Zwitterionic Inhaler with Synergistic Therapeutics for Reprogramming of M2 Macrophage to Pro-Inflammatory Phenotype.

Myriad lung diseases are life threatening and macrophages play a key role in both physiological and pathological processes. Macrophages have each pro-/anti-inflammatory phenotype, and each lung disease can be aggravated by over-polarized macrophage. Therefore, development of a method capable of mediating the macrophage phenotype is one of the solutions for lung disease treatment. For mediating the phenotype of macrophages, the pulmonary delivery system (PDS) is widely used due to its advantages, such as high efficiency and accessibility of the lungs. However, it has a low drug delivery efficiency ironically because of the perfect lung defense system consisting of the mucus layer and airway macrophages. In this study, zwitterion-functionalized poly(lactide-co-glycolide) (PLGA) inhalable microparticles (ZwPG) are synthesized to increase the efficiency of the PDS. The thin layer of zwitterions formed on PLGA surface has high nebulizing stability and show high anti-mucus adhesion and evasion of macrophages. As a reprogramming agent for macrophages, ZwPG containing dexamethasone (Dex) and pirfenidone (Pir) are treated to over-polarized M2 macrophages. As a result, a synergistic effect of Dex/Pir induces reprogramming of M2 macrophage to pro-inflammatory phenotypes.

A miR-194/PTBP1/CCND3 axis regulates tumor growth in human hepatocellular carcinoma.

Polypyrimidine tract-binding protein 1 (PTBP1) is one of the most investigated multifunctional RNA-binding proteins (RBP), controlling almost all steps of mRNA metabolism and processing. It has been reported that PTBP1 is overexpressed in many different types of cancer and this high expression is associated with increased proliferation and poor prognoses. However, there are no reports on a putative role for PTBP1 in the molecular abnormalities and pathogenesis of hepatocellular carcinoma (HCC). Here, we identified PTBP1 as a positive regulator of human HCC growth. The expression of PTBP1 was increased in human HCC cells and tissues compared to the corresponding controls, and this high expression was positively correlated with increased tumor size and a reduced survival rate. Mechanistically, PTBP1 enhanced cyclin D3 (CCND3) translation by interacting with the 5'-untranslated region (5'-UTR) of CCND3 mRNA, consequently facilitating cell cycle progression and tumor growth. Furthermore, we found that miR-194 inhibits PTBP1 expression by binding to the 3'-UTR of PTBP1 mRNA, resulting in reduced CCND3 levels and HCC cell growth; moreover, the levels of PTBP1 were negatively correlated with miR-194 levels in HCC. Taken together, these findings identify PTBP1 as a pivotal enhancer of HCC growth; the miR-194/PTBP1/CCND3 axis seemingly has a crucial role in the development and progression of HCC and targeting the axis could be a novel therapeutic strategy against human HCC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Glucose Controls the Expression of Polypyrimidine Tract-Binding Protein 1 via the Insulin Receptor Signaling Pathway in Pancreatic ß Cells.

In pancreatic ß cells, glucose stimulates the biosynthesis of insulin at transcriptional and post-transcriptional levels. The RNA-binding protein, polypyrimidine tract-binding protein 1 (PTBP1), also named hnRNP I, acts as a critical mediator of insulin biosynthesis through binding to the pyrimidine-rich region in the 3'-untranslated region (UTR) of insulin mRNA. However, the underlying mechanism that regulates its expression in ß cells is unclear. Here, we report that glucose induces the expression of PTBP1 via the insulin receptor (IR) signaling pathway in ß cells. PTBP1 is present in ß cells of both mouse and monkey, where its levels are increased by glucose and insulin, but not by insulin-like growth factor 1. PTBP1 levels in immortalized ß cells established from wild-type (ßIRWT) mice are higher than levels in ß cells established from IR-null (ßIRKO) mice, and ectopic re-expression of IR-WT in ßIRKO cells restored PTBP1 levels. However, PTBP1 levels were not altered in ßIRKO cells transfected with IR-3YA, in which the Tyr1158/1162/1163 residues are substituted with Ala. Consistently, treatment with glucose or insulin elevated PTBP1 levels in ßIRWT cells, but not in ßIRKO cells. In addition, silencing Akt significantly lowered PTBP1 levels. Thus, our results identify insulin as a pivotal mediator of glucose-induced PTBP1 expression in pancreatic ß cells.

Reduced expression of the RNA-binding protein HuD in pancreatic neuroendocrine tumors correlates with low p27Kip1 levels and poor prognosis.

For the majority of patients diagnosed with pancreatic neuroendocrine tumors (NETs), there is significant malignant potential with a poor prognosis; however, the molecular abnormalities and pathogenesis of pancreatic NETs have not been firmly established. Here, we report that loss of expression of the RNA-binding protein HuD correlates with low p27Kip1 (p27) levels and poor prognosis in pancreatic NETs. HuD expression was frequently lost in many human pancreatic NETs, and these pancreatic NETs showed aggressive clinicopathological phenotypes with low p27 levels, increased tumor size, higher World Health Organization grade and pT stage of the tumor, and the presence of angioinvasion. Furthermore, loss of HuD was an independent, progression-free prognostic factor in multivariate survival analysis. However, the level of HuR, a member of the same Hu protein family as HuD, was not significantly correlated with pancreatic NET size and progression. Mechanistically, HuD enhanced p27 mRNA translation by interacting with both the 5'-untranslated region (UTR) and the 3'-UTR of p27 mRNA, and consequently suppressed cell cycle progression and tumor growth. In addition, HuD competed with miR-30a-3p for binding to the 3'-UTR of p27 mRNA, suggesting an interplay between HuD and miR-30a-3p in controlling p27 translation. Our results identify HuD as a pivotal suppressor of pancreatic NET growth, and suggest that HuD has potential value as a prognostic factor of pancreatic NETs. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Self-assembled hyaluronic acid nanoparticles: Implications as a nanomedicine for treatment of type 2 diabetes.

Self-assembled hyaluronic acid nanoparticles (HA-NPs) have been extensively investigated for biomedical and pharmaceutical applications owing to their biocompatibility and receptor-binding properties. Here, we report that an empty HA-NP itself not bearing any drug has therapeutic effects on adipose tissue inflammation and insulin resistance. HA-NPs inhibited not only the receptor-mediated internalization of low-molecular-weight (LMW) free HA but also LMW free HA-induced pro-inflammatory gene expression in mouse primary bone marrow-derived macrophages (BMDMs) isolated from wild-type mice, but not in CD44-null (CD44-/-) BMDMs. An in vivo biodistribution study showed the distribution of HA-NPs and their co-localization with CD44 in adipose tissues including epididymal white adipose tissues (eWATs), but these were rarely observed in the eWATs of CD44-/- mice. In addition, CD44 expression and HA-NP accumulation in the eWATs were increased in mice with diet-induced obesity (DIO) compared to lean mice. Interestingly, treatment with HA-NPs in DIO mice suppressed adipose tissue inflammation as indicated by reduced macrophage content, the production of proinflammatory cytokines and NLRP3 inflammasome activity in eWATs, leading to improved insulin sensitivity and normalized blood glucose levels. Collectively, these results suggest that an empty HA-NP itself can be a therapeutic agent for the treatment of type 2 diabetes.