Neuronal maturation in the hippocampal dentate gyrus via chronic oral administration of Artemisa annua extract is independent of cyclooxygenase 2 signaling pathway in diet-induced obesity mouse model

Recently, we reported that Artemisia annua (AA) has anti-adipogenic properties in vitro and in vivo. Reduction of adipogenesis by AA treatment may dampen systemic inflammation and protect neurons from cytokine-induced damage. Therefore, the present study was undertaken to assess whether AA increases neuronal maturation by reducing inflammatory responses, such as those mediated by cyclooxygenase 2 (COX-2). Mice were fed normal chow or a high-fat diet with or without chronic daily oral administration of AA extract (0.2 g/10 mL/kg) for 4 weeks; then, changes in their hippocampal dentate gyri were measured via immunohistochemistry/immunofluorescence staining for bromodexoxyuridine, doublecortin, and neuronal nuclei, markers of neuronal maturation, and quantitative western blotting for COX-2 and Iba-1, in order to assess correlations between systemic inflammation (interleukin-6) and food type. Additionally, we tested the effect of AA in an Alzheimer's disease model of Caenorhabditis elegans and uncovered a potential benefit. The results show that chronic AA dosing significantly increases neuronal maturation, particularly in the high-fat diet group. This effect was seen in the absence of any changes in COX-2 levels in mice given the same type of food, pointing to the possibility of alternate anti-inflammatory pathways in the stimulation of neurogenesis and neuro-maturation in a background of obesity.

Analysis of porcine macrophage immune response to antigenic molecules and short chain fatty acids / 동물의과학연구지

Macrophages play an important role in both the innate and adaptive immune responses. These include phagocytosis, killing of microorganisms, antigen presentation, and induction of immune cytokines and antimicrobial genes. Macrophage activity is reported to be controlled by diverse exogenous antigenic or endogenous metabolic molecules, and the underlying mechanisms are well documented in human and mouse macrophage cells. Bacterial lipopolysaccharide (LPS) is known to be one of the most potent stimuli activating macrophages through the toll like receptor 4 (TLR4) signaling pathway. There are other antigenic molecules, such as muramyl dipeptide (MDP) and outer membrane protein A (OmpA), that are also known to activate immune cells. On the other hand, short chain fatty acids (SCFAs) such as acetate and butyrate are produced by gut microbiota and control host energy metabolism and signal transduction through GPR receptors. However, there are few studies demonstrating the effects of these molecules in macrophages from domestic animals, including domestic pigs. In this study, we attempted to characterize gene expression regulation in porcine macrophages (PoM2, Pig Monocytes clone 2) following treatment with LPS, MDP, OmpA, and two short chain fatty acids using porcine genome microarray and RT-PCR techniques. A number of novel porcine genes, including anti-microbial peptides and others, appeared to be regulated at the transcriptional level. Our study reports novel biomarkers such as SLC37A2, TMEN184C, and LEAP2 that are involved in the porcine immune response to bacterial antigen LPS and two short chain fatty acids.

Anti-adipogenic effect of Artemisia annua in diet-induced-obesity mice model

Obesity has increased continuously in western countries during the last several decades and recently become a problem in developing countries. Currently, anti-obesity drugs originating from natural products are being investigated for their potential to overcome adverse effects associated with chemical drugs. Artemisinic acid, which was isolated from the well-known anti-malaria herb Artemisia annua (AA) L., was recently shown to possess anti-adipogenic effects in vitro. However, the anti-adipogenic effects of AA in animal models have not yet been investigated. Therefore, we conducted daily oral administration with AA water extract in a diet-induced obesity animal model and treated 3T3-L1 cells with AA to confirm the anti-adipogenic effects in the related protein expressions. We then evaluated the physiology, adipose tissue histology and mRNA expressions of many related genes. Inhibition of adipogenesis by the AA water extract was observed in vitro. In the animal model, weight gain was significantly lower in the AA treated group, but there were no changes in food intake volume or calories. Reductions in lipid droplet size and mRNA expression associated with adipogenesis were also observed in animal epididymal fat. This study is the first to report that AA has an anti-obese effects in vivo.

Characterization of two antimicrobial peptides identified from a random peptide library and expressed in the methylotrophic yeast pichia pastoris / 동물의과학연구지

Antimicrobial peptides (AMPs) are an important component of innate defense mechanisms with broad-spectrum activities against various pathogenic microorganisms, including Gram-positive and Gram-negative bacteria, fungi, and viruses. Antibiotic resistance has become a pervasive and global health burden, resulting in the immediate need to develop a new class of antibiotic substances. We screened a 16-mer random peptide library using the yeast two-hybrid system with Beclin 1 as bait and found that two 16-mer peptides (named P4 and P30) appeared to interact with Beclin1 in the beta-gal assay. The two candidate cDNAs were introduced into the yeast secretory system of Pichia pastoris and their expression induced in the presence of methanol. Spectrophotometric analysis and Disc clear zone assay using the supernatant of the yeast growth media showed that both of the two peptides had strong activities against Staphylococcus aureus, MRSA (methicillin resistance Staphylococcus aureus), MRSA2242, and MRSA-2250, but no effect on commensal Lactobacillus strains. PCR analysis of the genomic DNA of transformed Pichia pastoris using AOX1 primers revealed that the two cDNAs were integrated into the genome at the AOX1 locus. Our result suggests that these peptides could be developed as a useful alternative to classic chemical antibiotics.

The immune-stimulating peptide WKYMVm has therapeutic effects against ulcerative colitis

In this study, we examined the therapeutic effects of an immune-stimulating peptide, WKYMVm, in ulcerative colitis. The administration of WKYMVm to dextran sodium sulfate (DSS)-treated mice reversed decreases in body weight, bleeding score and stool score in addition to reversing DSS-induced mucosa destruction and shortened colon. The WKYMVm-induced therapeutic effect against ulcerative colitis was strongly inhibited by a formyl peptide receptor (FPR) 2 antagonist, WRWWWW, indicating the crucial role of FPR2 in this effect. Mechanistically, WKYMVm effectively decreases intestinal permeability by stimulating colon epithelial cell proliferation. WKYMVm also strongly decreases interleukin-23 and transforming growth factor-beta production in the colon of DSS-treated mice. We suggest that the potent immune-modulating peptide WKYMVm and its receptor FPR2 may be useful in the development of efficient therapeutic agents against chronic intestinal inflammatory diseases.

Development of a type II diabetic mellitus animal model using Micropig(R) / 한국실험동물학회지

Diabetes, which has shown an explosive increase in terms of its incidence, is regarded as a serious disease that must be overcome for the sake of human life. Among animal models used for testing of drug efficacy, the mini-pig model has shown a rapid upload due to its many similarities with human, particularly concerning the pharmacokinetics of compounds after subcutaneous administration, the structure and function of the gastrointestinal tract, the morphology of the pancreas, and overall metabolic status. Based on these various advantages, we sought to develop an animal model of type II diabetic mellitus using the Micro-pig, which differs from other miniature pigs. We used six male Micro-pigs for induction of a moderate insulin deficient model with nicotinamide (NIA)/streptozotocin (STZ) treatment and three animals for control. For evaluation of incidence of type II diabetes, we measured blood glucose level, and performed oral glucose tolerance test and immunohistochemistry on pancreatic tissue using insulin antibody. Compared to control animals, all animals treated with NIA/STZ showed high levels of glucose and low levels of insulin. In addition, we observed the partially destroyed beta cell population from tissue of the pancreas in treated animals. Based on these results, we report that the Micro-pig model developed in this study can be used for testing of the efficacy of therapeutic agents for treatment of Type 2 diabetic mellitus.

Anticoccidial effects of Galla rhois extract on Eimeria tenella-infected chicken / 한국실험동물학회지

Anticoccidial effects of Galla rhois (GR) extract were evaluated in chickens after oral infection with Eimeria tenella. This study was performed using 3-day-old chickens (n=30). The animals were divided into 3 groups as follows: GR 0.5%/infected (n=10), untreated/infected (n=10), and non-infected control (n=10). The chickens were fed a standard diet supplemented with or without GR for 1 week before infection with E. tenella (10,000 sporulated oocysts per chicken). The effects of GR on E. tenella infection were assessed by 2 parameters, number of fecal oocysts and body weight gain, and the results of the polymerase chain reaction (PCR). The GR-fed chickens produced significantly lower number of fecal oocysts (P<0.05) than the E. tenella-infected chickens who were fed the standard diet. In addition, GR-based diet improved the loss of body weight caused by E. tenella infection. Positive findings of PCR were identified by distinct bands in the samples of E. tenella-inoculated chickens. However, PCR analysis revealed no E. tenella oocysts in the feces of GR-fed chickens. Our data showed that GR extracts had remarkable anticoccidial activities against E. tenella. This finding might have implications for the development of novel anticoccidial drugs.

T Cell Receptor Signaling That Regulates the Development of Intrathymic Natural Regulatory T Cells

T cell receptor (TCR) signaling plays a critical role in T cell development, survival and differentiation. In the thymus, quantitative and/or qualitative differences in TCR signaling determine the fate of developing thymocytes and lead to positive and negative selection. Recently, it has been suggested that self-reactive T cells, escape from negative selection, should be suppressed in the periphery by regulatory T cells (Tregs) expressing Foxp3 transcription factor. Foxp3 is a master factor that is critical for not only development and survival but also suppressive activity of Treg. However, signals that determine Treg fate are not completely understood. The availability of mutant mice which harbor mutations in TCR signaling mediators will certainly allow to delineate signaling events that control intrathymic (natural) Treg (nTreg) development. Thus, we summarize the recent progress on the role of TCR signaling cascade components in nTreg development from the studies with murine model.