Reduction of Salmonella enterica serovar enteritidis colonization in 20-day-old broiler chickens by the plant-derived compounds trans-cinnamaldehyde and eugenol

The efficacies of trans-cinnamaldehyde (TC) and eugenol (EG) for reducing Salmonella enterica serovar Enteritidis colonization in broiler chickens were investigated. In three experiments for each compound, 1-day-old chicks (n = 75/experiment) were randomly assigned to five treatment groups (n = 15/treatment group): negative control (-ve S. Enteritidis, -ve TC, or EG), compound control (-ve S. Enteritidis, +ve 0.75% [vol/wt] TC or 1% [vol/wt] EG), positive control (+ve S. Enteritidis, -ve TC, or EG), low-dose treatment (+ve S. Enteritidis, +ve 0.5% TC, or 0.75% EG), and high-dose treatment (+ve S. Enteritidis, +ve 0.75% TC, or 1% EG). On day 0, birds were tested for the presence of any inherent Salmonella (n = 5/experiment). On day 8, birds were inoculated with ～8.0 log(10) CFU S. Enteritidis, and cecal colonization by S. Enteritidis was ascertained (n = 10 chicks/experiment) after 24 h (day 9). Six birds from each treatment group were euthanized on days 7 and 10 after inoculation, and cecal S. Enteritidis numbers were determined. TC at 0.5 or 0.75% and EG at 0.75 or 1% consistently reduced (P < 0.05) S. Enteritidis in the cecum (≥3 log(10) CFU/g) after 10 days of infection in all experiments. Feed intake and body weight were not different for TC treatments (P > 0.05); however, EG supplementation led to significantly lower (P < 0.05) body weights. Follow-up in vitro experiments revealed that the subinhibitory concentrations (SICs, the concentrations that did not inhibit Salmonella growth) of TC and EG reduced the motility and invasive abilities of S. Enteritidis and downregulated expression of the motility genes flhC and motA and invasion genes hilA, hilD, and invF. The results suggest that supplementation with TC and EG through feed can reduce S. Enteritidis colonization in chickens.     

A Novel miR-451a isomiR,Associated with Amelanotypic Phenotype,Acts as a Tumor Suppressor in Melanoma by Retarding Cell Migration and Invasion

miRNAs are key regulatory small non-coding RNAs involved in critical steps of melanoma tumorigenesis; however, the relationship between sequence specific variations at the 5′ or 3′ termini (isomiR) of a miRNA and cancer phenotype remains unclear. Deep-sequencing and qRT-PCR showed reduced expression of miR-144/451a cluster and most abundant isomiR (miR451a.1) in dysplastic nevi, in-situ and invasive melanomas compared to common nevi and normal skin (n = 101). miRNA in situ hybridization reproducibly confirmed lost miR-451a.1 in melanoma compared to nevus cells or adjacent keratinocytes. Significantly higher expression of miR-451a.1 was associated with amelanotic phenotype in melanomas (n = 47). In contrast, miR-451a was associated with melanotic phenotype, absent pagetoid scatter of intraepidermal melanocytes, superficial spreading histological subtype and tumor inflammation. Sequencing miRNAs from cultured melanocytes with cytoplasmic melanin gradient (light, medium to dark) showed absent miR-451a while revealing other melanin-associated miRNAs, e.g. miR-30b, miR-100 and miR-590 in darkly and let-7a, let-7i and let-7f in lightly to moderately pigmented cultured melanocytes. Ectopic expression of miR-144/451a in melanoma cell lines resulted in markedly higher levels of mature miR-451a.1 than miR451a or miR-144; and significantly retarded cell migration and inhibited invasion in a glucose-sensitive manner. Surprisingly, these effects were not mediated by calcium binding protein 39 (CAB39), a proven miR451a gene target. miR-144/miR-451a cluster is a novel miRNA locus with tumor suppressive activity in melanoma.     

Structure determination and analysis of a haemolytic gingipain adhesin domain from Porphyromonas gingivalis

Porphyromonas gingivalis is an obligately anaerobic bacterium recognized as an aetiological agent of adult periodontitis. P. gingivalis produces cysteine proteinases, the gingipains. The crystal structure of a domain within the haemagglutinin region of the lysine gingipain (Kgp) is reported here. The domain was named K2 as it is the second of three homologous structural modules in Kgp. The K2 domain structure is a ‘jelly‐roll’ fold with two anti‐parallel β‐sheets. This fold topology is shared with adhesive domains from functionally diverse receptors such as MAM domains, ephrin receptor ligand binding domains and a number of carbohydrate binding modules. Possible functions of K2 were investigated. K2 induced haemolysis of erythrocytes in a dose‐dependent manner that was augmented by the blocking of anion transport. Further, cysteine‐activated arginine gingipain RgpB, which degrades glycophorin A, sensitized erythrocytes to the haemolytic effect of K2. Cleaved K2, similar to that found in extracted Kgp, lacks the haemolytic activity indicating that autolysis of Kgp may be a staged process which is artificially enhanced by extraction of the protein. The data indicate a functional role for K2 in the integrated capacity conferred by Kgp to enable the porphyrin auxotroph P. gingivalis to capture essential haem from erythrocytes.