Splenic vein thrombosis and pancreatic fistula after minimally invasive distal pancreatectomy

BACKGROUND

This study aimed to investigate the clinical relevance of splenic vein thrombosis (SVT) in the splenic vein remnant following minimally invasive distal pancreatosplenectomy (DPS).

METHODS

Medical records of patients who underwent laparoscopic or robotic distal pancreatectomy (DP) with or without splenectomy between January 2006 and August 2012 were reviewed. Rates of SVT and clinically relevant postoperative pancreatic fistula (POPF) were compared in a group of patients undergoing DPS and a group having spleen-preserving DP.

RESULTS

Seventy-nine patients had minimally invasive DP, of whom 38 (48 per cent) developed SVT in the splenic vein remnant. DPS was associated with POPF (P = 0.001) and SVT (P < 0.001). SVT length was closely related to the amount of peripancreatic fluid collection (P = 0.025) and POPF (P = 0.045). In a comparison of splenic vessel-sacrificing, spleen-preserving DP and DPS, postoperative platelet count was significantly higher in the DPS group (P < 0.001). In addition, grade of SVT (P = 0.092) and POPF (P = 0.065) tended to be associated with DPS, suggesting that SVT may be related to both splenectomy and POPF.

CONCLUSION

Minimally invasive DPS is associated with SVT and POPF. Preservation of the spleen should be considered when treating patients with benign and borderline malignant tumours of the distal pancreas.

InGaN/GaN microcolumn light-emitting diode arrays with sidewall metal contact

In this study, we produce InGaN/GaN microcolumn LED (MC-LED) arrays having nonpolar metal sidewall contacts using a top-down method, where the metal contacts only with the sidewall of the columnar LEDs with an open top for transparency. The trapezoidal profile of the as-etched columns was altered to a rectangular profile through KOH treatment, exposing the nonpolar sidewalls. While the MC-LED with no treatment emitted no light because of the etch-damaged region, the MC-LEDs with KOH treatment exhibited much improved the electrical properties with the much higher shunt resistance due to the removal of the etch-damaged region. The optical output power was strongest for the MC-LED with a 5-min treatment indicating an almost complete removal of the damaged region.

Detection and quantification of a radiation-associated mitochondrial DNA deletion by a nested real-time PCR in human peripheral lymphocytes

In this study we implemented a new assay using a nested real-time polymerase chain reaction (PCR) to detect radiation-induced common deletion (CD) in mitochondrial DNA (mtDNA) of human peripheral lymphocytes. A standard curve for real-time PCR was established by applying a plasmid DNA containing human normal mtDNA or mutated mtDNA. Human peripheral lymphocyte DNA was amplified and quantified by real-time PCR using primer sets for total damaged or mutated mtDNA, plus probes labeled with the fluorescent dyes. The first-round PCR generated multiple products were used as the template for a second-round PCR. We herein describe a nested real-time PCR assay capable of quantifying mtDNA bearing the CD in human peripheral lymphocytes following exposure (in vitro) to (137)Cs γ-rays in a dose range of 0.5 up to 5Gy. The reproducibility of this assay was evident for both unirradiated and irradiated samples by examining human blood lymphocytes from 14 donors. This technique was sensitive enough to detect deletions in mtDNA at low dose levels, as low as 0.5Gy, and higher levels of CD mtDNA were evident at higher doses (≥1Gy), however, there was no consistent dose-response relationship.

Identification of inositol polyphosphate 4-phosphatase type II as a novel tumor resistance biomarker in human laryngeal cancer HEp-2 cells

Although tumor resistance remains a significant impediment to successful radiotherapy, associated regulatory markers and detailed molecular mechanisms underlying this phenomenon are not well defined. In this study, we identified inositol polyphosphate 4-phosphatase type II (INPP4B) as a novel marker of radioresistance by systematically analyzing Unigene libraries of laryngeal cancer. INPP4B was highly expressed in radioresistant laryngeal cancer cells and was induced by treatment with either radiation or anticancer drugs in various types of cancer cells. Ectopic INPP4B overexpression increased radioresistance and anticancer drug resistance by suppressing apoptosis in HEp-2 cells. Conversely, INPP4B depletion with small interfering RNA resensitized HEp-2 as well as A549 and H1299 cells to radiation- and anticancer drug-induced apoptosis. Furthermore, radiation-induced INPP4B expression was blocked by inhibition of extracellular signal-regulated kinase (ERK). INPP4B depletion significantly attenuated radiation-induced increases in Akt phosphorylation, indicating an association of INPP4B-mediated radioresistance with Akt survival signaling. Taken together, our data suggest that ERK-dependent induction of INPP4B triggers the development of a tumor-resistance phenotype via Akt signaling and identify INPP4B as a potentially important target molecule for resolving the radioresistance of cancer cells.

Gamma irradiation-induced oxidative stress and developmental impairment in the hermaphroditic fish, Kryptolebias marmoratus embryo

This study investigated the effects of gamma radiation on the early developmental stages in hermaphroditic fish embryos of Kryptolebias marmoratus. The authors measured reactive oxygen species (ROS) level and antioxidant enzyme activities with the endpoint hatching rate after gamma irradiation of different embryonic stages. Then, the transcriptional changes of antioxidant enzyme-coding genes were evaluated by quantitative real-time reverse transcription polymerase chain reaction in response to gamma radiation on embryonic stages. Gamma radiation inhibited hatching rate and caused developmental impairment in a dose-dependent manner. Embryos showed tolerances in a developmental stage-dependent manner, indicating that early embryonic stages were more sensitive to the negative effects of gamma radiation than were later stages. After 5 Gy rate of radiation, the ROS level increased significantly at embryonic stages 2, 3, and 4 with a significant induction of all antioxidant enzyme activities. The expressions of glutathione S-transferase isoforms, catalase, superoxide dismutase (Mn-SOD, Cu/Zn-SOD), glutathione reductase, and glutathione peroxidase mRNA were upregulated in a dose-and-developmental stage-dependent manner. This finding indicates that gamma radiation can induce oxidative stress and subsequently modulates the expression of antioxidant enzyme-coding genes as one of the defense mechanisms. Interestingly, embryonic stage 1 exposed to gamma radiation showed a decreased expression in most antioxidant enzyme-coding genes, suggesting that this is also related to a lower hatching rate and developmental impairment. The results of this study provide a better understanding of the molecular mode of action of gamma radiation in aquatic organisms.

The effect of donor-recipient relationship on long-term outcomes of living related donor renal transplantation

BACKGROUND

Presensitization to human leukocyte antigen (HLA) tends to decrease renal graft survival. During the pregnancy, fetal blood is frequently exposed to the maternal circulation possibly inducing maternal immunization to paternal HLA inherited by the fetus. In this way, pregnancy may occasionally present a hazard to renal graft survival. In this study, we compared retrospectively graft survivals according to living related donor-recipient pairs.

MATERIALS AND METHODS

From July 1979 to January 2011, 374 patients underwent living related renal transplantation sharing at least one HLA haplotype with their donor. We compared acute rejection and complication rates as well as long-term graft survival according to the donor-recipient paring: child-to-mother, child-to-father, mother-to-child, father-to-child, and one haplotype-matched siblings. All patients received immunosuppressive therapy, consisting of a calcineurin inhibitor, mycophenolate mofetil, or azathioprine and prednisolone.

RESULTS

Twenty-one cases (5.6%) were child-to-father paring; 28 (7.5%), child-to-mother; 179 (47.9%), one-haplotype-matched siblings; 46 (12.3%), father-to-child; and 100 (26.7%), mother-to-child paring. Child-to-father pairing displayed the best graft survival; child-to-mother (hazard ratio [HR] = 1.709, P = .662) and one-haplotype-matched siblings (HR = 6.589, P = .062) showed no significant difference. Father-to-child pares experienced poorer outcomes than child-to-father pairs (HR = 11.579, P = .017) and mother-to-child, the poorest graft survival (HR 17.188, P = .005).

CONCLUSION

Pregnancy continues to be a significant source of presensitization in the course of gestation and after parturition. Graft failure can result from an anamnestic reaction subsequent to intrauterine exposure of the mother to HLA of a fetus due to sensitization.

The role of the altruistic unbalanced chain in exchange living donor renal transplantation: single-center experience

BACKGROUND

The exchange donor program in renal transplantation is an efficient solution for recipients with a blood type or crossmatch-incompatible donor. However, this program has some difficulties to define unacceptable human leukocyte antigen matches, deteriorating clinical potential recipient condition, and withdrawal of donor consent. We analyzed the outcomes of exchange donor renal transplantation through the altruistic unbalanced chain.

METHODS

Among 152 cases of exchange donor renal transplantation from 1991 to 2010 in our hospital, we performed 58 procedures through altruistic unbalanced chains. We compared their outcomes with the direct and balanced chain group. We analyzed retrospectively whether this program expanded the donor pool, seeking better immunologic, size, and age matching.

RESULTS

The graft survival and acute rejection rates did not differ significantly in the two groups. Of 152 cases, 58 (38.2%) renal transplantations were performed through an unbalanced chain. Seventeen waiting list recipients were transplanted through an altruistic unbalanced chain. In blood type O recipients (n = 32), the causes of registration in the exchange program were ABO incompatibility (93.3%), and positive crossmatch (6.7%). Nine altruistic blood type O donors and 9 (28.1%) type O recipients underwent transplantations through this chain.

CONCLUSIONS

We suggest the altruistic unbalanced chain may expand the donor pool with advantages for difficult-to-match pairs. The disadvantages of type O recipients may be overcome through the use of an unbalanced chain. The altruistic unbalanced exchange transplantation program can help easy-to-match subjects, shortening the waiting periods.

The utilization and advantages of an exchange donor program in living donor renal transplantation: a single-center experience

INTRODUCTION

The availability of donors is a major limiting factor in living donor renal transplantation. Approximately one third of patients with end-stage renal disease have willing potential living donors who are blood type or cross-match incompatible. The living donor kidney exchange has become an efficient solution for recipients in this situation. We analyzed the outcome and advantages of an exchange donor program compared with ABO-incompatible transplantation and desensitized protocol transplantation for highly sensitized patients.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 152 exchange donor cases from 1991 to 2010. We analyzed the risk factors, outcomes, matching factors, complication rates, and acute rejection rates of this program compared with other alternative strategies.

RESULTS

In our center, 22% of total living donor kidney transplantations were performed through an exchange program and an expanded donor pool. The graft survival, complication, and acute rejection rates were not significantly different compared with the alternatives. The severe complication rates were lower than with the alternatives and the immunosuppressant protocol and preoperative preparation were simpler. Blood type O recipients who registered in the exchange program showed no significant differences from the living related groups (P = .45), which were similar to the proportions for other ABO types. Upon multivariate analysis, an acute rejection episode and use of mycophenolate mofetil (MMF) were significant factors associated with graft survival (P = .015 and P = .007; odds ratio [OR] 5.968 and 7.324; 95% confidence interval [CI] .003-.533 and .098-.690).

CONCLUSION

Although exchange donor programs are not the sole solution, they show several advantages, such as the prescription of standard immunosuppression, simple preoperative preparation, low cost, and modest rates of severe complications compared with ABO-incompatible transplantation or desensitized protocols.

Cells with dysfunctional telomeres are susceptible to reactive oxygen species hydrogen peroxide via generation of multichromosomal fusions and chromosomal fragments bearing telomeres

During genotoxic stress, reactive oxygen species hydrogen peroxide (H(2)O(2)) is a prime mediator of the DNA damage response. Telomeres function both to assist in DNA damage repair and to inhibit chromosomal end-to-end fusion. Here, we show that telomere dysfunction renders cells susceptible to H(2)O(2), via generation of multichromosomal fusion and chromosomal fragments. H(2)O(2) caused formation of multichromosomal end-to-end fusions involving more than three chromosomes, preferentially when telomeres were erosive. Interestingly, extensive chromosomal fragmentation (yielding small-sized fragments) occurred only in cells exhibiting such multichromosomal fusions. Telomeres were absent from fusion points, being rather present in the small fragments, indicating that H(2)O(2) cleaves chromosomal regions adjacent to telomeres. Restoration of telomere function or addition of the antioxidant N-acetylcysteine prevented development of chromosomal aberrations and rescued the observed hypersensitivity to H(2)O(2). Thus, chromosomal regions adjacent to telomeres become sensitive to reactive oxygen species hydrogen peroxide when telomeres are dysfunctional, and are cleaved to produce multichromosomal fusions and small chromosomal fragments bearing the telomeres.

Nicotinamide phosphoribosyltransferase is essential for interleukin-1beta-mediated dedifferentiation of articular chondrocytes via SIRT1 and extracellular signal-regulated kinase (ERK) complex signaling

Although much is known about interleukin (IL)-1β and its role as a key mediator of cartilage destruction in osteoarthritis, only limited information is available on IL-1β signaling in chondrocyte dedifferentiation. Here, we have characterized the molecular mechanisms leading to the dedifferentiation of primary cultured articular chondrocytes by IL-1β treatment. IL-1β or lipopolysaccharide, but not phorbol 12-myristate 13-acetate, retinoic acid, or epidermal growth factor, induced nicotinamide phosphoribosyltransferase (NAMPT) expression, showing the association of inflammatory cytokines with NAMPT regulation. SIRT1, in turn, was activated NAMPT-dependently, without any alteration in the expression level. Activation or inhibition of SIRT1 oppositevely regulates IL-1β-mediated chondrocyte dedifferentiation, suggesting this protein as a key regulator of chondrocytes phenotype. SIRT1 activation promotes induction of ERK and p38 kinase activities, but not JNK, in response to IL-1β. Subsequently, ERK and p38 kinase activated by SIRT1 also induce SIRT1 activation, forming a positive feedback loop to sustain downstream signaling of these kinases. Moreover, we found that the SIRT1-ERK complex, but not SIRT1-p38, is engaged in IL-1β-induced chondrocyte dedifferentiation via a Sox-9-mediated mechanism. JNK is activated by IL-1β and modulates dedifferentiation of chondrocytes, but this pathway is independent on NAMPT-SIRT1 signaling. Based on these findings, we propose that IL-1β induces dedifferentiation of articular chondrocytes by up-regulation of SIRT1 activity enhanced by both NAMPT and ERK signaling.

The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in Jurkat cells.

Ultraviolet B retards growth, induces oxidative stress, and modulates DNA repair-related gene and heat shock protein gene expression in the monogonont rotifer, Brachionus sp

Ultraviolet B (UV-B) radiation causes direct cellular damage by breakage of DNA strands and oxidative stress induction in aquatic organisms. To understand the effect of UV-B radiation on the rotifer, Brachionus sp., several parameters including 24-h survival rate, population growth rate, and ROS level were measured after exposure to a wide range of UV-B doses. To check the expression of other important inducible genes such as replication protein A (RPA), DNA-dependent protein kinase (DNA-PK), Ku70, Ku80, and heat shock proteins (hsps) after UV-B radiation, we observed dose- and time-dependency at 2kJ/m(2). We also examined 13 hsp genes for their roles in the UV-B damaged rotifer. Results showed that UV-B remarkably inhibited the population growth of Brachionus sp. The level of intracellular reactive oxygen species (ROS) was high at 2kJ/m(2), suggesting that 2kJ/m(2) would already be toxic. This result was supported by other enzymatic activities, such as GSH levels, glutathione peroxidase, glutathione S-transferase, and glutathione reductase. For dose dependency, low doses of UV-B radiation (2, 4, and 6kJ/m(2)) significantly up-regulated the examined genes (e.g. RPA, DNA-PK, Ku70, and Ku80). For the time course study, RPA genes showed immediate up-regulation but returned to basal or lower expression levels compared to the control 3h after UV-B exposure. The DNA-PK and Ku70/80 genes significantly increased, indicating that they may be involved in repairing processes against a low dose of UV-B exposure (2kJ/m(2)). At the basal level, the hsp90α1 gene showed the highest expression, and followed by hsp10, hsp30, hsp60, and hsc70, and hsp90β in adults (w/o egg). In eggs, the hsp10 gene was expressed the highest, and followed by hsp30, hsp27, hsp90α1, and hsp60 genes. In real-time RT-PCR array on rotifer hsp genes, low doses of UV-B radiation (2 and 4kJ/m(2)) showed up-regulation of several hsp genes but most of the hsp genes showed down-regulation at 8kJ/m(2) and higher, indicating that significant Hsp-mediated cellular damage already occurred at low doses. For the time course study of four hsp genes (hsp20, hsp27, hsp70, hsp90α1), they showed a significant correlation for UV-B radiation (2kJ/m(2)). In this paper, we demonstrated that UV-B radiation would affect growth retardation with up- or down-regulation of some important genes in DNA replication, repair process, and chaperoning. This finding provides a better understanding of molecular mechanisms involved in UV-B-mediated cellular damage in the rotifer, Brachionus sp.

Paclitaxel stimulates chromosomal fusion and instability in cells with dysfunctional telomeres: implication in multinucleation and chemosensitization

The anticancer effect of paclitaxel is attributable principally to irreversible promotion of microtubule stabilization and is hampered upon development of chemoresistance by tumor cells. Telomere shortening, and eventual telomere erosion, evoke chromosomal instability, resulting in particular cellular responses. Using telomerase-deficient cells derived from mTREC-/-p53-/- mice, here we show that, upon telomere erosion, paclitaxel propagates chromosomal instability by stimulating chromosomal end-to-end fusions and delaying the development of multinucleation. The end-to-end fusions involve both the p- and q-arms in cells in which telomeres are dysfunctional. Paclitaxel-induced chromosomal fusions were accompanied by prolonged G2/M cell cycle arrest, delayed multinucleation, and apoptosis. Telomere dysfunctional cells with mutlinucleation eventually underwent apoptosis. Thus, as telomere erosion proceeds, paclitaxel stimulates chromosomal fusion and instability, and both apoptosis and chemosensitization eventually develop.

Clinical outcomes of multicenter domino kidney paired donation

Domino kidney paired donation (KPD) is a method by which an altruistic living nondirected donor (LND) is allocated to a pool of incompatible donor-recipient pairs (DRP) and a series of KPDs is initiated. To evaluate the feasibility and clinical outcomes of multicenter domino KPD, we retrospectively analyzed a cohort of DRPs who underwent domino KPD between February 2001 and July 2007 at one of 16 transplant centers. One hundred seventy-nine kidney transplants were performed, with 70 domino chains initiated by altruistic LND. There were 45 two-pair chains, 15 three-pair chains, 7 four-pair chains, 2 five-pair chains and 1 six-pair chain. A majority of donors were spouses (47.5%) or altruistic LNDs (39.1%). DRPs with a blood type O recipient or an AB donor comprised 45.9% of transplanted DRPs. HLA mismatch improved in transplanted donors compared to intended donors in pairs enrolled to improve HLA mismatch (3.4 +/- 0.7 vs. 4.8 +/- 1.0, p < 0.001). One-year and 5-year graft survival rates were 98.3% and 87.7%, respectively, with a median follow-up of 46 months. One-year and 5-year patient survival rates were 97.2% and 90.8%, respectively. In conclusion, multicenter domino KPD could multiply the benefits of donation from LNDs, with patients and graft survival rates comparable to those seen with conventional KPD.

The Rac1/MKK7/JNK pathway signals upregulation of Atg5 and subsequent autophagic cell death in response to oncogenic Ras

To prevent the development of malignancies, mammalian cells activate disposal programs, such as programmed cell death, in response to deregulated oncogene expression. However, the molecular basis for regulation of cellular disposal machinery in response to activated oncogenes is unclear at present. In this study, we show that upregulation of the autophagy-related protein, Atg5, is critically required for the oncogenic H-ras-induced autophagic cell death and that Rac1/mitogen-activated kinase kinase (MKK) 7/c-Jun N-terminal kinase (JNK) signals upregulation of Atg5. Overexpression of H-ras(V12) induced marked autophagic vacuole formation and cell death in normal fibroblasts, which remained unaffected by a caspase inhibitor. Pretreatment with Bafilomycin A1, an autophagy inhibitor, completely attenuated H-ras(V12)-induced cell death as well as autophagic vacuole formation. Selective production of Atg5 was observed in cells overexpressing H-ras(V12), and small interfering RNA (siRNA) targeting of Atg5 clearly inhibited autophagic cell death. Interestingly, inhibition of JNK or c-Jun by specific siRNA suppressed Atg5 upregulation and autophagic cell death. Moreover, inhibition of MKK7, but not MKK4, effectively attenuated H-ras(V12)-induced JNK activation. In addition, ectopic expression of RacN17 or Rac1-siRNA effectively inhibited MKK7-JNK activation, Atg5 upregulation and autophagic cell death. These data support the notion that upregulation of Atg5 is required for the oncogenic H-ras-induced autophagic cell death in normal fibroblasts and that activation of Rac1/MKK7/JNK-signaling pathway leads to upregulation of Atg5 in response to oncogenic H-ras. Our findings suggest that in cells acquiring deregulated oncogene expression, oncogenic stress triggers autophagic cell death, which protects cells against malignant progression.

p31comet Induces cellular senescence through p21 accumulation and Mad2 disruption

Functional suppression of spindle checkpoint protein activity results in apoptotic cell death arising from mitotic failure, including defective spindle formation, chromosome missegregation, and premature mitotic exit. The recently identified p31(comet) protein acts as a spindle checkpoint silencer via communication with the transient Mad2 complex. In the present study, we found that p31(comet) overexpression led to two distinct phenotypic changes, cellular apoptosis and senescence. Because of a paucity of direct molecular link of spindle checkpoint to cellular senescence, however, the present report focuses on the relationship between abnormal spindle checkpoint formation and p31(comet)-induced senescence by using susceptible tumor cell lines. p31(comet)-induced senescence was accompanied by mitotic catastrophe with massive nuclear and chromosomal abnormalities. The progression of the senescence was completely inhibited by the depletion of p21(Waf1/Cip1) and partly inhibited by the depletion of the tumor suppressor protein p53. Notably, p21(Waf1/Cip1) depletion caused a dramatic phenotypic conversion of p31(comet)-induced senescence into cell death through mitotic catastrophe, indicating that p21(Waf1/Cip1) is a major mediator of p31(comet)-induced cellular senescence. In contrast to wild-type p31(comet), overexpression of a p31 mutant lacking the Mad2 binding region did not cause senescence. Moreover, depletion of Mad2 by small interfering RNA induced senescence. Here, we show that p31(comet) induces tumor cell senescence by mediating p21(Waf1/Cip1) accumulation and Mad2 disruption and that these effects are dependent on a direct interaction of p31(comet) with Mad2. Our results could be used to control tumor growth.

Fission yeast-based screening to identify putative HDAC inhibitors using a telomeric reporter strain

Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the ura4(+) gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and p21(waf1/cip1) also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

Effect of fudosteine on mucin production

Fudosteine is a novel mucoactive agent, although little is known about how fudosteine decreases mucin production. The present study examined the effects of fudosteine on MUC5AC mucin synthesis and cellular signalling. An animal model of lipopolysaccharide (LPS)-induced inflammation and a bronchial epithelial cell line model of tumour necrosis factor (TNF)-alpha-induced inflammation were used. Fudosteine was administered before stimulation with LPS or TNF-alpha. The MUC5AC mucin levels were assayed and the expression of the MUC5AC gene was measured. Western blotting was carried out for the detection of phosphorylated epidermal growth factor receptor (p-EGFR), phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK) and phosphorylated extracellular signal-related kinase (p-ERK). MUC5AC mucin synthesis and the expression of the MUC5AC gene were increased by LPS in rats or TNF-alpha in NCI-H292 cells; these effects were inhibited by fudosteine treatment. After stimulation with LPS or TNF-alpha, the expression of p-EGFR, p-p38 MAPK and p-ERK were detected. Fudosteine treatment reduced the expression levels of p-p38 MAPK and p-ERK in vivo and of p-ERK in vitro. The present results suggest fudosteine inhibits MUC5AC mucin hypersecretion by reducing MUC5AC gene expression and the effects of fudosteine are associated with the inhibition of extracellular signal-related kinase and p38 mitogen-activated protein kinase in vivo and extracellular signal-related kinase in vitro.

A novel function for HSF1-induced mitotic exit failure and genomic instability through direct interaction between HSF1 and Cdc20

Although heat-shock factor (HSF) 1 is a known transcriptional factor of heat-shock proteins, other pathways like production of aneuploidy and increased protein stability of cyclin B1 have been proposed. In the present study, the regulatory domain of HSF1 (amino-acid sequence 212-380) was found to interact directly with the amino-acid sequence 106-171 of Cdc20. The association between HSF1 and Cdc20 inhibited the interaction between Cdc27 and Cdc20, the phosphorylation of Cdc27 and the ubiquitination activity of anaphase-promoting complex (APC). The overexpression of HSF1 inhibited mitotic exit and the degradations of cyclin B1 and securin, which resulted in production of aneuploidy and multinucleated cells, but regulatory domain-deficient HSF1 did not. Moreover, HSF1-overexpressing cells showed elevated levels of micronuclei and genomic alteration. The depletion of HSF1 from cells highly expressing HSF1 reduced nocodazole-mediated aneuploidy in cells. These findings suggest a novel function of HSF1 frequently overexpressed in cancer cells, to inhibit APC/C activity by interacting with Cdc20, and to result in aneuploidy development and genomic instability.

The micronucleus frequency in cytokinesis-blocked lymphocytes of cattle in the vicinity of a nuclear power plant

Cytogenetic and hematological analyses were performed on the peripheral blood lymphocytes (PBLs) obtained from Korean native cattle bred in the vicinity of three nuclear power plants (Wolsong, Uljin and Yeonggwang) and in a control area. The micronucleus (MN) rates for the cattle from the Wolsong, Uljin and Yeonggwang nuclear power plants and for the control area were 9.87 +/- 2.64, 8.90 +/- 3.84, 9.20 +/- 3.68 and 9.60 +/- 3.91 per 1,000 cytokinesis-blocked lymphocytes, respectively. The apparent difference is not statistically significant. The MN frequencies of PBLs from cattle bred in the four areas are within the background variation for this study. The MN frequencies and hematological values were similar regardless of whether the cattle were bred near a nuclear power plant or in the control area.