triggered lysosomal membrane permeabilization, which likely caused the decrease in enzymatic activity, defective acidification of lysosomes, and suppression of DQ-ovalbumin degradation. Taken together, our results suggest that the lysosomal-dependent autophagic pathway is blocked by C5b-9, which may play a key role in podocyte injury during the development of IMN.