Hormonal regulation of visfatin gene in avian Leghorn male hepatoma (LMH) cells

Total triiodothyronine level associated with disease severity for patients with emergent status

Thyroid hormones are metabolic indicators to evaluate the physical condition of emergency hospitalized patients, while the relationship between total triiodothyronine and the severity of emergency inpatients is still unclear. To explore the thyroid function levels of inpatients in emergency ward and the status of combined Nonthyroidal illness syndrome (NTIS), and to emphasize the importance of thyroid hormone examination for non-endocrinology inpatients. According to thyroid function of inpatients in emergency ward, they were divided into NTIS group and non-NTIS group, the hematological characteristics and TH levels of each group were analyzed. Based on clinical diagnoses, the hospitalized patients were divided into three major groups, namely infection group, non-infection group and impaired organ function group. Among them, infection group was further divided into sepsis group, lung infection group and local infection group, altogether five groups. The thyroid function levels and low values in each group were evaluated, and the correlation between hormone levels and inflammatory factors, nutritional indicators and the relationship with the risk of death was discussed. The inpatient rate in emergency ward complicated with NTIS was 62.29%, T3 was the most sensitive index of NTIS, followed by FT3. Compared to non-NTIS group, the NTIS group had an increased risk of death. The sepsis group and impaired organ function group had the highest rates of complicated NTIS, reaching 83.33% and 78.12% respectively. Spearman's correlation analysis implied T3/T4/FT3 levels were positively correlated with ALb and PLT (except T4), and negatively correlated with CRP, D-Dimer, IL-6 and Fer. The Receiver Operating Curve (ROC) and Area under the curve (AUC) showed T3 levels alone were strongly associated with the risk of death (AUC 0.750; 95% CI 0.673-0.828; P < 0.001). T3 is the most sensitive indicator for emergency patients, followed by FT3. The decrease of T3 level has a good predictive value for mortality risk. Thyroid function should be monitored in critically ill patients.

Hormonal regulation of visfatin and adiponectin system in quail muscle cells

Visfatin and adiponectin are two adipokines known to regulate energy homeostasis and stress response within different peripheral tissues. Their role and regulation in highly metabolically active tissue such as the muscle is of particular interest. As modern poultry exhibit insulin resistance, obesity, and hyperglycemia along with a lack of insight into the regulation of these avian adipokines, we undertook the present work to determine the regulation of visfatin and adiponectin system by cytokines and obesity-related hormones in a relevant in vitro model of avian muscle, quail muscle (QM7) cells. Cells were treated with pro-inflammatory cytokine IL-6 (5 and 10 ng/mL) and TNFα (5 and 10 ng/mL), as well as leptin (10 and 100 ng/mL) and both orexin-A and orexin-B (ORX-A/B) (5 and 10 ng/mL). Results showed significant increases in visfatin mRNA abundance under both cytokines (IL-6 and TNFα), and down regulation with ORX-B treatment. Adiponectin expression was also upregulated by pro-inflammatory cytokines (IL-6 and TNFα), but down regulated by leptin, ORX-A, and ORXB. High doses of IL-6 and TNFα up regulated the expression of adiponectin receptors AdipoR1 and AdipoR2, respectively. Leptin and orexin treatments also down regulated both AdipoR1 and AdipoR2 expression. Taken together, this is the first report showing a direct response of visfatin and the adiponectin system to pro-inflammatory and obesity-related hormones in avian muscle cells.

Avian Orexin: Feed Intake Regulator or Something Else?

Originally named for its expression in the posterior hypothalamus in rats and after the Greek word for “appetite”, hypocretin, or orexin, as it is known today, gained notoriety as a neuropeptide regulating feeding behavior, energy homeostasis, and sleep. Orexin has been proven to be involved in both central and peripheral control of neuroendocrine functions, energy balance, and metabolism. Since its discovery, its ability to increase appetite as well as regulate feeding behavior has been widely explored in mammalian food production animals such as cattle, pigs, and sheep. It is also linked to neurological disorders, leading to its intensive investigation in humans regarding narcolepsy, depression, and Alzheimer’s disease. However, in non-mammalian species, research is limited. In the case of avian species, orexin has been shown to have no central effect on feed-intake, however it was found to be involved in muscle energy metabolism and hepatic lipogenesis. This review provides current knowledge and summarizes orexin’s physiological roles in livestock and pinpoints the present lacuna to facilitate further investigations.

Phytogenic feed additives improve broiler feed efficiency via modulation of intermediary lipid and protein metabolism-related signaling pathways

Diets enriched with phytogenic feed additives (PFA) such as AV/HGP/16 premix (AVHGP), Superliv concentrate premix (SCP), and bacteriostatic herbal growth promotor (BHGP) with essential oils have been shown to improve feed efficiency (FE) in broilers. This FE improvement was achieved via modulation of hypothalamic neuropeptides, which results despite feed intake reduction, in increased breast yield without changes in body weight compared to the control group. To gain further insights into the mode of action of these PFA, the present study aimed to determine the potential involvement of signaling pathways associated with lipid and protein metabolism. One day-old male Cobb 500 chicks were randomly assigned into 1 of 4 treatments, comprising 8 replicates per treatment in a completely randomized design. The dietary treatments included a basal diet (control) or 0.55 g/kg diet of AVHGP, SCP, or BHGP. The birds had ad libitum access to water and feed. On day 35, after blood sampling, the liver, abdominal adipose tissue (AT), and breast muscle samples were collected. The levels of phosphorylated mechanistic target of rapamycin (mTOR)^Ser2481 as well as its levels of mRNA and those of its downstream mediator RPS6B1 were significantly upregulated in the muscle of the PFA-fed groups compared with the control group. In the liver, the phosphorylated levels of acetyl-CoA carboxylase alpha at Ser79, the rate-limiting enzyme in fat synthesis, was significantly induced in the PFA-fed groups compared with the control group, indicating a lower hepatic lipogenesis. The hepatic expression of hepatic triglyceride lipase (LIPC) and adipose triglyceride lipase (ATGL) was significantly upregulated in the AVHGP-fed group compared with the control group. These hepatic changes were accompanied by a significant downregulation of hepatic sterol regulatory element-binding protein cleavage-activating protein in all the PFA groups and an upregulation of peroxisome proliferator–activated receptor alpha and gamma in the SCP-fed compared with the control group. In the AT, the mRNA abundances of ATGL and LIPC were significantly increased in both SCP- and BHGP-fed birds compared with the control group. Together these data indicate that PFA improve FE via modulation of muscle mTOR pathway and hepatic lipolytic/lipogenic programs, thus, favoring muscle protein synthesis and lowering hepatic lipogenesis.

Regulation of avian uncoupling protein (av-UCP) expression by cytokines and hormonal signals in quail myoblast cells

Uncoupling proteins (UCPs), members of the mitochondrial anion carrier family, play a pivotal role in thermogenesis, redox balance, reactive oxygen species and many other cellular processes. They were extensively studied in mammalian species and have been shown to be tightly regulated at transcriptional and translational levels by various environmental and hormonal factors. Such studies are very limited in avian species which represent a unique model because they lack brown adipose tissue and they contain only one UCP (av-UCP) predominantly expressed in the muscle. The present study aimed, therefore, to determine the effects of pro-inflammatory cytokines (IL-6 and TNFα) and energy homeostasis-related hormones (leptin and T3) on the expression of av-UCP and its related transcription factors in quail myoblast (QM7) cells. Leptin treatment for 24 h significantly down-regulated av-UCP, and up-regulated PGC-1α, PPARα, and PPARγ expression in QM7 cells. IL-6 and TNFα administration significantly up-regulated the expression of av-UCP, however T3 had a biphasic effects (up-regulation with low dose and down-regulation with high dose) on av-UCP mRNA levels (P < .05). TNFα significantly induced PPARα and PPARγ mRNA abundances, however T3 and IL-6 down-regulated PPARα expression (P < .05). Together, these data are the first to report cytokine and hormonal regulation of av-UCP in avian muscle cells, suggesting that these effects are mediated through PPARs and PGC-1α, and opening a new vista for future functional and mechanistic studies.

Modulation of angiogenesis by topical application of leptin and high and low molecular heparin using the Japanese quail chorioallantoic membrane model

Pathological angiogenesis characterized by uncontrollable vessel growth is an accompanying feature of many diseases. The avian embryo chorioallantoic membrane (CAM) is an excellent model for angiogenesis research. In our study we used a less common Japanese quail CAM model for the testing of angiogenic potential of leptin, high-molecular (heparin sodium) andlow-molecular (nadroparin calcium) heparins. Heparins play a significant role in vascular endothelial cell function, and they are able to modulate the activities of angiogenic growth factors. On embryonic day 7 leptin (5 μg per CAM), heparin sodium (75 IU per CAM) and nadroparin calcium (47.5 IU per CAM) in 500 μl PBS were applied on the CAM surface. After 24 h the fractal dimension (Df) of the vasculature was evaluated. Samples from each group were histologically analyzed and VEGF-A and Quek1 expression were detected by qPCR. Df was significantly increased in the leptin group. A moderate stimulatory effect of heparin sodium and an inhibitory effect of nadroparin calcium were observed. Both leptin and heparin sodium caused a noticeable increase in the CAM thickness compared to the control and nadroparin calcium groups. We observed an increased number of blood vessels and accumulation of fibroblasts. There was no significant impact on gene expression of VEGF-A and Quek1 24 h after treatment, however, trends similar to the changes in Df and CAM thickness were present. The resulting effect of nadroparin administration on Quek1 levels was exactly the opposite to that of leptin (p < 0.05).