First Report of Alternaria Blight of Potato Caused by Alternaria tenuissima in China

Potato (Solanum tuberosum L.) is grown worldwide as a major food crop. Potato early blight is an important disease caused by Alternaria solani (4). In 2011, diseased potato leaves with blight symptoms were collected from 21 sites (incidence averaged 60% for about 2,000 ha of potato fields examined) in Gansu Province, northwest China. Small pieces of tissue taken from the margin between healthy and diseased tissues were surface-disinfected in 0.3% NaOCl for 2 min, rinsed with sterilized, distilled water, then placed on potato dextrose agar (PDA) at 25°C in the dark. Two of 24 Alternaria isolates from single-spore cultures were identified preliminarily as A. tenuissima, and the remaining isolates as A. solani or A. alternata, based on morphological traits. Colony appearance on potato carrot agar (PCA) was loosely cottony under a day/night cycle of 8 h fluorescent light/16 h dark at 22°C for 7 days (3). The isolates were characterized by formation of unbranched conidial chains up to 12 conidia in length, with one or two lateral branches forming occasionally. Conidia were typically ovoid to obclavate, and ranged from 20.4 to 42.4 × 7.7 to 13.2 μm. Transverse septa and longitudinal septa of conidia varied from 1 to 6 and 0 to 2, respectively. Short conidiophores arose singly and were 15.1 to 76.8 μm long by 2.4 to 6.2 μm wide. The internal transcribed spacer (ITS) region of rDNA and partial coding sequence of a histone gene were amplified from genomic DNA of the two A. tenuissima isolates using the ITS1/ITS4 and H3-1a/H3-1b primers (2), respectively. The ITS sequences of the two isolates (GenBank Accession Nos. JX495165 and JX495166) were 100% identical to those of A. tenuissima strains sdau 07-100 and BL08-3 (GQ871507 and AB470887), as well as to other Alternaria species, but the partial histone gene sequences (JX495167 and JX495168) were 99% identical to those of A. tenuissima isolates CR27, MA1, MA6, and CN-L-01 (AF404622, AF404633, AF404634, and EF371552, respectively) with less similarity to those of other Alternaria spp. Therefore, the isolates were identified as A. tenuissima based on morphological and molecular characteristics. Pathogenicity tests were conducted by inoculating detached leaves (30 per isolate) from 45-day-old plants of potato cv. Favorita with 20 μl drops (one drop per leaf) of a conidial suspension containing 10⁶ conidia/ml in sterilized, distilled water. Thirty control leaves were inoculated similarly with sterilized, distilled water. Inoculated leaves were incubated in chambers at 25°C and 90% RH with a 12-h photoperiod/day. After 7 days, symptoms on the inoculated leaves were similar to those naturally occurring on the original plants, and the two cultures were reisolated consistently from those leaves, and the species identity was confirmed by morphological and molecular characteristics, fulfilling Koch's postulates. The control leaves remained asymptomatic and Alternaria was not isolated from those leaves. Alternaria blight of potato caused by A. tenuissima was previously detected in Iran (1). To our knowledge, this is the first report of A. tenuissima causing blight on potatoes in China. References: (1) S. T. Ardestani et al. Iran. J. Plant Pathol. 45:83, 2010. (2) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (3) E. G. Simmons. Alternaria. An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, the Netherlands, 2007. (4) J. E. van der Waals et al. Plant Dis. 88:959, 2004.

Bladder cancer cell-derived exosomes inhibit tumor cell apoptosis and induce cell proliferation in vitro

Exosomes are small membrane vesicles released by a variety of mammalian cells into the extracellular space and are involved in cell‑to‑cell signaling. This study aimed to investigate the effects of bladder cancer cell‑derived exosomes on the regulation of tumor cell viability and apoptosis, as well as the underlying molecular events. Exosomes were purified from the supernatants of human bladder cancer T24 cell cultures. Transmission electron microscopy was used to confirm their morphology and western blot analyses determined the protein content of cells. Subsequently, bladder cancer cell lines were treated with different concentrations of exosomes. Tumor cell viability was shown to be reduced, as detected by the Cell Counting Kit‑8 assay. Annexin V/flow cytometric assays showed that exosomes inhibited apoptosis of bladder cancer cell lines in a dose- and time‑dependent manner. Exosomes were demonstrated to upregulate the expression of Bcl‑2 and Cyclin D1 proteins, but reduce the levels of Bax and caspase‑3 proteins in these cells. Moreover, exosomes dose‑dependently increased the expression of phosphorylated Akt and extracellular signal‑regulated protein kinase (ERK). In conclusion, this study demonstrated that bladder cancer cell‑derived exosomes inhibited tumor cell apoptosis, which was associated with the activation of Akt and ERK pathway genes, suggesting that tumor‑derived exosomes are involved in bladder cancer progression. Inhibition of exosome formation and release may therefore be a novel strategy in future treatment of bladder cancer.

First Report of Potato Stem Canker Caused by Rhizoctonia solani AG4 HGII in Gansu Province, China

Black scurf and stem canker on potato (Solanum tuberosum L.), caused by Rhizoctonia solani, is an important disease throughout the world. Isolates of R. solani AG3 are the principal cause of these diseases on potato (2). In August 2011, at the tuber bulking growth stage, symptoms typically associated stem canker, including dark brown stem lesions, were observed on 20% of potato plants collected from 23 locations (about 2,000 ha) in Gansu Province, northwest China. Stem pieces (each 5 mm long) taken from the margins of the healthy and diseased tissues were surface-disinfected with 0.5% NaOCl for 2 min, rinsed with sterilized water, dried, then placed on potato dextrose agar (PDA) at 25°C in the dark. Twenty-nine fungal isolates taken from single hyphal tips were identified as R. solani based on morphological traits, including mycelium branched at right angles with a septum near the branch and a slight constriction at the branch base. Hyphal cells were determined to be multinucleate (4 to 10 nuclei/cell) when stained with 4'-6-diamidino-2-phenylindole (DAPI). Anastomosis groups were determined by pairing with reference strains (kindly provided by N. Kondo, Hokkaido University, Japan), and three isolates (designed GS-15, GS-24, and GS-25) anastomosed with isolates of R. solani AG4. The internal transcribed spacer (ITS) region of rDNA was amplified from genomic DNA of each of the three isolates with primers ITS1 and ITS4. The resulting sequences (GenBank Accession Nos. JX843818, JX843819, and JX843820) were 100% identical to those of >10 R. solani AG4 HGII isolates (e.g., HQ629873.1; isolate ND13). Therefore, based on the anastomosis assay and molecular characteristics, the three isolates were identified as R. solani AG4 HGII. To determine pathogenicity of the AG4 HGII isolates, potato seed tubers (cv. Favorita) with 3 to 5 mm long sprouts were inoculated with wheat seeds (sterilized by autoclaving twice at 121°C for 1 h with a 24 h interval between autoclavings) colonized with each isolate (1). One sprouted tuber was planted in a sterilized plastic pot (1 liter) with a single colonized wheat seed placed 10 mm above the uppermost sprout tip in a sand/sawdust mixture (1:2 v/v, with dry heat sterilization at 161°C for 4 h before use). Plants were incubated in a glasshouse maintained at 25 to 27°C. The test was performed on 20 plants for each isolate, and the experiment was repeated. After 3 weeks, control plants inoculated with sterilized wheat seeds remained asymptomatic, and no Rhizoctonia spp. were isolated from these plants, whereas all inoculated plants showed symptoms of stem canker. R. solani AG4 HGII was reisolated consistently from symptomatic stems, and the identity of the reisolates confirmed by the morphological and molecular characteristics mentioned above, fulfilling Koch's postulates. Potato stem canker caused by R. solani AG4 HGII was reported previously in the United States (3). To our knowledge, this is the first report of R. solani AG4 HGII causing stem canker on potato in Gansu Province, the main potato-producing area of China. R. solani AG4 HGII can cause sheath blight on corn in China (4), which is commonly grown in rotation with potato. This rotation could increase the risk of soilborne infection to either crop by R. solani AG4 HGII. References: (1) M. J. Lehtonen et al. Plant Pathol. 57:141, 2008. (2) L. Tsror. J. Phytopathol. 158:649, 2010. (3) J. W. Woodhall et al. Plant Dis. 96:1701, 2012. (4) X. Zhou et al. J. Shenyang Agric. Univ. 43:33, 2012.

Reduced lesions in chickens with Clostridium perfringens-induced necrotic enteritis by Lactobacillus fermentum 1.20291

Previous studies have demonstrated that Lactobacillus has anti-inflammatory properties, but the protective functions of Lactobacillus and mechanisms of inhibition of necrotic enteritis (NE) in the intestines of chickens have not been fully clarified. In the present study, we selected a probiotic strain, Lactobacillus fermentum 1.2029, which has good adhesive ability and a high survival rate in low pH and bile salts. The objective of this study was to examine the anti-inflammatory properties of L. fermentum 1.2029 against NE in chickens. Two hundred forty 1-d-old male Arbor Acres broilers were blocked into 3 experimental groups as follows: (I) nonchallenge control group, (II) Clostridium perfringens challenge group, and (III) C. perfringens challenge + L. fermentum 1.2029 group. Lactobacillus fermentum 1.2029 (1.0 mL/d, 10(8) cfu/mL) was orally administered daily to group III during the course of the experiment, and all uninfected control chickens were inoculated accordingly with the same volume of PBS. Clostridium perfringens (0.5 mL on d 1 and 1.0 mL on d 14 to 21, 10(8) cfu/mL) was administered to chickens in group II. At 28 d, scoring of gross NE lesions was performed. Ileal segments of approximately 2 cm from 24 chickens in each experimental group were collected and fixed in 4% (wt/vol) neutral-buffered formalin solution for histological scoring. Ileal mucosa samples were also collected for mRNA analysis by real-time PCR. The results showed that L. fermentum 1.2029 reduced the severity of NE lesions in chickens. Histological scores revealed that L. fermentum 1.2029 also reduced the inflammation damage of NE in chickens. Changes in cytokines and Toll-like receptors (TLR) were determined, and L. fermentum 1.2029 was found to increase interleukin-10 levels and reduce interferon-γ and TLR2 levels in NE-infected chickens. The results showed that L. fermentum 1.2029 was able to regulate the intestinal mucosal immune response and ameliorate inflammation by changing expression levels of cytokines and TLR.

First Report of Sugar Beet Seedling Damping-Off Caused by Binucleate Rhizoctonia AG-A in China

Sugar beet (Beta vulgaris L.) is grown worldwide and produces one-third of the world's sugar supply. Sugar beet seedling Rhizoctonia damping-off is an important disease mainly caused by Rhizoctonia solani AG-2, AG-4, and AG-5 (2). In 2010, diseased sugar beet seedlings with about 20% incidence affected by damping-off, which showed dark brown lesions on the stems just below the soil surface and portions of the roots, were collected from nurseries in three locations in Heilongjiang province, northeast China. Root fragments taken from the margins of healthy tissues and lesions on roots were surface disinfected with 0.5% sodium hypochlorite for 2 min, rinsed with sterile water, then placed on potato dextrose agar (PDA) and incubated at 25°C in the dark. Three (designed HLJ-RAA1, HLJ-RAB1, HLJ-RAB2) of nine Rhizoctonia isolates were obtained from diseased tissues and preliminarily identified as binucleate Rhizoctonia (BNR) anamorph (teleomorph Ceratobasidium Rogers) species-like. Fungal colonies were white with large amounts of floccose, aerial hyphae. Hyphal cells were determined to be binucleate when stained with 4'-6-diamidino-2-phenylindole (DAPI) (1). No sclerotia were produced after 14 days on PDA. Average hyphal diameter of the three isolates were 4.2, 4.3, and 4.8 μm, respectively. Further, the internal transcribed spacer (ITS) region of rDNA was amplified from the genomic DNA extracted from hyphae by bead beating in 2% CTAB solution using stainless steel beads with primers ITS1 and ITS4. The ITS sequences (GenBank Accession Nos. JX073668, JX073669, and JX073670) were over 99% identical to those of more than 50 Ceratobasidium sp. AG-A isolates (e.g., GenBank Accession No. JQ688054.1; strain HY-15). Therefore, based on morphological and molecular characteristics, these isolates were identified to be BNR AG-A. To determine the pathogenicity of the isolates, sugar beet (cv. HI0305) seedlings were inoculated with wheat seeds colonized with each of the isolated Rhizoctonia strains (one seed per seedling), and grew in pots under greenhouse conditions (3). After 3 weeks, some inoculated plants showed damping-off as observed in the nurseries, whereas noninoculated control plants (sterile wheat seeds only) remained healthy. Disease incidence from the trials averaged 53.3%, 70%, and 53.3% for the isolates HLJ-RAA1, HLJ-RAB1, and HLJ-RAB2, respectively. The three BNR cultures of the pathogens were consistently reisolated from symptomatic roots, and their identities confirmed by morphological and molecular characteristics as described above, fulfilling Koch's postulates. BNR AG-A was previously reported to be pathogenic to soybean, pea, snap bean, and pak choy in China (4). However, to our knowledge, this is the first report of BNR AG-A causing sugar beet seedling damping-off in China. Sugar beet is often grown in crop rotation with soya bean and such a rotation could increase the risk of soilborne infection to either crop by BNR AG-A. References: (1) W. C. Kronland and M. E. Stanghellini. Phytopathology 78:820, 1988. (2) E. O'Sullivan and J. A. Kavanagh. Plant Pathol. 40:128, 1991. (3) C. E. Windels and D. J. Nabben. Phytopathology 79:83, 1989. (4) G. H. Yang et al. J. Phytopathol. 153:333, 2005.

Upregulation of cell adhesion through delta Np63 silencing in human 5637 bladder cancer cells

Some researchs have demonstrated that the loss of delta Np63 is associated with aggressive phenotypes and poor prognosis. However, other research indicates that delta Np63 is considered to have oncogenic properties. Delta Np63 overexpression is often observed in association with the oncogenic growth of squamous cell carcinomas and bladder cancer. In this study, we investigated the oncogenic role of delta Np63 in regulating cell adhesion in transitional cell carcinoma of the bladder (TCCB). The cells were stably transfected with the delta Np63 short hairpin RNA (shRNA) plasmid. Immunocytochemistry was performed to determine the knockdown efficiency. Tumour cells were studied for their ability to adhere to vascular endothelial cells. Confocal microscopy was used to analyse the changes in cytoskeletal F-actin. F-actin expression was measured by flow cytometry. Cell invasion ability was assessed using transwell chambers. The delta Np63-silenced tumour cells were shown to adhere more tightly than controls to vascular endothelial cells (P<0.05). The content of F-actin in the delta Np63-silenced cells was enhanced (P<0.05). The Matrigel invasion assays showed that human 5637 bladder cancer cells had a lower degree of motility when transfected with pdelta Np63-shRNA (P<0.05). In conclusion, silencing of the delta Np63 expression can enhance the adhesiveness of 5637 cells by inducing F-actin cytoskeleton production, and it will possibly inhibit the TCCB invasion and metastasis.

BLyS expression and JNK activation may form a feedback loop to promote survival and proliferation of multiple myeloma cells

B-Lymphocyte stimulator (BLyS), a member of tumor necrosis factor superfamily, is a potent co-activator of B cells in vitro, and in vivo induces B cell proliferation and immunoglobulin secretion. Multiple myeloma (MM) is an incurable malignancy of terminally differentiated B cells (plasma cells). Previous studies have well ascertained that BLyS plays an important contributory role in the pathogenesis and propagation of multiple myeloma by virtue of its ability to promote B cell survival, expansion, and differentiation. However, the intracellular signaling of BLyS in human MM cells remains undefined. This study was designed to see whether there was interaction between MAPK signaling pathway and BLyS expression. It was found that the active protein p-JNK was expressed in KM3, U266 and PBMCs of MM patients, and that the expression of BLyS could be changed by JNK pathway activator and inhibitor. In addition, recombinant BLyS activated JNK pathway, while BLyS siRNA treatment inhibited the activation of JNK pathway. The level of BLyS expression and the activation of JNK pathway were positively correlated. These findings suggest that JNK activation and BLyS expression in MM cells may form a positive feedback loop that promotes the survival and proliferation of MM cells, and these may shed some light on the pathogenesis and treatment of MM.

HepaCAM induces G1 phase arrest and promotes c-Myc degradation in human renal cell carcinoma

Hepatocyte cell adhesion molecule (hepaCAM) encodes a generally inactive phosphorylated glycoprotein which mediates cancer cell proliferation, migration, and differentiation. We have reported that hepaCAM is down-regulated in renal cell carcinoma (RCC) and takes responsibility of cell growth inhibition. However, the precise mechanisms of hepaCAM inhibits cell growth is still unknown. In this study, we demonstrated that re-expression of hepaCAM can cause an accumulation in G0/G1 phase in 786-0 cells. This reaction was accompanied by a substantial reduction of c-Myc expression through using an ectopic hepaCAM expression system. Furthermore, we found a comparable decrease in proliferation and G0/G1 accumulation of 786-0 and RC-2 cells after treatment with a small molecule c-Myc inhibitor, 10058-F4. This indicated that the down regulation of c-Myc was an essential process in controlling growth inhibitory actions of hepaCAM. Nevertheless, re-expression of hepaCAM results in apparent reduction of c-Myc protein with no corresponding reduction of c-Myc mRNA. This suggests that this reaction might take place at a post-transcriptional level rather than transcriptional one. Consistent with these findings, hepaCAM decreased c-Myc stability by increasing the proportion of c-Myc phosphorylation on T58 which can be abrogated by a proteasomal inhibitor (MG132). Thus, our research implies that the decrease in c-Myc protein expression, resulting from ectopic expression of hepaCAM, may contribute to the inhibition of proliferation in these cells.

[Glycosyl-phosphatidylinositol-anchored interleukin-2 expressed on tumor-derived exosomes induces anti-tumor immune response]

OBJECTIVE

To prepare IL-2-anchored and tumor-derived exosomes vaccine, and investigate the antitumor efficiency of the special cytotoxic T-lymphocytes induced by Ex/GPI-IL-2.

METHODS

To construct pEGFP-N1-IL2gpi plasmid coding a fusion gene of a DNA oligo encoding GPI-anchor signal sequence attaching to human IL-2 cDNA. Then T24 cell lines stably expressing GPI-IL-2 proteins (T24/GPI-IL-2) were established. Ex/GPI-IL-2 were isolated and purified by ultrafiltration and sucrose gradient centrifugation, and the morphology and molecule markers were analyzed. The mixed lymphocyte reaction study and cytotoxic study were performed to determine the proliferative effect of T lymphocytes and the cytotoxicity induced by Ex/GPI-IL-2.

RESULTS

The pEGFP-N1-IL2gpi plasmid was successfully constructed, and cell lines stably expressing GPI-IL-2 fusion proteins were established. Ex/GPI-IL-2 were small vesicular and saucer-shaped in diameter of 30-90 nm, containing heat shock protein 70, intercellular adhesion molecule-1, MAGE-1 and GPI-IL-2. Ex/GPI-IL-2-pulsed could dendritic cells induce proliferation of T cells and cytotoxic immune response more efficiently (P<0.05).

CONCLUSIONS

GPI-IL-2 gene-modified tumor cells can make the exosomes containing GPI-IL-2 with an increased anti-tumor effect. Our study provides a feasible approach for exosome-based tumor immunotherapy of bladder transitional cell tumors.

shRNA targeting PLCε inhibits bladder cancer cell growth in vitro and in vivo

OBJECTIVES

To investigate the role of phospholipase Cε (PLCε) by silencing PLCε with short hairpin RNA (shRNA) in human bladder cancer cells BIU-87 in vitro and in vivo.

METHODS

A PLCε shRNA expression vector was transfected into BIU-87 cells, and the expression of PLCε protein was detected by Western blotting. Cell proliferation was determined using the MTT assay, and the cell cycle was detected using flow cytometry. A tumor xenograft experiment was established to evaluate the tumor growth under the condition of PLCε knockdown, and the expression of PLCε, proliferating cell nuclear antigen, and cyclin D1 were detected by Western blotting or immunohistrochemistry.

RESULTS

PLCε shRNA reduced the protein level of PLCε, leading to marked proliferation inhibition and significant cell cycle arrest. Furthermore, PLCε shRNA reduced the tumor xenograft growth implanted with BIU-87 cells. The protein expression of PLCε, proliferating cell nuclear antigen, and cyclin D1 were downregulated in the bladder tumor xenograft.

CONCLUSIONS

The knockdown of PLCε by shRNA could inhibit bladder tumor growth and might be an alternative approach for human bladder cancer therapy.

Transforming growth factor-β1 short hairpin RNA inhibits renal allograft fibrosis

BACKGROUND

Transforming growth factor-β1 (TGF-β1) is known to be a key fibrogenic cytokine in a number of chronic fibrotic diseases, including chronic allograft nephropathy. We examined the effects of inhibition of TGF-β1 expression by RNA interference on renal allograft fibrosis, and explored the mechanisms responsible for these effects.

METHODS

A Sprague-Dawley-to-Wistar rat model of accelerated kidney transplant fibrosis was used. Sixty recipient adult Wistar rats were randomly divided into four groups: group J (sham-operated group), group T (plasmid-transfected group), group H (control plasmid group), and group Y (transplant only group). Rats in group T were transfected with 200 µg of TGF-β1 short hairpin RNA (shRNA). Reverse transcription-polymerase chain reaction and Western blotting were used to examine the expression of TGF-β1, Smad3/7, E-cadherin, and type I collagen. The distribution of type I collagen was measured by immunohistochemistry. The pathologic changes and extent of fibrosis were assessed by hematoxylin and eosin and Masson staining. E-cadherin and α-smooth muscle actin immunohistochemical staining were used to label tubular epithelial cells and fibroblasts, respectively.

RESULTS

Plasmid transfection significantly inhibited the expression of TGF-β1, as well as that of its target gene, type I collagen (P < 0.05 and P < 0.01, respectively). In addition, the degree of fibrosis was mild, and its development was delayed in plasmid-transfected rats. In contrast, TGF-β1-shRNA transfection maintained the expression of E-cadherin in tubular epithelial cells while it inhibited the transformation from epithelial cells to fibroblasts. Blood urea nitrogen and serum creatinine were lower in the plasmid group than in the control groups (P < 0.05 and P < 0.01, respectively).

CONCLUSIONS

This study suggests that transfection of a TGF-β1-shRNA plasmid could inhibit the fibrosis of renal allografts. The mechanism may be associated with the downregulation of Smad3 and upregulation of Smad7, resulting in suppressed epithelial-myofibroblast transdifferentiation and extracellular matrix synthesis.

Decreased chaperone activity of alpha-crystallins in naphthalene-induced cataract possibly results from C-terminal truncation

Naphthalene-induced cataract has been extensively used to test potential anticataract drugs. Because the morphology as well as the toxic manifestations of naphthalene-induced cataract are reported to be similar to that of age-related cataract, naphthalene cataractogenesis in rats has been used as a valuable animal model to study the aetiology of age-related cataract in humans. This study aimed to determine whether the molecular chaperone activity of the alpha-crystallins was altered in naphthalene-induced cataract, and to clarify the possible mechanism for these changes. The data showed that the chaperone activity of the alpha-crystallins decreased in naphthalene-induced cataract. By mass spectrometry, C-terminal truncation of 16 amino acids and other post-translational modifications such as acetylation, phosphorylation, oxidation and carbamylation of the alpha-crystallins were detected. Furthermore, the results suggested that, at the proteomics level, naphthalene-induced cataract is a valuable animal model for the study of age-related cataract in humans.

Interleukin-12-anchored exosomes increase cytotoxicity of T lymphocytes by reversing the JAK/STAT pathway impaired by tumor-derived exosomes

Tumor-derived exosomes express tumor antigens, leading to their promising utility as tumor vaccines, but they also can suppress T-cell signaling molecules and reduce cytotoxic effects. We investigated whether interleukin-12 (IL-12)-anchored exosomes (EXO/IL-12) reverse tumor exosome-mediated inhibition of T-cell activation and cytotoxicity was associated with inhibition of JAK3 and p-STAT5. A co-expression plasmid of pBudCE4.1/IL-12A/ IL-12B-GPI was constructed. EXO/IL-12 was identified by transmission electron microscopy and Western blotting, which induced proliferation and cytotoxicity of T-cells and were analyzed by CFSE-based flow cytometry. Expression of JAK2, JAK3 and p-STAT5 was detected by Western blotting. Our results showed that EXO/IL-12 was much more efficient in induction of the proliferation, release of IFN-gamma and cytotoxic effect of T lymphocytes than conventional exosomes in vitro. Exosomes inhibited the expression of JAK3 and phosphorylation of STAT5 in high doses in T-cells, but not JAK2, while EXO/IL-12 had much less attenuated reduction of the expression of p-STAT5. The enhanced cytotoxic effects of T lymphocytes might partly depend on EXO/IL-12 reversing the suppressed expression of p-Stat5 by Jak2/Stat5 pathway. These findings might provide an alternative approach for developing exosomes into tumor vaccines.

Exosomes derived from IL-12-anchored renal cancer cells increase induction of specific antitumor response in vitro: a novel vaccine for renal cell carcinoma

Exosome-based immunotherapy for cancer holds promise, but needs improvements, especially for tumor-derived exosomes. We investigated, whether exosomes derived from IL-12-anchored human renal cancer cells could enhance their immunogenicity and increase induction of specific antitumor response. A mammalian co-expression plasmid of glycolipid-anchored-IL-12 (GPI-IL-12) was constructed by subcloning IL-12A chain gene (P35 subunit) and a fusion gene containing GPI-anchor signal sequence of human placental alkaline phosphatase-1 (hPLAP-1) and IL-12B chain gene (P40 subunit) in pBudCE4.1. Then exosomes were prepared from renal cancer cells modified to express GPI-IL-12. The results showed that exosomes derived from IL-12-anchored renal cancer cells expressed renal cell carcinoma-associated antigen G250 and GPI-IL-12. The incorporation of GPI-IL-12 onto exosomes (exosomes-GPI-IL-12, EXO/IL-12) significantly promotes proliferation of T cells, and subsequently increased the release of IFN-gamma. Notably, stimulation with EXOs/IL-12 could efficiently induce antigen-specific cytotoxic T lymphocytes (CTLs), resulting in more significant cytotoxic effects in vitro. These results suggested that exosomes derived from IL-12-anchored renal cancer cells bore GPI-IL-12 and G250, which have tumor rejection antigen with enhanced immunogenicity and antitumor effects, representing a novel strategy of exosomes-based vaccine for renal cell carcinoma.

Polychlorinated biphenyls affect thyroid function and induce autoimmunity in Sprague-Dawley rats

Polychlorinated biphenyls (PCBs) have been reported to cause a variety of toxic effects. In order to assess the thyroid function after exposure to PCBs and investigate whether PCBs induce autoimmune process in the thyroid gland, we determined the levels of serum thyroid hormones (FT3, FT4, and T4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibody (TPOAb) in Sprague-Dawley rats treated with a commercial mixture of PCBs, Aroclor 1,254 (PCBs group), or the antithyroid drug, propylthiouracil (PTU group). The histopathology of the thyroid was also examined. Serum FT3, FT4, and T4 concentrations were significantly reduced, while TSH values were dramatically increased in PCBs group and PTU group compared with control rats (p < 0.05). TPOAb levels were significantly elevated in PCBs-treated rats (p < 0.05) but not in PTU group (p > 0.05). In contrast to the controls, treatment with PCBs lead to distinct histopathological changes in the thyroid gland, such as hyperplasia of the epithelia in follicles, colloid content reduction, vascularization, and lymphocytic infiltration in the perifollicular areas, whereas the major changes in the thyroid in PTU-treated rats were follicles shrinkage or collapse and colloid content reduction compatible with induced hypothyroidism. The results indicate that PCBs affect thyroid function via the induction of autoimmunity, which is a mechanism different from the effect of antithyroid drug on the thyroid gland.

Ecological stabilization of thickened wastewater sludge from CAST process

Wastewater sludge ecological stabilization (WWSES) pilot scale experiments were conducted for thickening treatment and disposal of sludge which came from Cyclic Activated Sludge Technology (CAST) process. The study was performed over the periods from June to November 2005 and from May to November 2006, on a bed of 80 m2. The sludge loadings were stopped for the winter from December 2005 and resumed in May 2006. The results shows that dried sludge layer has higher permeation coefficients of 0.15-1.3 m/h. It is suggested that the percolate did not filtrate downwards evenly, part of percolate filtrates downwards along stems, roots and cracks existing in dried sludge which have lower flow resistance. The relationship of dried sludge thickness and operation time is in accord with quadratic equation under fluctuating sludge loadings. Linear regression equation can indicate dried sludge thickness variation under fixed sludge loading. In comparison with natural ones, coarse protein content of Phragmites australis roots in the system is twice as high, coarse fiber content of roots, coarse fat content of stems and leaf are obviously higher; and coarse protein content of Typha augustifolia in the system are obviously higher, while coarse fat and coarse fiber contents have no significant difference.

[Effect of saffor (Carthamus tinctorius) injection on renal ischemia/reperfusion injury in rats]

OBJECTIVE

To study the effect and mechanism of saffor injection on renal ischemia/reperfusion (I/R) injury in rats.

METHOD

Seventy-five SD rats were randomly divided into five groups (n = 15, in each), normal control groups, I/R control groups, low-dose treatment groups, middle-dose treatment groups and high-dose treatment groups. After rat's I/R injury model was established, renal function was assessed by measuring serum creatinine, blood urea nitrogen, urine osmotic pressure and urine osmotic pressure/blood osmotic pressure, the apoptosis rate in I/R renal tissure was measured by TUNEL method and caspase-3 concentration was measured by immunohistochemistry.

RESULT

Reperfusion of the ischemic kidney induced marked renal dysfunction. Saffor injection significantly inhibited the reperfusion-associated increase in apoptosis rate and caspase-3 protein absorbance value. Moreover, the renal dysfunction at all treatment groups was markedly ameliorated by Saffor injection. (P < 0.01).

CONCLUSION

The results show that saffor injection significantly reduces the renal dysfunction and injury caused by I/R of the kidney, And the protective effect of Saffor injection may be related to the inhibition of cell apoptosis and caspase-3 gene expression following renal I/R.

[Expression of total RNA and amplification of myocardial troponin gene during monitoring viral cardiomyocyte injury.]

BACKGROUND

To investigate the value of circulating cTnI-mRNA detection for monitoring myocardial injury development and prognosis.

METHODS

Viral myocardial injury models in BALB/c mice were created by intraperitoneal inoculation with Coxsackievirus B3 (CVB3,1x108 TCID50) for inducing myocardial injury. The total RNAs were extracted and cTnI-mRNA in mice cardiac tissues and circulating blood were amplified by RT-PCR during mice myocardial injury.

RESULTS

In virus infected mice, the mRNA abundance for cTnI was up-regulated in heart and circulating blood and associated with salient myocardial histopathologic features, including myocardial swelling, inflammatory cell infiltration, pyknosis, karyorrhexis, karyolysis, denaturalization, necrosis, and calcification. The cTnI-mRNA form infected mice heart and circulating cardiac myocytes were analyzed by RT-PCR, the amplified gene fragments were found in all heart tissues. The incidence of cTnI-mRNA was 0, 0, 0, 16.7%, 40.0%, 71.4%, 83.3% and 87.5% in the controls, the 3rd, 6th, 9th, 12th, 15th, 18th,and 21st day in circulating bloods from the infected mice, respectively.

CONCLUSION

The present data suggest that cTnI-mRNA expression is up-regulated and released into blood on viral myocardial injury, and detection of circulating cTnI-mRNA is a sensitive genetic marker for monitoring myocardial injury development and prognosis.

[Relationship between expression of matrix metalloproteinase-9 (MMP-9) and angiogenesis in renal cell carcinoma]

BACKGROUND & OBJECTIVE

Matrix metalloproteinase-9 (MMP-9) is closely related to tumor invasion and metastasis. It has been recently found that MMP-9 also plays a role in tumor angiogenesis. This study was designed to investigate the relationship between MMP-9 and angiogenesis in renal cell carcinoma (RCC) and its clinical significance.

METHODS

SP immunohistochemistry was used to determine the expression of MMP-9, vascular endothelial growth factor (VEGF), and microvessel density (MVD) in 78 RCC tissues.

RESULTS

The expression of MMP-9 was related to the pathological stage and the histological grade in RCC (P< 0.05). The MVD value in MMP-9-positive group (110.46+/-50.16) was much higher than that in MMP-9-negative group (84.77+/-44.52)(P< 0.05). There was a positive correlation between the intensity of the expression of MMP-9 and that of VEGF in RCC tissues (r=0.4096,P< 0.01). MMP-9 and VEGF took synergistic effect on angiogenesis in RCC.

CONCLUSION

MMP-9 is associated with angiogenesis in RCC, and can serve as a biomarker for the potentialities of invasion and metastasis of RCC.

Src is an important mediator of extracellular signal-regulated kinase 1/2-dependent growth signaling by angiotensin II in smooth muscle cells from resistance arteries of hypertensive patients

The role of c-Src in growth signaling by angiotensin (Ang) II was investigated in vascular smooth muscle cells (VSMCs) from arteries of hypertensive patients. c-Src and extracellular signal-regulated kinase 1/2 (ERK1/2) activity, proto-oncogene expression, activating protein-1 (AP-1) DNA-binding activity, and DNA and protein synthesis were studied in Ang II-stimulated VSMCs derived from small peripheral resistance arteries of normotensive subjects (NTs, n=5) and age-matched untreated hypertensive patients (HTs, n=10). Ang II type 1 (AT(1)) and type 2 (AT(2)) receptor status was also assessed. Ang II dose-dependently increased the synthesis of DNA and protein, with enhanced effects in VSMCs from HTs. PD 098,059, a selective inhibitor of the ERK1/2 pathway, attenuated Ang II-stimulated growth in HTs. The effects of PD 098,059 were greater in HTs than in NTs. In NTs, Ang II transiently increased ERK1/2 phosphorylation, whereas in HTs, Ang II-stimulated actions were augmented and sustained. PP2, a selective Src inhibitor, reduced ERK1/2 activity and normalized ERK1/2 responses in HTs. Ang II-induced c-Src phosphorylation was 2- to 3-fold greater in HTs than in NTs. In HTs but not NTs, kinase activation was followed by overexpression of c-fos and enhanced AP-1 DNA-binding activity. PD 098,059 and PP2 attenuated these responses. AT(1) receptor expression was similar in NTs and HTs. In HT cells transfected with c-fos antisense oligodeoxynucleotide, Ang II-stimulated growth was reduced compared with sense oligodeoxynucleotide. Our findings suggest that augmented Ang II-stimulated VSMC growth is mediated via hyperactivation of c-Src-regulated ERK1/2-dependent pathways, leading to overexpression of c-fos mRNA and enhanced AP-1 DNA-binding activity. Because AT(1) receptor expression was unaltered in HTs, increased Ang II signaling may be a postreceptor phenomenon. These data define a signal transduction pathway whereby Ang II mediates exaggerated growth in VSMCs from HTs.

Role of c-Src in the regulation of vascular contraction and Ca2+ signaling by angiotensin II in human vascular smooth muscle cells

OBJECTIVE

Tyrosine kinases, typically associated with growth-signaling pathways, also play a role in Ang II-stimulated vascular contraction. However the specific kinases involved are unclear. We hypothesize here that c-Src, a non-receptor tyrosine kinase, is an important upstream regulator of vascular smooth muscle cell (VSMC) Ca2+ signaling and associated vascular contraction induced by Ang II.

METHODS

Cultured VSMCs from resistance arteries of healthy subjects were studied. Human VSMCs electroporated with anti-c-Src antibody and c-Src-deficient VSMCs from small arteries of c-Src knockout mice (Src-/-mVSMCs) were also investigated. Intracellular free Ca2+ concentration ([Ca2+]i), c-Src activity and IP3 production were measured by fura 2, immunoblot and radioimmunoassay respectively. Contraction was examined in intact rat small arteries.

RESULTS

Ang II rapidly increased VSMC c-Src activity, with peak responses obtained at 1 min. Ang II induced a biphasic [Ca2+]i response (Emax = 636 +/- 123 nmol/l). The initial [Ca2+]i transient, mediated primarily by Ca2+mobilization, was dose-dependently attenuated by the selective Src inhibitor, PP2, but not by PP3 (inactive analogue). Ang II-elicited [Ca2+]i responses were blunted in cells electroporated with anti-c-Src antibodies and in c-Src-/-mVSMCs. Src inhibition decreased Ang II-induced generation of IP3 in human VSMCs. Ang II dose-dependently increased vascular contraction (Emax = 40 +/- 6.5%). These responses were attenuated by PP2 (Emax = 7.8 +/- 0.08%) but not by PP3 (Emax = 35 +/- 4.5%).

CONCLUSIONS

Our findings identify c-Src as an important regulator of VSMC [Ca2+]i signaling and implicate a novel contractile role for this non-receptor tyrosine kinase in Ang II-stimulated vascular smooth muscle.

Cytotoxic prenylated depsidones from Garcinia parvifolia

Leaf extracts of Garcinia parvifolia provided relatively high yields of four novel, cytotoxic prenylated depsidones. The structures were determined mainly by detailed NMR spectral analysis and X-ray crystallography.