Dietary supplementation with 5-aminolevulinic acid modulates growth performance and inflammatory responses in broiler chickens

ABSTRACT The objective of this study was to investigate the effect of dietary supplementation with 5-aminolevulinic acid (5-ALA) on the immune system, inflammatory response, and growth performance of broiler chickens. The levels of cluster of differentiation 3 (CD3) mRNA in the spleens of chickens gradually increased with dietary 5-ALA concentration, while the expression levels of interleukin (IL)-2 decreased. Mitogen-induced proliferation of splenic mononuclear cells and blood mononuclear cell phagocytosis in chickens fed 0.001 and 0.01% 5-ALA-supplemented diets were significantly greater than in chickens fed a basal diet (control). Plasma thiobarbituric acid reactive substance (TBARS) concentration gradually increased along with 5-ALA supplement concentration. These results provide the first evidence that the use of dietary 0.001 and 0.01% 5-ALA supplementation induces the T-cell immune system via mild oxidative stress in chickens. Three hours after Escherichia coli lipopolysaccharideinduced immune stimulation, the levels of mRNA encoding pro-inflammatory cytokines, such as IL-6 and tumor necrosis factor-like ligand 1A (TL1A), in chickens fed a 0.001% 5-ALA-supplemented diet were significantly lower than those in chickens exposed to other treatments. The plasma caeruloplasmin concentration in chickens fed a 0.001% 5-ALA-supplemented diet was significantly lower than in controls or in chickens fed diets supplemented with other concentrations of 5-ALA 24 h after injection of LPS. In addition, BW at 21 and 50 d of age was significantly higher in chickens fed a 0.001% 5-ALA-supplemented diet than in control chickens. The findings suggest that supplementation of diets with 0.001% 5-ALA could prevent the catabolic changes induced by immunological stimulation. These results show that 5-ALA might be useful as an immunomodulator to stimulate T-cells via mild oxidative stress in growing broiler chickens, thereby improving the growth performance

MAPK and SHH pathways modulate type 3 deiodinase expression in papillary thyroid carcinoma.

Type 3 deiodinase (DIO3, D3) is reactivated in human neoplasias. Increased D3 levels in papillary thyroid carcinoma (PTC) have been associated with tumor size and metastatic disease. The objective of this study is to investigate the signaling pathways involved in DIO3 upregulation in PTC. Experiments were performed in human PTC cell lines (K1 and TPC-1 cells) or tumor samples. DIO3 mRNA and activity were evaluated by real-time PCR and ion-exchange column chromatography respectively. Western blot analysis was used to determine the levels of D3 protein. DIO3 gene silencing was performed via siRNA transfection. DIO3 mRNA levels and activity were readily detected in K1 (BRAF(V6) (0) (0E)) and, at lower levels, in TPC-1 (RET/PTC1) cells (P<0.007 and P=0.02 respectively). Similarly, DIO3 mRNA levels were higher in PTC samples harboring the BRAF(V600E) mutation as compared with those with RET/PTC1 rearrangement or negative for these mutations (P<0.001). Specific inhibition of BRAF oncogene (PLX4032, 3 μM), MEK (U0126, 10-20 μM) or p38 (SB203580, 10-20 μM) signaling was associated with decreases in DIO3 expression in K1 and TPC-1 cells. Additionally, the blockage of the sonic hedgehog (SHH) pathway by cyclopamine (10  μM) resulted in markedly decreases in DIO3 mRNA levels. Interestingly, siRNA-mediated DIO3 silencing induced decreases on cyclin D1 expression and partial G1 phase cell cycle arrest, thereby downregulating cell proliferation. In conclusion, sustained activation of the MAPK and SHH pathways modulate the levels of DIO3 expression in PTC. Importantly, DIO3 silencing was associated with decreases in cell proliferation, thus suggesting a D3 role in tumor growth and aggressiveness.info:eu-repo/semantics/publishe

Conjugates of Heme-Thiolate Enzymes with Photoactive Metal-Diimine Wires

Heme-thiolate enzymes, notably cytochromes P450 and nitric oxide synthases, use dioxygen to oxygenatesubstrates. Photoactive metal-diimine molecular wires that are capable of effecting rapid redox state changesat buried active sites have been developed to generate intermediates in the catalytic cycles of these enzymes.Wires that feature a photoactive head group tethered to an active-site ligand bind P450CAM and induciblenitric oxide synthase (iNOS) primarily by hydrophobic interactions. The wire-binding specificity of eachenzyme is critically dependent on the structural flexibility of the protein. P450CAM:wire conjugates canadopt open or partially open conformations, thereby accommodating a wide range of wires, whereas onlylong wires with smaller [Re(CO)_3(bpy)Im]^+ head groupsare able to bind tightly in the rigid active-site channel of iNOS. Dansyl-terminated molecular wires functionas highly sensitive and isoform specific fluorescent sensors for P450CAM

Conjugates of Heme-Thiolate Enzymes with Photoactive Metal-Diimine Wires

Heme-thiolate enzymes, notably cytochromes P450 and nitric oxide synthases, use dioxygen to oxygenatesubstrates. Photoactive metal-diimine molecular wires that are capable of effecting rapid redox state changesat buried active sites have been developed to generate intermediates in the catalytic cycles of these enzymes.Wires that feature a photoactive head group tethered to an active-site ligand bind P450CAM and induciblenitric oxide synthase (iNOS) primarily by hydrophobic interactions. The wire-binding specificity of eachenzyme is critically dependent on the structural flexibility of the protein. P450CAM:wire conjugates canadopt open or partially open conformations, thereby accommodating a wide range of wires, whereas onlylong wires with smaller [Re(CO)_3(bpy)Im]^+ head groupsare able to bind tightly in the rigid active-site channel of iNOS. Dansyl-terminated molecular wires functionas highly sensitive and isoform specific fluorescent sensors for P450CAM

Exploring the Biocatalytic Potential of a Self-Sufficient Cytochr ome P450 from Thermothelomyces thermophila

Among nature's arsenal of oxidative enzymes, cytochrome P450s (CYPs) catalyze the most challenging reactions, the hydroxylations of non‐activated C−H bonds. Human CYPs are studied in drug development due to their physiological role at the forefront of metabolic detoxification, but their challenging handling makes them unsuitable for application. CYPs have a great potential for biocatalysis, but often lack appropriate features such as high and soluble expression, self‐sufficient internal electron transport, high stability, and an engineerable substrate scope. We have probed these characteristics for a recently described CYP that originates from the thermophilic fungus Thermothelomyces thermophila (CYP505A30), a homolog of the well‐known P450‐BM3 from Bacillus megaterium. CYP505A30 is a natural monooxygenase‐reductase fusion, is well expressed, and moderately tolerant towards temperature and solvent exposure. Although overall comparable, we found the stability of the enzyme's domains to be inverse to P450‐BM3, with a more stable reductase compared to the heme domain. After analysis of a homology model, we created mutants of the enzyme based on literature data for P450‐BM3. We then probed the enzyme variants in bioconversions using a panel of active pharmaceutical ingredients, and activities were detected for a number of structurally diverse compounds. Ibuprofen was biooxidized in a preparative scale whole cell bioconversion to 1‐, 2‐ and 3‐hydroxyibuprofen