Effects of porcine brain hydrolysate on impairment of cognitive learning ability in amyloid β(1–40)‐infused rats

This study assessed whether administering porcine brain hydrolysate (PBH) ameliorates the impairment of spatial cognition learning ability in amyloid β (Aβ)‐infused rats. PBH was prepared using organic solvents (i.e., acetone and ethanol). Enzyme hydrolysates were derived from these PBH and the sequence of the Aβ peptide for infusion was selected. The results indicated the PBH, in particular EP (porcine brain extract with ethanol and protease N), demonstrated the potentials to reduce damage of neurodegenerative disorders in vitro and in vivo. The principal findings of this study indicate that PBH has prolyl endopeptidase inhibitory activity in vitro. Moreover, administering EP to Aβ(1–40)‐infused rats significantly improves their performance on reference, spatial performance, and working memory tests during water maze tasks; concurrent proportional decreases are also observed in malondialdehyde levels, acetylcholinesterase (AChE) activity, and Aβ accumulation levels in brain tissues. The PBH was suggested to ameliorate learning deficits associated with Alzheimer's disease by inhibition of lipid peroxidation in the brain of Aβ infused rat.     

Bta‐miR‐152 affects intracellular triglyceride content by targeting the UCP3 gene

According to our previous studies, bta‐miR‐152, PRKAA1 and UCP3 are differentially expressed in mammary gland tissues of high milk fat and low milk fat cows, and the trend in bta‐miR‐152 expression is opposite from those of PRKAA1 and UCP3. To further identify the function and regulatory mechanism of bta‐miR‐152 in milk fat metabolism, we investigated the effect of bta‐miR‐152 on cellular triglyceride content in bovine mammary epithelial cells cultured in vitro, on the basis of bta‐miR‐152 overexpression and inhibition assays. The target genes of bta‐miR‐152 were identified through qPCR, Western blotting and dual luciferase reporter gene detection. Compared with that in the control group, the expression of UCP3 was significantly lower in the bta‐miR‐152 mimic group, the expression of PRKAA1 was decreased, and the intracellular TAG content was significantly increased. After transfection with bta‐miR‐152 inhibitor, the expression of UCP3 increased significantly, and the expression of PRKAA1 decreased, but the difference was not significant; in addition, the intracellular TAG content decreased significantly. Therefore, we concluded that bta‐miR‐152 affects the intracellular TAG content by targeting UCP3.     

Tolerance evaluation of overdosed dietary levels of 25‐hydroxyvitamin D3 in growing piglets

Forty‐eight, cross‐bred (GL × LW × P) piglets were used in a 42‐day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25‐hydroxyvitamin D₃ (25‐OH‐D₃). Six‐week‐old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 μg vitamin D₃/kg feed. The experimental groups received 25‐OH‐D₃ at the recommended dose (T2: 50 μg/kg = 1x), at 250 μg/kg (T3: 5x) or at 500 μg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25‐OH‐D₃ plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25‐OH‐D₃ were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25‐OH‐D₃ intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25‐OH‐D₃ at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25‐OH‐D₃ can be regarded as a supplement with a very high safety margin when used at the recommended level.     

Orally Administered Pediococcus acidilactici and Saccharomyces boulardii–Based Probiotics Alter Select Equine Immune Function Parameters

To investigate the effects of a combination of Pediococcus acidilactici and Saccharomyces boulardii, the following experiments were performed. Initially, an in vitro experiment was performed in which the culture supernatant of S. boulardii and P. acidilactici was added to the culture media of isolated peripheral blood mononuclear cells (PBMCs), and the proliferative response to cellular stimulants was assayed. After this initial experiment, an in vivo experiment was performed in which 12 horses were used and assigned to one of two groups of six horses each: placebo controls or principle-treated horses. After a period of treatment, various end points were determined to test the effects of test article on (1) proliferative responses of cultured PBMCs; (2) serum immunoglobulin (Ig) concentrations; (3) lymphocyte phenotype subsets; (4) white blood cell count; and (5) response to vaccination. Results of the in vitro testing demonstrated a substantial reduction (23%) in proliferation of stimulated PBMCs. Results of in vivo testing demonstrated enhanced proliferation on day 72 in cells stimulated with phorbol (P = .04). On study day 37, the segmented neutrophil number was reduced and IgG concentration increased (mean, 329.0 vs. 185.9 ng/mL; P = .029). Results demonstrate that the test article did have some effects on systemic immunity, specifically proliferative responses, immunoglobulin G concentrations, and neutrophil numbers. Based on the findings of this study, further evaluation of these probiotics for equine wellness or disease modulation is warranted.     

In vitro Inhibition of Canine Complement‐Mediated Hemolysis

Background

Immune‐mediated hemolytic anemia (IMHA) is the most common hematologic immune‐mediated disease in dogs. Complement fixation on erythrocytes causes hemolysis. Complement inhibition decreases hemolysis in people with the hemolytic disease and also may prove effective in treating IMHA in dogs.

Hypothesis/Objectives

Evaluate the in vitro efficacy of 2 complement inhibitors used in humans against canine complement.

Methods

The inhibitory activity of the C3‐inhibitor compstatin and recombinant human C1‐esterase inhibitor (C1‐INH) was evaluated using an in vitro hemolytic assay and spectrophotometric measurement of released hemoglobin. Dose‐response curves for each inhibitor were generated.

Results

Compstatin decreased approximately 50% of canine complement‐mediated hemolysis in initial experiments. This inhibition largely was lost when a new lot of drug was purchased. C1‐INH showed a dose‐dependent inhibition. The highest concentration of C1‐INH tested (500 μg/mL) decreased >80% of canine complement‐mediated hemolysis, and the lowest concentration tested (31.25 μg/mL) decreased hemolysis >60%.

Conclusions and Clinical Importance

Human C1‐INH is a robust inhibitor of canine complement‐mediated hemolysis, whereas compstatin was minimally and variably effective. Human C1‐INH may substantially decrease complement‐mediated hemolysis in dogs with IMHA and warrants further investigation.     

MicroRNA‐145 regulates immune cytokines via targeting FSCN1 in Staphylococcus aureus‐induced mastitis in dairy cows

Dairy cow mastitis is a detrimental factor in milk quality and food safety. Mastitis generally refers to inflammation caused by infection by pathogenic microorganisms. Our studies in recent years have revealed the role of miRNA regulation in Staphylococcus aureus‐induced mastitis. In the present study, we overexpressed and suppressed miR‐145 to investigate the function of miR‐145 in Mac‐T cells. Flow cytometry, ELISA and EdU staining were used to detect changes in the secretion of several Mac‐T cytokines and in cell proliferation. We found that overexpression of miR‐145 in Mac‐T cells significantly reduced the secretion of IL‐12 and TNF‐α, but increased the secretion of IFN‐γ; the proliferation of bovine mammary epithelial cells was also inhibited. Using quantitative real‐time PCR (qRT‐PCR), Western blotting and luciferase multiplex verification techniques, we found that miR‐145 targeted and regulated FSCN1. Knock‐down of FSCN1 significantly increased the secretion of IL‐12, while the secretion of TNF‐α was significantly downregulated in Mac‐T cells. Upon S. aureus infection of mammary gland tissue, the body initiated inflammatory responses; Bta‐miR‐145 expression was downregulated, which reduced the inhibitory effect on the FSCN1 gene; and upregulation of FSCN1 expression promoted mammary epithelial cell proliferation to allow the recovery of damaged tissue. The results of the present study will aid in understanding the immune mechanism opposing S. aureus infection in dairy cows and will provide a laboratory research basis for the prevention and treatment of mastitis.     

Effects of pre‐partum milking of dairy cows on calcium metabolism at start of milking and at calving

This experiment studied the effect of pre‐partal milk removal on calcium metabolism at start of milking and at calving. Nine cows of the Swedish Red breed were milked for 1–7 days pre‐partum. The average milk yield at the first milking was 4.8 l, and the average yield the last day prior to calving was 13.4 l. Five cows were used as control cows and were only milked post‐partum. Samples of plasma and urine were taken to determine the effect of pre‐partum milking and calving on levels of calcium, magnesium, parathyroid hormone and plasma C‐terminal crosslinked telopeptide of type 1‐collagen (CTx), used as a marker of bone resorption. Pre‐partum milking resulted in a decrease in plasma calcium that was evident 2 days after the first milking. Parathyroid hormone increased at the same time, and CTx started to increase from 24 h after the first milking. There were no effects on plasma magnesium or urinary output of calcium or magnesium. The first week after calving, there were no differences between pre‐partum milked cows and control cows in plasma or urine variables, or in milk yield. In conclusion, pre‐partum milking activated the calcium‐restoring mechanisms but did not improve calcium status at calving.     

In vitro immunomodulatory effect of nisin on porcine leucocytes

Nisin, a lantibiotic bacteriocin, has been used for years as a natural food preservative. In addition to its antimicrobial activity, nisin also shows immunomodulatory properties, and the nisin‐producing Lactococcus lactis strain has been successfully tested as a probiotic in weaned piglets. However, the impact of nisin on porcine immune cells has not yet been explored. The objective of the present study was to examine the in vitro immunomodulatory effect of nisin on porcine peripheral blood leucocytes. The whole heparinized blood samples or freshly isolated peripheral blood mononuclear cells (PBMCs) were incubated with different nisin concentrations (0, 1.56, 3.125, 6.25, 12.5, 25 or 50 µg/ml) for 1, 24, 48 or 72 hr. Escherichia coli bacteria were used to stimulate blood phagocytes, while concanavalin A and lipopolysaccharide from E. coli were used as mitogens. Control cells remained unstimulated. MTT colorimetric assay was used to evaluate PBMCs viability and mitogenic response. Phagocyte activity and T‐cell proliferation were measured by flow cytometry. Flow cytometer was also used for immunophenotyping of T cells. Cytokine levels in the culture media were determined using commercial immunoassay (ELISA) kits. The highest concentration of nisin exhibited proliferative activity (p ? 0.05), stimulated interleukin‐1 beta (IL‐1β) and interleukin‐6 (IL‐6) production (both at p ? 0.001), and increased the percentage of CD4⁺CD8⁺ T cells (p ? 0.001) among unstimulated leucocytes. After cell stimulation, however, the highest nisin concentration showed antiproliferative activity (p ? 0.05), decreased phagocytic functions (p ? 0.05) and inhibited the synthesis of IL‐6 (time‐ and concentration‐dependent effect). As a typical bacterial product, nisin had a stronger impact on innate immune cells, and its effect on T cells was likely a consequence of the modulation of the activity of antigen‐presenting cells. Nisin may be a good candidate as an immunomodulator in pig breeding.     

Ultrastructural Characterization of Fresh and Vitrified In Vitro‐ and In Vivo‐Produced Sheep Embryos

The lower results in cryopreservation of in vitro‐produced (IVP) sheep embryos, when compared to the in vivo derived, limits its use. Four groups of blastocyst (BL) were evaluated: fresh IVP (n = 3), fresh in vivo derived (n = 3), warmed IVP cryopreserved in open pulled straws (OPS, n = 3) and warmed in vivo derived cryopreserved in OPS (n = 3). Ultrastructural observation of processed fresh embryos showed a reduced number of microvilli and mitochondria in the IVP ones, as well as a lower number of mature mitochondria, that can be associated with deficient metabolism in IVP embryos, possibly involved in the lower resistance to cryopreservation. Both in vivo‐derived and IVP embryos had a large number of vesicles, with light and dense content. In embryos vitrified by OPS, major changes were observed mainly in IVP embryos with small changes in grade 2 (fair) and high changes in grade 3 (bad) semithin scoring. The main changes associated with cryopreservation included disruption of cellular membranes and poor intracellular preservation, with loss of microvilli and the presence of cellular debris. In conclusion, ultrastructural evaluation of IVP blastocysts cryopreserved in OPS was herein described for the first time, reporting more severe cellular damage in these embryos when compared to those produced in vivo. This is probably associated with a lower cryotolerance that can be related to their lipid content and metabolism.     

Effects of different forage combinations in total mixed rations on in vitro gas production kinetics,ruminal and milk fatty acid profiles of lactating cows

This study aimed to determine the effects of different forage combinations on in vitro gas production (GP) kinetics, ruminal and milk fatty acid profiles. Forty‐five lactating cows were randomly arranged into three groups and fed three total mixed rations (TMRs) with different forage combinations: TMR1, 23% alfalfa hay, 7% Chinese wild ryegrass hay and 15% whole corn silage; TMR2, 30% corn stover plus 15% whole corn silage; TMR3, 30% rice straw plus 15% whole corn silage. In vitro dry matter disappearance ranked: TMR1 > TMR2 > TMR3, and highest cumulative GP and asymptotic GP occurred in TMR1 while no difference occurred between TMR2 and TMR3. The average GP rate ranked: TMR1 > TMR2 > TMR3. TMR1 in comparison with TMR2 and TMR3 presented lower rumen contents of acetate and butyrate and greater rumen contents of propionate, valerate, C13:0, C14:0, C15:0, C18:1cis‐9, C18:2n‐6, C18:3n‐3, C20:0 and C22:0 as well as milk C18:2n‐6 and C18:3n‐3 proportions. Transfer efficiencies of C18:2n‐6 and C18:3n‐3 from diet to milk ranked: TMR1 > TMR2 > TMR3. The findings suggest TMRs containing alfalfa hay and Chinese wild ryegrass hay in comparison with corn stover or rice straw improve rumen fermentation and transfer efficiency of C18:2n‐6 and C18:3n‐3.     

Effect of dietary fish oil on the expression of genes involved in lipid metabolism in liver and skeletal muscle of lactating sows

This study investigated the hypothesis that dietary supplementation of fish oil as a source of n‐3 polyunsaturated fatty acids (PUFA) influences the expression of target genes of sterol regulatory element‐binding proteins (SREBP)‐1 and (SREBP)‐2 involved in triacylglycerol (TAG) synthesis and fatty acid and cholesterol metabolism in the liver, and moreover activates the expression of target genes of peroxisome proliferation‐activated receptor (PPAR)‐α involved in TAG and fatty acid catabolism in liver and skeletal muscle. Twenty lactating sows were fed a control diet or a fish oil diet with either 50 g of a mixture of palm oil and soya bean oil (4:1, w/w) or fish oil per kg. The diet of the fish oil group contained 19.1 g of n‐3 PUFA (mainly 20:5 n‐3 and 22:6 n‐3) per 100 g of total fatty acids, while the diet of the control group contained 2.4 g of n‐3 PUFA (mainly 18:3 n‐3) per 100 g of total fatty acids. The fish oil group had reduced relative mRNA concentrations of various target genes of SREBP‐1 involved in fatty acid and TAG synthesis in comparison with the control group (p < 0.05). Relative mRNA concentrations of target genes of PPARα involved in fatty acid catabolism in both liver and muscle, and mRNA concentrations of target genes of SREBP‐2 involved in cholesterol synthesis and uptake were not influenced by fish oil supplementation. Concentrations of cholesterol and TAG in plasma, fat content of milk and weight gains of litters during the suckling period were not different between the two groups of sows. In conclusion, this study suggests that fish oil has only minor effects on hepatic lipid metabolism, which are non‐critical with respect to milk production in sows.     

N-carbamoylglutamate improves lipid metabolism,inflammation, and apoptosis responses in visceral adipocytes of Japanese seabass (Lateolabrax japonicus), in vivo and in vitro

This study applied in vivo and in vitro methods to investigate the effect of dietary N-carbamoylglutamate (NCG) on lipid metabolism, inflammation and apoptosis related-gene expression in visceral adipose tissue and isolated adipocytes of Japanese seabass (Lateolabrax japonicus). A basal diet and a test diet supplemented with 720 mg/kg NCG were fed to the fish for 10 weeks. During the growth trial, no mortality and no significant differences in growth performance were observed in fish between the 2 groups (P > 0.05). Plasma Arg content and mRNA level of argininosuccinate synthetase (ASS) in adipose tissue were significantly increased, which indicated that NCG inclusion promoted endogenous Arg synthesis. Thereafter, the potential effects of NCG treatment on lipid metabolism-related genes expression were studied through in vivo and in vitro methods. In the present study, we successfully established a primary adipocytes culture system and isolated pre-adipocytes in vitro of Japanese seabass for the first time. Both the results in vivo and in vitro showed that NCG treatment decreased the mRNA levels of genes related to adipogenesis (fatty acid synthase, FASN), cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase, HMGCR) and fat deposition (lipoprotein lipase [LPL] and leptin), which revealed the underlying mechanism of NCG on reducing fat deposition. The results of this study demonstrated that NCG inclusion reduced the expression of inflammatory and apoptosis cytokines markedly in vivo and in vitro. In conclusion, NCG did exert beneficial effects on ameliorating adipogenesis, inflammation and apoptosis via promoting Arg endogenous synthesis in Japanese seabass.     

The preliminary study on the effects of growth hormone and insulin‐like growth factor‐I on κ‐casein synthesis in bovine mammary epithelial cells in vitro

The effects of growth hormone (GH) and insulin‐like growth factor‐I (IGF‐I) on protein synthesis and gene expression of κ‐casein in bovine mammary epithelial cell in vitro were studied. The treatments were designed as follows: the growth medium without serum was set as the control group, while the treatments were medium supplemented with GH (100 ng/ml), IGF‐I (100 ng/ml), and GH (100 ng/ml) + IGF‐I (100 ng/ml). The quantity of κ‐casein protein was measured by ELISA, and the κ‐casein gene (CSN3) expression was examined by real‐time quantitative PCR (RT‐qPCR). Compared with the control group, all the experimental groups had greater (p < 0.05) expression of CSN3. The concentration of κ‐casein followed a similar response as CSN3, but the difference between the treatments and the control was not statistically significant (p > 0.05). Furthermore, no synergistic effect of GH and IGF‐I was observed for both the κ‐casein concentration and CSN3 expression. It is therefore concluded that GH or IGF‐I can independently promote the expression of CSN3 in bovine mammary epithelial cells in vitro.     

Blood and Colostrum/Milk Serum γ‐Glutamyltransferase Activity as a Predictor of Passive Transfer Status in Lambs

The importance of blood and colostrum/milk serum γ‐glutamyl transferase (γ‐GT) enzyme activity was evaluated to assess passive transfer status in healthy lambs. Thirty Akkaraman sheep (3–6 years old) were used which had normal pregnancy period and the same conditions, and the age of the lambs ranged between 0 and 15 days. Blood and colostrum/milk samples were collected from sheep and lambs after birth, before suckling (0) and after on 1st, 3rd, 7th and 15th days. Serum immunoglobulin G (IgG) concentration was determined by the use of Single Radial Immunodiffusion method. Serum γ‐GT activity was measured, using a commercially available kit in blood and colostrum/milk samples. Correlations were carried out between immunoglobulin and γ‐GT levels. Regression models (simple and multiple) were calculated with significant data. Linear correlation was determined between colostrum/milk γ‐GT activity and IgG concentrations and between serum γ‐GT activity and IgG concentrations in lambs on the 0 day. (r: 0.607, P: 0.001), 1st (r: 0.768, P: 0.001) and the 3rd (r: 0.603, P: 0.001) days and on the 1st (r: 0.637, P: 0.001) and 3rd (r: 0.478, P: 0.012) days in the experiment, respectively. Multivariate regression models were developed to estimate sample IgG concentration. Serum and colostrum/milk IgG concentration could be predicted using the formula: lamb serum IgG = 825 + 0.688 (lamb γ‐GT) + 52 (days); colostrum/milk IgG = 832 + 0.505 (colostrum/milk γ‐GT) ? 167 (days). The regression models were moderately accurate in predicting serum IgG concentration (R² = 0.51) and colostrum/milk IgG concentration (R² = 0.55). Test sensitivity and positive predictive values for serum γ‐GT enzyme activity were found to be 96 and 100% and for colostrum/milk γ‐GT enzyme activity were found to be 100 and 68% to prediction IgG concentration. Serum and colostrum/milk γ‐GT activity can be used to assess passive transfer status of lambs. Along with this, regression models used to calculate serum and colostrum/milk γ‐GT activities found to be useful to estimate sample IgG concentration. The use of serum and colostrum/milk γ‐GT enzyme activity was found useful especially after birth on the 0, 1st and 3rd days.     

Selective growth inhibition by suppression of F1Fo ATPase in canine malignant melanoma cell lines

Canine malignant melanoma (CMM) is a highly aggressive and fatal neoplasm. To identify potential therapeutic compounds and/or targets, 320 compounds were screened for their growth inhibitory activity in a CMM line (CMM‐1) using a chemical library known to target specific signaling pathways/cell growth‐related molecules. Among the compounds screened, the F1Fo ATPase inhibitor oligomycin showed potent growth inhibitory effects in CMM‐1 cells, while exhibiting less toxic effects in a non‐neoplastic control cell line (MDCK cells). The growth inhibitory effect of oligomycin A was then examined using six CMM lines and MDCK cells. Three CMM lines were highly sensitive to oligomycin A, with around 3000–20 000 times lower IC₅₀ compared with oligomycin A‐resistant CMM lines and MDCK cells. Oligomycin A‐sensitive CMM‐1 cells exhibited much greater oligomycin A‐induced decreases in cellular ATP compared to oligomycin A‐resistant cell lines. Although the oligomycins are clinically unsuitable because of its in vivo toxicity, these findings implicate the potential of F1Fo ATPase as a therapeutic target in a subset of CMM.     

Effect of dietary Schizochytrium microalga oil on selected markers of low‐grade inflammation in rats

The objective of the present study was to evaluate a potential of Schizochytrium microalga oil to alleviate possible negative effects of high‐fat‐high‐energy diets. Forty adult male rats (Wistar Albino) were fed 7 weeks the diet containing beef tallow + evaporated sweetened milk (diet T) intended to cause mild obesity and low‐grade systemic inflammation. Consequently, the animals were divided into four groups by 10 animals each and fed either the T‐diet (control) or the diet containing 6% of safflower oil (S), 6% of fish oil (F) and 6% of Schizochytrium microalga oil (A), respectively, for another 7 weeks. The A‐diet decreased (p < 0.05) live weight to 86% and glycaemia to 85% of control, respectively; an effect of the S‐ and F‐diet on these markers was insignificant (p > 0.05). In comparison with control, higher (p < 0.05) deposition of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in the epididymal adipose tissue (EAT) of the A‐rats correlated with increased (p < 0.05) plasma adiponectin concentration, but it was without the effect (p > 0.05) on cellular adiponectin content in the EAT. Higher (p < 0.05) EPA+DHA deposition in the liver of the A‐rats correlated with higher expression (149% of control; p < 0.05) of the gene coding for peroxisome proliferator‐activated receptor gamma, and with lower expression (82% and 66%; p < 0.05) of the genes coding for adiponectin receptors AdipoR1 and AdipoR2; no relationship to the expression of receptor GPR120 was found. The A‐diet did not affect amount of the nuclear fraction of the nuclear factor kappa B in the liver, but increased plasma level of anti‐inflammatory cytokine TGF‐β1 (p < 0.05). The presented data agree with results of other in vivo rodent and human studies, but not with literature data regarding in vitro experiments: it can be concluded that the effects of dietary oils on inflammatory markers need further investigation.     

Inhibition of PI3K‐Akt‐mTOR signal pathway dismissed the stimulation of glucose on goose liver cell growth

In the formation of goose fatty liver induced by a high‐carbohydrate diet, it is characterized by the quick cell growth of liver. The carbohydrate is mostly digested and absorbed in the small intestine by the form of glucose. Recent studies have suggested a crucial role for PI3K‐Akt‐mTOR pathway in regulating cell proliferation, and then we speculate that PI3K‐Akt‐mTOR pathway may mediate glucose‐induced liver cell proliferation. Goose primary hepatocytes were isolated and incubated in either no addition as a control or glucose or PI3K‐Akt‐mTOR pathway inhibitors or cotreatment with glucose and PI3K‐Akt‐mTOR pathway inhibitors. The results firstly showed that 35 mmol/l glucose stimulated the mRNA level and protein content of factors involved in PI3K‐Akt‐mTOR signal pathway in goose primary hepatocytes. Secondly, 35 mmol/l glucose evidently changed the cell cycle PI index and protein expression of cyclin D1. Meanwhile, the upregulation of 35 mmol/l glucose on the DNA synthesis rate, cell cycle PI index, the mRNA expression, protein content and protein expression of factors involved in the cell proliferation was decreased significantly by the inhibitors of PI3K‐Akt‐mTOR pathway, LY294002, rapamycin or NVP‐BEZ235. In summary, glucose could stimulate the cell proliferation, and the PI3K‐Akt‐mTOR pathway inhibitors could dismiss glucose‐induced the upregulation of cell proliferation in goose primary hepatocyte.     

Effects of Wnt10b on dermal papilla cells via the canonical Wnt/β‐catenin signalling pathway in the Angora rabbit

Wnt10b is a member of Wnt family that plays a variety of roles in biological functions, including those in the development of hair follicles. To investigate the effect of Wnt10b on hair growth in the Angora rabbit and to determine the underlying molecular mechanism, we cultured dermal papilla (DP) cells with exogenous Wnt10b in vitro. We observed the expressions of downstream critical gene β‐catenin and lymphoid enhancer‐binding factor 1 (LEF1) in Wnt/β‐catenin pathway. The levels of β‐catenin mRNA and protein were higher in the Wnt10b group of DP cells than in the Control group, and the mRNA level of LEF1 in the Wnt10b group was higher than in the Control group. Moreover, translocation of β‐catenin from cytoplasm to nucleus was activated in the Wnt10b group. Furthermore, the mRNA levels of the hair follicle‐regulatory genes, insulin‐like growth factor‐1 (IGF‐1) and alkaline phosphatase (ALP), and the protein activity of ALP was also upregulated in the Wnt10b group compared to their corresponding levels in the Control group. These data suggest that Wnt10b could activate the canonical Wnt/β‐catenin signalling pathway to induce DP cells in the Angora rabbit. In addition, the proliferation of DP cells was significantly promoted when cultured with Wnt10b for 48 and 72 hr, suggesting that Wnt10b plays a pivotal role in the proliferation and maintenance of DP cells in vitro. In conclusion, this study demonstrates that Wnt10b may promote hair follicle growth in Angora rabbit through the canonical Wnt/β‐catenin signalling pathway that promotes the proliferation of DP cells.