15-deoxy-Δ12,14-prostaglandin J2 relieved acute liver injury by inhibiting macrophage migration inhibitory factor expression via PPARγ in hepatocyte.

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) exhibited potential to alleviate liver inflammation in chronic injury but was less studied in acute injury. Acute liver injury was associated with elevated macrophage migration inhibitory factor (MIF) levels in damaged hepatocytes. This study aimed to investigate the regulatory mechanism of hepatocyte-derived MIF by 15d-PGJ2 and its subsequent impact on acute liver injury. In vivo, mouse models were established by carbon tetrachloride (CCl4) intraperitoneal injection, with or without 15d-PGJ2 administration. 15d-PGJ2 treatment reduced the necrotic areas induced by CCl4. In the same mouse model constructed using enhanced green fluorescent protein (EGFP)-labeled bone marrow (BM) chimeric mice, 15d-PGJ2 reduced CCl4 induced BM-derived macrophage (BMM, EGFP+F4/80+) infiltration and inflammatory cytokine expression. Additionally, 15d-PGJ2 down-regulated liver and serum MIF levels; liver MIF expression was positively correlated with BMM percentage and inflammatory cytokine expression. In vitro, 15d-PGJ2 inhibited Mif expression in hepatocytes. In primary hepatocytes, reactive oxygen species inhibitor (NAC) showed no effect on MIF inhibition by 15d-PGJ2; PPARγ inhibitor (GW9662) abolished 15d-PGJ2 suppressed MIF expression and antagonists (troglitazone, ciglitazone) mimicked its function. In Pparg silenced AML12 cells, the suppression of MIF by 15d-PGJ2 was weakened; 15d-PGJ2 promoted PPARγ activation in AML 12 cells and primary hepatocytes. Furthermore, the conditioned medium of recombinant MIF- and lipopolysaccharide-treated AML12 respectively promoted BMM migration and inflammatory cytokine expression. Conditioned medium of 15d-PGJ2- or siMif-treated injured AML12 suppressed these effects. Collectively, 15d-PGJ2 activated PPARγ to suppress MIF expression in injured hepatocytes, reducing BMM infiltration and pro-inflammatory activation, ultimately alleviating acute liver injury.

Single-cell RNA seq identifies Plg-RKT-PLG as signals inducing phenotypic transformation of scar-associated macrophage in liver fibrosis.

Hepatic macrophages play a central role in liver fibrosis. Scar-associated macrophages (SAMs), a recently identified subgroup of macrophages, play an important role in this process. However, the mechanism by which SAMs transform during liver fibrosis is still unclear. In this study, we aimed to characterize SAMs and elucidate the underlying mechanism of SAM transformation. Bile duct ligation (BDL) and carbon tetrachloride (CCl4) were used to induce mouse liver fibrosis. Non-parenchymal cells were isolated from normal/fibrotic livers and were analyzed using single cell RNA sequencing (scRNA-seq) or mass cytometry (CyTOF). The glucan-encapsulated siRNA particles (siRNA-GeRPs) was employed to perform macrophage selective gene knockdown. The results of scRNA-seq and CyTOF revealed that SAMs, which derived from bone marrow-derived macrophages (BMMs), accumulated in mouse fibrotic livers. Further analysis showed that SAMs highly expressed genes related to fibrosis, indicating the pro-fibrotic functions of SAMs. Moreover, plasminogen receptor Plg-RKT was highly expressed by SAMs, suggesting the role of Plg-RKT and plasminogen (PLG) in SAM transformation. In vitro, PLG-treated BMMs transformed into SAMs and expressed SAM functional genes. Knockdown of Plg-RKT blocked the effects of PLG. In vivo, selective knockdown of Plg-RKT in intrahepatic macrophages of BDL- and CCl4-treated mice reduced the number of SAMs and alleviated BDL- and CCl4-induced liver fibrosis, suggesting that Plg-RKT-PLG played an important role in liver fibrosis by mediating SAM transformation. Our findings reveal that SAMs are crucial participants in liver fibrosis. Inhibition of SAM transformation by blocking Plg-RKT might be a potential therapeutic target for liver fibrosis.

Sphingosine 1-Phosphate Receptor Blockade Affects Pro-Inflammatory Bone Marrow-Derived Macrophages and Relieves Mouse Fatty Liver Injury.

Fatty liver injury is characterized by liver fat accumulation and results in serious health problems worldwide. There is no effective treatment that reverses fatty liver injury besides etiological therapy. Inflammation is an important macrophage-involving pathological process of liver injury. Here, we investigated the role of sphingosine 1-phosphate receptors (S1PRs) in fatty liver injury and explored whether S1PR2/3 blockade could cure fatty liver injury. A methionine-choline-deficient and a high-fat (MCDHF) diet was used to induce fatty liver injury, and the number of macrophages was evaluated by flow cytometry. Gene expressions were detected using RT-qPCR and cytometric bead array. In MCDHF-diet-fed mice, pro-inflammatory factor expressions were upregulated by fatty liver injury. The S1P level and S1PR2/3 expressions were significantly elevated. Moreover, increased S1P level and S1PR2/3 mRNA expressions were positively correlated with pro-inflammatory factor expressions in the liver. Furthermore, the number of pro-inflammatory macrophages (iMφ) increased in injured liver, and they were mainly bone-marrow-derived macrophages. In vivo, S1PR2/3 blockade decreased the amount of iMφ and inflammation and attenuated liver injury and fibrosis, although liver fat accumulation was unchanged. These data strongly suggest that anti-inflammatory treatment by blocking the S1P/S1PR2/3 axis attenuates fatty liver injury, which might serve as a potential target for fatty liver injury.

Ultrasonic Assisted Extraction of Paclitaxel from Taxus x media Using Ionic Liquids as Adjuvants: Optimization of the Process by Response Surface Methodology.

(1) Background: Ionic liquids (ILs) are considered "green" solvents and have been widely used in the extraction and separation field in recent years; (2) Methods: In this study, some common ILs and functionalized magnetic ionic liquids (MILs) were used as adjuvants for the solvent extraction of paclitaxel from Taxus x media (T. x media) using methanol solution. The extraction conditions of methanol concentration, IL type and amount, solid-liquid ratio, extraction temperature, and ultrasonic irradiation time were investigated in single factor experiments. Then, three factors of IL amount, solid-liquid ratio, and ultrasonic irradiation time were optimized by response surface methodology (RSM); (3) Results: The MIL [C4MIM]FeCl3Br was screened as the optimal adjuvant. Under the optimization conditions of 1.2% IL amount, 1:10.5 solid-liquid ratio, and 30 min ultrasonic irradiation time, the extraction yield reached 0.224 mg/g; and (4) Conclusions: Compared with the conventional solvent extraction, this ultrasonic assisted extraction (UAE) using methanol and MIL as adjuvants can significantly improve the extraction yield, reduce the use of methanol, and shorten the extraction time, which has the potentiality of being used in the extraction of some other important bioactive compounds from natural plant resources.