Activated Natural Killer Cell Inoculation Alleviates Fibrotic Liver Pathology in a Carbon Tetrachloride-Induced Liver Cirrhosis Mouse Model.

Activated hepatic stellate cells (HSCs) play a detrimental role in liver fibrosis progression. Natural killer (NK) cells are known to selectively recognize abnormal or transformed cells via their receptor activation and induce target cell apoptosis and, therefore, can be used as a potential therapeutic strategy for liver cirrhosis. In this study, we examined the therapeutic effects of NK cells in the carbon tetrachloride (CCl4)-induced liver cirrhosis mouse model. NK cells were isolated from the mouse spleen and expanded in the cytokine-stimulated culture medium. Natural killer group 2, member D (NKG2D)-positive NK cells were significantly increased after a week of expansion in culture. The intravenous injection of NK cells significantly alleviated liver cirrhosis by reducing collagen deposition, HSC marker activation, and macrophage infiltration. For in vivo imaging, NK cells were isolated from codon-optimized luciferase-expressing transgenic mice. Luciferase-expressing NK cells were expanded, activated and administrated to the mouse model to track them. Bioluminescence images showed increased accumulation of the intravenously inoculated NK cells in the cirrhotic liver of the recipient mouse. In addition, we conducted QuantSeq 3' mRNA sequencing-based transcriptomic analysis. From the transcriptomic analysis, 33 downregulated genes in the extracellular matrix (ECM) and 41 downregulated genes involved in the inflammatory response were observed in the NK cell-treated cirrhotic liver tissues from the 1532 differentially expressed genes (DEGs). This result indicated that the repetitive administration of NK cells alleviated the pathology of liver fibrosis in the CCl4-induced liver cirrhosis mouse model via anti-fibrotic and anti-inflammatory mechanisms. Taken together, our research demonstrated that NK cells could have therapeutic effects in a CCl4-induced liver cirrhosis mouse model. In particular, it was elucidated that extracellular matrix genes and inflammatory response genes, which were mainly affected after NK cell treatment, could be potential targets.

iPSCs in NK Cell Manufacturing and NKEV Development.

Natural killer (NK) cell immunotherapies for cancer can complement existing T cell therapies while benefiting from advancements already made in the immunotherapy field. For NK cell manufacturing, induced pluripotent stem cells (iPSCs) offer advantages including eliminating donor variation and providing an ideal platform for genome engineering. At the same time, extracellular vesicles (EVs) have become a major research interest, and purified NK cell extracellular vesicles (NKEVs) have been shown to reproduce the key functions of their parent NK cells. NKEVs have the potential to be developed into a standalone therapeutic with reduced complexity and immunogenicity compared to cell therapies. This review explores the role iPSC technology can play in both NK cell manufacturing and NKEV development.

iPSC-Derived Natural Killer Cells for Cancer Immunotherapy.

The discovery of human pluripotent stem cells (PSCs) at the turn of the century opened the door to a new generation of regenerative medicine research. Among PSCs, the donors available for induced pluripotent stem cells (iPSCs) are greatest, providing a potentially universal cell source for all types of cell therapies including cancer immunotherapies using natural killer (NK cells). Unlike primary NK cells, those prepared from iPSCs can be prepared with a homogeneous quality and are easily modified to exert a desired response to tumor cells. There already exist several protocols to genetically modify and differentiate iPSCs into NK cells, and each has its own advantages with regards to immunotherapies. In this short review, we detail the benefits of using iPSCs in NK cell immunotherapies and discuss the challenges that must be overcome before this approach becomes mainstream in the clinic.

Effect of Multiple Reflows on the Interfacial Reactions and Mechanical Properties of an Sn-0.5Cu-Al(Si) Solder and a Cu Substrate.

In this study, the interfacial reactions and mechanical properties of solder joints after multiple reflows were observed to evaluate the applicability of the developed materials for high-temperature soldering for automotive electronic components. The microstructural changes and mechanical properties of Sn-Cu solders regarding Al(Si) addition and the number of reflows were investigated to determine their reliability under high heat and strong vibrations. Using differential scanning calorimetry, the melting points were measured to be approximately 227, 230, and 231 °C for the SC07 solder, SC-0.01Al(Si), and SC-0.03Al(Si), respectively. The cross-sectional analysis results showed that the total intermetallic compounds (IMCs) of the SC-0.03Al(Si) solder grew the least after the as-reflow, as well as after 10 reflows. Electron probe microanalysis and transmission electron microscopy revealed that the Al-Cu and Cu-Al-Sn IMCs were present inside the solders, and their amounts increased with increasing Al(Si) content. In addition, the Cu6Sn5 IMCs inside the solder became more finely distributed with increasing Al(Si) content. The Sn-0.5Cu-0.03Al(Si) solder exhibited the highest shear strength at the beginning and after 10 reflows, and ductile fracturing was observed in all three solders. This study will facilitate the future application of lead-free solders, such as an Sn-Cu-Al(Si) solder, in automotive electrical components.

OVOL1 Influences the Determination and Expansion of iPSC Reprogramming Intermediates.

During somatic cell reprogramming to induced pluripotent stem cells (iPSCs), fibroblasts undergo dynamic molecular changes, including a mesenchymal-to-epithelial transition (MET) and gain of pluripotency; processes that are influenced by Yamanaka factor stoichiometry. For example, in early reprogramming, high KLF4 levels are correlated with the induction of functionally undefined, transiently expressed MET genes. Here, we identified the cell-surface protein TROP2 as a marker for cells with transient MET induction in the high-KLF4 condition. We observed the emergence of cells expressing the pluripotency marker SSEA-1+ mainly from within the TROP2+ fraction. Using TROP2 as a marker in CRISPR/Cas9-mediated candidate screening of MET genes, we identified the transcription factor OVOL1 as a potential regulator of an alternative epithelial cell fate characterized by the expression of non-iPSC MET genes and low cell proliferation. Our study sheds light on how reprogramming factor stoichiometry alters the spectrum of intermediate cell fates, ultimately influencing reprogramming outcomes.

Microhomology-assisted scarless genome editing in human iPSCs.

Gene-edited induced pluripotent stem cells (iPSCs) provide relevant isogenic human disease models in patient-specific or healthy genetic backgrounds. Towards this end, gene targeting using antibiotic selection along with engineered point mutations remains a reliable method to enrich edited cells. Nevertheless, integrated selection markers obstruct scarless transgene-free gene editing. Here, we present a method for scarless selection marker excision using engineered microhomology-mediated end joining (MMEJ). By overlapping the homology arms of standard donor vectors, short tandem microhomologies are generated flanking the selection marker. Unique CRISPR-Cas9 protospacer sequences nested between the selection marker and engineered microhomologies are cleaved after gene targeting, engaging MMEJ and scarless excision. Moreover, when point mutations are positioned unilaterally within engineered microhomologies, both mutant and normal isogenic clones are derived simultaneously. The utility and fidelity of our method is demonstrated in human iPSCs by editing the X-linked HPRT1 locus and biallelic modification of the autosomal APRT locus, eliciting disease-relevant metabolic phenotypes.

Vascular enhancement pattern of mass in computed tomography may predict chemo-responsiveness in advanced pancreatic cancer.

INTRODUCTION: Chemo-responsiveness in pancreatic cancer is known to be dependent on fibrosis and vascularity. The purpose of this study was to assess vascular enhancement in advanced pancreatic adenocarcinoma with or without liver metastasis in computed tomography (CT) and to analyze the correlation between enhancement patterns and chemo-responsiveness. METHODS: Patients were assigned to either a responder group (partial response or stable disease) or a non-responder group (progressive disease) according to chemo-responsiveness assessed by CT before and after gemcitabine-based chemotherapy. Hounsefield unit (HU) was measured in pancreatic mass and the largest metastatic liver mass using region of interest (ROI). HU differences (ΔHU) between arterial and pre-contrast phase were calculated. RESULTS: Of the 101 study subjects, 78(77.2%) were assigned to the pancreas responder group {mean ΔHU (±SD), 36.7(±21.6)} and 23(22.8%) to the pancreas non-responder group {mean ΔHU (±SD), 20.6(±9.9)} (p = 0.001 for ΔHUs). Of the 46 study subjects with liver metastasis, 25(54.3%) were assigned to the liver metastasis responder group {mean ΔHU (±SD), 36.9(±21.0} and 21(45.7%) to the liver metastasis non-responder group {mean ΔHU (±SD), 17.1 (±24.0)}, (p = 0.005 for ΔHUs). CONCLUSION: CT determined mass vascular enhancement patterns may predict chemoresponse in advanced pancreatic cancer.

Duodenal perforation and esophageal ischemia following transarterial chemoembolization for hepatocellular carcinoma: A case report.

Transarterial chemoembolization (TACE) is frequently used for treatment of unresectable hepatocellular carcinoma (HCC) and can also be used for case of liver metastases from rectal cancer. Although it is recognized as safe and effective treatment, various complications have been reported. However, post-TACE duodenal perforation with duodenal and esophageal ischemia has not been reported in the literature. A 43-year-old male had experienced duodenal perforation combined with duodenal and lower esophageal ischemia after 8 times of repeated TACE for recurrent and unresectable HCCs, that was confirmed on esophagogastroduodenoscopy and abdominal computed tomography. Interestingly, operative findings showed complete recovery of duodenal ischemia except perforation, and he recovered with just the segmental duodenectomy and gastrojejunostomy. We report a case of duodenal perforation with necrosis and esophageal ischemia after 8th TACE for unresectable HCC. Although this complication is rare and unexpected, it may result in severe sequelae requiring surgical repair.The careful procedure during TACE followed by post-TACE careful monitoring is required in patients with posthepatectomy or repeated TACE, especially in the case with unusual clinical manifestations.

A randomized controlled trial of an educational video to improve quality of bowel preparation for colonoscopy.

BACKGROUND: High-quality bowel preparation is necessary for colonoscopy. A few studies have been conducted to investigate improvement in bowel preparation quality through patient education. However, the effect of patient education on bowel preparation has not been well studied. METHODS: A randomized and prospective study was conducted. All patients received regular instruction for bowel preparation during a pre-colonoscopy visit. Those scheduled for colonoscopy were randomly assigned to view an educational video instruction (video group) on the day before the colonoscopy, or to a non-video (control) group. Qualities of bowel preparation using the Ottawa Bowel Preparation Quality scale (Ottawa score) were compared between the video and non-video groups. In addition, factors associated with poor bowel preparation were investigated. RESULT: A total of 502 patients were randomized, 250 to the video group and 252 to the non-video group. The video group exhibited better bowel preparation (mean Ottawa total score: 3.03 ± 1.9) than the non-video group (4.21 ± 1.9; P < 0.001) and had good bowel preparation for colonoscopy (total Ottawa score <6: 91.6 % vs. 78.5 %; P < 0.001). Multivariate analysis revealed that males (odds ratio [OR] = 1.95, P = 0.029), diabetes mellitus patients (OR = 2.79, P = 0.021), and non-use of visual aids (OR = 3.09, P < 0.001) were associated with poor bowel preparation. In the comparison of the colonoscopic outcomes between groups, the polyp detection rate was not significantly different between video group and non-video group (48/250, 19.2 % vs. 48/252, 19.0 %; P = 0.963), but insertion time was significantly short in video group (5.5 ± 3.2 min) than non-video group (6.1 ± 3.7 min; P = 0.043). CONCLUSION: The addition of an educational video could improve the quality of bowel preparation in comparison with standard preparation method. TRIAL REGISTRATION: Clinical Research Information Service KCT0001836 . The date of registration: March, 08(th), 2016, Retrospectively registered.

Refractory pseudomembranous colitis that was treated successfully with colonoscopic fecal microbial transplantation.

Pseudomembranous colitis (PMC) is a nosocomial and opportunistic infection caused by Clostridium difficile. PMC is related to the use of antibiotics leading to intestinal dysbiosis and an overgrowth of C. difficile. Metronidazole or vancomycin is considered to be the standard therapy for the management of PMC. However, PMC has a 15%-30% recurrence rate and can be refractory to standard treatments, resulting in morbidity and mortality. Here we describe a patient who experienced refractory PMC who was treated with fecal microbiota transplantation. A 69-year-old woman was admitted to the hospital with consistent abdominal pain and diarrhea, which had been present for 5 months. She was diagnosed with PMC by colonoscopy and tested positive for C. difficile toxin. Even though she took metronidazole for 10 days, followed by vancomycin for 4 weeks, her symptoms did not improve. Because of her recurrent and refractory symptoms, we decided to perform fecal microbiota transplantation. Fifty grams of fresh feces from a donor were obtained on the day of the procedure, mixed with 500 mL of normal saline, and then filtered. The filtered solution was administered to the patient's colon using a colonoscope. After the procedure, her symptoms rapidly improved and a follow-up colonoscopy showed that the PMC had resolved without recurrence.

Engineering the AAVS1 locus for consistent and scalable transgene expression in human iPSCs and their differentiated derivatives.

The potential use of induced pluripotent stem cells (iPSCs) in personalized regenerative medicine applications may be augmented by transgenics, including the expression of constitutive cell labels, differentiation reporters, or modulators of disease phenotypes. Thus, there is precedence for reproducible transgene expression amongst iPSC sub-clones with isogenic or diverse genetic backgrounds. Using virus or transposon vectors, transgene integration sites and copy numbers are difficult to control, and nearly impossible to reproduce across multiple cell lines. Moreover, randomly integrated transgenes are often subject to pleiotropic position effects as a consequence of epigenetic changes inherent in differentiation, undermining applications in iPSCs. To address this, we have adapted popular TALEN and CRISPR/Cas9 nuclease technologies in order to introduce transgenes into pre-defined loci and overcome random position effects. AAVS1 is an exemplary locus within the PPP1R12C gene that permits robust expression of CAG promoter-driven transgenes. Gene targeting controls transgene copy number such that reporter expression patterns are reproducible and scalable by ∼2-fold. Furthermore, gene expression is maintained during long-term human iPSC culture and in vitro differentiation along multiple lineages. Here, we outline our AAVS1 targeting protocol using standardized donor vectors and construction methods, as well as provide practical considerations for iPSC culture, drug selection, and genotyping.

Inducible Transgene Expression in Human iPS Cells Using Versatile All-in-One piggyBac Transposons.

Transgenics is a mainstay of functional genomics. Conditionally overexpressing genes of interest (GOIs) helps to reveal their roles in the control of complex biological processes. Complemented by findings in classic animal model systems, recent advances in human embryonic stem cell (hESC) and patient-specific induced pluripotent stem cell (hiPSC) differentiation have led to sophisticated in vitro models of human development and disease. Yet, as transgenic elements encoding inducible systems must be introduced de novo into each genetically unique human stem cell line, robust and straightforward solutions to gene delivery are required. Transposons are a family of mobile DNA elements that have been adapted as experimental tools for stable genomic integration of transgenes. The piggyBac (PB) transposon from Trichoplusia ni presents a number of benefits over classic viral or BAC transgenesis: ease of application, simple integration-site mapping, and the unique capacity for traceless excision. Moreover, their large capacity permits the consolidation of multiple transgene components in a single vector system. In this chapter, we outline the features of a panel of "All-in-One" PB transposons designed for drug-inducible gene expression and provide guidelines to establish and validate populations or clones of transgenic hiPSCs.

The piggyBac Transposon as a Platform Technology for Somatic Cell Reprogramming Studies in Mouse.

Somatic cell reprogramming to induced pluripotent stem cells (iPSCs) is a revolutionary technology, with repercussions affecting modern functional genomics and regenerative medicine. Still, relatively little is known about the processes underlying this dramatic cellular and molecular metamorphosis. Reprogramming technology based on the implementation of piggyBac (PB) transposons has enabled studies of iPSC reprogramming mechanisms, shedding an increasing light on these processes. Unique characteristics of PB transposons such as efficient genomic integration, unlimited cargo capacity, robust gene expression, and even seamless excision highlight the importance of this transgenic tool in advancing stem cell biology. In this chapter, we provide a detailed overview of versatile primary iPSC generation from mouse somatic cells using PB transposons, and the subsequent establishment of robust secondary reprogramming systems. These protocols are highlighted with examples from recent studies as to how PB has been, and continues to be, conducive to the dissection of reprogramming processes at the cellular and molecular levels.

Conscious Sedation Using Midazolam and Sequential Flumazenil in Cirrhotic Patients for Prophylactic Endoscopic Variceal Ligation.

BACKGROUND/AIMS: This study investigated the safety of endoscopic variceal ligation (EVL) under conscious sedation with midazolam and sequential flumazenil after procedure in these patients. METHODS: A total of 279 patients who underwent secondary prophylactic EVL at our institution between April 2012 and June 2014, were enrolled. Conscious sedation was achieved using intravenous midazolam, and flumazenil was routinely used as an antidote immediately after EVL. Patients with sleep (n = 165) and non-sleep (n = 55) endoscopy were matched using propensity score analysis (3:1). Frequencies of overt hepatic encephalopathy (HEP) and patient' satisfactions with EVL were compared between the 2 groups. RESULTS: Of the 279 patients, 155 (55.6%) were of Child-Turcotte-Pugh (CTP) class, B or C, and 224 (80.3%) patients underwent sleep endoscopy. After propensity score analysis, overt HEP was observed in 1 (0.4%) of the 165 patients in the sedated group, but not found in any in the non-sedated group. Patient' satisfaction with EVL was better in the sedated group (p < 0.001). Twenty-nine (65.9%) of the 44 patients with CTP class C underwent sleep endoscopy, and only one (3.4%) experienced overt HEP. CONCLUSIONS: Prophylactic EVL under conscious sedation using midazolam and flumazenil is probably safe in cirrhotic patients without experience of HEP, even in those of CTP class C.

Reprogramming Roadblocks Are System Dependent.

Since the first generation of induced pluripotent stem cells (iPSCs), several reprogramming systems have been used to study its molecular mechanisms. However, the system of choice largely affects the reprogramming efficiency, influencing our view on the mechanisms. Here, we demonstrate that reprogramming triggered by less efficient polycistronic reprogramming cassettes not only highlights mesenchymal-to-epithelial transition (MET) as a roadblock but also faces more severe difficulties to attain a pluripotent state even post-MET. In contrast, more efficient cassettes can reprogram both wild-type and Nanog(-/-) fibroblasts with comparable efficiencies, routes, and kinetics, unlike the less efficient reprogramming systems. Moreover, we attribute a previously reported variation in the N terminus of KLF4 as a dominant factor underlying these critical differences. Our data establish that some reprogramming roadblocks are system dependent, highlighting the need to pursue mechanistic studies with close attention to the systems to better understand reprogramming.

Metformin-associated lactic acidosis: predisposing factors and outcome.

BACKGROUND: Metformin is considered the first choice oral treatment for type 2 diabetes patients in the absence of contraindications. Rarely, life-threatening complications associated with metformin treatment are seen in some patients with underlying diseases. The aim of this study was to further investigate the clinical profiles and risk factors for metformin-associated lactic acidosis (MALA) and the treatment modalities according to survival. METHODS: To identify MALA, we performed a retrospective study in seven diabetic patients who were taking metformin and had been diagnosed with lactic acidosis at Inha University Hospital between 1995 and 2012. For each patient, we recorded the age, sex, daily metformin dosage, laboratory test results, admission diagnosis, and risk factors. Also, concurrent conditions, treatment modalities, and outcomes were evaluated. RESULTS: Six patients had risk factors for lactic acidosis before admission. All patients had renal impairment on admission as a precipitating risk factor. Five patients survived and two patients died despite early renal replacement therapy. Older patients tended to have a poorer prognosis. CONCLUSION: Renal function must be monitored in elderly type 2 diabetes mellitus patients with underlying diseases and conditions causing renal impairment who begin metformin treatment. Accurate recognition of MALA and initiation of renal replacement are essential for treatment.

KLF4 N-terminal variance modulates induced reprogramming to pluripotency.

As the quintessential reprogramming model, OCT3/4, SOX2, KLF4, and c-MYC re-wire somatic cells to achieve induced pluripotency. Yet, subtle differences in methodology confound comparative studies of reprogramming mechanisms. Employing transposons, we systematically assessed cellular and molecular hallmarks of mouse somatic cell reprogramming by various polycistronic cassettes. Reprogramming responses varied in the extent of initiation and stabilization of transgene-independent pluripotency. Notably, the cassettes employed one of two KLF4 variants, differing only by nine N-terminal amino acids, which generated dissimilar protein stoichiometry. Extending the shorter variant by nine N-terminal amino acids or augmenting stoichiometry by KLF4 supplementation rescued both protein levels and phenotypic disparities, implicating a threshold in determining reprogramming outcomes. Strikingly, global gene expression patterns elicited by published polycistronic cassettes diverged according to each KLF4 variant. Our data expose a Klf4 reference cDNA variation that alters polycistronic factor stoichiometry, predicts reprogramming hallmarks, and guides comparison of compatible public data sets.

Effects of Therapeutic Hypothermia on Apoptosis and Autophagy After Spinal Cord Injury in Rats.

STUDY DESIGN: Animal study. OBJECTIVE: To further investigate the effects of therapeutic hypothermia (TH), the present study compared autophagy and apoptosis after treatment with either therapeutic moderate systemic hypothermia or methylprednisolone sodium succinate (MP) in a rat model of acute spinal cord injury (SCI). SUMMARY OF BACKGROUND DATA: The neuroprotective effects of TH have recently become an important topic in the field of SCI research. METHODS: All rats were subjected to a 25-g/cm spinal cord contusion over the ninth thoracic vertebrae. After the induction of SCI, the control group did not receive any further treatment, TH group immediately received moderate systemic hypothermia for 4 hours, and MP group was administered high-dose MP. The rats were killed either 2 or 7 days after SCI, and the injured spinal cord tissues were obtained. Apoptosis and autophagy were assessed by immunohistochemical analyses and Western blot analyses. In addition, the microarchitecture of the autophagosomes was evaluated using transmission electron microscopy, and the motor activity of the rats was assessed using the Basso-Beattie-Bresnahan (BBB) locomotor rating scale. RESULTS: Compared with controls, there was a significant reduction in the expression levels of cleaved caspase-8, -9, and -3 in the TH- and MP-treated groups 2 days after SCI. Moreover, compared with the control group, the expression of LC3II and Beclin-1 exhibited a significant decrease on day 2 after treatment with TH. The numbers of transferase dUTP nicked-end labeling and LC3-positive cells were significantly lower on days 2 and 7. The Basso-Beattie-Bresnahan ratings were significantly higher 6 weeks after SCI in both the TH- and MP-treated groups than in the control group. CONCLUSION: Both TH and MP have neuroprotective effects on injured spinal cord tissues via the inhibition of apoptosis and autophagy. Thus, the application of moderate systemic hypothermia may be a useful treatment modality after acute SCI. LEVEL OF EVIDENCE: N/A.

Fluorescence turn-on response of a conjugated polyelectrolyte with intramolecular stack structure to biomacromolecules.

An anionic conjugated polyelectrolyte based on polydiphenylacetylene showed a significant fluorescence turn-on response to positively-charged proteins through a conformational relaxation of its intramolecular stack structure.

BRG1 directly regulates nucleosome structure and chromatin looping of the alpha globin locus to activate transcription.

Alpha globin expression must be regulated properly to prevent the occurrence of alpha-thalassemias, yet many questions remain unanswered regarding the mechanism of transcriptional activation. Identifying factors that regulate chromatin structure of the endogenous alpha globin locus in developing erythroblasts will provide important mechanistic insight. Here, we demonstrate that the BRG1 catalytic subunit of SWI/SNF-related complexes co-immunoprecipitates with GATA-1 and EKLF in murine fetal liver cells in vivo and is recruited to the far-upstream major-regulatory element (MRE) and alpha2 promoter. Furthermore, based on our analysis of Brg1(null/ENU1) mutant mice, BRG1 regulates DNase I sensitivity, H3ac, and H3K4me2 but not CpG methylation at both sites. Most importantly, BRG1 is required for chromatin loop formation between the MRE and alpha2 promoter and for maximal RNA Polymerase II occupancy at the alpha2 promoter. Consequently, Brg1 mutants express alpha globin mRNA at only 5-10% of wild-type levels and die at mid-gestation. These data identify BRG1 as a chromatin-modifying factor required for nucleosome remodeling and transcriptional activation of the alpha globin locus. These data also demonstrate that chromatin looping between the MRE and alpha2 promoter is required as part of the transcriptional activation mechanism.