Shielding Ferritin with a Biomineralized Shell Enables Efficient Modulation of Tumor Microenvironment and Targeted Delivery of Diverse Therapeutic Agents

Ferritin (Fn) is considered a promising carrier for targeted delivery to tumors, but the successful application in vivo has not been fully achieved yet. Herein, strong evidence is provided that the Fn receptor is expressed in liver tissues, resulting in an intercept effect in regards to tumor delivery. Building on these observations, a biomineralization technology is rationally designed to shield Fn using a calcium phosphate (CaP) shell, which can improve the delivery performance by reducing Fn interception in the liver while re-exposing it in acidic tumors. Moreover, the selective dissolution of the CaP shell not only neutralizes the acidic microenvironment but also induces the intratumoral immunomodulation and calcification. Upon multiple cell line and patient-derived xenografts, it is demonstrated that the elaboration of the highly flexible Fn@CaP chassis by loading a chemotherapeutic drug into the Fn cavity confers potent antitumor effects, and additionally encapsulating a photosensitizer into the outer shell enables a combined chemo-photothermal therapy for complete suppression of advanced tumors. Altogether, these results support Fn@CaP as a new nanoplatform for efficient modulation of the tumor microenvironment and targeted delivery of diverse therapeutic agents.

Tumor Exosomes Reprogrammed by Low pH Are Efficient Targeting Vehicles for Smart Drug Delivery and Personalized Therapy against their Homologous Tumor

As membrane-bound extracellular vesicles, exosomes have targeting ability for specific cell types, and the cellular environment strongly impacts their content and uptake efficiency. Inspired by these natural properties, the impacts of various cellular stress conditions on the uptake efficiency of tumor iterated exosomes are evaluated, and low-pH treatment caused increased uptake efficiency and retained cell-type specificity is found. Lipidomics analyses and molecular dynamics simulations reveal a glycerolipid self-aggregation-based mechanism for the enhanced homologous uptake. Furthermore, these low-pH reprogrammed exosomes are developed into a smart drug delivery platform, which is capable of specifically targeting tumor cells and selectively releasing diverse chemodrugs in response to the exosome rupture by the near-infrared irradiance-triggered burst of reactive oxygen species. This platform exerts safe and enhanced antitumor effects demonstrated by multiple model mice experiments. These results open a new avenue to reprogram exosomes for smart drug delivery and potentially personalized therapy against their homologous tumor.

Mesenchymal Stem Cells-Derived Exosomes as Dexamethasone Delivery Vehicles for Autoimmune Hepatitis Therapy

Exosomes (Exos) are nanosized vesicles (around 100 nm) that recently serve as a promising drug carrier with high biocompatibility and low immunogenicity. Previous studies showed that Exos secreted from mesenchymal stem cells (MSCs) provide protection for concanavalin A (Con A)-induced liver injury. In this study, the protective effect of Exos is confirmed, and dexamethasone (DEX)-incorporated Exos named Exo@DEX are prepared. It is then investigated whether Exo@DEX can function more efficiently compared to free drugs and naive Exos in a Con A-induced autoimmune hepatitis (AIH) mouse model. The results show that Exo@DEX efficiently improves the accumulation of DEX in AIH in the liver. These data suggest that Exo@DEX is a promising drug carrier for AIH and could have applications in other diseases.

FOXD1-AS1 regulates FOXD1 translation and promotes gastric cancer progression and chemoresistance by activating the PI3K/AKT/mTOR pathway

Gastric cancer (GC) is a common gastrointestinal cancer with a high global mortality. Recent reports have suggested that long noncoding RNA (lncRNA) are implicated in multiple aspects of GC, including pathogenesis, progression, and therapeutic response. Herein, we investigated the function of FOXD1-AS1 in GC progression and chemoresistance. Expression of FOXD1-AS1 was low in normal stomach tissues but was upregulated in GC cell lines. Silencing of FOXD1-AS1 impaired GC cell proliferation and motility in vitro, and repressed tumor growth and metastasis in vivo. Importantly, FOXD1-AS1 upregulation increased the resistance of GC cells to cisplatin. Moreover, we found that FOXD1-AS1 promoted FOXD1 protein translation through the eIF4G-eIF4E-eIF4A translational complex. We also demonstrated that FOXD1-AS1 released eIF4E from phosphorylated 4E-BP1 and thereby strengthened the interaction of eIF4E with eIF4G by activating the PI3K/AKT/mTOR pathway. Activation of the PI3K/AKT/mTOR pathway was due to the post-transcriptional upregulation of PIK3CA, in turn induced by FOXD1-AS1-mediated sequestering of microRNA (miR)-466. Furthermore, we verified that FOXD1-AS1 facilitated GC progression and cisplatin resistance in a FOXD1-dependent manner. In conclusion, FOXD1-AS1 aggravates GC progression and chemoresistance by promoting FOXD1 translation via PIK3CA/PI3K/AKT/mTOR signaling. These findings highlight a novel target for treatment of patients GC, particularly patients with cisplatin resistance.

lncRNA SNHG11 Promotes Gastric Cancer Progression by Activating the Wnt/β-Catenin Pathway and Oncogenic Autophagy

Long non-coding RNAs (lncRNAs) are under active investigation in the development of cancers, including gastric cancer (GC). Oncogenic autophagy is required for cancer cell survival. The present study aimed to investigate the regulatory role of lncRNA small nucleolar host gene 11 (SNHG11) in GC. We show that SNHG11 is upregulated in GC, and that its upregulation correlated with dismal patient outcomes. Functionally, SNHG11 aggravated oncogenic autophagy to facilitate cell proliferation, stemness, migration, invasion, and epithelial-to-mesenchymal transition (EMT) in GC. Mechanistically, SNHG11 post-transcriptionally upregulated catenin beta 1 (CTNNB1) and autophagy related 12 (ATG12) through miR-483-3p/miR-1276, while the processing of precursor (pre-)miR-483/pre-miR-1276 was hindered by SNHG11. SNHG11 induced GSK-3β ubiquitination through interacting with Cullin 4A (CUL4A) to further activate the Wnt/β-catenin pathway. Intriguingly, SNHG11 regulated autophagy in a manner dependent on ATG12 rather than the Wnt/β-catenin pathway, whereas SNHG11 contributed to the malignant behaviors of GC cells via both pathways. Finally, SNHG11 upregulation in GC cells was shown to be transcriptionally induced by TCF7L2. In conclusion, we reveal that SNHG11 is an onco-lncRNA in GC and might be a promising prognostic and therapeutic target for GC.

APCCDC20-mediated degradation of PHD3 stabilizes HIF-1a and promotes tumorigenesis in hepatocellular carcinoma

CDC20 regulates cell cycle progression by targeting key substrates for destruction, but its role in hepatocellular carcinoma (HCC) tumorigenesis remains to be explored. Here, by using weighted gene co-expression network analysis (WGCNA), we identified CDC20 as a hub gene in HCC. We demonstrated that CDC20 expression is correlated with HIF-1 activity and overall survival (OS) of clinic HCC patients. The activity of HIF-1 is regulated by the stability of HIF-1a subunit, which is hydroxylated by oxygen-dependent prolyl hydroxylase enzymes, the PHDs. In addition, we show that genetic ablation or pharmacological inhibition of CDC20 can accelerate the degradation of HIF-1a and impair VEGF secretion in HCC cells. Mechanistically, we found that CDC20 binds to the destruction-box (D-box) motif present in the PHD3 protein to promote its polyubiquitination and degradation. The depletion of endogenous PHD3 in CDC20 knockdown HCC cells greatly attenuated the decline of HIF-1a protein and restored the secretion of VEGF. In contrast, overexpression of a non-degradable PHD3 mutant significantly inhibited the proliferation of HCC cells both in vitro and in vivo. Collectively, our findings indicate that CDC20 plays a crucial role in the development of HCC by governing PHD3 protein.

Protective Effects of Oridonin on Acute Liver Injury via Impeding Posttranslational Modifications of Interleukin-1 Receptor-Associated Kinase 4 (IRAK4) in the Toll-Like Receptor 4 (TLR4) Signaling Pathway

Objective

Recent researches have demonstrated that inflammation-related diseases are effectively regulated by posttranslational modifications (PTMs) including phosphorylation and acetylation. Our previous study found a new acetyltransferase inhibitor, oridonin, which had a protective effect on acute liver injury (ALI). In the present study, we further investigated its protective mechanism against D-galactosamine (D-Gal) combined with lipopolysaccharide- (LPS-) induced ALI in mice.

Methods

Intraperitoneal injections of LPS (40 μg/mouse)/D-Gal (5 mg/mouse) were given to the mice, and the experimental group was pretreated with intraperitoneal injection of oridonin (0.2 mg/mouse). To elucidate the protective mechanism of oridonin, we collected liver specimens and used RNA-sequencing (RNA-Seq) analysis. We focused on the genes that were upregulated by LPS/D-Gal and downregulated after pretreatment with oridonin. The downregulated genes examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were further verified by real-time polymerase chain reaction (PCR) and western blot.

Results

GO analysis showed that genes that were downregulated after pretreatment with oridonin were extremely concentrated in immune response, chemotaxis, and inflammatory response. Real-time PCR confirmed that the expression of these genes was upregulated by LPS/D-Gal induction and reduced after treatment with oridonin, which was consistent with RNA-Seq results. KEGG pathway analysis showed a significantly enriched downregulated gene that was present in the Toll-like receptor (TLR) 4 signaling cascade. Our results manifested that phosphorylation levels of upstream signaling molecules in the TLR4 signaling cascade, including extracellular signal-regulated kinase (ERK), P38, and IκB, were significantly inhibited by oridonin. Furthermore, LPS/D-Gal stimulation triggered posttranslational modifications of related gene loci in the TLR4 signaling pathway, including phosphorylation of IL-1 receptor-associated kinase 4 (IRAK4 T345/S346) and acetylation of IRAK4 (K34). However, after treatment with oridonin, the modification pattern of IRAK4 expression stimulated by LPS/D-Gal was suggestively attenuated.

Conclusion

Our study revealed that the protective effects of oridonin on LPS/D-Gal-induced ALI mediated by inhibition of the PTMs of IRAK4, including phosphorylation of T345/S346 and acetylation of K34.

Role of extracellular vesicles in diagnosis and treatment of liver fibrosis

Extracellular vesicles (EVs) mediate the intercellular communication of substances and are involved in the development of liver fibrosis. The vesicles secreted by hepatic stellate cells (HSCs) and hepatic parenchymal cells carry microRNAs to activate adjacent HSCs and up-regulate TGF-β signaling pathway. This results in increased expression of connective tissue growth factor, which eventually leads to the expression of α-smooth muscle actin and collagen, thereby mediating liver fibrosis. On the other hand, EVs secreted by healthy population and mesenchymal stem cells play a therapeutic role in liver fibrosis. This article reviews the structure, origin, and function of EVs as well as their role in the occurrence, development, diagnosis, and treatment of liver fibrosis.

Givinostat inhibition of hepatic stellate cell proliferation and protein acetylation

AIM: To explore the effect of the histone deacetylase inhibitor givinostat on proteins related to regulation of hepatic stellate cell proliferation.

METHODS: The cell counting kit-8 assay and flow cytometry were used to observe changes in proliferation, apoptosis, and cell cycle in hepatic stellate cells treated with givinostat. Western blot was used to observe expression changes in p21, p57, CDK4, CDK6, cyclinD1, caspase-3, and caspase-9 in hepatic stellate cells exposed to givinostat. The scratch assay was used to analyze the effect of givinostat on cell migration. Effects of givinostat on the reactive oxygen species profile, mitochondrial membrane potential, and mitochondrial permeability transition pore opening in JS-1 cells were observed by laser confocal microscopy.

RESULTS: Givinostat significantly inhibited JS-1 cell proliferation and promoted cell apoptosis, leading to cell cycle arrest in G0/G1 phases. Treatment with givinostat downregulated protein expression of CDK4, CDK6, and cyclin D1, whereas expression of p21 and p57 was significantly increased. The givinostat-induced apoptosis of hepatic stellate cells was mainly mediated through p38 and extracellular signal-regulated kinase 1/2. Givinostat treatment increased intracellular reactive oxygen species production, decreased mitochondrial membrane potential, and promoted mitochondrial permeability transition pore opening. Acetylation of superoxide dismutase (acetyl K68) and nuclear factor-κB p65 (acetyl K310) was upregulated, while there was no change in protein expression. Moreover, the notable beneficial effect of givinostat on liver fibrosis was also confirmed in the mouse models.

CONCLUSION: Givinostat has antifibrotic activities via regulating the acetylation of nuclear factor-κB and superoxide dismutase 2, thus inhibiting hepatic stellate cell proliferation and inducing apoptosis.

The involvement of NLRX1 and NLRP3 in the development of nonalcoholic steatohepatitis in mice

BACKGROUND

Increasing evidence suggests that innate immunity is involved in the development of nonalcoholic fatty liver disease. Nod-like receptors (NLRs) have recently been identified as key mediators of inflammatory and immune responses. The aim of this article is to explore the correlation of nucleotide-binding oligomerization domain (NOD)-like receptor (NLR)X1 and NLRP3 with nonalcoholic steatohepatitis (NASH) in mice.

METHODS

In our study, a high-fat diet, lipopolysaccharides (LPSs), and normal diet were given to C57BL mice to establish high fat (HF), HF + LPS, and control groups. Thereafter, serum alanine and aspartate aminotransferase (ALT and AST) levels were measured, and NASH severity was histologically examined. We measured tumor necrosis factor (TNF)-α levels by enzyme-linked immunosorbent assay, protein expression by Western blotting, and mRNA expression by real-time fluorescent quantitative reverse transcription-polymerase chain reaction.

RESULTS

Levels of ALT and AST were higher in HF + LPS mice than in HF mice (p < 0.05). NLRX1 mRNA and protein expression was lower in HF and HF + LPS mice than in control mice (p < 0.05). NLRP3 mRNA expression was higher in HF and HF + LPS mice than in control mice (p < 0.05). The mRNA and protein expression of TNF receptor-associated factor (TRAF)6, interleukin-1β, caspase-1, and apoptosis-associated speck-like protein were significantly higher in HF + LPS mice than in control and HF mice; furthermore, mRNA expression was higher in HF mice than in control mice (p < 0.05), but protein expression was similar.

CONCLUSION

NLRX1 and NLRP3 inflammasomes may be important in NASH development.

Mechanisms of trichostatin A inhibiting AGS proliferation and identification of lysine-acetylated proteins

AIM: To explore the effect of lysine acetylation in related proteins on regulation of the proliferation of gastric cancer cells, and determine the lysine-acetylated proteins and the acetylated modified sites in AGS gastric cancer cells.

METHODS: The CCK-8 experiment and flow cytometry were used to observe the changes in proliferation and cycle of AGS cells treated with trichostatin A (TSA). Real time polymerase chain reaction and Western blotting were used to observe expression changes in p21, p53, Bax, Bcl-2, CDK2, and CyclinD1 in gastric cancer cells exposed to TSA. Cytoplasmic proteins in gastric cancer cells before and after TSA treatment were immunoprecipitated with anti-acetylated lysine antibodies, separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis gel and silver-stained to detect the proteins by mass spectrometry after removal of the gel. The acetylated proteins in AGS cells were enriched with lysine-acetylated antibodies, and a high-resolution mass spectrometer was used to detect the acetylated proteins and modified sites.

RESULTS: TSA significantly inhibited AGS cell proliferation, and promoted cell apoptosis, leading to AGS cell cycle arrest in G0/G1 and G2/M phases, especially G0/G1 phase. p21, p53 and Bax gene expression levels in AGS cells were increased with TSA treatment duration; Bcl-2, CDK2, and CyclinD1 gene expression levels were decreased with TSA treatment duration. Two unknown protein bands, 72 kDa (before exposure to TSA) and 28 kDa (after exposure to TSA), were identified by silver-staining after immunoprecipitation of AGS cells with the lysine-acetylated monoclonal antibodies. Mass spectrometry showed that the 72 kDa protein band may be PKM2 and the 28 kDa protein band may be ATP5O. The acetylated proteins and modified sites in AGS cells were determined.

CONCLUSION: TSA can inhibit gastric cancer cell proliferation, which possibly activated signaling pathways in a variety of tumor-associated factors. ATP5O was obviously acetylated in AGS cells following TSA treatment.

IκB kinase-beta inhibitor attenuates hepatic fibrosis in mice

AIM: To investigate the anti-fibrosis effect of IκB kinase-beta inhibitor (IKK2 inhibitor IMD0354) in liver fibrosis.

METHODS: Twenty male C57BL6 mice were divided into four groups. Five high-fat fed mice were injected with lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally and five high-fat fed mice were without LPS injection to build models of liver injury, and the intervention group (five mice) was injected intraperitoneally with IKK2 inhibitor (IMD 30 mg/kg for 14 d), while the remaining five mice received a normal diet as controls. Hepatic function, pathological evaluation and liver interleukin-6 (IL-6) expression were examined. Western blotting and real-time polymerase chain reaction were used to detect the expressions of nuclear factor-κB (NF-κB), alpha-smooth muscle actin (α-SMA), tumor growth factor-beta1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), typeIand type III collagen proteins and mRNA.

RESULTS: A mouse model of liver injury was successfully established, and IMD decreased nuclear translocation of NF-κB p65 in liver cells. In the IMD-treated group, the levels of alanine aminotransferase (103 ± 9.77 μ/L vs 62.4 ± 7.90 μ/L, P < 0.05) and aminotransferase (295.8 ± 38.56 μ/L vs 212 ± 25.10 μ/L, P < 0.05) were significantly decreased when compared with the model groups. The histological changes were significantly ameliorated. After treatment, the expressions of IL-6 (681 ± 45.96 vs 77 ± 7.79, P < 0.05), TGF-β1 (Western blotting 5.65% ± 0.017% vs 2.73% ± 0.005%, P < 0.05), TNF-α (11.58% ± 0.0063% vs 8.86% ± 0.0050%, P < 0.05), typeIcollagen (4.49% ± 0.014% vs 1.90% ± 0.0006%, P < 0.05) and type III collagen (3.46% ± 0.008% vs 2.29% ± 0.0035%, P < 0.05) as well as α-SMA (6.19 ± 0.0036 μ/L vs 2.16 ± 0.0023 μ/L, P < 0.05) protein and mRNA were downregulated in the IMD group compared to the fibrosis control groups (P < 0.05).

CONCLUSION: IKK2 inhibitor IMD markedly improved non-alcoholic fatty liver disease in mice by lowering NF-κB activation, which could become a remedial target for liver fibrosis.

Signal transduction mechanism of TRB3 in rats with non-alcoholic fatty liver disease

AIM: To evaluate the possible role of Tribble 3 (TRB3) in a rat model of non-alcoholic fatty liver disease (NAFLD) and its signal transduction mechanism.

METHODS: Thirty Sprague-Dawley rats were randomized into three groups: normal control group, non-alcoholic fatty liver group A (fed on a high-fat diet for 8 wk) and group B (fed on a high-fat diet for 16 wk). To determine the degree of hepatic steatosis in rats of each group, livers were stained with hematoxylin and eosin, and evaluated; real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction was performed to measure the expression levels of TRB3 mRNA; and Western blotting analysis was done to determine the expression levels of protein kinase B (Akt) and phosphorylated protein kinase B (p-Akt-Thr308, p-Akt-Ser473).

RESULTS: Hepatic steatosis was evident in both NAFLD groups: mild to moderate hepatic steatosis occurred in group A, mainly as mild steatosis. Moderate to severe hepatic steatosis occurred in group B, mainly as severe steatosis. The expression level of TRB3 mRNA in group B was significantly higher than in the control group (122.28 ± 95.37 vs 3.06 ± 2.33, P = 0.001) and group A (122.28 ± 95.37 vs 5.77 ± 4.20, P = 0.001). There was no significant difference in the expression levels of Akt (1.03 ± 0.53 vs 1.12 ± 0.77, P = 0.729) and p-Akt-Thr308 (0.82 ± 0.45 vs 0.92 ± 0.38, P = 0.592) between group A and the control group. The expression level of Akt and p-Akt-Thr308 in group B was significantly lower than in group A (Akt 0.41 ± 0.16 vs 1.12 ± 0.77, P = 0.008; p-Akt-Thr308 0.47 ± 0.19 vs 0.82 ± 0.45, P = 0.036) and the control group (Akt 0.41 ± 0.16 vs 1.03 ± 0.53, P = 0.018; p-Akt-Thr308 0.47 ± 0.19 vs 0.92 ± 0.38, P = 0.010). The expression level of p-Akt-Ser473 in group A was significantly higher than in group B (1.48 ± 0.50 vs 0.81 ± 0.39, P = 0.041) as well as the control group (1.48 ± 0.50 vs 0.45 ± 0.26, P = 0.003).

CONCLUSION: TRB3 blocks insulin signaling by inhibiting Akt activation, which contributes to insulin resistance. It may be an important factor in the occurrence and development of NAFLD.