Hong Young Jun

Combined Radiofrequency Ablation and Double Anti-Angiogenic Protein Therapy to Increase Coagulation Efficacy: An Experimental Study in a Murine Renal Carcinoma Model

Objective To evaluate whether suppression of tumor microvasculature by double anti-angiogenic protein (DAAP) treatment could increase the extent of radiofrequency ablation (RFA)-induced coagulation in a murine renal cell carcinoma model. Materials and Methods Renal cell carcinoma cell lines were implanted subcutaneously into 10 nude mice. Four mice received adenoviral DAAP treatment and 6 mice received sterile 0.9% saline solution as DAAP-untreated group. The effect of DAAP was evaluated according to the vascularity by contrast-enhanced ultrasound (CEUS) using microbubbles. Four DAAP-treated mice and 4 DAAP-untreated mice were then treated with RFA, resulting in 3 groups: no-therapy (n = 2), RFA only (n = 4), and RFA combined with DAAP treatment (n = 4). Immediately after RFA, the size of coagulation necrosis and mitochondrial enzyme activity were compared between the groups using analysis of variance (ANOVA) and post hoc test. Results The contrast enhancement ratio for tumor vascularization on CEUS was significantly lower in the DAAP treated group than in DAAP-untreated group (30.2 ± 9.9% vs. 77.4 ± 17.3%; p = 0.021). After RFA, the mean coagulation diameter was 0 mm for no-therapy group, 6.7 ± 0.7 mm for the RFA only group and 8.5 ± 0.4 mm for the RFA with DAAP group (ANOVA, p < 0.001). The area of viable mitochondria within the tumor was 27.9 ± 3.9% in no-therapy group, 10.3 ± 4.5% in the RFA only group, and 2.1 ± 0.7% in the RFA with DAAP group (ANOVA, p < 0.001). Conclusion Our results suggest the potential value of combining RFA with anti-angiogenic therapy.

Shikonin-induced necroptosis is enhanced by the inhibition of autophagy in non-small cell lung cancer cells

BackgroundShikonin, a natural naphthoquinone pigment purified from Lithospermum erythrorhizon, induces necroptosis in various cancer types, but the mechanisms underlying the anticancer activity of shikonin in lung cancer are not fully understood. This study was designed to clarify whether shikonin causes necroptosis in non-small cell lung cancer (NSCLC) cells and to investigate the mechanism of action.MethodsMultiplex and caspase 8 assays were used to analyze effect of shikonin on A549 cells. Cytometry with annexin V/PI staining and MTT assays were used to analyze the mode of cell death. Western blotting was used to determine the effect of shikonin-induced necroptosis and autophagy. Xenograft and orthotopic models with A549 cells were used to evaluate the anti-tumor effect of shikonin in vivo.ResultsMost of the cell death induced by shikonin could be rescued by the specific necroptosis inhibitor necrostatin-1, but not by the general caspase inhibitor Z-VAD-FMK. Tumor growth was significantly lower in animals treated with shikonin than in the control group. Shikonin also increased RIP1 protein expression in tumor tissues. Autophagy inhibitors, including methyladenine (3-MA), ATG5 siRNA, and bafilomycin A, enhanced shikonin-induced necroptosis, whereas RIP1 siRNA had no effect on the apoptotic potential of shikonin.ConclusionsOur data indicated that shikonin treatment induced necroptosis and autophagy in NSCLC cells. In addition, the inhibition of shikonin-induced autophagy enhanced necroptosis, suggesting that shikonin could be a novel therapeutic strategy against NSCLC.

WHI-131 Promotes Osteoblast Differentiation and Prevents Osteoclast Formation and Resorption in Mice

The small molecule WHI‐131 is a potent therapeutic agent with anti‐inflammatory, antiallergic, and antileukemic potential. However, the regulatory effects of WHI‐131 on osteoblast and osteoclast activity are unclear. We examined the effects of WHI‐131 on osteoblast and osteoclast differentiation with respect to bone remodeling. The production of receptor activator of nuclear factor kappa‐B ligand (RANKL) by osteoblasts in response to interleukin (IL)‐1 or IL‐6 stimulation decreased by 56.8% or 50.58%, respectively, in the presence of WHI‐131. WHI‐131 also abrogated the formation of mature osteoclasts induced by IL‐1 or IL‐6 stimulation. Moreover, WHI‐131 treatment decreased RANKL‐induced osteoclast differentiation of bone marrow‐derived macrophages, and reduced the resorbing activity of mature osteoclasts. WHI‐131 further decreased the mRNA and protein expression levels of c‐Fos and nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) by almost twofold, and significantly downregulated the mRNA expression of the following genes: tartrate‐resistant acid phosphatase (TRAP), osteoclast‐associated receptor (OSCAR), DC‐STAMP, OC‐STAMP, ATP6v0d2, and cathepsin K (CtsK) compared with the control group. WHI‐131 further suppressed the phosphorylation of protein kinase B (Akt) and degradation of inhibitor of kappa B (IκB); Ca2+ oscillation was also affected, and phosphorylation of the C‐terminal Src kinase (c‐Src)–Bruton agammaglobulinemia tyrosine kinase (Btk)–phospholipase C gamma 2 (PLCγ2) (c‐Src‐Btk‐PLCg2 calcium signaling pathway) was inhibited following WHI‐131 treatment. The Janus kinase‐signal transducer and activator of transcription (JAK‐STAT) signaling pathway was activated by WHI‐131, accompanied by phosphorylation of STAT3 Ser727 and dephosphorylation of STAT6. In osteoblasts, WHI‐131 caused an approximately fourfold increase in alkaline phosphatase activity and Alizarin Red staining intensity. Treatment with WHI‐131 increased the mRNA expression levels of genes related to osteoblast differentiation, and induced the phosphorylation of Akt, p38, and Smad1/5/8. Furthermore, 5‐week‐old ICR mice treated with WHI‐131 exhibited antiresorbing effects in a lipopolysaccharide‐induced calvaria bone loss model in vivo and increased bone‐forming activity in a calvarial bone formation model. Therefore, the results of this study show that WHI‐131 plays a dual role by inhibiting osteoclast differentiation and promoting osteoblast differentiation. Thus, WHI‐131 could be a useful pharmacological agent to treat osteoporosis by promoting bone growth and inhibiting resorption.

Claudin 11 regulates bone homeostasis via bidirectional EphB4-EphrinB2 signaling

Claudins (Cldns) are well-established components of tight junctions (TJs) that play a pivotal role in the modulation of paracellular permeability. Several studies have explored the physiologic aspects of Cldn family members in bone metabolism. However, the effect of Cldn11, a major component of central nervous system myelin, on bone homeostasis has not been reported. In this study, we demonstrate that Cldn11 is a potential target for bone disease therapeutics as a dual modulator of osteogenesis enhancement and osteoclastogenesis inhibition. We found that Cldn11 played a negative role in the receptor activator of nuclear factor kappa B ligand-induced osteoclast (OC) differentiation and function by downregulating the phosphorylated form of extracellular signal-regulated kinase (ERK), Bruton’s tyrosine kinase, and phospholipase C gamma 2, in turn impeding c-Fos and nuclear factor in activated T cell c1 expression. The enhancement of osteoblast (OB) differentiation by positive feedback of Cldn11 was achieved through the phosphorylation of Smad1/5/8, ERK, and c-Jun amino-terminal kinase. Importantly, this Cldn11-dependent dual event in bone metabolism arose from targeting EphrinB2 ligand reverse signaling in OC and EphB4 receptor forward signaling in OB. In agreement with these in vitro effects, subcutaneous injection of Cldn11 recombinant protein exerted anti-resorbing effects in a lipopolysaccharide-induced calvarial bone loss mouse model and increased osteogenic activity in a calvarial bone formation model. These findings suggest that Cldn11 is a novel regulator in bone homeostasis.Bone metabolism: A new connectionClaudin 11 (Cldn11), a protein that helps form leak-proof connections between cells, also regulates bone density. Claudins are part of tight junctions, which connect cells that form barriers, such as skin cells. Some claudins have been reported to also affect bone metabolism. Ju-Young Kim and Myeung Su Lee from Wonkwang University in Iksan, South Korea, and colleagues investigated how Cldn11 affects bone metabolism. Bone undergoes constant remodeling, and the balance between new bone formation and old bone breakdown is critical. The team found that in cultured cells increasing Cldn11 increased the numbers of bone-forming cells and decreased the numbers of bone-degrading cells. In mice with experimentally induced bone weakness, injection of Cldn11 increased new bone formation and reduced bone resorption. Cldn11 provides a new target to study and treat diseases that cause bone loss, such as osteoporosis.

Hepatic Alanine Differentiates Nonalcoholic Steatohepatitis From Simple Steatosis in Humans and Mice: A Proton MR Spectroscopy Study With Long Echo Time

To evaluate the hepatic metabolic alterations in nonalcoholic fatty liver disease (NAFLD) by using 1H‐MRS (proton magnetic resonance spectroscopy) with long echo time and to test the reproducibility of human study in an animal model. Liver biopsy is the gold standard for diagnosing NAFLD but with practical constraints. 1H‐MRS allows in vivo assessment of hepatocellular metabolism and has shown potential for biochemical differentiation in diffuse liver disease.

Evaluation of connectivity map-discovered celastrol as a radiosensitizing agent in a murine lung carcinoma model: Feasibility study of diffusion-weighted magnetic resonance imaging

This study was designed to identify potential radiosensitizing (RS) agents for combined radio- and chemotherapy in a murine model of human lung carcinoma, and to evaluate the in vivo effect of the RS agents using diffusion-weighted magnetic resonance imaging (DW-MRI). Radioresistance-associated genes in A549 and H460 cells were isolated on the basis of their gene expression profiles. Celastrol was selected as a candidate RS by using connectivity mapping, and its efficacy in lung cancer radiotherapy was tested. Mice inoculated with A549 carcinoma cells were treated with single ionizing radiation (SIR), single celastrol (SC), or celastrol-combined ionizing radiation (CCIR). Changes in radiosensitization over time were assessed using DW-MRI before and at 3, 6, and 12 days after therapy initiation. The tumors were stained with hematoxylin and eosin at 6 and 12 days after therapy. The percentage change in the apparent diffusion coefficient (ADC) value in the CCIR group was significantly higher than that in the SC and SIR group on the 12th day (Mann–Whitney U-test, p = 0.05; Kruskal–Wallis test, p < 0.05). A significant correlation (Spearman’s rho correlation coefficient of 0.713, p = 0.001) was observed between the mean percentage tumor necrotic area and the mean ADC values after therapy initiation. These results suggest that the novel radiosensitizing agent celastrol has therapeutic effects when combined with ionizing radiation (IR), thereby maximizing the therapeutic effect of radiation in non–small cell lung carcinoma. In addition, DW-MRI is a useful noninvasive tool to monitor the effects of RS agents by assessing cellularity changes and sequential therapeutic responses.

Reduced radiation dose and improved image quality using a mini mobile digital imaging system in a neonatal intensive care unit

This study was aimed to assess the radiation dose and image quality of a mini-mobile digital imaging (mini-DI) system for neonatal chest radiography and compared to conventional digital radiography (DR). A total of 64 neonates were examined and anatomical landmarks were assessed. The entrance surface dose of mini DI and conventional DR was 26.64±0.15 μGy and 49.11±1.46 μGy, respectively (p<0.001). The mean SNR values for mini-DI and DR were 233.2±5.1 and 31.6±1.2, and 10% MTF values were 131 and 161μm. A newly developed mini-DI is capable of preserving the diagnostic information with dose reduction in neonates under intensive care.

Evaluation of a novel technique for intraperitoneal injections in mice.

Intraperitoneal injection is a common technique that safely delivers a substance into the peritoneal cavity but can induce high stress in animals. The authors have developed a new method for administering intraperitoneal injections in mice, with the goal of causing less stress during handling and injection. Here, they compare their novel technique with a conventional technique in three experiments. In the first experiment, the authors administered intraperitoneal injections of contrast medium using either technique and then used micro-computed tomography to evaluate the placement and retention of the medium. In the second and third experiments, the authors administered intraperitoneal injections or control treatments, then sampled blood to determine circulating concentrations of stress-related hormones. Imaging showed that both the novel and the conventional techniques properly delivered a contrast medium into the peritoneal cavity. The novel technique was also associated with lower concentrations of stress-related hormones than was the conventional technique. These results indicate that this novel technique might be beneficial to investigators that use intraperitoneal injections with mice.

Noninvasive Differential Diagnosis of Liver Iron Contents in Nonalcoholic Steatohepatitis and Simple Steatosis Using Multiecho Dixon Magnetic Resonance Imaging

RATIONALE AND OBJECTIVES The roles of iron stores in nonalcoholic fatty liver disease have not yet been clearly identified, and it is lack of uniform criteria and a standardized study design for assessing the liver iron content (LIC) in nonalcoholic steatohepatitis (NASH). This study was to compare LICs in biopsy-proven simple steatosis (SS) and NASH based on T2⁎-relaxometry. MATERIAL AND METHODS A total of 32 subjects divided to three groups, consisting of 10 healthy controls, 12 SS and 10 NASH. All MRI examinations were performed on a 3 T MRI with a 32-channel body coil. To measure T2⁎-value, we used a gradient echo sequence with six multiechoes within a single breath-hold. Hepatic iron contents among three groups were compared using Kruskal-Wallis H test and Mann-Whitneys posthoc tests. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics curve. To identify the reliability of iron measurements in the different region of interests, coefficient of variance (CV) was calculated overall CV values for the variability of measurements. Interobserver agreement and reliability were estimated by calculating the intraclass correlation coefficient. RESULTS The variations of all LIC measurements are not exceeded 20%, as a mean CV value 18.3%. intraclass correlation coefficients were higher than 0.9. Mean T2⁎-values at localized region of interests were healthy controls 45.42 ± 7.19 ms, SS 20.96 ± 4.28 ms, and NASH 15.49 ± 2.87 ms. The mean T2⁎-value in NASH is significantly shorter than that in SS (p = 0.008). The area under the receiver operating characteristics curve to distinguish NASH from SS was 0.908 (95% confidence interval 0.775-1.000, p = 0.001) at a cut-off of iron contents greater than 17.95 ms, and its diagnostic accuracy had 0.833 sensitivity and 0.800 specificity. CONCLUSION This study demonstrates that the T2⁎ calculation can help to differentially diagnose NASH.

Development of Portable Digital Radiography System with a Device for Monitoring X-ray Source-Detector Angle and Its Application in Chest Imaging

This study developed a device measuring the X-ray source-detector angle (SDA) and evaluated the imaging performance for diagnosing chest images. The SDA device consisted of Arduino, an accelerometer and gyro sensor, and a Bluetooth module. The SDA values were compared with the values of a digital angle meter. The performance of the portable digital radiography (PDR) was evaluated using the signal-to-noise (SNR), contrast-to-noise ratio (CNR), spatial resolution, distortion and entrance surface dose (ESD). According to different angle degrees, five anatomical landmarks were assessed using a five-point scale. The mean SNR and CNR were 182.47 and 141.43. The spatial resolution and ESD were 3.17 lp/mm (157 μm) and 0.266 mGy. The angle values of the SDA device were not significantly difference as compared to those of the digital angle meter. In chest imaging, the SNR and CNR values were not significantly different according to the different angle degrees. The visibility scores of the border of the heart, the fifth rib and the scapula showed significant differences according to different angles (p < 0.05), whereas the scores of the clavicle and first rib were not significant. It is noticeable that the increase in the SDA degree was consistent with the increases of the distortion and visibility score. The proposed PDR with a SDA device would be useful for application in the clinical radiography setting according to the standard radiography guidelines.