Zhi Ding

Immobilization of chitosan onto poly-L-lactic acid film surface by plasma graft polymerization to control the morphology of fibroblast and liver cells.

Surface functionalization of biodegradable poly-L-lactic acid (PLLA) was achieved by plasma coupling reaction of chitosan. The structure of modified PLLA surfaces was characterized by contact angle measurements and X-ray photoelectron spectroscopy. Two cell lines, L929 (mouse fibroblasts) and L02 (human hepatocytes), were cultured on the modified PLLA surface. It was found that cells cultured on this film could hardly spread and tend to become round, and the film was demonstrated to be a poorly adhering substrate. However, cells grown on this substrate can proliferate at almost the same speed as cultured on a glass surface. These results suggest that the new substrate can be used to control the morphology of cells, and has potential applications in tissue engineering. It may be helpful in understanding the mechanism of the switch between cell phases of growth and differentiation, which is necessary for the design of tissue regeneration biomaterials.

Lower irisin level in patients with type 2 diabetes mellitus: A case‐control study and meta‐analysis

Irisin is a newly identified myokine in mice and humans. Many studies have reported irisin concentrations in patients with type 2 diabetes mellitus (T2DM). The large variations in irisin concentrations in different studies may be attributable to differences in sample size or populations. The aim of the present study was to establish an accurate confidence interval of irisin levels in T2DM patients using a case‐control study and large‐scale meta‐analysis.

An orally administrated nucleotide-delivery vehicle targeting colonic macrophages for the treatment of inflammatory bowel disease.

Tumor necrosis factor-alpha (TNF-α) plays a central role in the pathogenesis of inflammatory bowel disease (IBD). Anti-TNF-α therapies have shown protective effects against colitis, but an efficient tool for target suppression of its secretion - ideally via oral administration - remains in urgent demand. In the colon tissue, TNF-α is mainly secreted by the colonic macrophages. Here, we report an orally-administrated microspheric vehicle that can target the colonic macrophages and suppress the local expression of TNF-α for IBD treatment. This vehicle is formed by cationic konjac glucomannan (cKGM), phytagel and an antisense oligonucleotide against TNF-α. It was given to dextran sodium sulfate (DSS) colitic mice via gastric perfusion. The unique swelling properties of cKGM enabled the spontaneous release of cKGM& antisense nucleotide (ASO) nano-complex from the phytagel scaffold into the colon lumen, where the ASO was transferred into colonic macrophages via receptor-mediated phagocytosis. The treatment significantly decreased the local level of TNF-α and alleviated the symptoms of colitis in the mice. In summary, our study demonstrates a convenient, orally-administrated drug delivery system that effectively targets colonic macrophages for suppression of TNF-α expression. It may represent a promising therapeutic approach in the treatment of IBD.

DNA/chitosan nanocomplex as a novel drug carrier for doxorubicin

The present study was to investigate the potentials of DNA/chitosan nanocomplexes as a carrier for small drug delivery. Two highly water-soluble chitosans (87 kDa and 18 kDa) were prepared and labeled with fluorescein isothiocyanate (FITC). DNA/chitosan nanocomplexes were prepared by mixing salmon testes DNA and the FITC labeled chitosan (FITC-chitosan) and their biophysical properties and biodistribution in vivo were then investigated. The molecular weight of chitosan and the ratio of the positive amino group of chitosan to the negative phosphate group of DNA (N/P ratio) influenced the physical properties of the nanocomplexes. The fluorescence intensity of both types of the free FITC-chitosan decreased rapidly within 4 hr post-injection. In contrast, the DNA/chitosan nanocomplexes were accumulated in the liver and kidneys and remained at a relatively high stable level in these tissues and in blood up to 24 hr post-injection. This study also assessed the stability of the anti-cancer drug doxorubicin (DOX) when it was conjugated to chitosan to form a chitosan-doxorubicin conjugate (chi-DOX), which was then mixed with DNA to form a DNA/chitosan-doxorubicin nanocomplex (DNA/chi-DOX). Both the chi-DOX and DNA/chi-DOX complexes exerted cytotoxic effects on HeLa, HepG2, QGY-7703, and L02 cells, while the non-malignant L02 cells were less sensitive to the DNA-containing complex than to the chi-DOX complex, suggesting possible selectivity. Studies in tumor-bearing animals demonstrated that DNA/chi-DOX could efficiently deliver doxorubicin to the tumor and liver, implying that the DNA/chitosan nanocomplex may represent a novel drug carrier.

Targeted delivery of let-7b to reprogramme tumor-associated macrophages and tumor infiltrating dendritic cells for tumor rejection.

Both tumor associated macrophages (TAMs) and tumor infiltrating dendritic cells (TIDCs) are important components in the tumor microenvironment that mediate tumor immunosuppression and promote cancer progression. Targeting these cells and altering their phenotypes may become a new strategy to recover their anti-tumor activities and thereby restore the local immune surveillance against tumor. In this study, we constructed a nucleic acid delivery system for the delivery of let-7b, a synthetic microRNA mimic. Our carrier has an affinity for the mannose receptors on TAMs/TIDCs and is responsive to the low-pH tumor microenvironment. The delivery of let-7b could reactivate TAMs/TIDCs by acting as a TLR-7 agonist and suppressing IL-10 production in vitro. In a breast cancer mouse model, let-7b delivered by this system efficiently reprogrammed the functions of TAMs/TIDCs, reversed the suppressive tumor microenvironment, and inhibited tumor growth. Taken together, this strategy, designed based upon TAMs/TIDCs-targeting delivery and the dual biological functions of let-7b (TLR-7 ligand and IL-10 inhibitor), may provide a new approach for cancer immunotherapy.

MicroRNA‐30b Suppresses Epithelial‐Mesenchymal Transition and Metastasis of Hepatoma Cells

Epithelial–mesenchymal transition (EMT) is critical for induction of invasiveness and metastasis in HCC. Growing evidence indicates that upregulation of Snail, the major EMT inducer, significantly correlates with the metastasis and poor prognosis of HCC. Here, we investigate the underlying mechanism of miR‐30b in suppressing metastasis of hepatoma cells by targeting Snail. In this study, we found that miR‐30b was significantly downregulated and negatively associated with Snail production in HCC cell lines with higher metastatic potentials. Gain‐ and loss‐of‐function studies revealed that miR‐30b could dramatically inhibit in vitro HCC cell migration and invasion. In vivo orthotopic liver xenograft model further demonstrated that stable over‐expression of miR‐30b significantly repressed the local invasion and lung metastasis of hepatoma cells. Meanwhile, the restoration of miR‐30b expression suppressed the distant colonization of hepatoma cells. Both gain‐ and loss‐of‐function studies showed that miR‐30b suppressed the EMT of hepatoma cells as indicated by the morphology changes and deregulation of epithelial and mesenchymal markers. Using RNAi, we further investigated the role of Snail in HCC cell EMT and demonstrated that knockdown of Snail significantly inhibited the EMT and cancer cell metastasis. Additionally, miR‐30b exhibited inhibitory effects on HCC cell proliferation in vitro and in vivo. In conclusion, our findings highlight the significance of miR‐30b downregulation in HCC tumor metastasis and invasiveness, and implicate a new potential therapeutic target for HCC metastasis. J. Cell. Physiol. 232: 625–634, 2017.

TGF-β-induced hepatocyte lincRNA-p21 contributes to liver fibrosis in mice

Hepatocyte death, as well as the following inflammatory and fibrogenic signaling cascades, is the key trigger of liver fibrosis. Here, we isolated hepatocytes from CCl4-induced fibrotic liver and found that hepatocyte lincRNA-p21 significantly increased during liver fibrosis. The increase of hepatocyte lincRNA-p21 was associated with the loss of miR-30, which can inhibit TGF-β signaling by targeting KLF11. We revealed that lincRNA-p21 modulated miR-30 availability by acting as a competing endogenous RNA (ceRNA). The physiological significance of this interaction is highlighted by the feedback loop, in which lincRNA-p21 works as a downstream effector of the TGF-β signaling to strengthen TGF-β signaling and mediate its role in promoting liver fibrosis by interacting with miR-30. In vivo results showed that knockdown of hepatocyte lincRNA-p21 greatly reduced CCl4-induced liver fibrosis and inflammation, whereas ectopic expression of miR-30 in hepatocyte exhibited the similar results. Mechanistic studies further revealed that inhibition of miR-30 impaired the effects of lincRNA-p21 on liver fibrosis. Additionally, lincRNA-p21 promoted hepatocyte apoptosis in vitro and in vivo, whereas the proliferation rate of hepatocyte was suppressed by lincRNA-p21. The pleiotropic roles of hepatocyte lincRNA-p21 suggest that it may represent an unknown paradigm in liver fibrosis and serve as a potential target for therapy.

Gua Sha, a press-stroke treatment of the skin, boosts the immune response to intradermal vaccination

Objective The skin is an important immunological barrier of the body as well as an optimal route for vaccine administration. Gua Sha, which involves press-stroke treatment of the skin, is an effective folk therapy, widely accepted in East Asia, for various symptoms; however, the mechanisms underlying its therapeutic effects have not been clarified. We investigated the influence of Gua Sha on the immunological features of the skin. Methods Gua Sha was performed on BALB/c mice and the effects were evaluated using anatomical, histological, and cytometric methods as well as cytokine determination locally and systemically. The effect on intradermal vaccination was assessed with antigen-specific subtype antibody responses. Results Blood vessel expansion, erythrocyte extravasation, and increased ratios of immune active cells were observed in the skin tissue following the treatment. Pro-inflammatory cytokines were up-regulated, and immunosuppressive cytokines, down-regulated, in the treated and untreated skin and systemic circulation; no obvious variations were detected in case of anti-inflammatory cytokines. Interestingly, intradermal delivery of a model vaccine following Gua Sha induced about three-fold higher IgG titers with a more Th1-biased antibody subtype profile. Conclusion Gua Sha treatment can up-regulate the innate and adaptive immune functions of the skin and boost the response against intradermal antigens. Thus, Gua Sha may serve as a safe, inexpensive, and independent physical adjuvant for intradermal vaccination.

TGF-β-mediated upregulation of Sox9 in fibroblast promotes renal fibrosis

TGF-β signaling plays a principal role in renal fibrosis, but the precise mechanisms and the downstream factors are still largely unknown. Sox9 exhibits diverse roles in regulating the production of extracellular matrix proteins. Here we found that Sox9 was induced by TGF-β in the kidney fibroblast and acted as an important downstream mediator of TGF-β signaling in promoting renal fibrosis. TGF-β/Smad signaling mediated the upregulation of Sox9 in kidney fibroblast by binding to a conserved enhancer. In different mouse models of renal fibrosis, as well as in the kidney biopsy tissue from patients with renal fibrosis, Sox9 expression significantly increased. Immunostaining confirmed the upregulation of Sox9 in the kidney fibroblast during renal fibrosis. Delivery of Sox9 knockdown plasmid to the kidney by ultrasound microbubble-mediated gene transfer suppressed the unilateral ureteral obstruction (UUO) or folic acid-induced mouse renal fibrosis, whereas ectopic expression of Sox9 aggravated renal fibrosis. In addition, we identified Sox9 as a direct target of miR-30. Notably, miR-30 expression was significantly inhibited by TGF-β1 in the kidney fibroblast and the downregulation of miR-30 was observed in renal fibrosis. Mechanistically, inhibition of miR-30 independently strengthened the effect of TGF-β/Smad signaling on Sox9 upregulation. Adenovirus-mediated ectopic expression of miR-30 in kidney fibroblast greatly reduced UUO-induced renal fibrosis by targeting Sox9. These findings link Sox9 to intrinsic mechanisms of TGF-β signaling in renal fibrosis and may have therapeutic potential for tissue fibrosis.