CircularRNA as novel biomarkers in liver diseases.

The liver is an essential organ that is primarily responsible for digestion and eliminating toxic substances from the body. After the industrial revolution, Western diet and lifestyle changes have increased the incidence of several liver diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma (HCC). NAFLD and NASH are mostly asymptomatic at early stages, and the disease progression from NAFLD to life-threatening HCC remains not fully understood. Circular RNA (circRNA) is consist of a circular structure, and the circRNA-microRNA(miRNA)-mRNA axes have been shown to be involved in several cellular events, including apoptosis, vascularization, metastasis, etc. The highly stable structure of circRNAs has enabled themselves to be used as putative biomarkers of several diseases. Here, we conducted a literature review and discussed the identified roles of circRNAs in NAFLD, NASH, liver cirrhosis, and HCC. For example, deficiency of circRNA_0046366 and circRNA_0046367 has been shown as the characteristics of NAFLD, and restoration of these circRNAs ameliorates the oxidative stress, lipotoxicity, and disease severity in NAFLD. Silencing of circ_0071410 was shown to alleviate hepatic stellate activation, the key step of liver cirrhosis. CDR1 and circ_0067934 can facilitate the invasion and metastasis of HCC, while circMTO1 negatively regulates the progression of HCC. Although several research works have been conducted, the whole picture of circRNA-related underlying mechanisms is unclear. Future works using high-throughput bioinformatic approaches will be needed to delineate the role of circRNAs in liver diseases and to further develop novel diagnostics and therapeutics.

Nanoparticle-delivery system enhanced the improvement and recovery in toxicity-induced acute hepatic failure.

BACKGROUND: The major curative remedy for advanced liver failure is hepatic transplantation. However, the conventional medicine still shows the limitations and obstacles for liver regeneration. Importantly, it is unclear whether we can get a rapid and high efficacy platform to facilitate to reprogram hepatic capability. The main work of this study was to develop a platform for a nanomedicine-based gene-delivery platform of novel nanoparticles (NNPs) to efficiently facilitate the liver function recovery. METHODS: In this study, we studied the feasibility and efficiency of NNP and produced the multiple abilities of NNPs for a potential platform of gene transduction. We showed that NNPs played an important role in hepatic protection. The cytoprotective effects of NNPs in toxic-hepatic cells were investigated and evaluated by cell viability, reactive oxygen species production, in vitro cell abilities, and in vivo animal studies. RESULTS: We demonstrated that NNPs possess the abilities to protect the cell after toxic-stress both in vitro and in vivo. Under the stress condition, our result showed that cell viabilities can be improved by NNP-carried hepatocyte nuclear factor 3 (HNF3) gene (NNP-HNF3), which is a famous hepatic transcriptional factor and regenerative marker to modulate essential molecular pathways activating various hepatic-specific markers. Importantly, compared to control and NNP-control, NNP-HNF3 exhibited the cytoprotective effects that prevented toxic-induced oxidative stress and cell damage in vitro as well as in vivo. Notably, our data showed that NNP-HNF3 treatment may improve toxic-induced hepatic encephalopathy. CONCLUSION: Herein, we demonstrated that novel nanoparticle, such as NNP-HNF3, serves as a key regulator for protecting the damaged hepatic cell and the bioproduct-based source for the new therapeutics of hepatic failure.

The subpopulation of CD44-positive cells promoted tumorigenicity and metastatic ability in lung adenocarcinoma.

BACKGROUND: Lung cancer is one of the major causes of carcinoma-related deaths in the world. Importantly, lung adenocarcinoma (LAC) is the most common type with poor outcome. However, the progressive clinical phenotype and biomolecular signature of lung cancer presenting the cancer stem-like and metastatic characteristics are still unclear. METHODS: In this study, we identified CD44 marker in lung cancers. The capabilities, including tumorigenic and migration assays, were analyzed in CD44 expression and CD44 expression subgroups. Meanwhile, the potential bio-signature and properties of lung tumor stem-like cells were further studied. RESULTS: The high expression of CD44 subpopulation (CD44-positive) in isolated lung cancer cells showed significantly higher abilities of tumorigenic colonies, tumor-sphere formation, and migratory properties when compared with the CD44 expression group. These subgroups of CD44-positive lung cancer cells further demonstrated the metastatic potential with epithelial-mesenchymal transition (EMT), as well as the high expression of Twist and Snail gene profile. Importantly, the overexpression of Snail with gene vector in CD44 expression cells further significantly promoted the properties of lung tumor stem-like cells. CONCLUSION: The results of this study highlighted the role of CD44-posivite subpopulation in modulating tumor initiation and EMT-based metastatic ability of lung malignancy.

Generation of high quality of hepatocyte-like cells from induced pluripotent stem cells with Parp1 but lacking c-Myc.

BACKGROUND: Induced pluripotent stem cells (iPSCs) have a great potential for application in patient-specific therapy. The reprogramming method that does not involve c-Myc reduces tumorigenic risk, but also largely reduces the efficiency of generation of iPSCs, especially for those reprogrammed from damaged cells. Poly(ADP-ribose) polymerase 1 (Parp1) catalyzes a reaction of poly(ADP-ribosylation) and has been reported to enhance cell reprogramming. METHODS: Using Oct-4/Sox2/Klf4/Parp1 (OSKP) reprogramming method, reprogramming factors plus Parp1 were capable of generation of iPSCs from adult fibroblasts and further toward to differentiate from iPSCs status into hepatocyte-like cells. RESULTS: Our results showed that Oct-4/Sox2/Klf4/Parp1 (OSKP)-derived iPSC exhibited regular pluripotent properties, long-term passages and more stable cellular-divided period. These OSKP-derived iPSCs can effectively differentiate into hepatocyte-like cells (OSKP-iPSC-Heps), and present high mRNA levels of Sox17, HNF3b, and HNF4a in OSKP-iPSC-Heps. The mature hepatic functions, including CYP3A4, LDL uptake, glycogen synthesis and urea secretion were analyzed and well detected in OSKP-iPSC-Heps on day 14 post-differentiation. CONCLUSION: In conclusion, we demonstrated that Parp1 promoted reprogramming process to generate the high quality of iPSCs, which could be used as a high quality source of hepatocytes.

Sox2, a stemness gene, regulates tumor-initiating and drug-resistant properties in CD133-positive glioblastoma stem cells.

BACKGROUND: Glioblastoma multiforme (GBM) is the most lethal type of adult brain cancer and performs outrageous growth and resistance regardless of adjuvant chemotherapies, eventually contributing to tumor recurrence and poor outcomes. Considering the common heterogeneity of cancer cells, the imbalanced regulatory mechanism could be switched on/off and contribute to drug resistance. Moreover, the subpopulation of GBM cells was recently discovered to share similar phenotypes with neural stem cells. These cancer stem cells (CSCs) promote the potency of tumor initiation. As a result, targeting of glioma stem cells has become the dominant way of improving the therapeutic outcome against GBM and extending the life span of patients. Among the biomarkers of CSCs, CD-133 (prominin-1) has been known to effectively isolate CSCs from cancer population, including GBM; however, the underlying mechanism of how stemness genes manipulate CSC-associated phenotypes, such as tumor initiation and relapse, is still unclear. METHODS: Tumorigenicity, drug resistance and embryonic stem cell markers were examined in primary CD133-positive (CD133(+)) GBM cells and CD133(+) subpopulation. Stemness signature of CD133(+) GBM cells was identified using microarray analysis. Stem cell potency, tumorigenicity and drug resistance were also tested in differential expression of SOX2 in GBM cells. RESULTS: In this study, high tumorigenic and drug resistance was noticed in primary CD-133(+) GBM cells; meanwhile, plenty of embryonic stem cell markers were also elevated in the CD-133+ subpopulation. Using microarray analysis, we identified SOX2 as the most enriched gene among the stemness signature in CD133(+) GBM cells. Overexpression of SOX2 consistently enhanced the stem cell potency in the GBM cell lines, whereas knockdown of SOX2 dramatically withdrew CD133 expression in CD133(+) GBM cells. Additionally, we silenced SOX2 expression using RNAi system, which abrogated the ability of tumor initiation as well as drug resistance of CD133(+) GBM cells, suggesting that SOX2 plays a crucial role in regulating tumorigenicity in CD133(+) GBM cells. CONCLUSION: SOX2 plays a crucial role in regulating tumorigenicity in CD133(+) GBM cells. Our results not only revealed the genetic plasticity contributing to drug resistance and stemness but also demonstrated the dominant role of SOX2 in maintenance of GBM CSCs, which may provide a novel therapeutic target to overcome the conundrum of poor survival of brain cancers.

Enhanced antioxidant capacity of dental pulp-derived iPSC-differentiated hepatocytes and liver regeneration by injectable HGF-releasing hydrogel in fulminant hepatic failure.

Acute hepatic failure (AHF) is a severe liver injury leading to sustained damage and complications. Induced pluripotent stem cells (iPSCs) may be an alternative option for the treatment of AHF. In this study, we reprogrammed human dental pulp-derived fibroblasts into iPSCs, which exhibited pluripotency and the capacity to differentiate into tridermal lineages, including hepatocyte-like cells (iPSC-Heps). These iPSC-Heps resembled human embryonic stem cell-derived hepatocyte-like cells in gene signature and hepatic markers/functions. To improve iPSC-Heps engraftment, we next developed an injectable carboxymethyl-hexanoyl chitosan hydrogel (CHC) with sustained hepatocyte growth factor (HGF) release (HGF-CHC) and investigated the hepatoprotective activity of HGF-CHC-delivered iPSC-Heps in vitro and in an immunocompromised AHF mouse model induced by thioacetamide (TAA). Intrahepatic delivery of HGF-CHC-iPSC-Heps reduced the TAA-induced hepatic necrotic area and rescued liver function and recipient viability. Compared with PBS-delivered iPSC-Heps, the HGF-CHC-delivered iPSC-Heps exhibited higher antioxidant and antiapoptotic activities that reduced hepatic necrotic area. Importantly, these HGF-CHC-mediated responses could be abolished by administering anti-HGF neutralizing antibodies. In conclusion, our findings demonstrated that HGF mediated the enhancement of iPSC-Hep antioxidant/antiapoptotic capacities and hepatoprotection and that HGF-CHC is as an excellent vehicle for iPSC-Hep engraftment in iPSC-based therapy against AHF.

Synergistic effects of carboxymethyl-hexanoyl chitosan, cationic polyurethane-short branch PEI in miR122 gene delivery: accelerated differentiation of iPSCs into mature hepatocyte-like cells and improved stem cell therapy in a hepatic failure model.

MicroRNA122 (miR122), a liver-specific microRNA, plays critical roles in homeostatic regulation and hepatic-specific differentiation. Induced pluripotent stem cells (iPSCs) have promising potential in regenerative medicine, but it remains unknown whether non-viral vector-mediated miR122 delivery can enhance the differentiation of iPSCs into hepatocyte-like cells (iPSC-Heps) and rescue thioacetamide-induced acute hepatic failure (AHF) in vivo. In this study, we demonstrated that embedment of miR122 complexed with polyurethane-graft-short-branch polyethylenimine copolymer (PU-PEI) in nanostructured amphiphatic carboxymethyl-hexanoyl chitosan (CHC) led to dramatically enhanced miR122 delivery into human dental pulp-derived iPSCs (DP-iPSCs) and facilitated these DP-iPSCs to differentiate into iPSC-Heps (miR122-iPSC-Heps) with mature hepatocyte functions. Microarray and bioinformatics analysis further indicated that CHC/PU-PEI-miR122 promoted the gene-signature pattern of DP-iPSCs to shift into a liver-specific pattern. Furthermore, intrahepatic delivery of miR122-iPSC-Heps, but not miR-Scr-iPSC-Heps, improved liver functions and rescued recipient survival, and CHC-mediated delivery showed a better efficacy than that using phosphate buffered saline as a delivery vehicle. In addition, these transplanted miR122-iPSC-Heps remained viable and could produce circulatory albumin for 4 months. Taken together, our findings demonstrate that non-viral delivery of miR122 shortens the time of iPSC differentiation into hepatocytes and the delivery of miR122-iPSC-Heps using CHC as a vehicle exhibited promising hepatoprotective efficacy in vivo. miR122-iPSC-Heps may represent a feasible cell source and provide an efficient and alternative strategy for hepatic regeneration in AHF.

Helicobacter pylori infection in patients with ulcer recurrence after partial gastrectomy.

BACKGROUND/AIMS: Recurrent ulceration of the stomach occurs in some patients after surgery for peptic ulcer disease. The aim of this study is to evaluate the association of Helicobacter pylori infection with ulcer recurrence in patients after partial gastrectomy due to peptic ulcer disease. METHODOLOGY: A total of 186 patients after partial gastrectomy with Billroth I or Billroth II anastomosis presenting with dyspepsia or bleeding were included. An ulcer recurrence was documented by endoscopic examination. Biopsy specimens were taken from the remnant gastric bodies in all patients. H. pylori infection was diagnosed by either a positive biopsy urease test or the presence of the microorganism on histology. RESULTS: Eighty-three (44.6%) patients among the 186 patients had recurrent ulcers. H. pylori infection was found in 29 (36%) patients in the ulcer group and 42 (41%) patients in the non-ulcer group. The incidence of H. pylori infection did not differ significantly between the two groups (P>0.05). CONCLUSIONS: H. pylori infection may not play an important role in the pathogenesis of recurrent ulcer after partial gastrectomy. Other factors should be studied further.