Fatty acid synthase inhibitor cerulenin inhibits topoisomerase I catalytic activity and augments SN-38-induced apoptosis

Fatty acid synthase (FASN) is overexpressed in a wide variety of human cancers, making it an attractive target for anticancer therapy. One of the most widely used inhibitors of FASN, cerulenin, is a natural product of Cephalosporium caerulens. Cerulenin is selectively toxic to human cancer cells in vitro. However, the mechanism by which FASN inhibition causes apoptosis in tumor cells remains unclear. Because of the widespread clinical interest in combining cerulenin with other chemotherapeutic agents, we performed this study to gain insight into the downstream effects of FASN inhibition that lead to apoptosis. Here, we observed the increased antitumor effect of cerulenin when combined with the topoisomerase inhibitor SN-38. We identified topoisomerase I as a potential mediator of cerulenin-induced apoptosis, possibly by upregulating intracellular polyunsaturation. Finally, we show that suppressing topoisomerase I catalytic activity results in synergistic effects between cerulenin and LY294002. Our results suggest that topoisomerase I could participate in cerulenin-induced apoptosis by upregulating intracellular polyunsaturation. These results will help determine the molecular basis of the cerulenin and SN-38 drug combination. Further investigation of this pathway will provide new insight into cancer cell metabolism and may aid in the design of additional cancer chemotherapeutic agents.

A purified extract from Clematis mandshurica prevents staurosporin-induced downregulation of 14-3-3 and subsequent apoptosis on rat chondrocytes

OBJECTIVE

To dissect the mechanism of the protection of staurosporin-induced apoptosis on rat chondrocytes by a purified extract from Clematis mandshurica.

DESIGN

Primary cultured rat articular chondrocytes as well as RCJ3.1C.18 cells were incubated with 1 microM staurosporin and 300 microg/ml purified extract from Clematis mandshurica. Western blot assay, silencing 14-3-3 gene and immunoprecipitation were conducted.

RESULTS

Clematis mandshurica prevented staurosporin-induced downregulation of several antiapoptotic bcl-2 family proteins Bcl-xL and Bcl-2, and staurosporin-induced upregulation of an apoptotic bcl-2 family protein Bax. Clematis mandshurica also prevented staurosporin-induced downregulation of a premitochondrial antiapoptotic protein 14-3-3. It is noticeable that siRNA to 14-3-3 abolished the prevention of caspase-3 activation by Clematis mandshurica. Furthermore viability assay corroborated that silencing of 14-3-3 gene abolished this apoptosis protection efficacy by Clematis mandshurica. Immunoprecipitation assay elucidated that Clematis mandshurica prevented the staurosporin-induced reduction of the interactions between 14-3-3 with phospho-ser112-Bad and Bcl-xL to phospho-ser155-Bad.

CONCLUSIONS

Clematis mandshurica prevents staurosporin-induced apoptosis of rat chondrocytes via 14-3-3.

A novel resveratrol analogue HS-1793 treatment overcomes the resistance conferred by Bcl-2 and is associated with the formation of mature PML nuclear bodies in renal clear cell carcinoma Caki-1 cells

Bcl-2 protects cancer cells from the apoptotic effects of various chemotherapeutic agents. Inhibition or downregulation of Bcl-2 represents a new therapeutic approach to bypass chemoresistance in cancer cells. Previously we designed and synthesized the resveratrol analogue HS-1793 displaying stronger antitumor efficacy than resveratrol and further demonstrated the HS-1793 resistance conferred by Bcl-2 in human leukemic U937 cells. We undertook this study to determine if HS-1793 treatment can bypass the anti-apoptotic effects of Bcl-2 in human renal cancer cells, with a specific focus on the involvement of promyelocytic leukemia nuclear bodies (PML-NBs). Experiments were conducted with Bcl-2-overexpressing human renal clear cell carcinoma Caki-1 cells. Various apoptosis assessment assays demonstrated that HS-1793 overcomes the resistance conferred by Bcl-2 in Caki-1 cells by inducing apoptosis. We elucidated that HS-1793-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with overcoming the anti-apoptotic effects of Bcl-2 in Caki-1 cells. Our findings show that the resveratrol analogue HS-1793 might provide a novel promising strategy for overcoming the resistance conferred by Bcl-2 via PML protein and the formation of mature PML-NBs.

Alterations of brain network hubs in reflex syncope: Evidence from a graph theoretical analysis based on DTI

OBJECTIVE

We evaluated global topology and organization of regional hubs in the brain networks and microstructural abnormalities in the white matter of patients with reflex syncope.

METHODS

Twenty patients with reflex syncope and thirty healthy subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on extracted DTI data, using DSI Studio. We then investigated differences in the network measures between the patients with reflex syncope and the healthy subjects. We also analyzed microstructural abnormalities of white matter using tract-based spatial statistics analysis (TBSS).

RESULTS

Measures of global topology were not different between patients with reflex syncope and healthy subjects. However, in reflex syncope patients, the strength measures of the right angular, left inferior frontal, left middle orbitofrontal, left superior medial frontal, and left middle temporal gyrus were lower than in healthy subjects. The betweenness centrality measures of the left middle orbitofrontal, left fusiform, and left lingual gyrus in patients were lower than those in healthy subjects. The PageRank centrality measures of the right angular, left middle orbitofrontal, and left superior medial frontal gyrus in patients were lower than those in healthy subjects. Regarding the analysis of the white matter microstructure, there were no differences in the fractional anisotropy and mean diffusivity values between the two groups.

CONCLUSIONS

We have identified a reorganization of network hubs in the brain network of patients with reflex syncope. These alterations in brain network may play a role in the pathophysiologic mechanism underlying reflex syncope.

Arabidopsis SIZ1 positively regulates alternative respiratory bypass pathways

Plant mitochondria possess alternative respiratory pathways mediated by the type II NAD(P)H dehydrogenases and alternative oxidases. Here, E3 SUMO ligase was shown to regulate alternative respiratory pathways and to participate in the maintenance of carbon and nitrogen balance in Arabidopsis. The transcript abundance of the type II NAD(P)H dehydrogenases NDA2 and NDB2 and alternative oxidases AOX1a and AOX1d genes was low in siz1-2 mutants compared to that in wild-type. The addition of nitrate or ammonium resulted in a decrease or an increase in the expression of the same gene families, respectively, in both wild-type and siz1-2 mutants. The amount of free sugar (glucose, fructose and sucrose) was lower in siz1-2 mutants than that in wild-type. These results indicate that low nitrate reductase activity due to the AtSIZ1 mutation is correlated with an overall decrease in alternative respiration and with a low carbohydrate content to maintain the carbon to nitrogen ratio in siz1-2 mutants.

Delay of explosive vaporization in pulsed laser-heated droplets

Measurements of time delays for explosion of pulsed CO(2) laser-heated droplets are presented. A simple model based on classical nucleation theory in superheated liquids, which neglects heat and mass transport, is used to interpret the data. The model shows good agreement with the experimental observations.

Nephrotic syndrome complicated with portal, splenic, and superior mesenteric vein thrombosis

Thromboembolism is a major complication of nephrotic syndrome. Renal vein thrombosis and deep vein thrombosis are relatively common, especially in membranous nephropathy. However, the incidence of portal vein and superior mesenteric vein (SMV) thrombosis in patients with nephrotic syndrome is very rare. To date, several cases of portal vein thrombosis treated by anticoagulation therapy, not by thrombolytic therapy, have been reported as a complication of nephrotic syndrome. Here, we report a case of portal, splenic, and SMV thrombosis in a patient with a relapsed steroid dependent minimal change disease who was treated successfully with anticoagulation and thrombolytic therapy using urokinase. Radiologic findings and his clinical conditions gradually improved. Six months later, a complete remission of the nephrotic syndrome was observed and the follow-up computed tomography scan showed the disappearance of all portal vein, splenic vein, and SMV thrombi.

Pseudomonas aeruginosa exotoxin A reduces chemoresistance of oral squamous carcinoma cell via inhibition of heat shock proteins 70 (HSP70)

PURPOSE

Oral squamous carcinoma (OSCC) cells exhibit resistance to chemotherapeutic agent-mediated apoptosis in the late stage of malignancy. Increased levels of heat shock proteins 70 (HSP70) in cancer cells are known to confer resistance to apoptosis. Since recent advances in the understanding of bacterial toxins have produced new strategies for the treatment of cancers, we investigated the effect of Pseudomonas aeruginosa exotoxin A (PEA) on HSP70 expression and induction of apoptosis in chemoresistant OSCC cell line (YD-9).

MATERIALS AND METHODS

The apoptotic effect of PEA on chemoresistant YD-9 cells was confirmed by MTT, Hoechst and TUNEL stains, DNA electrophoresis, and Western blot analysis.

RESULTS

While YD-9 cells showed high resistance to chemotherapeutic agents such as etoposide and 5-fluorouraci (5-FU), HSP70 antisense oligonucelotides sensitized chemoresistant YD-9 cells to etoposide and 5-FU. On the other hand, PEA significantly decreased the viability of YD-9 cells by deteriorating the HSP70-relating protecting system through inhibition of HSP70 expression and inducing apoptosis in YD-9 cells. Apoptotic manifestations were evidenced by changes in nuclear morphology, generation of DNA fragmentation, and activation of caspases. While p53, p21, and E2F-1 were upregulated, cdk2 and cyclin B were downregulated by PEA treatment, suggesting that PEA caused cell cycle arrest at the G2/M checkpoint.

CONCLUSION

Therefore, these results indicate that PEA reduced the chemoresistance through inhibition of HSP70 expression and also induced apoptosis in chemoresistant YD-9 cells.

Synthetic chenodeoxycholic acid derivative HS-1200-induced apoptosis of p815 mastocytoma cells is augmented by co-treatment with lactacystin

The antitumor activity of a synthetic chenodeoxycholic acid derivative, HS-1200, on the p815 mastocytoma cell line was investigated. We present several lines of evidence indicating that HS-1200 at 35 microM induced apoptosis of p815 cells. Reduction of mitochondrial membrane potential, the release of cytochrome to cytosol, activation of caspase-3, nuclear condensation, production of poly(ADP-ribose) polymerase cleavage, generation of DNA fragmentation and nuclear condensation were demonstrated. Importantly, HS-1200 inhibited proteasome activity. Next, the combination treatment of HS-1200 or a proteasome inhibitor lactacystin was undertaken. Although the single treatment of 20 microM HS-1200 or 1 microM lactacystin induced apoptosis slightly, the combination treatment of them augmented prominently the extent of apoptosis. The combination therapy of HS-1200 and lactacystin could be potentially a therapeutic strategy reducing the extent and severity of treatment-related toxicity.

Stanford type A aortic dissection secondary to infectious aortitis: a case report

Nowadays, infectious aortitis has become a rare disease thanks to antibiotics, but remains life-threatening. We present a case of a patient with acupuncture-induced infectious aortitis leading to aortic dissection. Chest computed-tomogram scan revealed Stanford type A dissection with pericardial effusion. Under the impression of an impending rupture, emergent surgery was performed. During surgery, infectious aortitis was identified incidentally, so she underwent resection of the infected aorta including surrounding tissues. Then the ascending aorta and hemi-arch were replaced with a prosthetic graft as an in situ fashion. The resected tissue and blood cultures revealed Staphylococcus aureus, so prolonged antibiotherapy was prescribed.

Purified extract from Clematis mandshurica prevents adenoviral-TRAIL induced apoptosis on rat articular chondrocytes

Since TNF-related apoptosis inducing ligand (TRAIL) is one of several apoptotic stimuli on articular chondrocytes, the modulation of the mechanism mediated by TRAIL could be considered as a novel strategy for the treatment of osteoarthritis (OA). Previous studies demonstrated that Clematis mandshurica prevents staurosporin-induced apoptosis in articular chondrocytes. This study was undertaken to examine whether Clematis mandshurica could prevent TRAIL-induced apoptosis in articular chondrocytes. Our data show that Clematis mandshurica prevents adenoviral TRAIL (Ad-TRAIL)-induced apoptosis in primary cultured articular chondrocytes. Clematis mandshurica prevents Ad-TRAIL-induced down-regulation of 14-3-3 and phosphorylated Akt. In addition, Clematis mandshurica treatment prevents the Ad-TRAIL-induced reduction of the interactions between 14-3-3 with phospho-ser112-Bad and phospho-ser136-Bad, and BcL-xL with phospho-ser155-Bad. A better understanding of the mechanism underlying inhibition of apoptosis in OA chondrocytes by Clematis mandshurica might lead to the development of a new therapeutic strategy for OA.

A case of tracheobronchomalacia due to relapsing polychondritis treated with Montgomery T-tube

Relapsing polychondritis is a rare and multi-system autoimmune disease of unknown etiology characterized by inflammation and destruction of cartilaginous structures. Its clinical manifestations include recurrent chondritis of the ears, nose, pinna, peripheral joints, and laryngotracheobronchial tree and can be life-threatening in advanced cases of laryngotracheal stenosis. Because of the rarity of relapsing polychondritis and lack of understanding of its pathogenesis, there is no standard medical therapy, and treatment is tailored according to disease activity and site of organ involvement. In respiratory failure due to laryngotracheal involvement, which has been reported in up to 50% of relapsing polychondritis patients and is a major cause of death, immediate procedures such as stenting and tracheostomy are very important. This report describes a 70-year-old male patient suffering from tracheobronchomalacia due to relapsing polychondritis who was treated with Montgomery T-tube insertion.

Combined effect of recombinant human bone morphogenetic protein-2 and low level laser irradiation on bisphosphonate-treated osteoblasts

Objectives

The purpose of this study was to evaluate the synergic effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-level laser therapy (LLLT) on bisphosphonate-treated osteoblasts.

Materials and Methods

Human fetal osteoblast cells (hFOB 1.19) were cultured with 100 µM alendronate. Low-level Ga-Al-As laser alone or with 100 ng/mL rhBMP-2 was then applied. Cell viability was measured with MTT assay. The expression levels of receptor activator of nuclear factor kappa-B ligand (RANKL), macrophage colony-stimulating factor (M-CSF), and osteoprotegerin (OPG) were analyzed for osteoblastic activity inducing osteoclastic activity. Collagen type and transforming growth factor beta-1 were also evaluated for bone matrix formation.

Results

The results showed that rhBMP-2 and LLLT had a synergic effect on alendronate-treated osteoblasts for enhancing osteoblastic activity and bone matrix formation. Between rhBMP-2 and LLLT, rhBMP-2 exhibited a greater effect, but did not show a significant difference.

Conclusion

rhBMP-2 and LLLT have synergic effects on bisphosphonate-treated osteoblasts through enhancement of osteoblastic activity and bone formation activity.

Comparative quantitative analysis of ultraviolet B-induced skin blood flow change using laser Doppler perfusion imaging technique

Laser Doppler perfusion imaging (LDI), recently developed, can generate a color-coded image of tissue perfusion, making it possible to assess the spatial distribution of skin perfusion without touching the surface. Using this apparatus, we investigated ultraviolet B (UVB)-induced perfusion profile of the skin and compared the results with those obtained from laser Doppler flowmetry (LDF). Fifteen adult male Korean volunteers were irradiated with several doses of UVB ranging from 25 mJ/cm2 to 186 mJ/cm2. Twenty-four hours later, the erythema reaction was evaluated with LDF and LDI systems. There was a significant correlation between the logarithmic dose of UVB and erythema values. The curves consisted of two parts, an initial, flat phase and then a linear, steep one. Also, there was a good correlation between LDF and LDI. The LDI is as sensitive as conventional LDF, but has the many advantages of measuring blood flow over large areas without contact with the skin surface. This instrument will be useful in the measurement of skin blood flow in many areas of dermatological application.

Depletion of alveolar surface active material by transbronchial plasma irrigation of the lung

Images

Murine bone marrow-derived mast cells exhibit evidence of both apoptosis and oncosis after IL-3 deprivation

IL-3 deprivation has been reported to induce apoptosis of bone marrow-derived mast cells. In order to evaluate this type of cell death further, we employed trypan blue and propidium iodide stainings, photometric enzyme immunoassay, fluorescence measurement of caspase-3, DNA electrophoresis, flow cytometry and transmission electron microscopy. In this experiment, although several evidences supporting apoptosis were demonstrated some findings were not consistent with typical apoptosis. On the other hand, electron microscopical observation demonstrated that most cells from all the time phases after IL-3 deprivation showed the morphology of typical oncosis, i.e. cell swelling, disintegration of ultrastructure and subsequent karyolysis. Only a small number of cells from the later time phases showed apoptotic morphology. We here suggest that BMMCs undergo both apoptosis and oncosis after IL-3 deprivation and that the dominant type of prelethal change is oncosis in all time phases, although apoptosis also plays a partial role in the late time phases.

Alterations of gray matter volumes and connectivity in patients with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an inherited genetic disorder caused by mutations in the TSC1 or TSC2 genes, encoding hamartin and tuberin. We aimed to evaluate structural volumes and connectivity of patients with TSC compared to those of healthy subjects. We consecutively enrolled 13 patients with a diagnosis of TSC and 15 age- and sex-matched healthy control subjects. Subjects underwent three-dimensional volumetric T1-weighted imaging, suitable for a quantitative analysis. Structural volumes were investigated using FreeSurfer image analysis software, and structural connectivity was calculated from a connectivity matrix, which was estimated from the correlation analysis of structural volumes using the Brain Analysis using Graph Theory software package. Differences in structural volumes and connectivity were analyzed between patients with TSC and healthy subjects. There were no differences of cortical volumes between the patients with TSC and healthy controls. However, we found decreased gray matter volumes in several subcortical regions in the patients with TSC compared to those in healthy controls, specifically in the putamen (0.3212 vs. 0.3841%, p = 0.001), even after multiple corrections. Regarding global structural connectivity, the small-worldness index was significantly decreased in patients with TSC compared to that in healthy controls (0.907 vs. 0.977, p = 0.049). This study revealed structural volumes and connectivity in patients with TSC that are significantly different from those in healthy controls. These alterations have implications for the pathogenesis of TSC.

Effect of phosphatidylcholine on the alpha-lactalbumin-induced fusion of vesicles

Previous studies on alpha-lactalbumin induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles are extended to vesicles composed of various combinations of phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine and cardiolipin. It was found that inclusion of phosphatidylcholine in the vesicles results in a depression of fusion. This depression of fusion appears to be caused by a reduction in the amount of irreversibly bound alpha-lactalbumin to vesicles containing phosphatidylcholine. It is suggested that in this system fusion is dependent upon the extent by which a particular protein segment penetrates the bilayer.

Endoscopic laser treatment of Dieulafoy's lesion

Dieulafoy’s disease is a distinctive arteriovenous malformation of the stomach, which presents with massive or recurrent gastrointestinal bleeding.

A case of Dieulafoy’s disease in an adult female, in which an endoscopic Nd: YAG (neodymium: yttrium aluminum garnet) laser was used successfully in controlling bleeding, is presented here.

Identification of focal epilepsy by diffusion tensor imaging using machine learning

OBJECTIVE

The aim of this study was to evaluate the feasibility of machine learning based on diffusion tensor imaging (DTI) measures to distinguish patients with focal epilepsy versus healthy controls and antiseizure medication (ASM) responsiveness.

METHODS

This was a retrospective study performed at a tertiary hospital. We enrolled 456 patients with focal epilepsy, who underwent DTI and were taking ASMs. We enrolled 100 healthy subjects as a control. We obtained the conventional DTI measures and structural connectomic profiles from the DTI.

RESULTS

The support vector machine (SVM) classifier based on the conventional DTI measures revealed an accuracy of 76.5% and an area under curve (AUC) of 0.604 (95% Confidence interval (CI), 0.506-0.695). Another SVM classifier combined with structural connectomic profiles demonstrated an accuracy of 82.8% and an AUC of 0.701 (95% CI, 0.606-0.784). Of the 456 patients with epilepsy, 242 patients were ASM good responders, whereas 214 patients were ASM poor responders. In the classification of the ASM responders, an SVM classifier based on the conventional DTI measures revealed an accuracy of 54.9% and an AUC of 0.551 (95% CI, 0.443-0.655). Another SVM classifier combined with structural connectomic profiles demonstrated an accuracy of 59.3% and an AUC of 0.594 (95% CI, 0.485-0.695).

CONCLUSION

DTI using a machine learning is useful for differentiating patients with focal epilepsy from healthy controls, but it cannot classify ASM responsiveness. Combining structural connectomic profiles results in a better classification performance than the use of conventional DTI measures alone for identifying focal epilepsy and ASM responsiveness.

Alteration of brain connectivity in neurologically asymptomatic patients with chronic kidney disease

Our previous study demonstrated that patients with end-stage renal disease had decreased structural and functional brain connectivity, and there was a significant association between brain connectivity and cognitive function. The aim of this study was to evaluate the alterations of structural and functional connectivity using graph theoretical analysis in neurologically asymptomatic patients with relatively early-stage chronic kidney disease (CKD).We enrolled 18 neurologically asymptomatic patients with early CKD and 28 healthy controls. All the subjects underwent diffusion-tension imaging and resting functional magnetic resonance imaging. We calculated structural and functional connectivity based on diffusion-tension imaging and resting functional magnetic resonance imaging using a graph theoretical analysis. Then, we investigated differences of structural and functional connectivity between the CKD patients and the healthy controls.All the measures of structural connectivity were significantly different between the patients with CKD and healthy controls. The global efficiency, local efficiency, mean clustering coefficient, and small-worldness index were decreased, whereas the characteristic path length was increased in the patients with CKD compared with healthy controls. The structural betweenness centrality of the left calcarine and right posterior cingulum was also significantly different from that in healthy participants. However, all the measures of global functional connectivity in patients with CKD were not different from those in healthy controls. In patients with CKD, the functional betweenness centrality of the right insular cortex, right occipital pole, and right thalamus was significantly different from that in healthy participants.There are significant alterations of the global structural connectivity between the patients with CKD and the healthy subjects, whereas the global functional connectivity of the brain network is preserved. We find that the efficiency of the structural brain network is decreased in the patients with CKD.

Renal Infarction Caused by Isolated Spontaneous Renal Artery Intramural Hematoma

BACKGROUND

Acute renal infarction is an uncommon condition resulting from an obstruction or a decrease in renal arterial blood flow. Isolated spontaneous renal artery intramural hematoma is a rare cause of renal infarction.

CASE REPORT

A 46-year-old healthy man presented to our emergency room because of sudden onset of severe right flank pain. An enhanced abdominal computed tomography scan showed a low-attenuated lesion in the lateral portion of the right kidney but no visible thromboembolisms in the main vessels. Computed tomography angiography revealed acute infarction resulting from intramural hematoma of the anterior segmental artery of the right kidney, with distal occlusion.

CONCLUSIONS

The rarity and non-specific clinical presentation of renal infarction often lead to a delayed diagnosis that may result in impaired renal function. Clinical suspicion is important in the early diagnosis, and intramural hematoma of the renal artery should be considered the cause of renal infarction even in healthy patients without predisposing factors.