miR-26a suppresses autophagy in swine Sertoli cells by targeting ULK2.

A large number of microRNAs (miRNAs) have been detected from porcine testicular tissues thanks to the development of high-throughput sequencing technology. However, the regulatory roles of most identified miRNAs in swine testicular development or spermatogenesis are poorly understood. In our previous study, ULK2 (uncoordinated-51-like kinase 2) was predicted as a target gene of miR-26a. In this study, we aimed to investigate the role of miR-26a in swine Sertoli cell autophagy. The relative expression of miR-26a and ULK2 levels has a significant negative correlation (R2  = .5964, p ≤ .01) in nine developmental stages of swine testicular tissue. Dual-luciferase reporter assay results show that miR-26a directly targets the 3'UTR of the ULK2 gene (position 618-624). In addition, both the mRNA and protein expression of ULK2 were downregulated by miR-26a in swine Sertoli cells. These results indicate that miR-26a targets the ULK2 gene and downregulates its expression in swine Sertoli cells. Based on the expression of marker genes (LC3, p62 and Beclin-1), overexpression of miR-26a or knock-down of ULK2 inhibits swine Sertoli cell autophagy. Taken together, these findings demonstrate that miR-26a suppresses autophagy in swine Sertoli cells by targeting ULK2.

SOX8 regulates cancer stem-like properties and cisplatin-induced EMT in tongue squamous cell carcinoma by acting on the Wnt/ß-catenin pathway.

A sub-population of chemoresistant cells exhibits biological properties similar to cancer stem cells (CSCs), and these cells are believed to be a main cause for tumor relapse and metastasis. In our study, we explored the role of SOX8 and its molecular mechanism in the regulation of the stemness properties and the epithelial mesenchymal transition (EMT) of cisplatin-resistant tongue squamous cell carcinoma (TSCC) cells. We found that SOX8 was upregulated in cisplatin-resistant TSCC cells, which displayed CSC-like properties and exhibited EMT. SOX8 was also overexpressed in chemoresistant patients with TSCC and was associated with higher lymph node metastasis, advanced tumor stage and shorter overall survival. Stable knockdown of SOX8 in cisplatin-resistant TSCC cells inhibited chemoresistance, tumorsphere formation, and EMT. The Wnt/ß-catenin pathway mediated the cancer stem-like properties in cisplatin-resistant TSCC cells. Further studies showed that the transfection of active ß-catenin in SOX8 stable-knockdown cells partly rescued the SOX8 silencing-induced repression of stem-like features and chemoresistance. Through chromatin immunoprecipitation and luciferase assays, we observed that SOX8 bound to the promoter region of Frizzled-7 (FZD7) and induced the FZD7-mediated activation of the Wnt/ß-catenin pathway. In summary, SOX8 confers chemoresistance and stemness properties and mediates EMT processes in chemoresistant TSCC via the FZD7-mediated Wnt/ß-catenin pathway.

Variations of rhizosphere bacterial communities in tea (Camellia sinensis L.) continuous cropping soil by high-throughput pyrosequencing approach.

AIMS: The goal was to investigate the dynamics of soil bacterial community in the chronosequence tea orchards. METHOD AND RESULTS: In this study, soils from tea orchards with continuously cropping histories for 1, 10 and 20 years were collected for investigating rhizosphere bacterial communities using 454 pyrosequencing. The results indicated that Gammaproteobacteria, Alphaproteobacteria, Acidobacteria and Actinobacteria were the main phyla in the tea orchard soils and accounted for more than 60% of the bacterial sequences. At the genus level, the relative abundance of beneficial bacteria, such as Pseudomonas, Rhodanobacter, Bradyrhizobium, Mycobacterium and Sphingomonas, significantly decreased in the 20-year tea orchard soils. Similar patterns of bacterial community structure were observed between 1-year and 10-year tea orchards, which significantly differed from those of 20-year tea orchards. Redundancy analysis indicated that soil organic carbon and pH showed high correlations (positive or negative) with the majority of the taxa. CONCLUSION: Long-term tea cultivation altered the composition and structure of soil bacterial community, which led to the reduction in the beneficial bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The results can provide clues on how to regulate the soil microbial community and maintain the health of soils in tea orchard systems.

External quality assessment of prenatal diagnosis of a rare and subtle chromosomal structural abnormality.

PURPOSE OF THE STUDY: To explore the misdiagnosis probability of subtle chromosomal structural abnormalities and find proper strategy to improve the accuracy of prenatal genetic diagnosis, we carried out a preliminary external quality assessment of prenatal detection of a rare case. PATIENTS AND METHODS: Three karyograms of a rare case of cri du chat syndrome associated with t(11;22) translocation [46,XY, del(5)(p15.2), t(11;22)(q23;q11.2)] were chosen. The patient's information and karyograms were emailed to 21 laboratories simulating the scenarios of prenatal diagnosis. The laboratories were required to provide a report using current nomenclature. RESULTS: Seven laboratories sent results for evaluation (response rate: 33.33%). For t(11;22), Two labs incorrectly reported that chromosome 22 was deletion. 5 of 7 labs reported t(11;22) translocation consistent with the actual karyotype. Among them, lab 6 suspected the abnormal 5q and lab 7 incorrectly considered chromosome 22 was deletion or reduplication. All laboratories missed to report the karyotype of del(5). CONCLUSIONS: Conventional cytogenetic analysis couldn't always detect subtle chromosomal structure abnormalities correctly during prenatal diagnosis. To improve the quality of prenatal genetic diagnosis, an excellent external quality assessment (EQA) scheme is currently imperative in China.

First Report of Powdery Mildew Caused by Erysiphe diffusa, Oidium neolycopersici, and Podosphaera xanthii on Papaya in Taiwan.

Powdery mildew can be found in most papaya (Carica papaya L.) fields during the winter and spring seasons in Taiwan. It usually causes severe yellowing of the leaf lamina and petiole and serious defoliation. Three types of powdery mildew fungi were isolated from papaya leaves in Chiayi City (23.28°N, 120.28°E) at the beginning of 2008. Conidia of the first one were single, globose, hyaline, and 24 to 36 × 14 to 18 µm (average 30.2 × 15.6 µm) without fibrosin bodies and with straight or occasionally flexuous conidiophores at the base. The second one had short pseudo-chains of two to four conidia which were ellipsoidal to ovoid, hyaline, and 24 to 40 × 12 to 16 µm (average 29.7 × 13.4 µm) without fibrosin bodies. The third type had chains of ellipsoidal conidia that were hyaline, 24 to 28 × 12 to 16 µm (average 26.3 × 14.4 µm) and contained fibrosin bodies. To confirm the identity of the three fungi, the internal transcribed spacer (ITS) region of rDNA was amplified using the primer pairs G1 (5'-TCC GTA GGT GAA CCT GCG GAA GGA T-3')/Ed2 (5'-CGC GTA GAG CCC ACG TCG GA-3'), G1 (5'-TCC GTA GGT GAA CCT GCG GAA GGA T-3')/On2 (5'-TGT GAT CCA TGT GAC TGG AA-3'), and S1 (5'-GGA TCA TTA CTG AGC GCG AGG CCC CG-3')/S2 (5'-CGC CGC CCT GGC GCG AGA TAC A-3'). The alignment of obtained sequences (GenBank Accession Nos. GU358452, 507 bp; GU358451, 580 bp; and GU358450, 455 bp) showed a sequence identity of 100, 99, and 99% with the ITS sequences of Erysiphe diffusa, Oidium neolycopersici, and Podosphaera xanthii (GenBank Accession Nos. FJ378880, EU909694, and GQ927254), respectively. On the basis of morphological characteristics and ITS sequence similarities, these fungi were identified as E. diffusa (Cooke & Peck) U. Braun & S. Takam., O. neolycopersici L. Kiss, and P. xanthii (Castagne) U. Braun & S. Takam., respectively (1,3). Single colonies on papaya leaves infected with powdery mildew were identified in the laboratory and maintained on papaya leaves as inoculum. Pathogenicity was confirmed through inoculations by gently pressing a single colony of each fungus onto leaves of healthy papaya seedlings (cv. Horng-Fe). Five seedlings were inoculated for each fungus and then covered with plastic bags for 2 days. Five noninoculated seedlings served as control. After inoculation, treated plants were maintained separately from the control in different rooms of a greenhouse at 25°C under natural daylight conditions. Seven days after inoculation, typical symptoms of powdery mildew were observed on inoculated plants, but not on noninoculated plants. The same species from diseased lesions following artificial inoculation with each fungus were identified with light microscopy. Papaya was previously described as a host to O. caricae Noack in many tropical and subtropical areas of the world including Taiwan (2). However E. cruciferarum, Golovinomyces cichoracearum, Oidiopsis sicula, O. caricae, O. caricae-papayae, O. caricicola, O. indicum, O. papayae, Ovulariopsis papayae, P. caricae-papayae, P. macularis, P. xanthii, and Streptopodium caricae were reported to infect papaya (4). To our knowledge, this is the first report of papaya powdery mildew caused by E. diffusa and O. neolycopersici in the world and the first report of the three fungi found on papaya in Taiwan. References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (2) H. S. Chien and H. L. Wang. J. Agric. Res. China 33:320, 1984. (3) L. Kiss et al. Mycol. Res. 105:684, 2001. (4) J. R. Liberato et al. Mycol. Res. 108:1185, 2004.

Printing conducting polymers.

Recent developments in both materials science and printing technologies have led to a rapid expansion in the field of printed conducting polymers. This review provides an overview of the most common printing methods currently in use and the material requirements of each. Examples of printed devices fabricated from a range of conducting polymers are given with an emphasis on the development of sensors.

Effects of caponization and different forms of exogenous androgen implantation on immunity in male chicks.

This study determined the caponization effects on the immune responses in male chicks. Different forms of exogenous androgen implantation on male chick immunity were compared. Healthy, uniform male Single Comb White Leghorn chicks were caponized at 3 wk of age. Birds were housed in individual cages (35 x 30 x 40 cm, length x width x height). Each of 27 sham-operated (sham) and caponized (capon) male chickens were used for trial 1. Trial 2 used 60 capons divided into 4 treatments with implants of either 1 mm i.d. x 3 mm o.d. 58 mg of cholesterol, testosterone (TES), 5alpha-dihydrotestosterone (5alpha-DHT), or 19-nortestosterone (19-NorT). The exogenous androgen was implanted immediately after caponization and resupplied every 4 wk for an entire 13-wk feeding trial. The results from trial 1 showed that the relative bursa weight increased compared with the sham treatment (P < 0.05). The 2 wk post-Newcastle disease virus titer and the delayed-type hypersensitivity (DTH) of 48 h post-phytohemagglutinin phosphate (PHA-P) injection were increased compared with the sham treatment (P < 0.05). In trial 2, implanted 5alpha-DHT and 19-NorT could decrease the relative bursa weight in capons (P < 0.05). The 2 wk post-Newcastle disease virus titer in the 5alpha-DHT group was higher than that in the cholesterol group (P < 0.05). The 19-NorT group had the highest (P < 0.05) PHA-P response. Peripheral blood lymphocyte subset population analysis revealed that the percentage of CD4 T cells in the TES group was lower (P < 0.05) compared with that of the 5alpha-DHT group. Differently, the percentage of CD8 T cells in the TES and 19-NorT groups was higher (P < 0.05) than that in the 5alpha-DHT group. Male chicks that were caponized had increased bursa weight and PHA-P response, whereas different forms of exogenous androgen implantation reverted the phenomena in an order of potency of 5alpha-DHT and 19-NorT > TES, and the PHA-P response was TES > 5alpha-DHT >19-NorT.

First Report of Anthracnose on Cucurbitaceous Crops Caused by Glomerella magna in Taiwan.

During the summer and fall of 2006, leaf anthracnose samples were collected from fields of cucumber (Cucumis sativus L.), calabash gourd (Lagenaria siceraria (Molina) Standley), and luffa (Luffa cylindrica (L.) M. Roem.) in southern Taiwan. On cucumber leaves, spots start as water-soaked areas and expand into brown spots. Leaf lesions on calabash gourd and luffa begin as water soaked and then become light brown-to-reddish spots. Centers of lesions sometimes fall out; giving infected leaves a shot-hole appearance. Small pieces (approximately 2 × 2 mm) of diseased leaf tissue from margins of individual lesions were surface disinfected in 1% sodium hypochlorite solution for 1 min, rinsed in sterile water, plated on water agar, and incubated at 25°C. After 4 days, mycelium was isolated, transferred to potato dextrose agar (PDA), and then incubated at 25°C in a 12-h light/darkness regimen. Fast-growing colonies on PDA were white to orange or pink with abundant acervuli but no perithecium. One-celled conidia were ovoid to oblong and 12 to 20 × 4 to 6 (15.9 × 5.0) µm. The morphological traits were identical to those of Colletotrichum magna (teleomorph Glomerella magna Jenkins & Winstead) and clearly distinct from those of C. orbiculare (Berk. & Mont.) Arx (synonym C. lagenarium (Pass.) Ellis & Halst. (conidia were mostly oblong, measuring 7 to 11 × 2 to 6 [9.3 × 4.2] µm, with slow-growing gray colonies) (2,3). Koch's postulates were performed to verify that the isolates were capable of causing anthracnose on cucurbitaceous crops. Pathogenicity tests were conducted in the greenhouse at 25°C under natural daylight conditions. Isolate C0604 was grown on PDA for 14 days and a spore suspension was made (106 spores/ml). Three 14-day-old seedlings at the two- to three-leaf stage of muskmelon (Cucumis melo L. var. reticulatus Naud., cv. Sapphire), squash (Cucurbita moschata Duch., cv. Achen), calabash gourd (cv. Huapu), and luffa (cv. 623) were sprayed with the spore suspension and then covered with plastic bags. Control treatments were sprayed with sterile water. After 2 days, the bags were removed. Typical anthracnose symptoms developed on all inoculated seedlings 7 days after inoculation. G. magna was reisolated from inoculated leaves following the protocol used for the original isolation. Control seedlings developed no symptoms. To confirm the identity of the fungus, PCR amplification and DNA sequencing of the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 of rRNA gene of the isolate C0604 was performed by using ITS1/ITS4 as the PCR and sequencing primers. Sequence analysis of the 558-bp PCR product (GenBank Accession No. GU358453) showed 100% identity to the rRNA sequence of G. magna (GenBank Accession No. DQ003103) (1). PCR amplification of the ITS region was also carried out using species-specific primer GmF (5'- GTG AAC ATA CCT CAA ACG TTG CC -3')/GmR (5'- GGA GGG TCC GCC ACT GTA TTT CG -3') designed in this study. A DNA fragment of approximately 378 bp was amplified from nine isolates of G. magna, whereas no amplification products were obtained from reference cultures of C. gloeosporioides (Penz.) Penz. & Sacc. and C. orbiculare. To our knowledge, this is the first report of G. magna causing anthracnose on cucurbitaceous crops in Taiwan. References: (1) M. Du et al. Mycologia 97:641, 2005. (2) S. F. Jenkins, Jr. and N. N. Winstead. Phytopathology 54:452, 1964. (3) T. A. Zitter et al., eds. Compendium of Cucurbit Diseases. The American Phytopathological Society, St. Paul, MN, 1996.

Effects of caponization and testosterone implantation on immunity in male chickens.

This study examined the effects of caponization using different doses of testosterone (TES) on sexuality, hematology, and immune responses in male chickens. Healthy male chickens were caponized at 12 wk of age and selected at 16 wk of age for a 10-wk experiment. Fifteen intact male and 15 caponized male chickens were assigned to trial 1. In trial 2, ten sham-operated male chickens (sham) and 40 capons (randomly divided into 4 treatments) were implanted with cholesterol (CHOL, 9.24+/-0.36 mg), low TES (5.88+/-0.23 mg), medium TES (9.81+/-0.17 mg), or high TES (16.7+/-0.24 mg) administered at 16, 20, and 24 wk of age. Results from trial 1 showed caponization decreased the comb length, height and weight, and hematocrit (P<0.05) and increased the hemagglutination inhibition (HI; 1 wk postchallenge) and hemagglutination titer after Newcastle disease virus (NDV) and SRBC injections (P<0.05). In trial 2, the medium TES increased the comb length and height as compared with the CHOL group. Only the high TES increased the comb weight (P<0.05). The HI titer (1 wk postchallenge) in the CHOL group was higher than the sham (P<0.05). The medium TES decreased the HI titer (P<0.05) to the level of the sham (P>0.05). The phytohemagglutinin response was higher in the high TES group 24 h postinjection (P<0.05) and in the medium TES 48 h postinjection (P<0.05) as compared with the CHOL group. High dose TES implantation decreased the white blood cell counts as compared with the CHOL and sham groups (P<0.05). It appears that caponization decreased the blood androgen concentration and enhanced the humoral (anti-NDV and anti-SRBC) immune response. Testosterone implantation up to a threshold concentration could inhibit the humoral (anti-NDV) immune response and increase the cell-mediated (phytohemagglutinin) immune response.

Direct enhancement of the phagocytic and bactericidal capability of abdominal macrophage of chicks by beta-1,3-1,6-glucan.

Salmonella enterica serovar Enteritidis is the major zoonotic and intracellular pathogen. Different strategies have been developed to prevent the S. Enteritidis infection. The beta-1,3-1,6-glucan of Schizophyllum commune was used as an immunological booster to determine the minimal dietary level of beta-glucan that would restrict S. Enteritidis infection through the effects of beta-glucan on the activity of macrophages and direct physical protection of the intestine. One-day-old male Single Comb White Leghorn chicks were used in all trials. In trials 1 and 2, the 0.1% beta-1,3-1,6-glucan treatment completely eliminated the viable S. Enteritidis from spleen and liver in an oral challenge of 10(8) S. Enteritidis without any harmful effect on BW, serum proteins, and immunoglobulin. Instead of a 21-d feeding period of beta-glucan, a 14-d treatment was enough to eliminate the S. Enteritidis in spleen and liver. In trial 3, an increase in the relative weight of bursa of Fabricius and phytohemagglutinin-P-inducing cutaneous basophil hypersensitivity was observed (P < 0.05). In trials 2, 3, and 4, the direct or indirect effect of beta-1,3-1,6-glucan on abdominal macrophages was examined. Sterilized 3% Sephadex G-50 was injected to induce abdominal (peritoneal) phagocytes in chicks fed with or without 0.1% beta-1,3-1,6-glucan. Significantly increased phagocytic and bactericidal capability to S. Enteritidis was found in abdominal macrophages either pretreated or in vitro treated with 0.1% beta-1,3-1,6-glucan. In conclusion, in addition to the physical properties to block S. Enteritidis entrance, 0.1% dietary beta-1,3-1,6-glucan may enhance the host defense to S. Enteritidis by directly upregulating the phagocytosis and bactericidal activity of abdominal macrophages in chicks.

Comparison of the association of age with the infection of Salmonella and Salmonella enterica Serovar Typhimurium in Pekin ducks and Roman geese.

Nontyphoid Salmonella have a broad host range in poultry and mammals, and serovar Typhimurium is a threat to public health. In this study, normal and sick ducks and geese were collected from 12 farms in Taiwan to investigate the age-associated infection of Salmonella and Salmonella Typhimurium in Roman geese (Anser anser domesticus) and Pekin ducks (Anas platyrhynchos domesticus). In normal birds, the prevalence of Salmonella differed between species, and with age [e.g., 1-wk group, 37.5% (30/80) for ducks and 5.2% (6/116) for goslings (P < 0.05) vs. 4-wk group, 1% (1/96) for ducks and 12.1% (21/174) for geese]. Salmonella Typhimurium was identified from the visceral organs of moribund young geese suffering with colibacillosis and riemerellosis isolated from 2 goose farms (farm A and B, respectively). At farm B, 22.9% (27/118) of 4-wk geese with diarrhea were Salmonella Typhimurium-positive compared with 4.6% (8/174) of 4-wk normal geese. All Salmonella Typhimurium strains except one harbored a 94.7-kb virulence plasmid. Subcutaneous injection of Salmonella Typhimurium isolate 91NGL1 resulted in different clinical signs and pathogenesis between ducks and geese. In addition, the mean infectivity dose ratios of ducks to geese were 3.2 and 85.0 for 4- and 12-d birds, respectively, suggesting that goslings were more susceptible to Salmonella Typhimurium and resistance to Salmonella Typhimurium increased with age, especially for ducks. Therefore, Salmonella Typhimurium infection should be more common in goose farms than in duck farms, especially in the younger birds.

Investigation on mechanism of catalysis by Pt-LiCoO2 for hydrolysis of sodium borohydride using X-ray absorption.

The synthesis of platinum nanoparticle loaded LiCoO2 (Pt-LiCoO2) was carried out successfully by an impregnation method followed by sintering at different temperatures. The catalytic role of Pt-LiCoO2 composite in hydrogen generation during hydrolysis of sodium borohydride (NaBH4) was studied for fuel cell applications. X-ray diffraction (XRD), transmission electron microscopy (TEM), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) have been used to elucidate the structural and catalytic properties of Pt-LiCoO2. It was found that the 15 wt % of Pt nanoparticles on LiCoO2 sintered at 450 degrees C support showed the maximum efficiency for the catalysis reaction of hydrogen production. X-ray absorption near edge structure (XANES) analysis and extended X-ray absorption fine structure (EXAFS) analysis using a synchrotron radiation source were performed to carry out ex situ measurements in order to understand the mechanism of the catalytic process for the production of hydrogen during the hydrolysis of NaBH4. Co K-edge XANES showed a small percentage of cobalt in the metallic form after hydrogen generation which suggests the reduction of the cobalt during the hydrolysis of NaBH4.

Uptake of beta-carotene by ovarian and uterine tissues and effects on steroidogenesis during the estrous cycle in cats.

OBJECTIVES: To determine uptake of beta-carotene by ovarian and uterine tissues and influence of dietary beta-carotene on steroidogenesis and production of uterine protein during the estrous cycle in cats. ANIMALS: 56 female cats. PROCEDURE: Cats were fed diets containing 0, 0.4, 2, or 10 mg of beta-carotene daily for 8 weeks prior to detection of estrus. At time of observed estrus, all cats were manually induced to ovulate. Blood samples were obtained at estrus and every 2 days until day 14 after ovulation. On that day, cats underment laparotomy, and the ovaries and uterus were removed. Uterine contents were flushed, and luteal and endometrial tissues were obtained. RESULTS: Concentrations of beta-carotene in plasma and luteal and endometrial tissues increased in a dose-dependent manner. Concentrations of plasma progesterone were higher between days 6 and 10 after ovulation in cats fed diets containing beta-carotene and continued to increase through day 14 after ovulation in cats fed a diet containing 10 mg of beta-carotene. Plasma concentration of estradiol-17beta also was higher between days 0 and 4 after ovulation in cats fed diets containing beta-carotene. Cats fed a diet containing 10 mg of beta-carotene had the highest plasma estradiol concentration. Total uterine protein concentration was higher in cats fed beta-carotene, compared with values for cats fed an unsupplemented diet. CONCLUSION AND CLINICAL RELEVANCE: Cats readily absorb beta-carotene. Increased concentrations of progesterone, estradiol, and uterine protein may provide more optimal ovarian function or a better uterine environment for embryonic survival and development.

Dietary beta-carotene absorption by blood plasma and leukocytes in domestic cats.

Three experiments were conducted to study the uptake of oral beta-carotene by blood plasma and leukocytes in domestic cats. In Experiment 1, mature female Tabby cats (12 mo old) were given once orally 0, 10, 20 or 50 mg of beta-carotene and blood taken at 0, 12, 24, 30, 36, 42, 48 and 72 h after dosing. Concentrations of plasma beta-carotene increased in a dose-dependent manner. Peak concentrations were observed at 12-24 h and declined gradually thereafter. The half-life of plasma beta-carotene was 12-30 h. In Experiment 2, cats were dosed daily for six consecutive days with 0, 1, 2, 5 or 10 mg beta-carotene. Blood was sampled once daily at 12 h after each feeding. Daily dosing of cats with beta-carotene for 6 d resulted in a dose-dependent increase in circulating beta-carotene. Experiment 3 was designed to study the uptake of beta-carotene by blood leukocytes. Cats were fed 0, 5 or 10 mg of beta-carotene daily for 14 d. Blood leukocytes were obtained on d 7 and 14 to determine beta-carotene content in whole lymphocytes and in subcellular fractions. Blood lymphocytes took up large amounts of beta-carotene by d 7 of feeding. Furthermore, beta-carotene accumulated mainly in the mitochondria (40-52%), with lower amounts accumulating in the microsomes (20-35%), cytosol (15-34%), and nuclei (1.5-6%). Therefore, domestic cats readily absorb beta-carotene across the intestinal mucosa and transfer the beta-carotene into peripheral blood leukocytes and their subcellular organelles. beta-Carotene uptake kinetics show that some aspects of beta-carotene absorption and metabolism in cats are similar to those of humans.

Dietary beta-carotene stimulates cell-mediated and humoral immune response in dogs.

The role of beta-carotene on immune response in domestic dogs is not known. Female Beagle dogs were fed 0, 2, 20 or 50 mg beta-carotene/d; blood was sampled at wk 0, 1, 2, 4 and 8 for analysis of the following: lymphoproliferation, leukocyte subpopulations and concentrations of interleukin-2 (IL-2), immunoglobulin (Ig)G and IgM. Delayed-type hypersensitivity (DTH) response was assessed at wk 0, 3 and 7. beta-Carotene supplementation increased plasma beta-carotene concentrations in a dose-dependent manner. Compared with unsupplemented dogs, those fed 20 or 50 mg of beta-carotene had higher CD4+ cell numbers and CD4:CD8 ratio. However, there was no treatment difference in CD8+, CD21+ and major histocompatability complex (MHC) class II+ cells. Plasma IgG, but not IgM concentration was higher in dogs fed beta-carotene throughout the study period. The DTH response to phytohemagglutinin (PHA) and vaccine was heightened in beta-carotene-supplemented dogs. beta-Carotene feeding did not influence mitogen-induced lymphocyte proliferation or IL-2 production. Immune response was impaired in dogs classified as low beta-carotene absorbers compared with similar dogs fed the same amount of beta-carotene. Therefore, dietary beta-carotene heightened cell-mediated and humoral immune responses in dogs.

Dietary beta-carotene is taken up by blood plasma and leukocytes in dogs.

beta-Carotene uptake by blood plasma and leukocytes was studied in mature beagle dogs. In expt. 1, dogs were fed once orally with 0, 50, 100 or 200 mg of beta-carotene and their blood was sampled at 0, 1. 5, 3, 6, 10, 18 and 24 h. Plasma beta-carotene concentrations increased dose-dependently to peak at 6 h postfeeding. Concentrations decreased rapidly thereafter, showing a half-life of 3 to 4 h. In expt. 2, dogs were given daily doses for seven consecutive days with 0, 12.5, 25, 50 or 100 mg beta-carotene. Plasma beta-carotene concentrations increased dose-dependently; concentrations after the last dose were two- to fourfold higher than after the first dose. In expt. 3, dogs were fed 0, 50 or 100 mg beta-carotene daily for 30 d. beta-Carotene was elevated in lymphocytes and neutrophils in supplemented dogs. Furthermore, beta-carotene was taken up by the cytosol, mitochondria, microsomes (lymphocytes and neutrophils) and nuclei (lymphocytes only), proving that dogs can absorb beta-carotene. beta-Carotene is taken up by subcellular organelles of blood lymphocytes and neutrophils and in the plasma and leukocytes beta-carotene may have physiological importance as it relates to immunity in dogs. Uptake kinetics indicated that dogs are not an appropriate animal model for studying beta-carotene absorption and metabolism in humans.

Beta-carotene uptake and changes in ovarian steroids and uterine proteins during the estrous cycle in the canine.

The uptake of beta-carotene by reproductive tissues and the effects of beta-carotene on reproductive function in the dog are unknown. We studied the uptake of beta-carotene by blood, corpus luteum, and uterine endometrium and the role of dietary beta-carotene in influencing ovarian steroid and uterine protein production during the estrous cycle in the dog. Mature female Beagle dogs (n = 56) were fed diets containing 0, 2, 20, or 50 mg of beta-carotene daily for approximately 6 wk before estrus detection. Blood was sampled at regular intervals from estrus through d 45 after ovulation (d 0 = ovulation), when laparotomy was performed. The ovaries were obtained for the isolation of corpus luteum. The uterus was flushed with phosphate-buffered saline and the endometrium obtained by scraping. Beta-carotene was not detectable in plasma, corpus luteum, or endometrium of unsupplemented dogs. However, beta-carotene and alpha-carotene in plasma, corpus luteum, and uterine endometrium increased in a dose-dependent manner. Alpha-carotene made up a high percentage of total carotenoids even though the alpha-carotene content in the dietary source was very low. Dogs fed 50 mg of beta-carotene had significantly higher concentrations of plasma progesterone between d 12 and 26 compared with unsupplemented dogs. Dietary beta-carotene did not influence plasma estradiol-17beta and total uterine proteins. Therefore, beta-carotene is absorbed into plasma, corpus luteum, and uterine endometrium of dogs. Furthermore, dietary beta-carotene increased plasma progesterone concentrations during the estrous cycle. It is possible that dietary beta-carotene may improve reproductive function in the canine.

Dietary lutein stimulates immune response in the canine.

The possible immuno-modulatory action of dietary lutein in dogs is not known. Female Beagle dogs (17-18-month old; 11.4+/-0.4kg body weight) were supplemented daily with 0, 5, 10 or 20mg lutein for 12 weeks. Delayed-type hypersensitivity (DTH) response to saline, phytohemagglutinin (PHA) and a polyvalent vaccine was assessed on Weeks 0, 6 and 12. Blood was sampled on Weeks 0, 2, 4, 8 and 12 to assess (1) lymphocyte proliferative response to PHA, concanavalin A (Con A), and pokeweed mitogen (PWM), (2) changes in peripheral blood mononuclear cell (PBMC) populations, (3) interleukin-2 (IL-2) production and (4) IgG and IgM production. After the completion of 12-week study, we continued to collect the blood weekly up to 17 weeks to evaluate the changes in immunoglobulin production upon first and second antigenic challenges on Weeks 13 and 15. Plasma lutein+zeaxanthin was undetectable in unsupplemented dogs but concentrations increased (P<0.05) rapidly on Week 2 in lutein-supplemented dogs. Thereafter, concentrations generally continued to increase in dose-dependent manner, albeit at a much slower rate. Dogs fed lutein had heightened DTH response to PHA and vaccine by Week 6. Dietary lutein increased (P<0.05) lymphocyte proliferative response to all three mitogens and increased the percentages of cells expressing CD5, CD4, CD8 and major histocompatibility complex class II (MHC II) molecules. The production of IgG increased (P<0.05) in lutein-fed dogs after the second antigenic challenge. Lutein did not influence the expression of CD21 lymphocyte marker, plasma IgM or IL-2 production. Therefore, dietary lutein stimulated both cell-mediated and humoral immune responses in the domestic canine.

Modulation of humoral and cell-mediated immune responses by dietary lutein in cats.

The immuno-modulatory role of dietary lutein in domestic cats is unknown. Female Tabby cats (10-month old; n=56) were supplemented daily for 12 weeks with 0, 1, 5 or 10mg lutein. Blood was collected on Weeks 0, 2, 4, 8 and 12 to assess the following: (1) mitogen-induced peripheral blood mononuclear cells (PBMCs) proliferation, (2) changes in PBMC subpopulations, (3) interleukin-2 (IL-2) production and (4) plasma immunoglobulin (Ig)G production. In addition, delayed-type hypersensitivity (DTH) response to concanavalin A (Con A) or a polyvalent vaccine was performed on Weeks 0, 6 and 12. Dietary lutein increased plasma lutein concentrations in a dose-dependent manner (p<0.001) and concentrations had not reached steady state after 12 weeks of feeding in cats given 5 or 10mg lutein. Concentrations of plasma retinol and alpha-tocopherol were not influenced by diet. The DTH response to vaccine but not to Con A increased (p<0.05) in a dose-dependent manner on Week 6. Compared to control, cats fed lutein also showed enhanced Con A- and pokeweed mitogen-stimulated PBMCs proliferation. Dietary lutein also increased the percentages of CD4+ and CD21+ lymphocytes on Week 12 but had no significant effect on pan T, CD8 and MHC class II markers. Plasma IgG was higher (p<0.05) in cats fed 10mg lutein on Weeks 8 and 12. These results support the immuno-modulatory action of lutein in domestic cats.

Modification of the ADP-ribosyltransferase and NAD glycohydrolase activities of a mammalian transferase (ADP-ribosyltransferase 5) by auto-ADP-ribosylation.

Mono-ADP-ribosylation, a post-translational modification in which the ADP-ribose moiety of NAD is transferred to an acceptor protein, is catalyzed by a family of amino acid-specific ADP-ribosyltransferases. ADP-ribosyltransferase 5 (ART5), a murine transferase originally isolated from Yac-1 lymphoma cells, differed in properties from previously identified eukaryotic transferases in that it exhibited significant NAD glycohydrolase (NADase) activity. To investigate the mechanism of regulation of transferase and NADase activities, ART5 was synthesized as a FLAG fusion protein in Escherichia coli. Agmatine was used as the ADP-ribose acceptor to quantify transferase activity. ART5 was found to be primarily an NADase at 10 microM NAD, whereas at higher NAD concentrations (1 mM), after some delay, transferase activity increased, whereas NADase activity fell. This change in catalytic activity was correlated with auto-ADP-ribosylation and occurred in a time- and NAD concentration-dependent manner. Based on the change in mobility of auto-ADP-ribosylated ART5 by SDS-polyacrylamide gel electrophoresis, the modification appeared to be stoichiometric and resulted in the addition of at least two ADP-ribose moieties. Auto-ADP-ribosylated ART5 isolated after incubation with NAD was primarily a transferase. These findings suggest that auto-ADP-ribosylation of ART5 was stoichiometric, resulted in at least two modifications and converted ART5 from an NADase to a transferase, and could be one mechanism for regulating enzyme activity.