Colony collapse disorder (CCD), a phenomenon of honeybees disappearance, has been reported since 2006. Chronic exposure to neonicotinoid insecticides, particularly imidacloprid, has been suggested to impair forager’s ability for foraging and be a main cause of CCD. Recently, it has been reported that imidacloprid induces insulin resistance in animal cell line by blocking glucose uptake. Similarly to human insulin, insulin-like peptide (ILP) of insects is involved in maintaining blood glucose contents in hemolymph by regulating the concentration of trehalose and glycogen. Therefore, we have hypothesized that sublethal concentration of neonicotinoid may affect the metabolic pathway of honey bees as well. We investigated the transcription levels of the genes involved in the insulin/insulin-like signaling (IIS) pathway, such as AmILP and AmInR, following an acute or a chronic dietary exposure of sublethal concentrations of imidacloprid to foragers. In both experiments, honeybees showed increased expression levels of ILP and InR in a dose-dependent manner. Our results suggest that sublethal dose of imidacloprid likely upregulates IIS pathway, thereby rendering honey bees to become resistant to insulin.

This study is performed to evaluate the effect of insulin in the porcine parthenogenetic embryo development. In porcine embryo culture, insulin is helpful factor in the process of embryo development. To identify this, insulin is used in pig embryos development. Therefore, this study was performed to investigate the effect of insulin on early embryonic development in pigs. For that, insulin positive or negative (0, 10 ug/mL) was supplemented in the porcine IVM media and then compared two groups divided by the cytoplasm of the black groups and white ring groups based on the distribution of lipid material of the cell cytoplasm in microscope. In maturation rates of porcine oocytes, significant higher black group rates were shown in the insulin positive groups compared with other groups (56.0±2.1 vs 46.2±0.3). In the embryo culture, black groups were showed the significant higher cleavage rates (82.1±0.8, 78.3±0.1 vs 63.2±0.3, 63.4±0.0), and blastocyst formation rates (15.5±3.6, 16.6±0.4 vs 11.7±1.3, 7.4±0.2) regardless of whether the addition of insulin. Also, black groups were showed higher cell number of blastocyst (33.2±2.5, 35.5±2.6 vs 31.2±2.1, 31.3±2.2). In conclusion, supplement of insulin producing black group in vitro maturation, it was effective in vitro maturation and embryonic development of pig embryos.

This study was conducted to determine the association between dietary calcium intake and biomarkers related to lipid and glucose metabolism and inflammation in Korean patients with type 2 diabetes. Seventy-five subjects (41 males, 34 females) were recruited from a group of patients who had visited the department of endocrine medicine. Data on anthropometric characteristics, clinical indices such as hemoglobin A1c and C-reactive protein (CRP), and dietary nutrient intakes were collected. Subjects were divided into three groups on the basis of their calcium intake [<EAR (below estimated average requirement), EAR-RNI (between EAR and recommended nutrient intake), >RNI (above RNI)]. Average calcium intake of <EAR, EAR-RNI, >RNI groups were 462.7±18.7, 649.7±12.8, and 895.7±21.7 mg, respectively. Energy intake was not different among groups but intakes of protein, total and saturated fatty acids were significantly higher in >RNI group than <EAR group. Analysis of covariance revealed that HDL cholesterol level was significantly higher in EAR-RNI group, as compared to <EAR group after adjustment with confounders such as age, sex, BMI and energy intake (p<0.05). Levels of CRP and homeostasis model assessment 2-insulin resistance (HOMA2-IR) were significantly lower in EAR-RNI group. Total cholesterol level was higher in EAR-RNI and >RNI groups, although within the normal range. Our results suggest that dietary calcium intake may influence the levels of HDL-cholesterol, CRP and HOMA2-IR and subsequently, help management/treatment of type 2 diabetes patients.

Insulin detemir is a long-acting basal insulin analogue recently introduced in veterinary medicine for treatment of canine diabetes mellitus. As there are only limited studies in dogs, long-term evaluation of insulin detemir in veterinary medicine is required. In this study, we investigated trends in12-hour blood glucose concentration during hospitalization and evaluated initial and following doses of insulin detemir for several months in six diabetic dogs. The mean levels of blood glucose over 12-hour periods were between 113.5 to 327.2 mg/dL, and the average glucose nadir was 103 mg/dL in the six dogs. The dogs were treated with a mean dosage of 0.24 U/kg of insulin detemir, but hypoglycemia was observed in four of the dogs at the first monthly follow-up. Thus, insulin doses were adjusted according to the nadir levels of glucose observed during the follow-up periods (range, 1 to 16 months). The total range of insulin doses throughout the study period was between 0.1 and 0.4 U/kg. Changes in insulin doses in each dog during the follow-up period were not variable. We suggest that insulin detemir might be not only an alternative choice against traditional insulin for patients with insulin resistance or concurrent disease but also an effective home therapy medication in canine patients with DM. This study could help inform veterinary practitioners regarding the use of insulin detemir for canine insulin-dependent DM.

A 10-year-old castrated male Korean shorthair cat weighing 4 kg was referred with signs of insulin-resistant diabetes mellitus based on clinical signs of polyuria, polydipsia, and polyphagia. Diagnosis of pituitary-dependent hyperadrenocorticism (PDH) was made based on results of an adrenocorticotropic hormone stimulation test and a dexamethasone screening test. In addition, plasma concentrations of insulin-like growth factor 1 (IGF-1) increased. Radiography, ultrasonography, and computed tomography (CT) revealed hepatomegaly, renomegaly, and adrenomegaly affecting both adrenal glands as well as multiple cysts in a generally enlarged pancreas. Magnetic resonance imaging (MRI) showed that the cat’s pituitary gland was enlarged. The pituitary gland had a predominantly unilateral extension to the left. The signal intensity of the pituitary gland on precontrast T1 weighted images was hypointense compared to that of soft tissue and hyperintense compared to that of cerebrospinal fluid. On T2 weighted images, the pituitary gland was predominantly hypointense with a hyperintense rim. Contrast enhancement of the pituitary gland was not evident, and a mild degree of ring-like enhancement was seen. In addition, mild peritumoral edema was present. This is the first report of a cat with suspected double adenoma of the pituitary gland on the basis of compatible clinical signs, increased serum IGF-1 concentration, PDH, CT images, and MRI findings in diabetic cats with insulin resistance.

Like vertebrate insulins, insulin-like peptides (ILPs) play crucial roles in controlling immature growth, adult lifespan, and plasma sugar level in some insects. An ILP gene (SeILP1) was predicted from a transcription database of Spodoptera exigua. SeILP1 encodes 95 amino acid sequence, which shares sequence homologies (33~83%) with other insects ILPs. The predicted B and A chains possess six cysteine residences. SeILP1 was expressed in all developmental stages of S. exigua. However, its expression was detected in fat body, gut and epidermis, but not in hemocytes. Its expression increased with feeding activity. Plasma trehalose levels of fifth instar larvae maintained at relatively stable concentration of 2.31±0.62 mM. However, starvation induced a significant increase of plasma trehalose level by more than two fold in 48 h, at which SeILP1 expression kept at a low level. RNA interference of SeILP1 induced a significant increase of plasma trehalose level. Interestingly, a bovine insulin decreased plasma trehalose level in a dose-dependent manner. These results indicate mat SeILP1 plays a role in suppressing plasma trehalose level in S. exigua.

Recently, with the increase of meat production, high quality and safety of meat have been strongly emphasized by Korean consumers. Marbling in beef has been regarded as an important criterion deciding meat quality in Korea. The purpose of this study was to identify the transcriptional level of insulin-like growth factor-1 (IGF-1) in longissimus muscle samples of 46 Hanwoo. The level of IGF-1 transcripts was measured by real-time polymerase chain reaction (PCR) and molecular connection of IGF-1 was analyzed using the Pathway Studio program (Ver 9.0). Increase of marbling score (MS) induced increase of IGF-1 transcripts level in the muscle and there is a significant correlation (p<0.05) between IGF-1 mRNA expression and MS. The pathway study showed that IGF-1 genes are regulated in insulin, fatty acid synthase, leptin, and corticotrophin releasing hormone. These results suggest that IGF-1 might be used as a useful marker for the improvement of economic traits in Hanwoo.

Insulin in vertebrates plays a crucial role in maintaining homeostasis of blood sugar level. Insulin-like peptide (ILP) has been identified in insects, such as Drosophila melanogaster and Aedes aegypti. Plasma sugars and polyols of the diamondback moth, Plutella xylostella were separated by a Bio-LC. Among seven peaks, trehalose was the most predominant blood sugar and maintained at approximately 3.5 mM in the larval plasma. However, the feeding activity affected the plasma trehalose level, in which starvation significantly up-regulated the trehalose level. Analysis of ILP expression upon feeding indicated that feeding stimulated the gene expression of ILP. Interestingly, an injection of a vertebrate insulin significantly suppressed the hypertrehalosemia induced by starvation. These results suggest that ILP is a endocrine signal to down-regulate the plasma trehalose level in P. xylostella.

This study compared the nutrient intake of obese versus non-obese non-insulin dependent diabetes mellitus (NIDDM) patients for Diabetes Medical Nutrition Therapy. The study was conducted at medical hospitals in Gyeonggi and Seoul from April 2009 to November 2009. Fifty-six adult male NIDDM patients were enrolled and divided into two groups: 36 into an obese group (BMI ≥25) and 20 into a non-obese group (BMI〈25). To conduct this study, anthropometric measurements, and daily nutrient intake of obese and non-obese NIDDM patients were measured. Daily nutrient intake was estimated by 24hr-recall and analyzed by the CAN program. In the results, anthropometric measurements of the two groups showed significant differences in weight and BMI (p〈0.001). Daily nutrient intake of the two groups showed no significant differences, except for vitamin E intake (p〈0.05). The total energy intake of the non-obese and obese groups were 2,669.9±964 kcal and 2,555.4±803 kcal, respectively, which were both above 113% of the recommended Dietary Reference Intakes for Korean (KDRIs). Cholesterol and sodium intake were 378.1±215.6 mg and 6,478.9±2755.1 mg, respectively for the non-obese group. Cholesterol and sodium intake were 308.1±155.6 mg and 6,306.8±2788.9 mg, respectively, for the obese group. Both groups were above 150% of the recommended levels set by the Korean Diabetes Association (KDA). However, their antioxidant nutrient intake was appropriate. Meanwhile, their fiber intake was 10.7±5.1 g and 9.8±5.2 g, respectively, which was lower than 40% of the recommended intake set by the KDA. The results show that the nutritional education for obese and non-obese NIDDM male patients must aim to reduce total energy, cholesterol, and sodium intake, while increasing fiber intake. In addition, the factors related to a patient's glycosylated hemoglobin, serum lipids, blood pressure, and weight change must be calibrated for the appropriate energy, fat, cholesterol, sodium, and dietary fiber intake.

A polydnavirus, Cotesia plutellae bracovirus (CpBV), is symbiotic to an endoparasitoid wasp, C. plutellae, which specifically parasitizes young larvae of the diamondback moth, Plutella xylostella. Parasitization by an endoparasitoid wasp, Cotesia plutellae, delays the larval development and metamorphosis in Plutella xylostella. Nutritional deprivation by the wasp may induce these developmental alterations in growing host. This study focussed on the change of insulin signaling of the parasitized host. The parasitized larvae exhibit a significant suppression in insulin-like peptide (ILP) expression, which was induced only by the injection of the CpBV. Reduced ILP expression significantly increased the blood sugar level (trehalose) level in the parasitized host, which was mimicked by starvation. Foxo was expressed in the parasitized larvae, but localized mostly in the nucleus. Overexpression of ILP gene in the parasitized larvae induced translation of Foxo to cytoplasm and significantly decreased trehalose level in the plasma. Interestingly, the overexpression of ILP gene significantly prevented the successful parasitization and allowed the host metamorphosis.

To investigate the effects of coated liposome from Discorea rhizoma extract (DRE) in streptozotocin (STZ)-induced, we evaluated changes in body weight, fasting blood glucose, blood insulin and blood lipid concentrations in mice. Mice were divided into four groups: (DC), diabetic DRE at 10 ㎎/㎏ (DRE-1), diabetic DRE at 50 ㎎/㎏ (DRE-2), and diabetic DRE at 250 ㎎/㎏ (DRE-3). Mice had free access to water and diet (10 weeks). The DC group showed higher blood cholesterol than the DRE-1, DRE-2, DRE-3 groups. In glucose tolerance test, the DRE-1, DRE-2, and DRE-3 groups increased after 30 minutes in decremental glycemic response area under the curve. Fasting blood glucose levels in the DRE groups significantly decreased through 4 weeks. Plasma total cholesterol, triglyceride and LDL-cholesterol concentrations were also lower in the DRE groups. On the other hand, the DRE-1, DRE-2 and DRE-3 groups showed higher HDL-cholesterol and insulin levels than the DC group. Moreover, blood glucose and lipid levels significantly decreased in streptozotocin (STZ)-induced diabetic mice treated with DRE. These results indicate that DRE may reduce elevated blood glucose levels and serum lipid concentrations in hypoglycemic and diabetic mice, suggesting its usefulness as a functional food.

The purpose of this study was to investigate the effects of resistance exercise training on % body fat and insulin resistance in obese middle school male students. Subjects were composed of 20 students(exercise training group: 10, control group: 10, body

Insulin/insulin-like peptide-binding protein (IBP) is abundantly found in venom of the solitary hunting wasp, Eumenes pomiformis (Hymenoptera: Eumenidae). E. pomiformis IBP (EpIBP) is most similar to insect IBP-like proteins that are known to inhibit insect growth and insulin signaling. To investigate the toxicity and target protein, EpIBP was in vivo expressed by Escherichia coli. Spodoptera exigua (Lepidoptera: Noctuidae) larvae injected with EpIBP showed a 20% lower pupation rate than the control larvae, although their body weight was not significantly different from the control when the larvae were provided artificial diet after the injection. EpIBP extended the larval stage without inducing paralysis of S. exigua larvae. To investigate the effects of EpIBP on caterpillar under a starvation condition, survivorship and body weight of the EpIBP-injected were evaluated without providing artificial diet until all the larvae died. The survivorship of the EpIBP-injected larvae was 24-36% higher than the control larvae at 4-5 d post-injection. The body weight of the control larvae reduced to 59% that is approximately 10% lower than the body weight of the EpIBP-injected larvae. These results suggest that EpIBP might inhibit the metabolism of the caterpillars, which is likely related with insulin-like peptide signaling pathway, suppress the loss of body weight and eventually extend the larval stage. An EpIBP-binding protein (EpIBPBP) isolated by immunoprecipitation was matched with a coiled-coil domain-containing protein of the fruit fly. The full-length sequence analysis of EpIBPBP is in progress.

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of Tuj1 increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous Igf2 may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

젖소는 분만전후기에 당 및 지방대사를 조절하여 태아와 유선에서 요구하는 영양소를 충족하고자 한다. 이러한 대사적 적응과정에서 중요한 역할을 하는 호르몬으로 insulin을 꼽을 수 있으며, 특 히 지방조직에 작용하여 동물체내 필요한 에너지를 충족시키기 위해 지방산의 재배치를 촉진하고 분만전 말기에 insulin resistance를 야기시킨다. 분만전에 혈중 유리 지방산의 농도가 증가됨에 따라 insulin resistance가 발생하며 이것은 사료섭취량의 감소와 밀접한 관계가 있다. Insulin resistance을 완화시키는 물질로 PPARγ agoinst인 thiazolidinedione (TZD)는 분만전후기에 발 생하는 대사성 질병의 발생을 억제하여 젖소의 건강 및 유생산 증가를 도모할 수 있다고 사료된다.

젖소의 분만 전․후기는 일반적으로 전환기라고 칭하며 분만후 유생산을 준비하기 위해 동물체내 대사 및 생리적 상태가 급격히 변화하는 시기라 할 수 있다. 젖소는 이 시기에 간조직에서 당신합성을 통해 유당합성을 위한 glucose의 생산을 촉진하고, 지방조직에서는 분만 전부터 지질을 축적하고 비유개시에 맞추어 혈중 NEFA (nonesterified fatty acid)의 농도를 증가시켜 유지방 합성을 준비한다. 이러한 대사조절에 epinephrine 및 insulin이 조절 호르몬으로 작용하여 유생산을 위한 탄수화물 및 지질대사를 변화시키고 사료 섭취량의 부족에 기인한 전체 에너지의 감소를 체내 영양소의 재분배로 충족시킨다.