Metabolomics and miRNA profiling reveals feature of gallbladder cancer-derived biliary extracellular vesicles

BACKGROUND

Although there are several studies in the development of various human cancers, the role of exosomes is poorly understood in the progression of gallbladder cancer. This study aims to characterize the metabolic changes occurring in exosomes obtained from patients with gallbladder cancer compared with those from other gallbladder disease groups.

METHODS

Biliary exosomes were isolated from healthy donors (n = 3) and from patients with gallbladder cancer (n = 3), gallbladder polyps (n = 4), or cholecystitis (n = 3) using a validated exosome isolation kit. Afterward, we performed miRNA profiling and untargeted metabolomic analysis of the exosomes. The results were validated by integrating the results of the miRNA and metabolomic analyses.

RESULTS

The gallbladder cancer group exhibited a significant reduction in the levels of multiple unsaturated phosphatidylethanolamines and phosphatidylcholines compared to the normal group, which resulted in the loss of exosome membrane integrity. Additionally, the gallbladder cancer group demonstrated significant overexpression of miR-181c and palmitic acid, and decreased levels of conjugated deoxycholic acid, all of which are strongly associated with the activation of the PI3K/AKT pathway.

CONCLUSIONS

Our findings demonstrate that the contents of exosomes are disease-specific, particularly in gallbladder cancer, and that altered metabolites convey critical information regarding their phenotype. We believe that our metabolomic and miRNA profiling results may provide important insights into the development of gallbladder cancer.

Characteristics of Hf0.5Zr0.5O2 Thin Films Prepared by Direct and Remote Plasma Atomic Layer Deposition for Application to Ferroelectric Memory

Hf_0.5Zr_0.5O₂ (HZO) thin film exhibits ferroelectric properties and is presumed to be suitable for use in next-generation memory devices because of its compatibility with the complementary metal-oxide-semiconductor (CMOS) process. This study examined the physical and electrical properties of HZO thin films deposited by two plasma-enhanced atomic layer deposition (PEALD) methods- direct plasma atomic layer deposition (DPALD) and remote plasma atomic layer deposition (RPALD)-and the effects of plasma application on the properties of HZO thin films. The initial conditions for HZO thin film deposition, depending on the RPALD deposition temperature, were established based on previous research on HZO thin films deposited by the DPALD method. The results show that as the measurement temperature increases, the electric properties of DPALD HZO quickly deteriorate; however, the RPALD HZO thin film exhibited excellent fatigue endurance at a measurement temperature of 60 °C or less. HZO thin films deposited by the DPALD and RPALD methods exhibited relatively good remanent polarization and fatigue endurance, respectively. These results confirm the applicability of the HZO thin films deposited by the RPALD method as ferroelectric memory devices.

Anterior cruciate ligament remnant-preserving and re-tensioning reconstruction: a biomechanical comparison study of three different re-tensioning methods in a porcine model

BACKGROUND

With the developments in the arthroscopic technique, anterior cruciate ligament (ACL) remnant-preserving reconstruction is gradually gaining attention with respect to improving proprioception and enhancing early revascularization of the graft. To evaluate the mechanical pull-out strength of three different methods for remnant-preserving and re-tensioning reconstruction during ACL reconstruction.

METHODS

Twenty-seven fresh knees from mature pigs were used in this study. Each knee was dissected to isolate the femoral attachment of ACL and cut the attachment. An MTS tensile testing machine with dual-screw fixation clamp with 30° flexion angle was used. The 27 specimens were tested after applying re-tensioning sutures with No. 0 polydioxanone (PDS), using the single stitch (n = 9), loop stitch (n = 9), and triple stitch (n = 9) methods. We measured the mode of failure, defined as (1) ligament failure (longitudinal splitting of the remnant ACL) or (2) suture failure (tearing of the PDS stitch); load-to-failure strength; and stiffness for the three methods. Kruskal-Wallis test and Mann-Whitney U-test were used to compare the variance of load-to-failure strength and stiffness among the three groups.

RESULTS

Ligament failure occurred in all cases in the single stitch group and in all but one case in the triple stitch group. Suture failure occurred in all cases in the loop stitch group and in one case in the triple stitch group. The load-to-failure strength was significantly higher with loop stich (91.52 ± 8.19 N) and triple stitch (111.1 ± 18.15 N) than with single stitch (43.79 ± 11.54 N) (p = 0.002). With respect to stiffness, triple stitch (2.50 ± 0.37 N/mm) yielded significantly higher stiffness than the other methods (p = 0.001).

CONCLUSIONS

The results suggested that loop stitch or triple stitch would be a better option for increasing the mechanical strength when applying remnant-preserving and re-tensioning reconstruction during ACL reconstruction.

Efficacy of bone formation of microporous sphere-shaped biphasic calcium phosphate in a rabbit skull bone defect model

Bone graft is required in various surgical procedures. Although autograft is the gold standard, it has limited availability. Various compounds have been proposed as alternatives such as biphasic calcium phosphate (BCP), which is the most widely used compound. The newly synthesized microporous sphere-shaped BCP has the advantage of increasing contact surface, and it can induce the formation of microbone structures. A putty-type contains the addition of a fluid carrier to the sphere-shaped BCP and can be easily used for a small orifice large bone defect. To compare the widely used BCP products, new bone formation and residual graft materials (RGM) were evaluated for 6 and 12 weeks in a rabbit calvarial bone defect model. Although existing BCP products and the microporous sphere-type product did not differ significantly with respect to new bone formation and RGM, the putty-type product was largely washed out and had low new bone formation at 6 and 12 weeks. Overall, the results suggest that microporous sphere-shaped BCP showed similar bone formation capability to existing products and was able to maintain higher initial mechanical stability.

Titanium Porous Coating Using 3D Direct Energy Deposition (DED) Printing for Cementless TKA Implants: Does It Induce Chronic Inflammation?

Because of the recent technological advances, the cementless total knee arthroplasty (TKA) implant showed satisfactory implant survival rate. Newly developed 3D printing direct energy deposition (DED) has superior resistance to abrasion as compared to traditional methods. However, there is still concern about the mechanical stability and the risk of osteolysis by the titanium (Ti) nanoparticles. Therefore, in this work, we investigated whether DED Ti-coated cobalt-chrome (CoCr) alloys induce chronic inflammation reactions through in vitro and in vivo models. We studied three types of implant surfaces (smooth, sand-blasted, and DED Ti-coated) to compare their inflammatory reaction. We conducted the in vitro effect of specimens using the cell counting kit-8 (CCK-8) assay and an inflammatory cytokine assay. Subsequently, in vivo analysis of the immune profiling, cytokine assay, and histomorphometric evaluation using C57BL/6 mice were performed. There were no significant differences in the CCK-8 assay, the cytokine assay, and the immune profiling assay. Moreover, there were no difference for semi-quantitative histomorphometry analysis at 4 and 8 weeks among the sham, smooth, and DED Ti-coated samples. These results suggest that DED Ti-coated printing technique do not induce chronic inflammation both in vitro and in vivo. It has biocompatibility for being used as a surface coating of TKA implant.

X-ray reflectivity study on the structure and phase stability of mixed phospholipid multilayers

Vertically oriented multilayers composed of two saturated phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoserine (DPPS), were deposited on silicon. X-ray reflectivity was used to investigate the structures of the variously mixed phospholipid multilayers as a function of composition. Then, the phase stability was investigated at various annealing temperatures under humid conditions. The results indicated that the lipid spacing of the mixed phospholipid multilayers varied systematically as a function of the DPPC/DPPS ratio and that no macroscopic phase separation occurred during the annealing process under both dry and humid conditions.

Combretoxazolones: synthesis, cytotoxicity and antitumor activity

Two series of combretoxazolones including 3,4-diaryloxazolones (6) and 4,5-diaryloxazolones (7) were synthesized and evaluated for cytotoxicity and antitumor activity. Both series showed strong cytotoxicities against a variety of tumor cell lines. Compound 6g exhibited a significant antitumor activity in BDF1 mice bearing B16 murine melanoma cells with inhibition rates of 67 and 61% at 100 and 30 mg/kg/day, respectively.

Null RPGRIP1 alleles in patients with Leber congenital amaurosis

We isolated and characterized the entire coding sequence of a human gene encoding a protein that interacts with RPGR, a protein that is absent or mutant in many cases of X-linked retinitis pigmentosa. The newly identified gene, called "RPGRIP1" for RPGR-interacting protein (MIM 605446), is located within 14q11, and it encodes a protein predicted to contain 1,259 amino acids. Previously published work showed that both proteins, RPGR and RPGRIP1, are present in the ciliary structure that connects the inner and outer segments of rod and cone photoreceptors. We surveyed 57 unrelated patients who had Leber congenital amaurosis for mutations in RPGRIP1 and found recessive mutations involving both RPGRIP1 alleles in 3 (6%) patients. The mutations all create premature termination codons and are likely to be null alleles. Patients with RPGRIP1 mutations have a degeneration of both rod and cone photoreceptors, and, early in life, they experience a severe loss of central acuity, which leads to nystagmus.

Syntheses of Certain 3-Aryl-2-propenoates and Evaluation of their Cytotoxicity

A series of 3-aryl-2-propenoates including cinnamates, (E)-methyl/ethyl 3-[2-(1,4-dimethoxy-5,8-dione)naphthalenyl]-2-propenoates (8ba, 8bb) and (E)-methyl/ethyl 3-[2-(1,4-dihydroxy-9,10-dione)anthracenyl]-2-propenoates (9aa,9ab) was synthesized and evaluated for antitumor cytotoxicity. It was found that the ortho- or para-dihydroxy funtionality on the aryl ring was essential for the cytotoxicity of cinnamates. Compounds 8ba, 8bb and 9aa, 9ab showed potent cytotoxicity against various tumor cell lines.

Retinitis pigmentosa GTPase regulator (RPGRr)-interacting protein is stably associated with the photoreceptor ciliary axoneme and anchors RPGR to the connecting cilium

Retinitis pigmentosa (RP) is a blinding retinal disease in which the photoreceptor cells degenerate. Mutations in the gene for retinitis pigmentosa GTPase regulator (RPGR) are a frequent cause of RP. The function of RPGR is not well understood, but it is thought to be a putative guanine nucleotide exchange factor for an unknown G protein. Ablation of the RPGR gene in mice suggested a role in maintaining the polarized distribution of opsin across the cilia. To investigate its function, we used a protein interaction screen to identify candidate proteins that may interact physiologically with RPGR. One such protein, designated RPGR-interacting protein (RPGRIP), is expressed specifically in rod and cone photoreceptors. It consists of an N-terminal region predicted to form coiled coil structures linked to a C-terminal tail that binds RPGR. In vivo, both proteins co-localize in the photoreceptor connecting cilia. RPGRIP is stably associated with the ciliary axoneme independent of RPGR and is resistant to extraction under conditions that partially solubilized other cytoskeletal components. When over-expressed in heterologous cell lines, RPGRIP appears in insoluble punctate and filamentous structures. These data suggest that RPGRIP is a structural component of the ciliary axoneme, and one of its functions is to anchor RPGR within the cilium. RPGRIP is the only protein known to localize specifically in the photoreceptor connecting cilium. As such, it is a candidate gene for human photoreceptor disease. The tissue-specific expression of RPGRIP explains why mutations in the ubiquitously expressed RPGR confer a photoreceptor-specific phenotype.

A retinitis pigmentosa GTPase regulator (RPGR)- deficient mouse model for X-linked retinitis pigmentosa (RP3)

The X-linked RP3 locus codes for retinitis pigmentosa GTPase regulator (RPGR), a protein of unknown function with sequence homology to the guanine nucleotide exchange factor for Ran GTPase. We created an RPGR-deficient murine model by gene knockout. In the mutant mice, cone photoreceptors exhibit ectopic localization of cone opsins in the cell body and synapses and rod photoreceptors have a reduced level of rhodopsin. Subsequently, both cone and rod photoreceptors degenerate. RPGR was found normally localized to the connecting cilia of rod and cone photoreceptors. These data point to a role for RPGR in maintaining the polarized protein distribution across the connecting cilium by facilitating directional transport or restricting redistribution. The function of RPGR is essential for the long-term maintenance of photoreceptor viability.

Effect of extracellular cations on the chemotherapeutic efficacy of anticancer drugs

Cancer development and the efficiency of chemotherapy relies on the patients calcium-related pathological status such as hyper- or hypocalcemia. In the present study, we investigated the effect of extracellular cations such as calcium and magnesium on the therapeutic efficacy of antitumor drugs. The analytic parameters used were cellular drug uptake/excretion and the chemosensitivity of the human breast cancer cell lines, MCF7 and MCF7/ADR. Both calcium and magnesium ions decreased the membrane permeability of cancer cells, which was determined by cell size analysis. These divalent ions also lowered the drug uptake and the cytoplasmic levels of rhodamine 123 and adriamycin, suggesting that they might interfere with the diffusion of these drugs by modifying the physical properties of the cytoplasmic membrane. The acute cytotoxicity of adriamycin after a short period of incubation correlated with changes in its cytoplasmic level. Our results indicate that these extracellular cations might play an important role in the therapeutic activities of anticancer drugs in cancer patients. These results also provide insight a new aspect of chemotherapy, because they suggest that the therapeutic doses of anti-cancer drugs should be modified in cancer-bearing patients presenting with abnormal blood calcium levels.

Cytotoxicity of urushiols isolated from sap of Korean lacquer tree (Rhus vernicifera Stokes)

Cytotoxicities of four urushiols, congeners isolated from the sap of Korean lacquer tree (Rhus vernicifera Stokes), to 29 human cancer cell lines originated from 9 organs were evaluated. Their values of 50% growth inhibition were below 4 microg/ml, and showed cell line specific cytotoxicity. The present result is the first report on the cytotoxicity of urushiols suggesting that they would have an anticancer activity to human cancer cells.

Induction of mucin gene expression in human colonic cell lines by PMA is dependent on PKC-epsilon

Treatment of HT-29 cells with phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), induces MUC2 expression. To investigate the role of PKC in regulating mucin genes in intestinal cells, we examined the regulation of MUC1, MUC2, MUC5AC, MUC5B, and MUC6 expression in two human mucin-producing colonic cell lines, T84 and HT29/A1. T84 and HT29/A1 cells (at 80-90% confluency) were exposed to 100 nM PMA for 0, 3, and 6 h. Twofold or greater increases in mRNA levels for MUC2 and MUC5AC were observed in both cell lines during this time period, whereas the levels of MUC1, MUC5B, and MUC6 mRNAs were only marginally affected. These results indicated that PKC differentially regulates mucin gene expression and that it may be responsible for altered mucin expression. Our previous results suggested that the Ca(2+)-independent PKC-epsilon isoform appeared to mediate PMA-regulated mucin exocytosis in these cell lines. To determine if PKC-epsilon was also involved in MUC2/MUC5AC gene induction, HT29/A1 cells were stably transfected with either a wild-type PKC-epsilon or a dominant-negative ATP-binding mutant of PKC-epsilon (PKC-epsilon K437R). Overexpression of the dominant-negative PKC-epsilon K437R blocked induction of both mucin genes, whereas PMA-induced mucin gene expression was not prevented by overexpression of wild-type PKC-epsilon. PMA-dependent MUC2 mucin secretion was also blocked in cells overexpressing the dominant-negative PKC-epsilon K437R. On the basis of these observations, PKC-epsilon appears to mediate the expression of two major gastrointestinal mucins in response to PMA as well as PMA-regulated mucin exocytosis.

Inhibition of human tumor growth by 2'-hydroxy- and 2'-benzoyloxycinnamaldehydes

2'-Hydroxycinnamaldehyde (HCA) was isolated from Cinnamomum cassia Blume (Lauraceae) and 2'-benzoyloxycinnamaldehyde (BCA) was prepared by the reaction of HCA and benzoyl chloride. HCA and BCA strongly inhibited in vitro growth of 29 kinds of human cancer cells and in vivo growth of SW-620 human tumor xenograft without the loss of body weight in nude mice. HCA prevented adherence of SW-620 cells to the culture surface but did not inhibit oncogenic K-Ras processing, implying its antitumor mechanisms at the cellular level.

A new internal ribosomal entry site 5' boundary is required for poliovirus translation initiation in a mouse system

Four mutants of the virulent Mahoney strain of poliovirus were generated by introducing mutations in nucleotides (nt) 128 to 134 of the genome, a region that contains a part of the stem-loop II (SLII) structure located within the internal ribosomal entry site (IRES; nt 120 to 590) (K. Shiroki, T. Ishii, T. Aoki, Y. Ota, W.-X. Yang, T. Komatsu, Y. Ami, M. Arita, S. Abe, S. Hashizume, and A. Nomoto, J. Virol. 71:1-8, 1997). These mutants (SLII mutants) replicated well in human HeLa cells but not in mouse TgSVA cells that had been established from the kidney of a poliovirus-sensitive transgenic mouse. Their neurovirulence in mice was also greatly attenuated compared to that of the parental virus. The poor replication activity of the SLII mutants in TgSVA cells appeared to be attributable to reduced activity of the IRES. Two and three naturally occurring revertants that replicated well in TgSVA cells were isolated from mutants SLII-1 and SLII-5, respectively. The revertants recovered IRES activity in a cell-free translation system from TgSVA cells and returned to a neurovirulent phenotype like that of the Mahoney strain in mice. Two of the revertant sites that affected the phenotype were identified as being at nt 107 and within a region from nt 120 to 161. A mutation at nt 107, specifically a change from uridine to adenine, was observed in all the revertant genomes and exerted a significant effect on the revertant phenotype. Exhibition of the full revertant phenotype required mutations in both regions. These results suggested that nt 107 of poliovirus RNA is involved in structures required for the IRES activity in mouse cells.

MDR-1 gene expression is a minor factor in determining the multidrug resistance phenotype of MCF7/ADR and KB-V1 cells

The relevance of MDR-1 gene expression to the multidrug resistance phenotype was investigated. Drug-resistant cells, KB-V1 and MCF7/ADR, constantly expressed mRNA of the MDR-1 gene and were more resistant to vinblastine and adriamycin than drug-sensitive cells, KB-3-1 and MCF7. The drug efflux rate of KB-V1 was the same as KB-3-1 although the MDR-1 gene was expressed in only the resistant cell. The higher intracellular drug concentration of KB-3-1 than KB-V1 was due to the large drug influx. In the case of MCF7 and MCF7/ADR, the influx and efflux of the drug had nearly the same pattern and drug efflux was not affected by verapamil. The amount of ATP, cofactor of drug pumping activity of P-glycoprotein, was not changed by the resistance. These observations suggested that drug efflux mediated by MDR-1 gene expression was not a major determining factor of drug resistance in the present cell systems, and that the drug resistance could be derived from the change in drug uptake and other mechanisms.

Limitation of Hu-PBL-scid mouse model in direct application to immunotoxicity assessment

Hu-PBL-scid mice were directly introduced to the methods of immunotoxicity assessments. Human IgG and IgM was detected 1 week after transplantation. Cyclosporin A (CsA) and cyclophosphamide (CP), which were injected i.p. 4 weeks after transplantation, decreased the serum concentration of IgM after 2-4 days of treatment but not that of IgG. Lymphocyte proliferation induced by various mitogens and primary T-dependent antibody responses to sheep red blood cells could not be measured by using splenocytes of hu-PBL-scid mice. These results were correlated with the fact that human cells were not detected in the spleen, thymus, or blood of hu-PBL-scid mouse but were detected in lymph nodes of the intestine, which were observed by flow cytometric and immunohistochemical examinations. The present results suggest using hu-PBL-scid mice in routine immunotoxicity investigations: lymph nodes of intestines could be used as the lymphocyte source. In addition, the determination of serum Ig concentration might be used as a experimental item.

Protein kinase C-epsilon is the likely mediator of mucin exocytosis in human colonic cell lines

The phorbol ester, phorbol 12-myristate 13-acetate (PMA), induces mucin secretion in the colonic tumor cell line T84 in a Ca(2+)-independent manner. To determine whether a specific protein kinase C (PKC) isoform is involved in colonic cells, we compared PMA-dependent mucin secretion by three human colonic tumor cell lines (T84, HT-29/A1, and LS 180) with the expression of PKC isoforms alpha, beta, delta, epsilon, and zeta, previously identified in human colon (L. A. Davidson, Y. H. Jiang, J. D. Derr, H. Aukema, J. R. Lupton, and R. S. Chapkin. Arch. Biochem. Biophys. 312:547-553, 1994). In each cell line PMA (10(-7) M) caused mucin secretion within 30 min. PMA-dependent mucin secretion was three to four times greater from HT-29/A1 and T84 cells than from LS 180 cells. All three-cell lines contained mRNA for PKC-alpha, PKC-epsilon, and PKC-zeta but not PKC-beta or -delta. Each cell line also expressed PKC-alpha, -epsilon, and -zeta protein. PKC-epsilon expression (mRNA and protein) was three to four times greater in HT-29/A1 and T84 cells than in LS 180 cells, correlating with PMA-responsive mucin secretion, whereas all cell lines contained similar levels of PKC-alpha mRNA and protein. When cells were stimulated by PMA, only PKC-epsilon was translocated from cytosol to membrane fractions early enough to stimulate mucin secretion. Because PKC-epsilon is also a Ca(2+)-independent isoform, it is likely to mediate mucin exocytosis in colonic cells.

Efficient fixation procedure of human leukemia cells in sulforhodamine B cytotoxicity assay

The fixation procedures in sulforhodamine B (SRB) assay for human leukemia cells were modified to produce more reliable results. It was found that the concentration of the fixative agent, trichloroacetic acid (TCA), was critical in the selective fixation of cellular protein. While a TCA solution of 80% fixed both cells and serum proteins, a 50% solution fixed only cells with a very low interference of the serum proteins. Accordingly, we selected 50% TCA as a fixative agent which made the final absorbance of the SRB assay to be exactly matched to the cell density with a small deviation and a low background. Besides the change of TCA concentration, a precentifugation of microplate just before fixation also improved the previous assay procedures in the two points of view. The 2-h standing step was simply substituted for only 1 min of centrifugation. Both the rapid and slow application of TCA solution in fixation produced the same extents of fixation. In an actual application, these two kinds of modifications in the previous SRB assay procedure were also proved to be effective in the determination of cytotoxicities of doxorubicin by using human leukemias.

Facilitation of apoptosis by autologous serum and related immunosuppression in the splenocyte culture

The addition of adult mouse serum (MS) to the culture of mouse splenocytes resulted in an accelerated decrease of viable cell number during initial 24 h of culture as determined by the trypan blue dye exclusion test and the propidium iodide staining method. Furthermore, the extent of DNA fragmentation, the hallmark of apoptosis, determined by agarose gel electrophoresis and the amount of fragmented DNA measured by ELISA method showed that the extent of apoptosis was clearly increased in splenocytes cultured in the presence of MS. Under the scanning and transmission electron microscopic observations, the large portion of splenocytes showed morphological characteristics of apoptotic cells such as apoptotic body, condensed chromatin and shrunken appearance. With the accelerated rate of apoptosis, the immunocompetence of splenocytes such as the antibody production, natural killer cell activity, and proliferation by mitogens was strongly suppressed. When analyzed by surface immunolabelling flow cytometry, the subsets of lymphocytes (B, T, CD4+T and CD8+T cells) were affected in a global non-selective manner. As determined by ultrafiltration, the molecular weights of apoptosis-facilitating factors present in MS appeared to be greater than 10 kDa. Upon fractionation with Sephadex G-200, the apoptotic factors were separated into 2 fractions. In summary, results obtained in the present study indicate that some unidentified endogeneous macromolecules present in MS may produce the stimulatory effect on the apoptosis and cause immunosuppression of splenocytes under culture.

Stimulation of humoral and cell mediated immunity by polysaccharide from mushroom Phellinus linteus

Polysaccharide was purified from mycelial culture of Phellinus linteus (PL) and its effect on immunocompetence of normal splenocytes was observed. Overall in vitro immune function was enhanced by addition of PL into culture of mouse spleen lymphocyte and i.p. injection into mouse, while beta-glucans and other polysaccharides only raised the level of T lymphocyte-mediated immunity. PL stimulated immune functions of T lymphocytes, such as proliferation of T lymphocyte induced by mixed lymphocytes reaction and cytotoxicity of cytotoxic T cells responding to alloantigen. Nonspecific immune functions mediated by natural killer cells and macrophages were increased by treatment of PL in vivo and in vitro. PL also stimulated humoral immune function positively, such as T-dependent and T-independent primary antibody response, and acted as a polyclonal activator on B cell. PL exhibited a wider range of immunostimulation and antitumor activity than other polysaccharides isolated from Basidiomycetes.

Protein kinase C isoforms in muscle cells and their regulation by phorbol ester and calpain

Objectives were to identify the PKC isoforms in cultured muscle cells, to examine roles of Ca(2+)-dependent proteinases (calpains) in processing of various muscle PKC isozymes and to obtain a mechanistic description of the processing of PKCs by examining the temporal relationships between phorbol ester-dependent translocation of muscle PKCs and calpains between cytosolic and membrane compartments. Using six isoform (alpha, beta, gamma, delta, epsilon, zeta)-specific polyclonal antibodies, PKC alpha, delta and zeta were detected in rat skeletal muscle and in L8 myoblasts and myotubes. PKC alpha and zeta were primarily localized in the cytosolic fraction of L8 myotubes whereas PKC delta was more abundant in the membrane fraction. Phorbol ester (TPA) caused rapid depletion of myotube PKC alpha and PKC alpha and PKC delta isoforms from the cytosolic compartment and rapid appearance of these isoforms in the membrane fraction. However, long-term exposure of myotubes to TPA eventually caused down-regulation of PKCs in the membrane compartment. Down-regulation of PKCs in the membrane fraction was partially blocked by calpain inhibitor II. However, the rapid TPA-dependent cytosolic depletion of PKCs was unaffected by calpain inhibitor. This suggests that calpains may be responsible for membrane-associated down-regulation of PKCs but not for cytosolic depletion. In the final study we assessed the effects of phorbol ester on compartmentation of m-calpain with PKCs in muscle cells. Like the PKCs, TPA caused rapid association of m-calpain with the membrane fraction followed by down-regulation. This demonstrates that phorbol esters cause translocation of both PKCs and calpains to membranes where processing of PKCs may occur via the limited proteolysis exerted by calpains.

Effects of dexamethasone on protein degradation and protease gene expression in rat L8 myotube cultures

We examined the effects of a synthetic glucocorticoid (dexamethasone; Dex) on protoeolysis and on protease messenger RNA (mRNA) concentrations in rat L8 skeletal myotube cultures. Protein degradation was measured as release of radioactive trichloroacetic acid-soluble material from intracellular proteins pre-labelled with [3H]tyrosine. Dex (1 microM) stimulated protein degradation (P < 0.01). This effect was entirely blocked by the glucocorticoid antagonist, RU38486 (mifepristone; P < 0.01). Hence, actions of Dex on muscle protein degradation are mediated via intracellular glucocorticoid receptors. Molecular mechanisms by which glucocorticoids stimulate protein degradation in skeletal muscle are not known. Here, we investigated the regulation of protease (cathepsin B, cathepsin D, proteasome C2 subunit and m-calpain) mRNA concentrations by Dex in cultured L8 muscle cells. Cathepsin B mRNA concentration was enhanced 3.3-fold by Dex. This effect was blocked by RU38486. RU38486 alone did not affect cathepsin B mRNA concentration or mRNAs of other proteases. Concentrations of cathepsin D and m-calpain mRNAs were also increased by Dex. These effects were also abolished by RU38486. Proteasome C2 mRNA was unaffected by Dex and Dex reduced alpha-tubulin mRNA. Thus, glucocorticoids specifically regulate the concentrations of mRNAs encoding some proteases in muscle cells. The regulation of protease mRNA concentration is mediated via interaction between Dex with glucocorticoid receptors and is independent of the actions of Dex on mRNA encoding house-keeping proteins. These changes may underlie glucocorticoid-dependent control of proteolysis in muscle.

Comparative studies of adriamycin and 28-deacetyl sendanin on in vitro growth inhibition of human cancer cell lines

The limonoid compound (28-deacetyl sendanin) isolated from the fruit of Melia toosendan SIEB. et ZUCC. was evaluated on anticancer activity. According to a standard in vitro cytotoxicity assay, eight human cancer cell lines and SRB assay were introduced for present evaluation. As a positive standard, adriamycin was tested in parallel. The cell lines were originated from six different organs. In view of dose-response profiles to 28-deacetyl sendanin, the most sensitive cells were SF-539 and PC-3 which were derived from CNS and prostate, respectively. In contrast, all the cell lines responded similarly to adriamycin to give rise to nearly identical dose-response profiles. By comparison of Gl50 between 28-deacetyl sendanin and adriamycin, six cell lines were more sensitive to 28-deacetyl sendanin and two were more resistant. As a result, 28-deacetyl sendanin had more sensitive and selective inhibitory effects on in vitro growth of human cancer cell lines in a comparison with adriamycin.

Comparison of glucose-consumption and thymidine-incorporation endpoints in histocultured human superficial bladder tumors

Glucose consumption and tritiated thymidine incorporation were monitored for 54 days in histocultured human superficial transitional cell carcinoma of the bladder, indicating that long-term histoculture of human transitional cell carcinoma of the bladder is feasible. The glucose-consumption rate was relatively similar among the histocultured specimens and depended on the size of the explant in histoculture. Tritiated thymidine incorporation, on the other hand, varied greatly between the histocultured specimens. In addition, [3H]thymidine incorporation varied in single histocultures between cells in the original explant and those invading the gel. From these results, we conclude that the glucose consumption rate in histocultured human superficial bladder tumor is more reliable and sensitive than thymidine incorporation. The glucose-consumption endpoint is simple to measure and nondestructive, allowing multiple measurements on a single culture, unlike the thymidine incorporation endpoint.

[Diagnosis and management of obstetric acute disseminated intravascular coagulation]

Twenty-seven in-patients with obstetric DIC in our hospital from Jan. 1971 to Dec. 1990 were analysed retrospectively. The incidence was 0.12% in the first decade and 0.02%, in the second, showing a difference of significance between them. The most common predisposing factors included amniotic fluid embolism, abruptio placenta and hemorrhagic shock. Bleeding from multi-organs in various extent and coagulation disorders occurred in all those 27 cases. [Besides anti-shock treatment, heparin was employed together with fibrinogen in 4 postpartum and 1 antepartum DIC patients, fibrinogen alone in 8 cases, and hysterectomy in 11 cases. 17 patients were saved and 9 died. It is important that early diagnosis and much attention paid to clinical characteristics together with serial laboratory tests. Key management should include prompt treatment and eradication of predisposing factors. Quick decision spite of to terminate the pregnancy and even hysterectomy should be done in some risks.

Portal and superior mesenteric venous gas with retroperitoneal abscess--CT diagnosis (case report)

We present a case of portal and superior mesenteric venous gas in a 31-year-old diabetic woman with a left-sided retroperitoneal abscess. Five years prior to admission, patient was diagnosed with diabetes mellitus and developed emphysematous pyelonephritis, requiring nephrectomy on the left side. A CT examination showed air distributed throughout the portal venous system and superior mesenteric vein.

Whole body slotted tube resonator (STR) for proton NMR imaging at 2.0 Tesla

Design principles of a whole body Slotted Tube Resonator (STR) RF coil are given and fabrication details of the RF coil for a 2.0 Tesla NMR imaging system are presented. Experimental study proved efficient operation of the coil at 2.0 Tesla field and indicated potential for the extension of the technique to the even higher fields.

Flow cytometric DNA and 5'-nucleotide phosphodiesterase in endometrium

One hundred endometrium specimens have been studied with flow cytometry for DNA analysis (FCDA) and a proliferative enzyme marker, 5'-nucleotide phosphodiesterase (5'-NPD). FCDA data showed that aneuploidy was present in only 5 of 40 cancer specimens. However, with corrected histograms, a higher DNA value was observed in the G2/M (6%) of all cancer compared with noncancer specimens (4%). Thus, FCDA can be a useful diagnostic aid for endometrial cancer. The determination of 5'-NPD was done with a quenching method based on the use of 5'-(5-iodo-3-indoxyl)-thymidine phosphodiester as a substrate and 4',6-diamidino-2-phenylindole for DNA. This method could qualitatively define which population of the cell cycle had a higher enzyme level and also quantitatively gave the enzyme units per cell. It was found that 12.5% of all cancer specimens had 5'-NPD activity in the G0/G1 cells and 87.5% in the S and/or G2/M cells, whereas in the noncancer specimens 5'-NPD was found in 28.5% of the G0/G1 cells and 71.5% of the specimens had 5'-NPD in the S and/or G2/M cells. Furthermore, the concentration of 5'-NPD was found to be five times higher in the G2/M cells of the cancer specimens than that in the noncancer specimens. However, in the hyperplasia specimens, the activity was only two times higher in the same cell cycle fraction than in the normal specimens. The results of this investigation provided for the first time evidence that this exonuclease activity alters in the cell cycle fractions and that a decrease in the enzyme activity in G0/G1 cells and an increase in G2/M cells may be a useful marker for neoplastic development in human endometrial cancer.

Flow cytometric DNA analysis as a diagnostic aid for cervical condyloma and cancer

Flow cytometric DNA analysis data (FCDA) were obtained from 324 samples provided through the Gynecology-Oncology Clinic. These samples consisted of 294 combined endoectocervical and vaginal smears and 30 peritoneal washings. Using a conventional scheme for G0/G1, S + G2/M and the coefficient of variation with computer correction for the cell-cycle kinetics, it was possible to assign a diagnostic Class I, II, III or V similar to that used by the Cytology Laboratory. These data were then compared with the histopathologic and colposcopic diagnoses. The correlation between FCDA and cytologic results were essentially similar to the previous data obtained from only endocervical sampling. The most interesting finding in this study was the recognition of an FCDA pattern showing a higher DNA content in the G0/G1 and the early S regions in 70 of 94 (74.5%) of samples from patients with condyloma acuminata. All condyloma samples were diagnosed either by cytologic, histopathologic, or colposcopic examination, or a combination of two or three. All biopsy specimens were then reviewed by one pathologist to verify any discrepancies. The relationship of this pattern to the viral etiology of this disease is discussed with the three methods of diagnosis and electron microscopic observations. It is suggested that, based on this study. FCDA analysis of pap smears may also be useful in determining the presence of condyloma in a gynecology clinic. The potential value of FCDA analysis from peritoneal washings for the diagnosis of gynecologic cancer can not be ascertained in this preliminary investigation because of insufficient samples.