LO2 Cells Research Articles

Hepatoprotective effect and structural analysis of Hedysarum polysaccharides in vivo and in vitro.

The crude Hedysarum polysaccharides (HPS: HPS-50 and HPS-80) obtained from Radix Hedysari exhibited great pharmacological activities in our previous research. This study investigated the effects of HPS on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury (ALI) in mice and LPS-induced injury in LO2 cells, as well as the relationship between structural characteristics and hepatoprotective activities. The in vivo results showed that compared with HPS-80, HPS-50 showed stronger hepatoprotection, which improved histopathological changes to normal levels. HPS-50 significantly decreased the levels of ALT, AST, MPO, and MDA, increased the activities of SOD, CAT, and GSH, and suppressed the LPS/D-GalN-triggered production of TNF-α, IL-1β, and IL-6 (p < .05). The results in vitro showed that HPS-50-P (HPS-50-1, HPS-50-2, and HPS-50-3) purified from HPS-50 played significant protective roles against LPS-induced injury in LO2 cells by reducing cell apoptosis and relieving cell cycle arrest. HPS-50-2 restored the percentage of normal cells from 54.8% to 94.7%, and reduced the S phase cells from 59.40% to 47.05% (p < .01). By analyzing the structure of HPS-50-P, including monosaccharide composition, molecular weight, chain conformation, and surface morphology, we speculated that the best protective effect of HPS-50-2 might be attributed to its beta configuration, highest molecular weight, and high glucose and galactose contents. These findings indicate that HPS-50 might be a promising source of functional foods for the protection and prevention of ALI. PRACTICAL APPLICATIONS: In this study, the protective effect of HPS on ALI was evaluated from multiple perspectives, and HPS-50-2 was screened as a potential active ingredient. This study has two practical applications. First, it provides a new way to improve ALI, and a new option for patients to prevent and treat ALI. Second, this work also complements the pharmacological activity of Radix Hedysari and provides a basis for the development of Radix Hedysari as a functional food.

Bone morphogenetic protein 4 alleviates nonalcoholic steatohepatitis by inhibiting hepatic ferroptosis

Nonalcoholic steatohepatitis (NASH) is a state of simple steatosis that progresses to inflammation and liver injury accompanied by ferroptosis. Bone morphogenetic protein 4 (BMP4) plays an important role in adipogenesis and differentiation, as well as in hepatic steatosis and iron regulation. However, the direct impact of BMP4 on NASH remains unclear. In this study, our aim was to investigate the effect of BMP4 on NASH and its underlying mechanism. We first explored BMP4 expression in vivo in mice and patients and in vitro in HepG2 and LO2 cell lines, and then, determined whether ferroptosis occurs in NASH. Further overexpression or inhibition of BMP4 was induced to observe the effect of BMP4 on liver ferroptosis in NASH. BMP4 expression was upregulated in patients and mice with nonalcoholic fatty liver disease, and free fatty acid (FFA)-induced HepG2 and LO2 cell lines. We observed ferroptosis in high-fat diet and high-fructose diet-fed mice and FFA-induced HepG2 and LO2 cell lines. BMP4 overexpressing plasmid was constructed and the HepG2 and LO2 cells were transfected with lentivirus (oe-BMP4), or treated with exogenously added recombinant human BMP4 or BMP antagonist noggin. BMP4 suppressed the markers of hepatic steatosis, liver inflammation, and liver injury. Upregulated BMP4 expression in HepG2 and LO2 cells reduced reactive oxygen species and malondialdehyde content and relieved ferroptosis. Mechanistically, BMP4 overexpression in hepatocytes upregulated the mRNA and protein levels of glutathione peroxidase 4 (GPX4), a central regulator of ferroptosis, while exogenous inhibition of BMP4 by noggin decreased their levels. Immunoprecipitation assays demonstrated a physical interaction between BMP4 and GPX4 in HepG2 and LO2 cells, and confocal imaging confirmed colocalization of BMP4 and GPX4. Consistently, BMP4 overexpression plays an important role in NASH by increasing GPX4 expression, therefore decreasing hepatic ferroptosis. This study proposes BMP4 as a therapeutic target for preventing steatohepatitis.

CCN1 Promotes Inflammation by Inducing IL-6 Production via α6β1/PI3K/Akt/NF-κB Pathway in Autoimmune Hepatitis.

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease with unknown etiology. CCN1, an extracellular matrix-associated protein, is associated with carcinoma, inflammation, liver fibrosis, and even autoimmune diseases. However, the role that CCN1 plays in AIH has remained undetermined. In this study, expression of CCN1 in liver was detected by real-time PCR, western blot and immunohistochemistry (IHC). CCN1 level in serum was detected by ELISA. Diagnostic value of CCN1 was determined by receiver operating characteristic (ROC) curve analysis. CCN1 conditional knockout (CCN1 fl/fl Cre+) mice were generated by mating CCN1 fl/fl C57BL/6J and CAG-Cre-ERT C57BL/6J mice. Autoimmune hepatitis mice model was induced by concanavalin A (ConA). IKKα/β, IκBα, NF-κB p65 and Akt phosphorylation were determined by western blot. NF-κB p65 nuclear translocation was examined by immunofluorescence. Here, we found that CCN1 was over-expressed in hepatocytes of AIH patients. CCN1 level also increased in serum of AIH patients compared to healthy controls (HC). ROC curve analysis results showed that serum CCN1 was able to distinguish AIH patients from HD. In ConA induced hepatitis mice model, CCN1 conditional knockout (CCN1 fl/fl Cre+) attenuated inflammation by reducing ALT/AST level and IL-6 expression. In vitro, CCN1 treatment dramatically induced IL-6 production in LO2 cells. Moreover, the production of IL-6 was attenuated by CCN1 knockdown. Furthermore, we showed that CCN1 could activate IL-6 production via the PI3K/Akt/NF-κB signaling pathway by binding to α6β1 receptor. In summary, our results reveal a novel role of CCN1 in promoting inflammation by upregulation of IL-6 production in AIH. Our study also suggests that targeting of CCN1 may represent a novel strategy in AIH treatment.

Dihydromyricetin reduces lipid accumulation in LO2 cells via AMPK/mTOR-mediated lipophagy pathway and inhibits HepG2 cell proliferation in vitro

To explore the mechanism underlying the hepatoprotective effect of dihydromyricetin (DMY) against lipid accumulation in light of the lipophagy pathway and the inhibitory effect of DMY on HepG2 cell proliferation. LO2 cells were cultured in the presence of 10% FBS for 24 h and treated with 100 μg/mL DMY, or exposed to 50% FBS for 24 h followed by treatment with 50, 100, or 200 μg/mL DMY; the cells in recovery group were cultured in 50% FBS for 24 h and then in 10% FBS for another 24 h. Oil red O staining was used to observe the accumulation of lipid droplets in the cells, and the levels of TC, TG, and LDL and activities of AST, ALT and LDH were measured. The expression of LC3 protein was detected using Western blotting. AO staining and transmission electron microscopy were used to determine the numbers of autophagolysosomes and autophagosomes, respectively. The formation of autophagosomes was observed with MDC staining, and the mRNA expression levels of LC3, ATG7, AMPK, mTOR, p62 and Beclin1 were determined with q-PCR. Flow cytometry was performed to analyze the effect of 50, 100, and 200 μg/mL DMY on cell cycle and apoptosis of HepG2 cells; DNA integrity in the treated cells was examined with cell DNA fragmentation test. DMY treatment and pretreatment obviously inhibited lipid accumulation and reduced the levels of TC, TG, LDL and enzyme activities of AST, ALT and LDH in LO2 cells (P < 0.05). In routinely cultured LO2 cells, DMY significantly promoted the formation of autophagosomes and autophagolysosomes and upregulated the expression of LC3 protein. DMY obviously attenuated high FBS-induced inhibition of autophagosome formation in LO2 cells, up- regulated the mRNA levels of LC3, ATG7, Beclin1 and AMPK, and downregulated p62 and mTOR mRNA levels (P < 0.05 or 0.01). In HepG2 cells, DMY caused obvious cell cycle arrest, inhibited cell proliferation, and induced late apoptosis and DNA fragmentation. DMY reduces lipid accumulation in LO2 cells by regulating the AMPK/ mTOR-mediated lipophagy pathway and inhibits the proliferation of HepG2 by causing cell cycle arrest and promoting apoptosis.

Empagliflozin-Enhanced Antioxidant Defense Attenuates Lipotoxicity and Protects Hepatocytes by Promoting FoxO3a- and Nrf2-Mediated Nuclear Translocation via the CAMKK2/AMPK Pathway.

Lipotoxicity is an important factor in the development and progression of nonalcoholic steatohepatitis. Excessive accumulation of saturated fatty acids can increase the substrates of the mitochondrial electron transport chain in hepatocytes and cause the generation of reactive oxygen species, resulting in oxidative stress, mitochondrial dysfunction, loss of mitochondrial membrane potential, impaired triphosphate (ATP) production, and fracture and fragmentation of mitochondria, which ultimately leads to hepatocellular inflammatory injuries, apoptosis, and necrosis. In this study, we systematically investigated the effects and molecular mechanisms of empagliflozin on lipotoxicity in palmitic acid-treated LO2 cell lines. We found that empagliflozin protected hepatocytes and inhibited palmitic acid-induced lipotoxicity by reducing oxidative stress, improving mitochondrial functions, and attenuating apoptosis and inflammation responses. The mechanistic study indicated that empagliflozin significantly activated adenosine 5’-monophosphate (AMP)-activated protein kinase alpha (AMPKα) through Calcium/Calmodulin dependent protein kinase kinase beta (CAMKK2) instead of liver kinase B1 (LKB1) or TGF-beta activated kinase (TAK1). The activation of empagliflozin on AMPKα not only promoted FoxO3a phosphorylation and thus forkhead box O 3a (FoxO3a) nuclear translocation, but also promoted Nrf2 nuclear translocation. Furthermore, empagliflozin significantly upregulated the expressions of antioxidant enzymes superoxide dismutase (SOD) and HO-1. In addition, empagliflozin did not attenuate lipid accumulation at all. These results indicated that empagliflozin mitigated lipotoxicity in saturated fatty acid-induced hepatocytes, likely by promoting antioxidant defense instead of attenuating lipid accumulation through enhanced FoxO3a and Nrf2 nuclear translocation dependent on the CAMKK2/AMPKα pathway. The CAMKK2/AMPKα pathway might serve as a promising target in treatment of lipotoxicity in nonalcoholic steatohepatitis.

Screening Potential Drugs for the Development of NAFLD Based on Drug Perturbation Gene Set.

Nonalcoholic fatty liver disease (NAFLD) has become one of the problems affecting the health of the population worldwide. The progressive disease includes nonalcoholic steatohepatitis (NASH) and fibrosis, which with no approved therapy, system identification of effective drugs remains challenging. In this work, we applicated drug perturbation gene set enrichment analysis to screen drugs for the development of NAFLD. A total 15490 small-molecule compounds were analyzed in our study; based on the p value of enrichment score, 7 small-molecule compounds were found to have a potential role in NASH and fibrosis. After pathway analyses, we found indoximod had effects on nonalcoholic fatty liver disease through regulated TNFa, AP-1, AKT, PI3K, etc. Furthermore, we established the NAFLD cell model with LO2 cells induced using PA; ELISA showed that the levels of TG, ALT, and AST were significantly improved by indoximod. In summary, our study offers optimal therapeutic drugs, which may provide novel insight into the precise treatment of NAFLD and promote researches.

Cholesterol-induced leucine aminopeptidase 3 (LAP3) upregulation inhibits cell autophagy in pathogenesis of NAFLD.

Objectives: Leucine aminopeptidase 3 (LAP3), an M1 member of leucine aminopeptidase, was reported to be significantly upregulated in serum of nonalcoholic fatty liver disease (NAFLD) patients. However, the underlying mechanisms of LAP3 in NAFLD pathogenesis are still unknown. We aim to investigate the role of LAP3 in NAFLD pathogenesis and explore whether LAP3 has the potential to be a candidate biomarker in serum for NAFLD diagnosis.Methods: Liver tissues and serum from NASH rats, serum from patients with NAFLD were obtained to evaluate the LAP3 expression. Detection of GSSG/GSH, intracellular reactive oxygen species (ROS), and LC3 expression by elevation/ reduction of LAP3 expression to determine the role of LAP3 in NAFLD pathogenesis. Finally, the correlation analysis was conducted to evaluate the association between LAP3 expression and clinical indexes of NAFLD.Results: LAP3 expression was upregulated in hepatocytes and serum in E3 rats with NASH after 6-month HFD feeding. Cholesterol (CHO) dramatically upregulated LAP3 in LO2 cells, and then lead to negative regulation of autophagy. Moreover, LAP3 levels were also significantly increased in NAFLD patients compared to healthy controls. Correlation analysis revealed that serum LAP3 levels were positively correlated with TG, γ-glutamyltranspeptidase (GGT), and fasting blood glucose levels, while there was a negative correlation with HDL levels.Conclusions: The cholesterol-dependent upregulation of LAP3 in hepatocytes plays a critical role in the pathogenesis of NAFLD via inhibiting autophagy. Moreover, LAP3 could serve as a potential novel candidate biomarker for the diagnosis of NAFLD.

Development of oxoisoaporphine derivatives with topoisomerase I inhibition and reversal of multidrug resistance in breast cancer MCF-7/ADR cells

A series of oxoisoaporphine derivatives with topoisomerase I inhibition and cytotoxic activities. Among them, compound 14 showed the most potent cytotoxic activity against all cancer cell lines tested, and substantially lower cytotoxicity to LO2 cells. Molecular docking studies, dynamics simulation and a follow-up enzyme inhibition assay indicated that 14 could interfere with DNA and significantly inhibit the activity of topoisomerase I. Further mechanistic studies revealed that 14 could arrest cell cycle at the G1 phase, and finally killed MCF-7 cells via apoptosis. In addition, 14 exhibited remarkable chemoreversal ability on multidrug-resistant MCF-7/ADR breast cancer cells. Some of its mechanisms may be related to inhibition of MCF-7/ADR P-gp-mediated Rhodamine (Rh123) efflux function and expression level, as well as inhibition of ROS, increase of ADR accumulation in MCF7/ADR cells, and enhancement of ADR in inducing apoptosis of MCF7/ADR cells. As 14 has little toxic and side effects, it may have the potential for further research.

Inonotus obliquus and its bioactive compounds alleviate non-alcoholic fatty liver disease via regulating FXR/SHP/SREBP-1c axis

Non-alcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. However, there is still lack of specific drugs for treating NAFLD in clinic. Inonotus obliquus (IO), a folk medicinal fungus, has long been used to prevent against metabolic syndrome related diseases, such as hypertension and diabetes, etc. However, the study of IO anti-NAFLD effect has been reported rarely. This study aimed to investigate whether IO has an inhibitory effect on NAFLD, identify the active compounds in IO and clarify the underlying mechanisms of its anti-NAFLD effects. The results of Oil Red O(ORO) and Hematoxylin-Eosin (HE) staining, lipid extraction and determination showed that IO and its extracts, including inotodiol (Ino), lanosterol (Lan) and trametenolic acid (TA), could remarkably ameliorate lipid accumulation in MCD diet-induced mouse livers or OA-induced LO2 hepatocytes. Moreover, qPCR analysis revealed that IO and its compounds significantly downregulated the mRNA levels of lipogenic genes, such as SREBP-1c, ACC1 and FASN, and upregulated the mRNA levels of FXR and SHP. We found that the administration of guggulsterone (GS), a FXR inhibitor, abolished the inhibitory effect of Ino on lipid deposition in OA-induced LO2 cells. In conclusion, IO and its compounds attenuate hepatic lipid accumulation in NAFLD by inhibiting liver lipogenesis. The anti-NAFLD effects of Ino, a bioactive compound in IO, are through regulating FXR/SHP/SREBP-1c pathway. Our results suggested that IO and its bioactive compound Ino may become promising drugs to treat NAFLD.

Inhibition of Protease Activated Receptor 2 Attenuates HBx-Induced Inflammation and Mitochondria Oxidative Stress.

BackgroundHepatitis B virus (HBV) infection is one of the global public problems. Among the known infection cases, HBV X protein (HBx) is one of the key inducements of viral replication and host infection. This study was aimed to uncover the role of protease activated receptor 2 (PAR2) on HBx-induced liver injury.MethodsA PAR2-KO mouse model expressing HBx was constructed using hydrodynamics-based in vivo gene transfection method. In addition, pcDNA3.1-HBx was used to over-express HBx in LO2 cells. The effects of HBx overexpression on inflammation and mitochondria oxidative stress were evaluated.ResultsWe found that PAR2 protein level was increased by HBx overexpression. The enforced HBx inhibited LO2 cells apoptosis. Meanwhile, HBx induced inflammation reactions through promoting the secretion of pro-inflammatory cytokines such as TNF-α, IL-6, and CXCL-2. Overexpressed HBx also resulted in mitochondria oxidative stress by upregulation of ROS level and downregulation of MMP and ATP. However, in FSLLRY-NH2 (PAR2 antagonist) treated LO2 cells or PAR2-KO mice, PAR2 blockade reversed the above adverse effects of HBx on liver cells or tissues.ConclusionInhibition of PAR2 may suppress inflammation and mitochondria oxidative stress caused by HBx, pointing out the potential application values of PAR2 antagonist on the treatment of HBV infection in clinic.

Nonselective Cell Necrosis Mediated by the Total Flavones of Penthorum Chinensis Pursh and Thonningianin-A in Human Hepatic and Hepatoma Cells

Penthorum chinensis Pursh (PCP), family Penthoraceae, has been used for hundreds of years in China. With the launch of PCP tablets, clinical applications focused on liver fibrosis and hepatocarcinoma. The purpose of this research was to explore the selectivity and toxicity of the active pharmacodynamic ingredients of PCP in vitro. The total flavones of PCP (TFPCE) and thonningianin-A (Th-A), a major flavone in TFPCE, were investigated on the cell death patterns in human hepatoma cells (HepG2) and human hepatic cells (LO2), followed by a concentration detection of LDH in the supernatants. Apoptosis and necrosis detection kits were used to validate the patterns of cell death caused by TFPCE and Th-A. Finally, the cytotoxicity of both TFPCE and Th-A were reproduced in the colorectal adenocarcinoma cells (NCI-H716). The results indicated that TFPCE inhibits the cell viability of HepG2 cells at a concentration lower than 25 μg/mL. Alternatively, the cell viability of LO2 cells dramatically decreased in the treatment of TFPCE at 25 μg/mL. The effects of Th-A on the cell viability of HepG2 cells and LO2 cells were consistent with TFPCE. LDH detection indicated that TFPCE and Th-A increased the LDH concentration of the supernatants in a dose-dependent way, indicating the pattern of cell necrosis. Fluorescence staining verified the necrosis cell death caused by TFPCE and Th-A. A dose-dependent tendency was obtained in NCI-H716 cells, indicating that the cell viability of NCI-H716 cells was significantly suppressed with the treatment of TFPCE and Th-A. Our results bring the potential toxicity of PCP to the forefront of public attention. Therefore, the clinical application of P chinensis is required to focus more on its cytotoxic effect.

Nuclear Factor Erythroid-2-Related Factor 2 (Nrf2) Signalling Pathway and Apoptosis Impact on the Effect of Tetramethylpyrazine against H2O2-Damage in Human Hepatic Cell Line (LO2 Cells)

Nuclear Factor Erythroid-2-Related Factor 2 (Nrf2) Signalling Pathway and Apoptosis Impact on the Effect of Tetramethylpyrazine against H2O2-Damage in Human Hepatic Cell Line (LO2 Cells)

Protective effects of curcumin/cyclodextrin polymer inclusion complex against hydrogen peroxide-induced LO2 cells damage.

The objective of the present study was to explore the protective effects of the curcumin/cyclodextrin polymer (CUR/CDP) inclusion complex on hydrogen peroxide (H2O2)‐induced LO2 cells damage. In this study, a H2O2‐induced cells oxidative injury model was established to test the protective effects of the CUR/CDP inclusion complex. The cell viability of cells was detected by the thiazolyl blue tetrazolium bromide (MTT) assay. The extracellular lactate dehydrogenase (LDH) activity, catalase (CAT) activity, and malondialdehyde (MDA) level were detected by assay kits. The cellular reactive oxygen species (ROS) level was detected using the dichlorodihydrofluorescein (DCF) fluorescence assay. Western blotting analysis was conducted to assess the changes of phosphorylated‐p53 and caspase‐3. The results showed that 700 μM H2O2‐treated LO2 cells for 3 h resulted in a significant decrease of cell viability to 53.00 ± 1.68%, which established the cell oxidative injury model. Cells treated with H2O2 led to a significant increase of extracellular LDH activity, MDA content, and ROS level, and decreased CAT activity. Treatment with CUR/CDP significantly reversed the changes of the above indicators. Moreover, CUR/CDP treatment at 20 and 40 μg/ml inhibited H2O2‐induced increase in phosphorylated‐p53 and caspase‐3 expression, indicating that CUR/CDP suppressed cell apoptosis to alleviate liver injury. The results of those studies demonstrated that CUR/CDP had a protective effect on the oxidative damage of LO2 cells, and it could be developed as a new type of natural liver protection product to apply in the prevention of liver injury.

Carbon tetrachloride induced mitochondrial division, respiratory chain damage, abnormal intracellular [H+] and apoptosis are due to the activation of 5-HT degradation system in hepatocytes

Previously we found that acute liver injury (ALI) with inflammation caused by carbon tetrachloride (CCl4) was associated with the activation of the 5-HT degradation system (5DS), which includes monoamine oxidase A (MAO-A), the 5-HT2A receptor, and 5-HT synthases in hepatocytes. This study aimed to determine the role of 5DS in mitochondrial damage and apoptosis. In hepatocyte LO2 cells, CCl4 activated 5-HT2A receptor at the gene level, and then 5-HT2A receptor mediated the expression of 5-HT synthase and MAO-A at the gene level. Suppression of 5DS with the 5-HT2A receptor antagonist, MAO-A inhibitor, or gene silencing MAO-A significantly reduced the CCl4-induced production of mitochondrial reactive oxygen species (ROS). The ROS-associated upregulation of mitochondrial division proteins (FIS1 and DRP1); downregulation of mitochondrial fusion-associated protein 1, respiratory chain proteins (ND1 and CYTB), and ATP6; and decrease of ATP levels were reversed. Moreover, ROS-associated abnormal levels of caspase pathway-associated proteins (Bcl-2, Bax, cleaved-caspase3 and cleaved-caspase9) and apoptosis were suppressed. Notably, a combination of 5-HT2A receptor antagonist and MAO-A inhibitor almost abolished CCl4 cytotoxicity; abolished mitochondrial membrane potential (MMP) depolarization, mitochondrial structural abnormality, and high mitochondrial pH, with low pH states of the nucleus and cytoplasm. The effects of both were more significant than either alone. LO2 cells exposed to H2O2 or depleted mitochondrial ROS showed that ROS induced mitochondrial division and apoptosis and inhibited the levels of respiratory chain proteins. CCl4-induced abnormalities of ATP generation and MMP were dependent on both ROS and other 5DS-associated factors, probably NH3. Investigation of CCl4-induced ALI mice showed that hepatic injury and apoptosis occur at the site of 5DS activation and are significantly inhibited by the 5-HT2A receptor antagonist and 5-HT synthetic inhibitor in a synergistic manner, as well as mitochondrial damage. Together, we revealed the close relationship between CCl4-induced activation of 5DS and mitochondrial damage, abnormal intracellular [H+], and apoptosis in hepatocytes.

Short divalent ethacrynic amides as pro-inhibitors of glutathione S-transferase isozyme Mu and potent sensitisers of cisplatin-resistant ovarian cancers

The linking of ethacrynic acid with ethylenediamine and 1,4-butanediamine gave EDEA and BDEA, respectively, as membrane-permeable divalent pro-inhibitors of glutathione S-transferase (GST). Their divalent glutathione conjugates showed subnanomolar inhibition and divalence-binding to GSTmu (GSTM) (PDB: 5HWL) at ∼0.35 min−1. In cisplatin-resistant SK-OV-3, COC1, SGC7901 and A549 cells, GSTM activities probed by 15 nM BDEA or EDEA revealed 5-fold and 1.0-fold increases in cisplatin-resistant SK-OV-3 and COC1 cells, respectively, in comparison with the susceptible parental cells. Being tolerable by HEK293 and LO2 cells, BDEA at 0.2 μM sensitised resistant SK-OV-3 and COC1 cells by ∼3- and ∼5-folds, respectively, released cytochrome c and increased apoptosis; EDEA at 1.0 μM sensitised resistant SK-OV-3 and A549 cells by ∼5- and ∼7-fold, respectively. EDEA at 1.7 μg/g sensitised resistant SK-OV-3 cells to cisplatin at 3.3 μg/g in nude mouse xenograft model. BDEA and EDEA are promising leads for probing cellular GSTM and sensitising cisplatin-resistant ovarian cancers.

Poly-adenine-mediated spherical nucleic acid probes for live cell fluorescence imaging of tumor-related microRNAs.

Accurately detecting and quantifying tumor-related microRNAs (miRNAs) in living cells is of great value for early cancer diagnosis. Herein, we present poly-adenine (polyA)-mediated spherical nucleic acid (SNA) nanoprobes for intracellular miRNA imaging in living cells. polyA-mediated spherical nucleic acid (pASNA) nanoprobes consist of gold nanoparticles (AuNPs) anchored with fluorophore-labeled DNA molecules pre-hybridized with recognition sequences and polyA tails. The detection performance for miRNAs in vitro was studied to confirm the feasibility of pASNA nanoprobes for imaging live cell miRNAs. Before the pASNA nanoprobes were used for imaging intracellular miRNAs in MCF-7, HeLa, and LO2 cells, the stability and non-cytotoxicity were investigated using Dnase I and a standard colorimetric CCK8 assay. Flow cytometry, qRT-PCR analyses were conducted to confirm the different expression levels of miR-155 in live cells. Results showed that the pASNA nanoprobes had good detection sensitivity and specificity, excellent stability, and low toxicity. After incubating with pASNA nanoprobes, noticeable fluorescence signal enhancement could be clearly observed in MCF-7 and HeLa cells but not LO2 cells by confocal microscopy. Flow cytometry analysis and qRT-PCR indicated that MCF-7 and HeLa cells had higher miR-155 expression levels compared to LO2 cells. The pASNA nanoprobes we developed had good sensitivity and specificity, excellent nuclease stability and low toxicity, thus representing a new approach to exquisitely reveal the distribution of endogenous miRNAs in live cells.

Bdh1 overexpression ameliorates hepatic injury by activation of Nrf2 in a MAFLD mouse model

In 2020, a group of experts officially suggested metabolic dysfunction associated with fatty liver disease “MAFLD” as a more appropriate overarching term than NAFLD, indicating the key role of metabolism in fatty liver disease. Bdh1, as the rate-limiting enzyme of ketone metabolism, acts as an important metabolic regulator in liver. However, the role of Bdh1 in MAFLD is unclear. In this study, we used the transgenic db/db mice as a MAFLD mouse model and observed the downregulated expression of Bdh1 in fatty liver. In addition, expression of Bdh1 was also reduced by palmitic acid (PA) treatment in LO2 cells. Bdh1 knockdown led to ROS overproduction and ROS-induced inflammation and apoptosis in LO2 cells, while Bdh1 overexpression protected LO2 cells from lipotoxicity by inhibiting ROS overproduction. Mechanistically, Bdh1-mediated βOHB metabolism inhibits ROS overproduction by activation of Nrf2 through enhancement of metabolic flux composed of βOHB-AcAc-succinate-fumarate. Notably, adeno-associated virus (AAV)-mediated Bdh1 overexpression successfully reversed the hepatic function indexes, fibrosis, inflammation, and apoptosis in fatty livers from db/db mice. In conclusion, our study revealed a Bdh1-mediated molecular mechanism in pathogenesis of metabolic dysfunction related liver disease and identified Bdh1 as a novel potential therapeutic target for MAFLD.

Antimicrobial activity of PvH4a, a peptide derived from histone H4 of Penaeus vannamei

Histones are important players in the formation and transcriptional regulation of eukaryotic nucleosomes. In most vertebrates, histones and histone-derived peptides have also been implicated in antimicrobial activities against various pathogenic microbes. In this study, the sera of Vibrio parahaemolyticus -infected Penaeus vannamei shrimp were filtered through 3 kDa ultrafiltration tubes followed by analysis using reversed-phase high performance liquid chromatography (HPLC). A novel histone H4-derived peptide (TVTAMDVVYALK) was identified and designated as PvH4a. Peptide PvH4a had strong antimicrobial activity against Gram-negative bacteria with the MIC value of 15.6–62.5 μg/mL ( Vibrio. parahaemolyticus, Vibrio fluvialis and Vibrio alginolyticus ) and no effect on Gram-positive bacteria ( Staphylococcus aureus and Streptococcus iniae ). In addition, PvH4a increased the inner-membrane permeability of V. parahaemolyticus concentration-dependently at 1 × MIC and had no adverse effects on normal human hepatocytes (LO2 cells) even at high concentrations (16 × MIC), with a cell survival rate of more than 90.3%. Furthermore, SEM analysis revealed that PvH4a could destroy the cell walls of Gram-negative bacteria as part of its antimicrobial action. Put together, the current findings indicate that during immune response to bacteria infection, shrimp histone H4 generates antimicrobial peptides such as PvH4a as part of the innate immune response. • A novel AMP PvH4a was identified from sera of V. parahaemolyticus -infected P. vannamei . • PvH4a had strong antimicrobial activity against Gram-negative bacteria and no adverse effects on normal human hepatocytes (LO2). • PvH4a comes from the C-terminal of shrimp P. vannamei histone H4. • The antimicrobial activity of PvH4a is executed by increasing the membrane permeability of bacterial.

Synthesis and Antitumor Activity of Evodiamine Derivatives With Nitro, Amino, and Methoxy Groups

MS, and IR, 1H NMR and 13C NMR spectroscopy were employed to elucidate 4 novel evodiamine (EVO) derivatives with nitro, amino, and methoxy groups, namely 2-NO2-EVO (7a), 10-OCH3-2-NO2-EVO (7b), 2-NH2-EVO (8a), and 10-OCH3-2-NH2-EVO (8b). The amino compounds (8a, 8b) were obtained by the reduction of nitro derivatives (7a, 7b) with SnCl2/HCl. The antiproliferative activities of these compounds were tested by Cell Counting Kit-8 assay for 48 h against the MDA-MB-231 and sw620 cancer cell lines, as well as the normal LO2 cells. The in vitro experiment showed that 8a possesses the most potent inhibitory activities against MDA-MB-231 and SW620 cells, with IC50 values of 0.79 and 1.28 μM, respectively. The cytotoxicity of 8a against the 2 cancer cell lines was higher than that of EVO.

Conjugation of the glutelin hydrolysates-glucosamine by transglutaminase and functional properties and antioxidant activity of the products

A novel mixture of glycopeptides was prepared from corn glutelin and glucosamine (GlcN). The functional properties and antioxidative activities of this mixture were investigated. Corn glutelin was limited hydrolyzed by Alcalase, and then its hydrolysates were glycosylated with GlcN by transglutaminase (TGase) to modify its main and side chain, respectively. Under the optimized conditions, the content of GlcN conjugated to peptides was 81.98 ± 1.98 mg/g glutelin peptides. According to electrospray ionization mass spectrometry (ESI-MS) analysis, there are two types of glycopeptides in the mixture, TGase and non-enzymatic glycated counterparts. Compared with original glutelin, the glycosylated glutelin hydrolysates exhibited better solubility in the pH range of 2–11 and other functional properties except foaming stability. Meanwhile, it is more easily digested by pepsin and trypsin, and possessed excellent antioxidative activities. It also exhibited cytoprotective effects and intracellular ROS scavenging activities in LO2 cells subjected to oxidative stress by oxidation with ethanol solution.