Expression Of Nutrient Transporters Research Articles

Autolyzed yeast and sodium butyrate supplemented alone to diets promoted improvements in performance, intestinal health and nutrient transporter in weaned piglets

This study investigated the effects of supplemental nucleotides, autolyzed yeast (Saccharomyces cerevisiae), and sodium butyrate in diets for nursery pigs on growth performance, diarrhea incidence, blood profile, intestinal morphology, mRNA expression of nutrient transporters, inflammatory markers, antioxidant profile, and tight junction proteins in the small intestine. One hundred eighty 21-day-old pigs (5.17 ± 0.57 kg) were assigned in a randomized block design to 1 of 4 dietary treatments: (1) CON: control, basal diet, (2) NUC: CON + nucleotides, (3) YSC: CON + lysed yeast S. cerevisiae, (4) ASB: CON + acidifier sodium butyrate. Pigs were fed for 24 days, phase 1 (21–32 days) and 2 (32–45 days). During phase 1, YSC and ASB improved average daily gain (ADG) and feed conversion (FC) compared with CON. At the overall period, ASB improved ADG and YSC improved FC compared with CON. The NUC diet did not affect growth performance. The ASB increased ileal villus height compared to CON. The YSC and ASB reduced the number of Peyer’s patches in the ileum compared with CON. The YSC increased mRNA expression of nutrient transporters (SMCT2, MCT1, and PepT1), tight junction proteins (OCL and ZO-1), antioxidants (GPX), and IL1-β in the jejunum compared with CON. The ASB increased mRNA expression of nutrient transporters (SGLT1 and MCT1), tight junction proteins (OCL and ZO-1), and antioxidants (GPX and SOD) compared with CON. In conclusion, autolyzed yeast and sodium butyrate promoted growth performance by improving the integrity of the intestinal barrier, the mRNA expression of nutrient transporters, and antioxidant enzymes in the jejunum of nursery pigs whereas supplementation of nucleotides did not show such effects.

The type of fatty acid dictates their impact on gut permeability and nutrient absorption

We showed that short- and long-term (3 to 12 weeks) high-fat diet (HFD) feeding reduced protein expression of nutrient transporters in the proximal jejunum of mice. The most abundant fatty acids (FA) in HFD were oleic (OA), palmitic (PA) and stearic (EA) acid. Because PA and EA are generally regarded as pro-inflammatory, we hypothesize that dietary PA and EA alter gut permeability and absorption via inflammatory activation. To test this hypothesis, we orally administered HFD-matched doses of OA, PA, and EA to male C57BL/6 mice, fed on purified diet control (LFD), for 3 weeks. Food intake and body weight were monitored, and composition were also evaluated. We next qPCR-assessed the mRNA expression of cytokines ( TNF-α, IL-6, IL-1β, IFN-γ, IL-10) and inflammatory signaling transducers ( MD-2 and Myd88) as well as the protein content of nutrient transporters (Glut2, Pept1, Fat/cd36 and Npc1l1) and cell-cell adhesion proteins (Occludin) in the gut. Small intestinal permeability was assessed ex vivo and gut morphology was histologically determined. In addition, Caco-2 enterocytes were used to assess the impact of specific cytokines on nutrient transport and gut barrier integrity. All dietary FA reduced food intake without affecting lean or fat mass. In the jejunum, OA increased TNF-α gene expression whereas PA upregulated IFN-γ and MD-2 gene expression. Furthermore, OA reduced the nutrient transporters Glut2, Pept1, and Fat/cd36 without affecting Npc1l1, whereas PA and EA reduced Occludin protein content. PA, but not OA and EA, increased jejunum paracellular permeability ex vivo and increased villus length. In Caco-2 cells, while Tnf-α did not affect Glut2, Pept1 and Fat/cd36 or Npc1l1 content, Ifn-γ downregulated Occludin protein content. We conclude that OA and, more potently, PA exert inflammatory effects which contribute to damage gut barrier integrity and downregulate nutrient absorption. Our data point to IFN-γ as a main player coupling dietary stress from PA to altered gut homeostasis. Funding: FAPESP (grants number: 2014/12871-9, 2019/05086-7, 2020/12201-4, and 2022/14545). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Differentiation of intestinal stem cells toward goblet cells under systemic iron overload stress are associated with inhibition of Notch signaling pathway and ferroptosis

Iron overload can lead to oxidative stress and intestinal damage and happens frequently during blood transfusions and iron supplementation. However, how iron overload influences intestinal mucosa remains unknown. Here, the aim of current study was to investigate the effects of iron overload on the proliferation and differentiation of intestinal stem cells (ISCs). An iron overload mouse model was established by intraperitoneal injection of 120 mg/kg body weight iron dextran once a fortnight for a duration of 12 weeks, and an iron overload enteroid model was produced by treatment with 3 mM or 10 mM of ferric ammonium citrate for 24 h. We found that iron overload caused damage to intestinal morphology with a 64 % reduction in villus height/crypt depth ratio, and microvilli injury in the duodenum. Iron overload mediated epithelial function by inhibiting the expression of nutrient transporters and enhancing the expression of secretory factors in the duodenum. Meanwhile, iron overload inhibited the proliferation of ISCs and regulated their differentiation into secretory mature cells, such as goblet cells, through inhibiting Notch signaling pathway both in mice and enteroid. Furthermore, iron overload caused oxidative stress and ferroptosis in intestinal epithelial cells. In addition, ferroptosis could also inhibit Notch signaling pathway, and affected the proliferation and differentiation of ISCs. These findings reveal the regulatory role of iron overload on the proliferation and differentiation of ISCs, providing a new insight into the internal mechanism of iron overload affecting intestinal health, and offering important theoretical basis for the scientific application of iron nutrition regulation.

Effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets

BackgroundPromoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization. The rational allocation of dietary starch sources and the exploration of appropriate dietary glucose release kinetics may promote the dynamic balance of dietary glucose and amino acid supplies. However, research on the effects of diets with different glucose release kinetic profiles on amino acid absorption and portal amino acid appearance in piglets is limited. This study aimed to investigate the effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets.MethodsSixty-four barrows (15.00 ± 1.12 kg) were randomly allotted to 4 groups and fed diets formulated with starch from corn, corn/barley, corn/sorghum, or corn/cassava combinations (diets were coded A, B, C, or D respectively). Protein retention, the concentrations of portal amino acid and glucose, and the relative expression of amino acid and glucose transporter mRNAs were investigated. In vitro digestion was used to compare the dietary glucose release profiles.ResultsFour piglet diets with different glucose release kinetics were constructed by adjusting starch sources. The in vivo appearance dynamics of portal glucose were consistent with those of in vitro dietary glucose release kinetics. Total nitrogen excretion was reduced in the piglets in group B, while apparent nitrogen digestibility and nitrogen retention increased (P < 0.05). Regardless of the time (2 h or 4 h after morning feeding), the portal total free amino acids content and contents of some individual amino acids (Thr, Glu, Gly, Ala, and Ile) of the piglets in group B were significantly higher than those in groups A, C, and D (P < 0.05). Cluster analysis showed that different glucose release kinetic patterns resulted in different portal amino acid patterns in piglets, which decreased gradually with the extension of feeding time. The portal His/Phe, Pro/Glu, Leu/Val, Lys/Met, Tyr/Ile and Ala/Gly appeared higher similarity among the diet treatments. In the anterior jejunum, the glucose transporter SGLT1 was significantly positively correlated with the amino acid transporters B0AT1, EAAC1, and CAT1.ConclusionsRational allocation of starch resources could regulate dietary glucose release kinetics. In the present study, group B (corn/barley) diet exhibited a better glucose release kinetic pattern than the other groups, which could affect the portal amino acid contents and patterns by regulating the expression of amino acid transporters in the small intestine, thereby promoting nitrogen deposition in the body, and improving the utilization efficiency of dietary nitrogen.

Shifts in microbiota and gene expression of nutrient transporters, mucin and interleukins in the gut of fast-growing and slow-growing chickens infected by Salmonella Enteritidis.

Slow-growing breeds are more resistant to Salmonella infection compared to fast-growing broilers. However, it is unclear whether that is associated with innate resistance or rather rely on differences in Salmonella-induced gut responses. We investigated the microbial composition and gene expression of nutrient transporters, mucin, and interleukin in the gut of a fast-growing (Cobb500) and a slow-growing naked neck (NN) chicken breeds challenged with Salmonella Enteritidis. Hatchlings were inoculated at two days of age using sterile broth (sham) or Salmonella Enteritidis (SE) and distributed according to a completely randomized design into four treatments: Cobb-sham; Cobb-SE; NN-sham; and NN-SE. Cecal SE counting and microbial composition by 16S rRNA sequencing were determined at 24-, 96-, and 168-hours post-inoculation (hpi). Gene expression of amino acid (Asct1) and peptide transporters (PepT1), glucose transporters (Sglt1, Glut2 and Glut5) and mucin (Muc2) in the jejunum and expression of interleukins (IL1 beta, IL8, IL17 and IL22) in the cecum was assessed by qPCR at 24 and 168 hpi. NN birds were colonized by SE just as Cobb birds but showed innate upregulation of Muc2, IL8 and IL17 in comparison to Cobb. While nutrient transporter mRNA expression was impaired in SE-challenged Cobb birds, the opposite was observed in NN. There were no differences in microbial diversity at different sampling times for Cobb-SE, whereas the other groups had higher diversity and lower dominance at 24 hpi compared with 96 hpi and 168 hpi. NN birds apparently develop earlier gut microbial stability, have higher basal level of mucin gene expression as well as differential nutrient transporter and interleukin gene expression in the presence of SE which might mitigate the effects of SE infection compared to Cobb birds.

Cannabidiol Exposure During Rat Pregnancy Leads to Labyrinth-Specific Vascular Defects in the Placenta and Reduced Fetal Growth.

Introduction: Cannabis use is increasing among pregnant people, and cannabidiol (CBD), a constituent of cannabis, is often perceived as "natural" and "safe" as it is non-intoxicating. In utero, cannabis exposure is associated with negative health outcomes, including fetal growth restriction (FGR). The placenta supplies oxygen and nutrients to the fetus, and alterations in placental development can lead to FGR. While there has been some investigation into the effects of Δ9-THC, there has been limited investigation into the impacts of in utero gestational CBD exposure on the placenta. Methods: This study used histological and transcriptomic analysis of embryonic day (E)19.5 rat placentas from vehicle and CBD (3 mg/kg intraperitoneal injection) exposed pregnancies (E6.5-18.5). Results: The study revealed that pups from CBD-exposed pregnancies were 10% smaller, with the placentae displaying a decreased fetal blood space perimeter-to-area ratio. The transcriptomic analysis supported compromised angiogenesis and blood vessel formation with downregulated biological processes, including tube morphogenesis, angiogenesis, blood vessel morphogenesis, blood vessel development and vasculature development. Further, the CBD-exposed placentas displayed changed expression of glucose transporters (decreased GLUT1 and GR expression and increased GLUT3 expression). Transcriptomic analysis further revealed upregulated biological processes associated with metabolism. Finally, histological and transcriptomic analysis revealed altered cell populations within the placenta, specifically to syncytiotrophoblast layer II and endothelial cells. Conclusion: Together these results suggest that the structural changes in CDB-exposed placentae, including the altered expression of nutrient transporters and the changes to the placental fetal vasculature, may underlie the reduced fetal growth.

In-Ovo Glutamine Administration Enhances Intestinal Development and Functions in Broiler Chickens: Insights from Enteroid Models

BackgroundEarly life events play significant roles in tissue development and animal health in their later life. Early nutrition, through in-ovo delivery, has shown beneficial effects on improving intestinal health in broiler chickens. However, the underlying mechanism is not fully investigated. A recently developed enteroid culture technique allows investigations on intestinal epithelial functions that are close to physiologic conditions. ObjectivesIn this study, we evaluated the short- and long-term effects of in-ovo administration of glutamine (Gln) on intestinal epithelial development and functions by using intestinal enteroid culture and tissue electrophysiologic analysis. MethodsA hundred eggs of commercial Cobb500 broilers were in-ovo injected with 0.2 mL of either phosphate-buffered saline (PBS) or 3% Gln at embryonic day 18 (E18). Chicks were killed on the day of hatch, and at 3- and 14-d posthatch. Enteroids were generated from the small intestine. After 4 d of culture, enteroids were harvested for 5-ethynyl-2′-deoxyuridine proliferation, fluorescein isothiocyanate-4 kDa dextran permeability, and glucose absorption assays. At day 3 (d3) and day 14 (d14), intestinal barrier and nutrient transport functions were measured by the Ussing chamber. The gene expression of epithelial cell markers, nutrient transporters, and tight-junction proteins were analyzed in both intestinal tissues and enteroids. ResultsIn comparison with the PBS control group, in-ovo Gln increased intestinal villus morphology, epithelial cell proliferation, and differentiation, and altered epithelial cell population toward increased number of enteroendocrine and goblet cells while decreasing Paneth cells. Enteroids gene expression of nutrient transporters (B0AT1, SGLT1, and EAAT3), tight junction (ZO2), glucose absorption, and barrier functions were enhanced on the day of hatch. Long-term increases of intestinal di-peptide and alanine transport were observed at day 14 posthatch. ConclusionsTogether our results suggested that the in-ovo injection of Gln stimulated intestinal epithelium proliferation and programmed the epithelial cell differentiation toward absorptive cells.

Overexpression of Human sFLT1 in the Spongiotrophoblast Is Sufficient to Induce Placental Dysfunction and Fetal Growth Restriction in Transgenic Mice.

Preeclampsia (PE) is characterized by maternal hypertension and placental dysfunction, often leading to fetal growth restriction (FGR). It is associated with an overexpression of the anti-angiogenic sFLT1 protein, which originates from the placenta and serves as a clinical biomarker to predict PE. To analyze the impact of sFLT1 on placental function and fetal growth, we generated transgenic mice with placenta-specific human sFLT1 (hsFLT1) overexpression. Immunohistochemical, morphometrical, and molecular analyses of the placentas on 14.5 dpc and 18.5 dpc were performed with a focus on angiogenesis, nutrient transport, and inflammation. Additionally, fetal development upon placental hsFLT1 overexpression was investigated. Dams exhibited a mild increase in serum hsFLT1 levels upon placental hsFLT1 expression and revealed growth restriction of the fetuses in a sex-specific manner. Male FGR fetuses expressed higher amounts of placental hsFLT1 mRNA compared to females. FGR placentas displayed an altered morphology, hallmarked by an increase in the spongiotrophoblast layer and changes in labyrinthine vascularization. Further, FGR placentas showed a significant reduction in placental glycogen storage and nutrient transporter expression. Moreover, signs of hypoxia and inflammation were observed in FGR placentas. The transgenic spongiotrophoblast-specific hsFLT1 mouse line demonstrates that low hsFLT1 serum levels are sufficient to induce significant alterations in fetal and placental development in a sex-specific manner.

141 Adrenomedullin upregulates mRNA expression of nutrient transporters in human trophoblast cell line: implications for GDM

141 Adrenomedullin upregulates mRNA expression of nutrient transporters in human trophoblast cell line: implications for GDM

Rotavirus-mediated DGAT1 degradation: A pathophysiological mechanism of viral-induced malabsorptive diarrhea.

Gastroenteritis is among the leading causes of mortality globally in infants and young children, with rotavirus (RV) causing ~258 million episodes of diarrhea and ~128,000 deaths annually in infants and children. RV-induced mechanisms that result in diarrhea are not completely understood, but malabsorption is a contributing factor. RV alters cellular lipid metabolism by inducing lipid droplet (LD) formation as a platform for replication factories named viroplasms. A link between LD formation and gastroenteritis has not been identified. We found that diacylglycerol O-acyltransferase 1 (DGAT1), the terminal step in triacylglycerol synthesis required for LD biogenesis, is degraded in RV-infected cells by a proteasome-mediated mechanism. RV-infected DGAT1-silenced cells show earlier and increased numbers of LD-associated viroplasms per cell that translate into a fourfold-to-fivefold increase in viral yield (P < 0.05). Interestingly, DGAT1 deficiency in children is associated with diarrhea due to altered trafficking of key ion transporters to the apical brush border of enterocytes. Confocal microscopy and immunoblot analyses of RV-infected cells and DGAT1-/- human intestinal enteroids (HIEs) show a decrease in expression of nutrient transporters, ion transporters, tight junctional proteins, and cytoskeletal proteins. Increased phospho-eIF2α (eukaryotic initiation factor 2 alpha) in DGAT1-/- HIEs, and RV-infected cells, indicates a mechanism for malabsorptive diarrhea, namely inhibition of translation of cellular proteins critical for nutrient digestion and intestinal absorption. Our study elucidates a pathophysiological mechanism of RV-induced DGAT1 deficiency by protein degradation that mediates malabsorptive diarrhea, as well as a role for lipid metabolism, in the pathogenesis of gastroenteritis.

Superiority of Intestinal Adaptation by Hepatocyte Growth Factor in the Jejunum: An Experimental Study in a Short-Bowel Rat Model

BackgroundWe evaluated the effect of recombinant human hepatocyte growth factor (rh-HGF) on intestinal adaptation in a rat model of short-bowel syndrome (SBS). MethodsSprague–Dawley rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90 % small bowel resection. The animals were divided into 3 groups: TPN/SBS (control group, n = 7), TPN/SBS/intravenous recombinant human hepatocyte growth factor (HGF) (0.3 mg/kg/day) (HGF group, n = 7), and TPN/SBS/intravenous c-Met inhibitor (0.3 mg/kg/day) (anti-HGF group, n = 5). On day 7, rats were euthanized and histologically evaluated. Serum diamine oxidase (S-DAO) levels were evaluated using an enzyme-linked immunosorbent assay. The nutrient transporter and glucagon-like peptide-2 (GLP-2) receptor expression were evaluated using real-time polymerase chain reaction. ResultsThe jejunal and ileal villus heights were higher and the S-DAO concentrations significantly higher (p = 0.04) in the HGF group than in the control and anti-HGF groups. The sodium-dependent glucose transporter 1 expression in the HGF group was significantly higher than in the control group and significantly suppressed in the anti-HGF group (p < 0.01). The peptide transporter 1 expression in the jejunum was higher in the HGF group than in the other groups and significantly suppressed in the anti-HGF group (p < 0.01). The GLP-2 receptor expression in the jejunum was higher in the HGF group than the other groups, and it was significantly suppressed in the anti-HGF group (p < 0.01). These jejunal results regarding nutrient transporter an GLP-2 receptor were not found in the ileum. ConclusionsThe administration of rh-HGF appears to be more effective in the jejunum than in the ileum. Type of StudyExperimental Research. Level of EvidenceN/A.

WU-NK-101 (W-NK), a Memory-like (ML) NK Cell, Naturally Overcomes Tumor Microenvironment (TME) Metabolic Challenges, Retaining Anti-Tumor Potency

Cellular engineering revolutionized adoptive cell therapy (ACT) through improved antigen recognition and cellular activation. Cancer cells are metabolically active and extensively consume nutrients from the TME, rendering it nutrient-deprived, acidic, and hypoxic, and resulting in intratumoral metabolic demands which negatively impact ACT antitumor activity. This is central to T cells, however, some of these challenges can be overcome through engineering, an ideal solution would be to have a cellular product that is inherently adept at overcoming these challenges. W-NK is a cytokine-reprogrammed, expanded, cryopreserved, ML-NK cell product derived from healthy human peripheral blood mononuclear cells; it comes with naturally effective potency towards tumor cell killing, and importantly can overcome metabolic challenges present in the TME. We aim at deciphering what metabolic features make W-NK particularly potent in adverse TME. W-NK characterization of metabolic fitness/adaptability was with transcriptomics (sc-RNA-seq; 10X Genomics) flow cytometry, bioenergetics (Seahorse Real-Time Cell Metabolic Analysis; Agilent), and proteomic (Sciex Zeno TOF 7600 tandem-mass spectrometry). The aforementioned assays evaluated the effect of differing media/TME on W-NK: 1) conventional (N) media (pH 7, glucose 11 mM); 2) TME-aligned media (pH 5.9, glucose 6 mM, immune suppressive agents, e.g., PGE2, TGFb1); and 3) ascites derived from patients with malignancy. Media composition was analyzed biochemically using clinical assays (Core Lab Clinical Studies at Washington University, St. Louis, USA), and by immune secretome profiling (Nomic Bio, Quebec, CA). At baseline, W-NK cells have a unique metabolic phenotype, with higher expression of cell surface nutrient transporters, e.g., GLUT1, CD98, ASCT2, MCT1 and PiT1, compared to conventional NK cells (cNK); additionally, W-NK metabolism was consistent with aerobic (“Warburg”) glycolysis, with ~80% of ATP coming from glycolysis vs. ~30% for cNK. In TME/ascites media, W-NK surface nutrient receptor expression adapted to meet metabolic demand. For example, transporters for amino acids, lactate and pyruvate are upregulated in these hypoglycemic medias. This coincided with a 50% shift in ATP manufacturing from glycolysis to mitochondria, suggesting that nutrients bypassed glycolysis to enter tricarboxylic acid cycle and oxidative phosphorylation. Proteomic analyses of W-NK cells cultured with either TME-aligned media or ascites supported this hypothesis, with up-regulation of metabolic pathways (ShinyGO) capturing amino-acid and lipid metabolism, and mitochondrial function. Overall, W-NK retained cytotoxic function in TME and ascites, as well as in native TME-aligned 3D assays from primary surgical tumor samples. Conversely, cNKs did not adapt to TME media, whether in nutrient transporter expression or ATP manufacturing, and demonstrated reduced survival and function, including cytotoxicity. W-NK has enhanced metabolic fitness, flexibility, and plasticity. This enables W-NK to utilize diverse macronutrients, engage different metabolic pathways, and maintain optimal ATP manufacturing. Overall, W-NK inherently survives and maintains function in the TME, a limiting factor for immune cell-based ACT. These data herald the promise of NK cell therapy; a Phase 1 clinical study of W-NK in acute myeloid leukemia is currently open and enrolling patients (NCT# 05470140).

Effect of Phytobiotics and Antibiotic on Growth Performance, Intestinal Morphology and Nutrients Transporters Expression of Broiler Chickens

This study investigated the effect of Phytobiotics (PB) and Antibiotic Growth Promoter (AGP) on performance, intestinal morphology and nutrients transporters mRNA gene expression of broiler chickens. One hundred eighty unsexed one-day-old Ross strains with an average initial body weight (BW) of 45 ± 0.5 g were randomly assigned into three treatments with six replications of 10 chicks in each pen. (1) Control group (CON), basal diets only; (2) antibiotic group, Antibiotic Growth promoter (AGP), basal diet supplemented with 5 mg/kg tetramycin; (3) Phytobiotics (PB), basal diet supplemented with 0.5g/kg, phytobiotics the research lasted for 42 days. Average Daily Feed Intake (ADFI), Average Daily Gain (ADG) and Feed Conversion Ratio (FCR) were calculated weekly, and intestinal morphology of Villus Height (VH), Crypt Depth (CD), and Villus Height to crypt depth ratio (VH: CD) from the duodenum, jejunum, and ileum, nutrients transporters qRT-PCR mRNA expression of GLUT1, SGLT4, GLUT5, PEPT2, CAT1, and LAT1 were evaluated at day 42. Chicks fed PB had significantly (P=0.0413) higher ADG at 1-42 days, PB and AGP significantly had lower FCR (P=0.0001) and (P=0.0001) at 22-42 d and 1-42 days, respectively, in duodenum the villus height was significantly (P=0.0001) longer in PB fed chickens and the lowest was recorded in CON, while the CD and VH: CD were significantly longer in AGP and PB fed chickens, in jejunum VH and CD were significant (P=0.0001) longer in PB and AGP than the CON fed chickens, in ileum PB fed birds had significant higher VH and CD than the AGP and CON fed groups, in duodenum and ileum GLUT1, SGLT4 and GLUT5 expression were highly expressed in AGP and PB fed chickens similar results was obtained in jejunum and ileum by PEPT2 and CAT1. These findings suggest that supplementing phytobiotics in broiler diets improves growth performance and intestinal morphology and up-regulated the expression of nutrient transporters' genes. However, the underlying detailed biological mechanisms and dose standardisation for inclusion in broiler diets need to be further studied.

Fetoplacental Disposition and Toxicity of Cadmium in Mice Lacking the Bcrp Transporter.

The environmental toxicant cadmium (Cd) impairs the growth of rodents and humans in utero which in turn heightens susceptibility to diseases later in life. We previously demonstrated that the maternal-facing efflux transporter, breast cancer resistance protein (human BCRP/ABCG2, mouse Bcrp/Abcg2) confers resistance against Cd toxicity in human trophoblasts. In the current study, we sought to determine whether the absence of Bcrp alters the fetoplacental disposition and toxicity of Cd in mice. Pregnant female wild-type (WT) and Bcrp-null mice (n = 9-10/group) were administered a single injection of saline (5 ml/kg) or CdCl2 (5 mg/kg) on gestational day (GD) 9. Following Cd treatment, Bcrp-null offspring were shorter and accumulated more Cd in their placentas on GD 17 compared to WT mice. Because Cd can adversely impact placentation and transplacental nutrient delivery in mice, multiple pathways were assessed using morphometrics and immunohistochemistry including placenta zonation, vasculature development, and nutrient transporter expression. Most notably, the placentas of Bcrp-null mice had reduced immunostaining of the cell adhesion marker, β-catenin, and the trophoblast marker, cytokeratin, as well as decreased expression of divalent metal nutrient transporters (Dmt1, Zip14, and ZnT1) following Cd treatment. In summary, the absence of Bcrp expression increased placental concentrations of Cd which was associated with shorter fetal size that may be related to differential changes in molecular patterns of placental development and nutrition.

283 Awardee Talk: Effects of Late Gestational Maternal Nutrient Balance on Nutrient Partitioning to the Gravid Uterus in Beef Cattle

Abstract Successful intrauterine growth relies on adequate placental nutrient transfer capacity and is determined by placental size, placental morphology, uteroplacental blood supply, nutrient transporter abundance, and the nutrients available in maternal circulation. The majority of bovine fetal growth occurs during late gestation and must be accompanied by similar exponential increases in uteroplacental development to allow for necessary nutrient delivery. Competition for nutrients in young females between maternal growth and satisfying pregnancy, lactation, and maintenance requirements is still poorly understood. Our current work investigated the relationships between maternal, fetal, and uteroplacental factors and the impacts of late gestational nutrient restriction on prenatal nutrient delivery to the calf. Analysis of 113 full-term expelled placentas revealed that primiparous dams and dams in thin body condition had smaller placentas than their older or fleshier counterparts, suggesting the addition of growth requirements or exhausted nutrient reserves limited placental and fetal development. Calf size at birth and placental weight were positively correlated among all females, but it is still unknown which controls and signals for the growth of the other. Uterine blood flow measured during late gestation was positively correlated with calf birth weight; however, uterine blood flow and placental weight were only positively correlated closer to parturition at 40 and 20 d before calving. Additionally, contralateral uterine blood flow may have a disproportionately greater contribution to placental and fetal growth as it more closely resembled total blood flow associations than did ipsilateral. In 2 experiments, primiparous females fed 70% of energy and protein requirements during late gestation lost body weight and condition, had less metabolites in circulation, and had lower maternal heart rates than those fed to meet requirements. In Exp. 1, nutrient restricted dams had less contralateral placental growth, yet total uterine blood flow and placental weight were maintained and ensured fetal growth similar to control offspring. In Exp. 2, nutrient restriction reduced calf birth weight by 15%. Fetal growth perturbations were largely driven by a 17% reduction in placental size along with less nutrients available from maternal circulation, independent of a concomitant decrease in uterine blood flow. At 48 h of age, calf visceral organs were smaller due to nutrient restriction, but asymmetrical growth allowed for growth of the brain, lungs, and bone to be spared. Ongoing analysis of cotyledonary nutrient transporter and angiogenic factor gene expression will provide crucial insight into another determinant of placental nutrient transfer capacity. These findings demonstrate that pregnant beef females in a negative nutrient balance will attempt to spare fetal growth but at a certain threshold placental adaptation can be compromised, resulting in intrauterine growth restriction. A better understanding of nutrient delivery to the gravid uterus will allow for improved management strategies to ensure optimal fetal growth.

Graded levels of Eimeria infection modulated gut physiology and temporarily ceased the egg production of laying hens at peak production

An experiment was conducted to investigate the changes in gastrointestinal physiology, including intestinal leakage, immune response, oxidative stress, along with performance traits, of Hy-Line W-36 laying hens following Eimeria infection at peak egg production. A total of 360 laying hens, at 25 wk of age, were assigned randomly to 5 treatment groups, each consisting of 6 replicate cages, including a nonchallenged control group. The other 4 groups were inoculated with graded levels of mixed Eimeria species as high, medium-high, medium-low, and low doses, respectively. The body weight (BW) and body weight gain (BWG) of laying hens were measured from 0 to 14 days postinoculation (DPI). Average daily feed intake (ADFI) and hen-day egg production (HDEP) were measured from 0 to 15 and 0 to 28 DPI, respectively. Gut permeability was measured on 5 DPI, whereas oxidative stress, immune response, and expression of nutrient transporter genes were measured on 6 and 14 DPI. A significant linear reduction in BW and BWG was observed with increasedEimeriainoculation dosage on both 6 and 14 DPI (P < 0.001,P-Lin < 0.0001). An interaction between theEimeriadosages and DPI was observed for ADFI (P < 0.0001). Feed intake in the challenged groups decreased starting at 4 DPI, with the most significant drop occurring at 7 DPI, which did not recover until 15 DPI. Following the challenge, gastrointestinal physiology shifted toward the host defense against the Eimeria infection by upregulating mRNA expression of tight junction proteins and immune responses while downregulating the expression of key nutrient transporters on 6 and 14 DPI (P < 0.05). An interaction between theEimeriainoculation dosage and DPI was also observed for daily HDEP (P < 0.0001). Overall, HDEP was lower in the challenged groups compared to the control. Daily HDEP in the challenged groups dropped from 8 DPI and became similar to the control birds only after 24 DPI. Egg production temporarily ceased in most of the laying hens infected with the high and medium-high dosages of Eimeria. In conclusion, Eimeria infection activated the host immune response, negatively affecting the gastrointestinal health, growth performance, and temporarily ceased the egg production of Hy-Line W-36 laying hens when infected at peak production.

Interactive effects of a stimbiotic supplementation and wheat bran inclusion in corn- or wheat-based diets on growth performance, ileal digestibility, and expression of nutrient transporters of broilers chickens

A 42-day experiment was conducted to investigate the interactive effects of a stimbiotic (STB) and wheat bran (WB) in broiler chickens receiving diets (DT) based on corn or wheat. A total of 960 Cobb 500 male broiler chicks at zero-day old were allocated to 64 pens with 8 treatments, 8 replicates per treatment, and 15 birds per replicate. The treatments were arranged in a randomized complete block design with 2×2×2 factorial, with the factors as diet (corn-soybean meal or wheat-soybean meal), STB (with or without), and WB (0 or 50 g/kg). Body weight gain (BWG), feed intake (FI), and mortality-corrected FCR data were collected for the starter (d 0-10), grower (d 10-28), and finisher (d 28-42) phases. Ileal digesta and jejunal tissue were collected on d 18 and 42. Data were analyzed as a 2×2×2 factorial using a mixed model of JMP. There was no significant 3-way interaction for growth performance and expression of nutrient transporters. There was a significant SB×WB for FCR (P < 0.05) in the grower phase. Stimbiotic supplementation and WB inclusion individually improved (P < 0.05) FCR regardless of cereal type, but this effect was not observed when the two were combined. In the overall phase (d 0-42), birds receiving corn-based diets had higher (P < 0.05) FI and BWG than those receiving wheat-based diets. There was a significant 3-way interaction for ileal digestible energy (IDE) (P < 0.05) and N digestibility (ND) on d 18 and 42 (P < 0.05). There was no effect of STB or WB in corn-based diets, whereas WB inclusion decreased IDE in wheat-based diets, but STB supplementation increased IDE with or without WB. In corn-based diets, WB inclusion increased ND, whereas ND was decreased in wheat-based diets. Supplementation with STB had no effect on ND, but STB increased ND in wheat-based diets with and without WB. Ileal DE was greater (P < 0.05) for wheat- than corn-based diets on d 42. Wheat bran inclusion increased ND in corn-based diets whereas, with STB supplementation, there was no difference in ND with or without WB. There was no difference in ND with or without STB or WB in wheat-based diets. There was a significant STB×DT on the expression of GLUT-1 (P < 0.05). In corn-based diets, STB produced an upward expression of GLUT-1, whereas in wheat-based diets, STB supplementation had no effect. On d 42, stimbiotic supplementation produced upward (P < 0.05) expression of SGLT-1. In conclusion, STB supplementation in wheat- or corn-based diets and with WB inclusion improved energy digestibility. On the other hand, WB inclusion in wheat-based diets decreased nutrient digestibility especially on d 18, thus making room for a positive response to STB supplementation in wheat-based diets compared to the marginal response to STB supplementation observed in corn-based diets.

Graded levels of Eimeria infection linearly reduced the growth performance, altered the intestinal health, and delayed the onset of egg production of Hy-Line W-36 laying hens when infected at the prelay stage

The aim of this experiment was to investigate how different levels of Eimeria infection affect the performance, intestinal health, oxidative status, and egg production of Hy-Line W-36 pullets and laying hens. Three hundred and sixty Hy-Line W-36 pullets, aged 15 wk, were randomly distributed into 5 treatment groups, each comprising 6 replicates and a nonchallenged control. At 15 wk, pullets were inoculated with different levels of mixed Eimeria species as high-dose, medium-high, medium-low, and low-dose treatments. The growth performance and average daily feed intake (ADFI) were measured from 0- to 18-days postinoculation (DPI), whereas hen day egg production (HDEP) was recorded from wk 19. The markers of gastrointestinal health and oxidative status were measured at 6 DPI, 14 DPI, and 23 wk of age. The findings revealed a significant linear reduction in growth performance in response to increasedEimeriachallenge dosage on 6 and 14 DPI (P < 0.0001,P-L < 0.0001). An interaction between thegraded level of Eimeriainfection and DPI was observed for ADFI. The challenged pullets showed a reduction in ADFI starting at 4 DPI, which persisted until 14 DPI, when ADFI recovered back to normal. The most significant drop in feed intake was observed in 6 DPI in all the Eimeria-infected groups. The markers of gastrointestinal health (gastrointestinal permeability and tight junction proteins) were upregulated in challenged pullets because of infection, whereas the relative mRNA expression of key nutrient transporters was downregulated following infection on 6 and 14 DPI (P < 0.05). As a result of an infection on 6 DPI, the oxidative equilibrium was shifted toward the oxidative stress, and at the same time, upregulation of proinflammatory and inflammatory cytokines was observed (P < 0.05). An interaction between the Eimeria challenge dosage and bird age was observed for HDEP (P=0.0427). The pullets infected with Eimeria started to lay eggs later than the Control birds. However, the HDEP of the challenged groups became similar to Control only at wk 22, 3 wk after laying eggs. In conclusion, coccidiosis reduced growth performance, altered gastrointestinal health, induced oxidative stress, and delayed egg production when infected at the prelay stage of pullets and negatively impacted the laying hens' overall performance.

Modulation of fetoplacental growth, development and reproductive function by endocrine disrupters.

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions.

TGF-β and SHH Regulate Pluripotent Stem Cell Differentiation into Brain Microvascular Endothelial Cells in Generating an In Vitro Blood-Brain Barrier Model.

Blood-brain barrier (BBB) models are important tools for studying CNS drug delivery, brain development, and brain disease. In vitro BBB models have been obtained from animals and immortalized cell lines; however, brain microvascular endothelial cells (BMECs) derived from them have several limitations. Furthermore, obtaining mature brain microvascular endothelial-like cells (BME-like cells) from human pluripotent stem cells (hPSCs) with desirable properties for establishing BBB models has been challenging. Here, we developed an efficient method for differentiating hPSCs into BMECs that are amenable to the development and application of human BBB models. The established conditions provided an environment similar to that occurring during BBB differentiation in the presence of the co-differentiating neural cell population by the modulation of TGF-β and SHH signaling. The developed BME-like cells showed well-organized tight junctions, appropriate expression of nutrient transporters, and polarized efflux transporter activity. In addition, BME-like cells responded to astrocytes, acquiring substantial barrier properties as measured by transendothelial electrical resistance. Moreover, the BME-like cells exhibited an immune quiescent property of BBB endothelial cells by decreasing the expression of adhesion molecules. Therefore, our novel cellular platform could be useful for drug screening and the development of brain-permeable pharmaceuticals.