Dolichos Biflorus Agglutinin Research Articles

Alterations in the intestine of Patagonian silverside (Odontesthes hatcheri) exposed to microcystin-LR: Changes in the glycosylation pattern of the intestinal wall and inhibition of multidrug resistance proteins efflux activity

Accumulation and toxicity of cyanobacterial toxins, particularly microcystin-LR (MCLR) have been extensively studied in fish and aquatic invertebrates. However, MCLR excretion mechanisms, which could reduce this toxin⿿s effects, have received little attention. The Patagonian silverside, Odontesthes hatcheri, is an omnivorous-planktivorous edible fish, which has been shown to digest cyanobacterial cells absorbing MCLR and eliminating the toxin within 48h without suffering significant toxic effects. We studied the effects of MCLR on glycoconjugate composition and the possible role of multidrug resistance associated proteins (Abcc) in MCLR export from the cells in O. hatcheri intestine. We treated O. hatcheri with 5μg MCLRg⿿1 body mass administered with the food. Twenty four hours later, the intestines of treated and control fish were processed for lectin-histochemistry using concanavalin A (ConA), Triticum vulgaris agglutinin (WGA), and Dolichos biflorus agglutinin (DBA). MCLR affected the distribution of glycoconjugates by augmenting the proportion of ConA-positive at the expense of WGA-positive cells. We studied MCLR effects on the transport of the Abcc-like substrates 2,4-dinitrophenyl-S-glutathione (DNP-SG) and calcein in ex vivo intestine preparations (everted and no-everted sacs and strips). In treated preparations, CDNB together with MCLR (113μg MCLRg⿿1 intestine, equivalent to 1.14μmolL⿿1 when applied in the bath) or the Abcc inhibitor, MK571 was applied for one hour, during which DNP-SG was measured in the bath every 10min in order to calculate mass-specific DNP-SG transport rate. MCLR significantly inhibited DNP-SG transport (p<0.05), especially in middle intestine (47 and 24%, for luminal and serosal transport, respectively). In middle intestine strips, MCLR and MK571inhibited DNP-SG transport in a concentration dependent fashion (IC50 3.3 and 0.6μmolL⿿1, respectively). In middle intestine strips incubated with calcein-AM (0.25μmolL⿿1), calcein efflux was inhibited by MCLR (2.3μmolL⿿1) and MK571 (3μmolL⿿1) by 38 and 27%, respectively (p<0.05). Finally, middle intestine segments were incubated with different concentrations of MCLR applied alone or together with 3μM MK571. After one hour, protein phosphatase 1 (PP1) activity, the main target of MCLR, was measured. 2.5μM MCLR did not produce any significant effect, while the same amount plus MK571 inhibited PP1 activity (p<0.05). This effect was similar to that of 5μM MCLR. Our results suggest that in O. hatcheri enterocytes MCLR is conjugated with GSH via GST and then exported to the intestinal lumen through Abcc-like transporters. This mechanism would protect the cell from MCLR toxicity, limiting toxin transport into the blood, which is probably mediated by basolateral Abccs. From an ecotoxicological point of view, elimination of MCLR through this mechanism would reduce the amount of toxin available for trophic transference.

Spermatogonial stem cell organization in felid testis as revealed by Dolichos biflorus lectin.

Spermatogonial stem cells are being exploited in many species as a tool to recover fertility, but may also be used to manipulate the genetic pool. Whatever the purpose, these cells must be fully characterized and easily identifiable, and our goal was to improve this procedure in the domestic cat, used as an animal model for endangered felid species and for some human diseases/physiological processes. We have therefore screened several markers that might be used to distinguish and study the undifferentiated spermatogonia population insitu and invitro via immunohistochemistry applied to tissue sections and whole mounts of the domestic cat seminiferous tubules. Our results show that, although they label the cytoplasm and nucleus of gonocytes and spermatogonia in pre-pubertal animals, PGP9.5 and FoxO1 cannot be considered markers of undifferentiated spermatogonia in adult animals, as almost all spermatogonia, namely type A and B, express these proteins. Nonetheless, the Dolichos biflorus agglutinin (DBA lectin) was able to label the cell surface and cytoplasm of a small type A spermatogonial population in the adult animals. Analysis of the number and distribution of the DBA-labeled cells showed they were present in low number, which did not vary with epithelium seminiferous stage. Morphometric analysis revealed that DBA-labeled cells present tropism to a peculiar area of the seminiferous tubules, namely the area in direct contact with Leydig cells. Whole mounts of DBA-stained seminiferous tubules revealed the arrangement of DBA-stained cells in small clones up to eight cells. Noteworthy, the clonal cells presented variable staining intensity suggesting the existence of asymmetric distribution of O-glycosylated proteins within each clone. Our results strongly suggest that the DBA lectin is a marker of undifferentiated spermatogonia in domestic cat, and illustrate the peculiar characteristics of spermatogonial stem cell development and organization in this species.

Differentiation-related glycan epitopes identify discrete domains of the muscle glycocalyx.

The neuromuscular junction (NMJ) is enriched with glycoproteins modified with N-acetylgalactosamine (GalNAc) residues, and four nominally GalNAc-specific plant lectins have historically been used to identify the NMJ and the utrophin-glycoprotein complex. However, little is known about the specific glycan epitopes on skeletal muscle that are bound by these lectins, the glycoproteins that bear these epitopes or how creation of these glycan epitopes is regulated. Here, we profile changes in cell surface glycosylation during muscle cell differentiation and identify distinct differences in the binding preferences of GalNAc-specific lectins, Wisteria floribunda agglutinin (WFA), Vicia villosa agglutinin (VVA), soybean agglutinin (SBA) and Dolichos biflorus agglutinin (DBA). While we find that all four GalNAc binding lectins specifically label the NMJ, each of the four lectins binds distinct sets of muscle glycoproteins; furthermore, none of the major adhesion complexes are required for binding of any of the four GalNAc-specific lectins. Analysis of glycosylation-related transcripts identified target glycosyltransferases and glycosidases that could potentially create GalNAc-containing epitopes; reducing expression of these transcripts by siRNA highlighted differences in lectin binding specificities. In addition, we found that complex N-glycans are required for binding of WFA and SBA to murine C2C12 myotubes and for WFA binding to wild-type skeletal muscle, but not for binding of VVA or DBA. These results demonstrate that muscle cell surface glycosylation is finely regulated during muscle differentiation in a domain- and acceptor-substrate-specific manner, suggesting that temporal- and site-specific glycosylation are important for skeletal muscle cell function.

Embryoglycan: a highly branched poly-N-acetyllactosamine in pluripotent stem cells and early embryonic cells.

Embryonal carcinoma cells, stem cells of teratocarcinomas, are pluripotent stem cells and also prototypes of embryonic stem cells. Embryonal carcinoma cells contain large amounts of a highly branched poly-N-acetyllactosamine called embryoglycan, which has a molecular weight of approximately 10,000 or greater, and is asparagine-linked. This glycan was found by analyses of fucose-labeled glycopeptides, and its characteristics were established by biochemical analyses. The content of embryoglycan progressively decreases during the in vitro differentiation of embryonal carcinoma cells. Embryoglycan is also abundant in mouse embryonic stem cells and preimplantation mouse embryos, and decreases during embryogenesis. Embryoglycan carries a number of carbohydrate markers of murine pluripotent stem cells. Lewis x markers, such as SSEA-1, 4C9 antigen, and binding sites for Lotus tetragonolobus agglutinin are of particular importance. 4C9 antigenicity requires clustering of Lewis x, best accomplished by poly-N-acetyllactosamine branching, whereas SSEA-1 does not. Although in vivo evidence is lacking, these epitopes have been suggested to participate in cell-to-cell and cell-to-substratum adhesion. Other markers on embryoglycan include α-galactosyl antigens such as ECMA-2, and binding sites for Dolichos biflorus agglutinin, the epitope of which is considered to be identical to Sda antigen, namely, GalNAcβ1-4(NeuAcα2-3)Galβ1-4GlcNAc. While embryoglycan is also present in human teratocarcinoma cells, the carbohydrate markers characterized in human pluripotent stem cells to date are largely carried by glycolipids and keratan sulfate. Information on embryoglycan and markers carried by it may assist in the development of new markers of human pluripotent stem cells and their progenies.

Dietary Plant Lectins Affect Lifespan and Dopaminergic Neurons in Ceanorhabditis elegans Model Organism

Our preliminary data in Caenorhabditis elegans (C. elegans) proved the concept that dietary plant lectins might be an etiologic agent and/or chaperone for viruses/toxin(s) to induce Parkinson's disease as they can trans‐synaptically transport into the nervous system. Those data supported Braak's hypothesis of an “unknown pathogen” that enters the central nervous system via retrograde/anterograde transport after penetrating the gastrointestinal wall. A recent Danish study showed that vagotomy resulted in a 40% lower incidence of PD over 20 years. Using fluorescent microscopy, laser scanning microscopy, and lifespan assays in C.elegans (egIs1 [dat‐1p::GFP]) to build up a library of lectins, we further tested thirteen more dietary plant lectins that might be transported to DAergic neurons (DAergic‐N). The animals were maintained in liquid culture in 96‐well plates (20°C), fed with standard lab food E. coli (OP50), and treated with florescent tagged‐lectins (lectins‐TRITC) with or without additional specific inhibiting sugars. Laser scanning microscopy demonstrated that Arachis hypogaea Agglutinin (PNA, 0.018–0.18μM) co‐localized with GFP‐DAergic‐N in C. elegans. Succinylated Wheat Germ Agglutinin (S‐WGA, 0.046 or 0.138μM) or Glycine max Agglutinin (SBA, 0.017μM) reduced the number of DAergic‐N (P&lt;0.05). Lens Culinaris Agglutinin (LcH −0.5μM) or PNA (0.018μM) increased visibility of the numbers of GFP‐DAergic‐N from 5±0.2 to 7±0.4 or from 6±0.4 to 7±0.6 (P&lt;0.05). Fluorescent intensity of GFP‐DAergic‐N was reduced (P&lt;0.05) by Pisum Sativum Agglutinin (PSA, 0.43μM), Ulex Europaeus Agglutinin I (UEA I, 0.033–0.33μM) or Phaseolus Vulgaris Leucoagglutinating (PHA‐L, 0.017 or 0.054μM). The intensity of GFP‐DAergic‐N was increased by Phaseolus Vulgaris Erythroagglutinating (PHA‐E, 0.017–0.17μM), WGA (0.46μM), S‐WGA (0.046–0.46μM), Griffonia Simplicifolia I (GS I, 0.018–0.18μM), Dolichos biflorus Agglutinin (DBA) or Hippeastrum hybrid Agglutinin (HHA, 0.04–0.4μM). The size of GFP‐DAergic‐N was reduced (P&lt;0.05) by PHA‐E (0.17μM), PSA (0.043μM), WGA (0.046–0.46μM), UEA I (0.033–0.33μM), S‐WGA (0.046–0.46μM) or SBA (0.017μM), increased by PHA‐L (0.017–0.17μM) or DBA (0.018–0.18μM). Treatment of PHA‐E (0.054μM), PSA (0.043, or 0.43μM), WGA (0.46μM), UEA I (0.033μM), S‐WGA (0.046μM) or LcH (0.05μM) increased lifespan (P&lt;0.05). Lifespan was reduced (P&lt;0.05) by S‐WGA (0.46μM), LcH (0.5μM), SBA (0.17μM), PHA‐L (0.17μM), Artocarpus integrifolia Agglutinin (AIA, 0.031–0.31μM), HHA (0.12 or 0.4μM), PNA (0.054μM or 0.18μM), GS I (0.18μM) or DBA (0.18μM). Our results substantiated our hypothesis that dietary plant lectins can be transported to GFP‐DAergic neurons in C. elegans model being an “unknown pathogen” that might have the potential damaging DAergic neurons that leading to Parkinson's disease.

Uterine natural killer cell partnerships in early mouse decidua basalis.

The decidua basalis of developing mouse implantation sites is highly enriched in CD45+ leukocytes. In intact, syngeneically mated C57BL/6 decidua basalis examined at gestation day 8.5 by whole-mount in situ immunohistochemistry, leukocyte, but not trophoblast, conjugations were reported. Nothing is known regarding time course, frequency, composition, or importance of physiologic decidual CD45+ cell pairing. In this study, we confirmed the presence of anti-CD54+/anti-CD11a+ immune synapses in CD45+ decidual cell conjugates and characterized their cellular heterogeneity. Conjugated cell pairs were virtually absent before implantation (virgin and gestation days 3.5 and 4.5), were infrequent at gestation day 5.5, but involved 19% of all CD45+ cells by gestation day 8.5, then declined. By gestation day 8.5, almost all CD45+ cells coexpressed CD31, and 2 CD45+CD31+ cells composed most conjugates. Conjugation partners were defined for 2 nonoverlapping uterine natural killer cell subsets (Ly49C/I +/Dolichos biflorus agglutinin lectin- and Ly49C/I-/Dolichos biflorus agglutinin lectin+). Ly49C/I+ uterine natural killer cells were the major subset from before mating up to gestation day 6.5. At gestation day 5.5/6.5, uterine natural killer cell conjugates involving Ly49C/I + cells were more abundant. By gestation day 8.5/9.5, Dolichos biflorus agglutinin lectin+ uterine natural killer cells were the dominant subset with Dolichos biflorus agglutinin lectin+/Dolichos biflorus agglutinin lectin+ homologous conjugates and Dolichos biflorus agglutinin lectin+/Dolichos biflorus agglutinin lectin- heterologous conjugates dominating uterine natural killer cell pairings. At gestation day 6.5, both Ly49C/I+/CD45+ and Dolichos biflorus agglutinin lectin+/CD45+ heterologous conjugate pairs strongly engaged antigen-presenting cells (CD11c+, CD68+, or major histocompatibility complex class II+). By gestation day 8.5, dominant partners of Ly49C/I+/CD45+ and Dolichos biflorus agglutinin lectin+/CD45+ heterologous conjugates are T cells (CD8+ >CD4+). Heterologous conjugates that did not involve uterine natural killer cells occurred but did not suggest antigen presentation to T cells. These data identify gestation day 6.5-8.5 in the pregnant mouse as a critical window for leukocyte interactions that may establish immune regulation within implantation sites.

The Transcription Factor NFIL3 Is Essential for Normal Placental and Embryonic Development but Not for Uterine Natural Killer (UNK) Cell Differentiation in Mice.

Mice ablated for the gene encoding the transcription factor Nfil3 lack peripheral natural killer (NK) cells but retain tissue-resident NK cells, particularly in mucosal sites, including virgin uterus. We undertook a time course histological study of implantation sites from syngeneically (Nfil3(-/-)) and allogeneically (BALB/c) mated Nfil3(-/-) females. We also examined implantation sites from Rag2(-/-)Il2rg(-/-) females preconditioned by adoptive transfer of Nfil3(-/-) marrow or uterine cell suspensions to identify the Nfil3(-/-) pregnancy aberrations that could be attributed to nonlymphoid cells. Uterine NKs (UNKs) reactive and nonreactive with the lectin Dolichos biflorus agglutinin (DBA) differentiate, localize, and mature within Nfil3(-/-) implantation sites, although at reduced abundance. The DBA nonreactive UNK cells were enriched following Nfil3(-/-) marrow transplantation. Uterine lumen closure, early embryonic development, and differentiation of antimesometrial decidua were delayed in Nfil3(-/-) implantation sites. Major disturbances to the decidual-trophoblast interface that did not lead to fetal death were attributed to NFIL3 deficiency in trophoblast. At midgestation, vessels of the placental labyrinth were enlarged, suggestive of reduced branching morphogenesis. A major term complication in most Nfil3(-/-) × Nfil3(-/-) pregnancies but not Nfil3(-/-) × Nfil3(+/-) pregnancies was dystocia. These studies highlight the differentiation potential and functions of Nfil3(-/-) UNK cell progenitors and illustrate that much of the implantation site histopathology associated with this strain is due to Nfil3 deletion in nonlymphoid cell lineages.

Dietary Plant Lectins Appear to Be Transported from the Gut to Gain Access to and Alter Dopaminergic Neurons of Caenorhabditis elegans, a Potential Etiology of Parkinson's Disease.

Lectins from dietary plants have been shown to enhance drug absorption in the gastrointestinal tract of rats, be transported trans-synaptically as shown by tracing of axonal and dendritic paths, and enhance gene delivery. Other carbohydrate-binding protein toxins are known to traverse the gut intact in dogs. Post-feeding rhodamine- or TRITC-tagged dietary lectins, the lectins were tracked from gut to dopaminergic neurons (DAergic-N) in transgenic Caenorhabditis elegans (C. elegans) [egIs1(Pdat-1:GFP)] where the mutant has the green fluorescent protein (GFP) gene fused to a dopamine transport protein gene labeling DAergic-N. The lectins were supplemented along with the food organism Escherichia coli (OP50). Among nine tested rhodamine/TRITC-tagged lectins, four, including Phaseolus vulgaris erythroagglutinin (PHA-E), Bandeiraea simplicifolia (BS-I), Dolichos biflorus agglutinin (DBA), and Arachis hypogaea agglutinin (PNA), appeared to be transported from gut to the GFP-DAergic-N. Griffonia Simplicifolia and PHA-E, reduced the number of GFP-DAergic-N, suggesting a toxic activity. PHA-E, BS-I, Pisum sativum (PSA), and Triticum vulgaris agglutinin (Succinylated) reduced fluorescent intensity of GFP-DAergic-N. PHA-E, PSA, Concanavalin A, and Triticum vulgaris agglutinin decreased the size of GFP-DAergic-N, while BS-I increased neuron size. These observations suggest that dietary plant lectins are transported to and affect DAergic-N in C. elegans, which support Braak and Hawkes’ hypothesis, suggesting one alternate potential dietary etiology of Parkinson’s disease (PD). A recent Danish study showed that vagotomy resulted in 40% lower incidence of PD over 20 years. Differences in inherited sugar structures of gut and neuronal cell surfaces may make some individuals more susceptible in this conceptual disease etiology model.

Immunogenicity of Renal Microvascular Endothelial Cells From Genetically Modified Pigs.

Disrupting the porcine GGTA1 and CMAH genes [double knockout (DKO)] that produce the gal-α(1,3)-gal and N-glycolylneuraminic acid xenoantigens reduces human antibody binding to porcine peripheral blood mononuclear cells. It is important to examine rejection pathways at an organ-specific level. The object of this study is to evaluate the human preformed antibody reactivity against DKO renal microvascular endothelial cells (RMEC) in vitro. Characteristics of DKO RMEC were analyzed using flow cytometry. Human IgG/M binding to primary RMEC, immortalized RMEC (iRMEC), and iRMEC-deficient in B4GALNT2 genes were examined using flow cytometric crossmatch assay. Porcine RMEC expressed gal-α(1,3)-gal, N-glycolylneuraminic acid, and Dolichos biflorus agglutinin glycans recognized by human preexisting antibodies in humans. Antigenicity of DKO RMEC was lower than GGTA1 KO RMEC. The disruption of B4GALNT2 gene in DKO iRMEC further reduced human IgG/IgM binding. Silencing the porcine GGTA1, CMAH, and B4GALNT2 genes is an effective strategy to reduce human preformed antibody binding to RMEC. Porcine RMEC will be a useful reagent for the further study of xenoimmunology.

Isolation, proliferation, and induction of Bama mini-pig spermatogonial stem cells in vitro.

Spermatogonial stem cells (SSCs), the unique seed cells of testes, can undergo meiosis and form spermatozoa, thus transmitting genetic information to offspring. Research concerning these cells explores the mechanism underlying spermatogenesis, making possible the induction of their differentiation into spermatozoa in vitro. SSCs have therefore attracted much interest among scientists. Although the proliferation of such cells in vitro has been demonstrated, we are unaware of any long-term laboratory culture of porcine SSCs. The objective of this study was to isolate, characterize, culture, and induce the differentiation of Bama mini-pig SSCs. SSCs were isolated using differential plating and cultured for over 100 days on an STO feeder cell layer without serum. Cell clusters appeared after three passages and continuously formed during subsequent cultivation. Staining showed that these clusters were positive for UCHL1 and CDH1, could be bound by Dolichos biflorus agglutinin, and that some cells expressed OCT4. Ultrastructure observations revealed SSCs in testis tissue to be round in shape, while those cultured in vitro were flat and bound together. Our attempts at inducing differentiation showed that SSCs cultured in vitro could undergo meiosis. In this study, we describe an effective culture system for Bama mini-pig SSCs capable of producing enough cells to establish a platform for further SSC research, such as genetic manipulation or exploration of the mechanism underlying spermatogenesis.

Derivation, enrichment and characterization of goat (Capra hircus) spermatogonial stem cells from pre-pubertal testes

Isolation of goat spermatogonial stem cells (gSSC) from pre-pubertal testes (3 to 6 months of age) by double enzymatic digestion is reported. The isolated cells were further enriched for spermatogonial stem cell population by filtration through 80- and 60-μm nylon mesh filters, followed by differential plating on DSA-Lectin coated dishes. After overnight incubation, the unattached cells (putative gSSCs) were cultured on sertoli cell feeder layers in SSC medium, composed of DMEM supplemented with 10% FBS, GDNF (Glial cell line derived neurotrophic factor, 40 ng mL-1), bFGF (Basic fibroblast growth factor, 10 ng mL-1) and EGF (Epidermal growth factor, 10 ng mL-1). After 10-15 days, the putative SSCs started to develop and the cultures were maintained till the colonies stopped growing. The colonies were characterized for their affinity to Dolichos biflorus Agglutinin (DBA), alkaline phosphatase (AP) activity and various spermatogonial stem cell markers (PLZF, THY1, UCHL1, BCL6B and ID4). The developed colonies were positive for DBA, AP and all other markers, which is an indication of their being spermatogonial stem cells. In the present study, goat SSCs have been successfully isolated and characterized and the culture conditions will be improved further for developing more efficient and long term in vitro spermatogonial stem cell culture system in goat.

Isolation and Identification of Prepubertal Buffalo (Bubalus bubalis) Spermatogonial Stem Cells.

Isolation and culture of spermatogonial stem cells (SSCs) are attractive for production of genetic modified offspring. In the present study, buffalo spermatogonial stem-like cells were isolated, cultured and expression pattern of different germ cell marker genes were determined. To recover spermatogonia, testes from age 3 to 7 months of buffalo were decapsulated, and seminiferous tubules were enzymatically dissociated. Two types of cells, immature sertoli cell and type A spermatogonia were observed in buffalo testes in this stage. Germ cell marker genes, OCT3/4 (Pou5f1), THY-1, c-kit, PGP9.5 (UCHL-1) and Dolichos biflorus agglutinin, were determined to be expressed both in mRNA and protein level by reverse transcription polymerase chain reaction and immunostaining in buffalo testes and buffalo spermatogonial stem-like cells, respectively. In the following, when the isolated buffalo buffalo spermatogonial stem-like cells were cultured in the medium supplemented 2.5% fetal bovine serum and 40 ng/mL glial cell-derived neurotrophic factor medium, SSCs proliferation efficiency and colony number were significantly improved than those of other groups (p<0.05). These findings may help in isolation and establishing long term in vitro culture system for buffalo spermatogonial stem-like cells, and accelerating the generation of genetic modified buffaloes.

Concanavalin agglutinin levels are decreased in peripheral blood of Alzheimer's disease patients.

Alzheimer's disease (AD) seriously threatens patients' lives and causes severe burden to the families. Early prevention and treatment can alleviate the development of the disease; therefore it is important to find new effective and non-traumatic biomarkers for early diagnosis. In this study, peripheral blood samples were collected from 24 AD patients and the same number of age- and gender-matched control subjects. Lectin reactive glycosylation levels including beta-D-galactosyl ricinus communis agglutinin 120 (RCA), peanut agglutinin (PNA), concanavalin agglutinin (Con A), alpha-L-fucosyl ulex europeus agglutinin (UEA), dolichos biflorus agglutinin (DBA), and galanthus nivalis (GNL), in the red blood cells of peripheral blood were examined by western blotting. We found that lectin levels were altered with aging and gender; some lectin levels were different between AD patients and the control subjects. Only Con A levels were significantly decreased in AD patients compared to age-matched control subjects. These results suggest that Con A levels in peripheral blood may be a potent diagnostic marker for AD.

In vivo regulation of colonic cell proliferation, differentiation, apoptosis, and P27Kip1 by dietary fish oil and butyrate in rats.

We have shown that dietary fish oil is protective against experimentally induced colon cancer, and the protective effect is enhanced by coadministration of pectin. However, the underlying mechanisms have not been fully elucidated. We hypothesized that fish oil with butyrate, a pectin fermentation product, protects against colon cancer initiation by decreasing cell proliferation and increasing differentiation and apoptosis through a p27(Kip1)-mediated mechanism. Rats were provided diets of corn or fish oil, with/without butyrate, and terminated 12, 24, or 48 hours after azoxymethane (AOM) injection. Proliferation (Ki-67), differentiation (Dolichos Biflorus Agglutinin), apoptosis (TUNEL), and p27(Kip1) (cell-cycle mediator) were measured in the same cell within crypts in order to examine the coordination of cell cycle as a function of diet. DNA damage (N(7)-methylguanine) was determined by quantitative IHC analysis. Dietary fish oil decreased DNA damage by 19% (P = 0.001) and proliferation by 50% (P = 0.003) and increased differentiation by 56% (P = 0.039) compared with corn oil. When combined with butyrate, fish oil enhanced apoptosis 24 hours after AOM injection compared with a corn oil/butyrate diet (P = 0.039). There was an inverse relationship between crypt height and apoptosis in the fish oil/butyrate group (r = -0.53, P = 0.040). The corn oil/butyrate group showed a positive correlation between p27(Kip1) expression and proliferation (r = 0.61, P = 0.035). These results indicate the in vivo effect of butyrate on apoptosis and proliferation is dependent on dietary lipid source. These results demonstrate the presence of an early coordinated colonocyte response by which fish oil and butyrate protects against colon tumorigenesis.

Occurrence of immune cells in the intestinal wall of Squalius cephalus infected with Pomphorhynchus laevis.

A sub-population of 34 specimens of chub, Squalius cephalus, was sampled from the River Brenta (Northern Italy) and examined for ecto- and endo-parasites. Pomphorhynchus laevis (Acanthocephala) was the only enteric helminth encountered. Immunofluorescence and ultrastructural studies were conducted on the intestines of chub. Near the site of parasite's attachment, mucous cells, mast cells (MCs), neutrophils and rodlet cells (RCs) were found to co-occur within the intestinal epithelium. The numbers of mucous cells, MCs and neutrophils were significantly higher in infected fish (Mann-Whitney U test, p < 0.05). Dual immunofluorescence staining with the lectin Dolichos Biflorus Agglutinin (DBA) and the macrophage-specific MAC387 monoclonal antibody, with parallel transmission electron microscopy, revealed that epithelial MCs often made intimate contact with the mucous cells. Degranulation of a large number of MCs around the site of the acanthocephalan's attachment and in proximity to mucous cells was also documented. MCs and neutrophils were abundant in the submucosa. Immune cells of the intestinal epithelium have been described at the ultrastructural level and their possible functions and interactions are discussed.

Factors supporting long-term culture of bovine male germ cells.

Spermatogonial stem cells (SSCs) are unipotent in nature, but mouse SSCs acquire pluripotency under the appropriate culture conditions. Although culture systems are available for rodent and human germ-cell lines, no proven culture system is yet available for livestock species. Here, we examined growth factors, matrix substrates and serum-free supplements to develop a defined system for culturing primitive germ cells (gonocytes) from neonatal bovine testis. Poly-L-lysine was a suitable substrate for selective inhibition of the growth of somatic cells and made it possible to maintain a higher gonocyte:somatic cell ratio than those maintained with gelatin, collagen or Dolichos biflorus agglutinin (DBA) substrates. Among the serum-free supplements tested in our culture medium, knockout serum replacement (KSR) supported the proliferation and survival of gonocytes better than the supplements B-27 and StemPro-SFM after sequential passages of colonies. Under our optimised culture conditions consisting of 15% KSR supplement on poly-L-lysine-coated dishes, the stem-cell and germ-cell potentials of the cultured gonocytes were maintained with normal karyotype for more than 2 months (over 13 passages). The proposed culture system, which can maintain a population of proliferating bovine germ stem cells, could be useful for studying SSC biology and germline modifications in livestock animals.

Effect of 3-bromopyruvate and atovaquone on infection during in vitro interaction of Toxoplasma gondii and LLC-MK2 cells.

Toxoplasma gondii infection can be severe during pregnancy and in immunocompromised patients. Current therapies for toxoplasmosis are restricted to tachyzoites and have little or no effect on bradyzoites, which are maintained in tissue cysts. Consequently, new therapeutic alternatives have been proposed as the use of atovaquone has demonstrated partial efficacy against tachyzoites and bradyzoites. This work studies the effect of 3-bromopyruvate (3-BrPA), a compound that is being tested against cancer cells, on the infection of LLC-MK2 cells with T. gondii tachyzoites, RH strain. No effect of 3-BrPA on host cell proliferation or viability was observed, but it inhibited the proliferation of T. gondii. The incubation of cultures with lectin Dolichos biflorus agglutinin (DBA) showed the development of cystogenesis, and an ultrastructural analysis of parasite intracellular development confirmed morphological characteristics commonly found in tissue cysts. Moreover, the presence of degraded parasites and the influence of 3-BrPA on endodyogeny were observed. Infected cultures were alternatively treated with a combination of this compound plus atovaquone. This resulted in a 73% reduction in intracellular parasites after 24 h of treatment and a 71% reduction after 48 h; cyst wall formation did not occur in these cultures. Therefore, we conclude that the use of 3-BrPA may serve as an important tool for the study of (i) in vitro cystogenesis; (ii) parasite metabolism, requiring a deeper understanding of the target of action of this compound on T. gondii; (iii) the alternative parasite metabolic pathways; and (iv) the molecular/cellular mechanisms that trigger parasite death.

Harvest and primary culture of the murine aldosterone-sensitive distal nephron.

The aldosterone-sensitive distal nephron (ASDN) exhibits axial heterogeneity in structure and function from the distal convoluted tubule to the medullary collecting duct. Ion and water transport is primarily divided between the cortex and medulla of the ASDN, respectively. Transcellular transport in this segment is highly regulated in health and disease and is integrated across different cell types. We currently lack an inexpensive, high-yield, and tractable technique to harvest and culture cells for the study of gene expression and physiological properties of mouse cortical ASDN. To address this need, we harvested tubules bound to Dolichos biflorus agglutinin lectin-coated magnetic beads from the kidney cortex and characterized these cell preparations. We determined that these cells are enriched for markers of distal convoluted tubule, connecting tubule, and cortical collecting duct, including principal and intercalated cells. In primary culture, these cells develop polarized monolayers with high resistance (1,000-1,500 Ω * cm(2)) and maintain expression and activity of key channels. These cells demonstrate an amiloride-sensitive short-circuit current that can be enhanced with aldosterone and maintain measurable potassium and anion secretion. Our method can be easily adopted to study the biology of the ASDN and to investigate phenotypic differences between wild-type and transgenic mouse models.

Preeclampsia and preeclampsia superimposed on chronic hypertension in Buenos Aires

Preeclampsia and preeclampsia superimposed on chronic hypertension in Buenos Aires

Goat uterine DBA+ leukocytes differentiation and cytokines expression respond differently to cloned versus fertilized embryos.

High rate of fetal mortality in ruminant somatic cell nuclear transfer (SCNT) pregnancies is due, at least in part, to immune-mediated abortion of fetuses. In the present study, goat uterine leukocytes were isolated by Dolichos biflorus agglutinin (DBA) coated magnetic beads, and with majority being were CD56+CD16- in phenotype with low levels of perforin and Granzyme B expression. The responses of the isolated cells to SCNT and in vitro fertilization (IVF) embryos conditioned mediums containing hormone steroids were compared by measuring their phenotype and cytokines expression. The results showed there was a 2-fold increase in the numbers of isolated uterine leukocytes after incubation with different conditioned mediums for 120 h. However, significantly lower percentage and absolute numbers of uterine CD56+CD16- leukocytes incubated with SCNT conditioned mediums were detected as compared with those incubated with IVF conditioned mediums (P < 0.05). The group treated with progesterone (P4) or the combination of P4 and 17β-estradiol (E2) were associated with significantly higher percentage and absolute numbers of CD56+CD16- cells as compared with those treated with E2 alone (P < 0.05). Furthermore, in the presence of steroids, the isolated leukocytes incubated with SCNT conditioned mediums associated with greater levels of IFN-γ secretion and expression, as well as lesser levels of VEGF, as compared with those treated with IVF conditioned mediums (P < 0.05). In conclusion, this study demonstrates that SCNT embryos have a profound effect on the phenotype expression of goat uterine DBA+ leukocytes, as well as the secretion and expression of IFN-γ and VEGF by these cells in vitro.