Tetrathiomolybdate Decreases the Expression of Alkaline Phosphatase in Dermal Papilla Cells by Increasing Mitochondrial ROS Production.

Dermal papilla cells (DPCs) play important roles in hair growth regulation. However, strategies to regrow hair are lacking. Here, global proteomic profiling identified the tetrathiomolybdate (TM)-mediated inactivation of copper (Cu) depletion-dependent mitochondrial cytochrome c oxidase (COX) as the primary metabolic defect in DPCs, leading to decreased Adenosine Triphosphate (ATP) production, mitochondrial membrane potential depolarization, increased total cellular reactive oxygen species (ROS) levels, and reduced expression of the key marker of hair growth in DPCs. By using several known mitochondrial inhibitors, we found that excessive ROS production was responsible for the impairment of DPC function. We therefore subsequently showed that two ROS scavengers, N-acetyl cysteine (NAC) and ascorbic acid (AA), partially prevented the TM- and ROS-mediated inhibition of alkaline phosphatase (ALP). Overall, these findings established a direct link between Cu and the key marker of DPCs, whereby copper depletion strongly impaired the key marker of hair growth in the DPCs by increasing excessive ROS production.

Combined Omics Analysis Further Unveils the Specific Role of Butyrate in Promoting Growth in Early-Weaning Animals.

Abnormal mutations in the microbial structure of early-weaning mammals are an important cause of enteritis. Based on the multiple known beneficial functions of butyrate, we hypothesized that butyrate would alleviate the imbalance of intestinal homeostasis induced by early weaning in animals. However, the mechanisms of action between butyrate and intestinal microbes are still poorly explored. In this study, we aimed to investigate whether butyrate exerts beneficial effects on the structure of the intestinal flora of weanling rabbits and their intestinal homeostasis, growth and development, and we attempted to elucidate the potential mechanisms of action through a combined omics analysis. We found that dietary butyrate upregulated the transcription of tight junction-related proteins in the epithelial barrier and improved the intestinal microbial structure by suppressing harmful bacteria and promoting beneficial ones. Intestinal and plasma metabolomes were also altered. The bile acid secretion, α-linolenic acid, apoptotic, and prostate cancer pathways responded to the positive dietary butyrate-induced metabolic changes in the weanling rabbits, resulting in the inhibition of inflammation, improved antioxidant capacity, increased rates of cell proliferation and survival, and decreased levels of apoptosis. Additionally, dietary butyrate suppressed the release of pro-inflammatory factors and enhanced positive appetite regulation, which increased the average daily gain of the rabbits. These results demonstrated that dietary butyrate can help maintain the integrity of the intestinal epithelial barrier, improve the structural composition of the intestinal microflora, enhance organismal metabolism, inhibit inflammation, reduce post-weaning anorexia, and promote growth and development in early-weaning rabbits. These positive effects of dietary butyrate were exerted via the modulation of the microbe-gut-brain axis.

Copper Modulates Mitochondrial Oxidative Phosphorylation to Enhance Dermal Papilla Cells Proliferation in Rex Rabbits.

Copper (Cu) is an important coenzyme factor in cell signaling, such as cytochrome c oxidase (Complex IV). Metabolism plays an important role in regulating the fate of mammalian cells. The aim of this study is to experimentally investigate the effect of copper on cell metabolism in the dermal papilla cells of the Rex rabbit. In this study, Cu promoted proliferation of dermal papilla cells (p = 0.0008) while also increasing levels of cellular CIII, CIV, Complex IV and ATP. Moreover, fifty metabolites that were significantly different between Cu and controls were identified as potential biomarkers of Cu stimulation. Copper-stimulated cells had altered levels of arachidonic acid derivatives, S-glutamic acid, and citric acid, which were primarily linked to two different pathways: arachidonic acid metabolism (p < 0.0001) and alanine, aspartate and glutamate metabolism (p = 0.0003). The addition of Cu can increase the proliferation of Rex rabbit dermal papilla cells. Increased levels of ubiquinol-cytochrome c reductase complex core protein 2 (CIII) and cytochrome c oxidase subunit 1 (CIV) were associated with the increased levels of cellular cytochrome c oxidase (Complex IV) and adenosine triphosphate (ATP). In a word, copper promotes cell proliferation by maintaining the function of the cellular mitochondrial electron transport chain (ETC) pathway.

Supplementation with Exogenous Catalase from Penicillium notatum in the Diet Ameliorates Lipopolysaccharide-Induced Intestinal Oxidative Damage through Affecting Intestinal Antioxidant Capacity and Microbiota in Weaned Pigs.

The present study aimed to explore the protective effects of exogenous catalase (CAT) from microorganisms against lipopolysaccharide (LPS)-induced intestinal injury and its molecular mechanism in weaned pigs. Fifty-four weaned pigs (21 days of age) were randomly allocated to CON, LPS, and LPS+CAT groups. The pigs in CON and LPS groups were fed a basal diet, whereas the pigs in LPS+CAT group fed the basal diet with 2,000 mg/kg CAT supplementation for 35 days. On day 36, six pigs were selected from each group, and LPS and LPS+CAT groups were administered with LPS (50 µg/kg body weight). Meanwhile, CON group was injected with an equivalent amount of sterile saline. Results showed that LPS administration damaged intestinal mucosa morphology and barrier. However, CAT supplementation alleviated the deleterious effects caused by LPS challenge through enhancing intestinal antioxidant capacity which was benefited to decrease proinflammatory cytokines concentrations and suppress enterocyte apoptosis. Besides, LPS-induced gut microbiota dysbiosis was significantly shifted by CAT through decreasing mainly Streptococcus and Escherichia-Shigella. Our study suggested that dietary supplemented with 2,000 mg/kg catalase was conducive to improve intestinal development and protect against LPS-induced intestinal mucosa injury via enhancing intestinal antioxidant capacity and altering microbiota composition in weaned pigs. IMPORTANCE Exogenous CAT derived from microorganisms has been widely used in food, medicine, and other industries. Recent study also found that exogenous CAT supplementation could improve growth performance and antioxidant capacity of weaned pigs. However, it is still unknown that whether dietary exogenous CAT supplementation can provide a defense against the oxidative stress-induced intestinal damage in weaned pigs. Our current study suggested that dietary supplemented with 2,000 mg/kg CAT was conducive to improve intestinal development and protect against LPS-induced intestinal mucosa injury via enhancing intestinal antioxidant capacity and altering microbiota composition in weaned pigs. Moreover, this study will also assist in developing of CAT produced by microorganisms to attenuate various oxidative stress-induced injury or diseases.

Deoxynivalenol Induces Inflammation in the Small Intestine of Weaned Rabbits by Activating Mitogen-Activated Protein Kinase Signaling.

Deoxynivalenol (DON) can activate related signaling pathways and induce gastrointestinal disorders. Based on the results of previous studies, this study tried to explore the relationship between DON-induced intestinal inflammation of weaned rabbits and the ERK-p38 signaling pathway. Forty-five weaned rabbits were divided into three treatments: control, LD and HD group. All rabbits were treated with diet containing a same nutrient content, but animals in the LD and HD groups were additionally administered DON via drinking water at 0.5 and 1.5 mg/kg b.w./d, respectively. The protocol consisted of a total feeding period of 31 days, including a pre-feeding period of 7 days. Western blotting, qRT-PCR, and immunohistochemistry were applied for analysis the expression of protein and mRNA of extracellular signal-regulated kinase (ERK), p38, double-stranded RNA-activated protein kinase (PKR), and hematopoietic cell kinase (Hck) in the duodenum, jejunum, and ileum of rabbits, as well as the distribution of positive reactants. The results proved that DON intake could enhance the levels of inflammatory factors in serum and damage the intestinal structure barrier of rabbits. Meanwhile, DON addition can stimulate the protein and mRNA expression for ERK, p38, PKR, and Hck in the intestine of rabbits, especially in the duodenum, as well as expand the distribution of positive reactants, in a dose-dependent manner.

Acetate stimulates lipogenesis via AMPKα signaling in rabbit adipose-derived stem cells.

Acetate plays an important role in host lipid metabolism. However, the regulatory network underlying acetate-regulated lipometabolism remains unclear. The aim of this study was to determine whether any cross talk occurs among adenosine 5'-monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinases (MAPKs) and acetate in regulating lipid metabolism. The compound C (an AMPK inhibitor), and SB203580 (a p38 MAPK inhibitor) were used to treat rabbit adipose-derived stem cells (ADSCs) with or without acetate, respectively. It indicated that acetate (6 mM) for 6 h increased the lipid deposition in rabbit ADSCs. Besides, acetate treatment (6 mM) increased significantly phosphorylated protein level of AMPKα and p38 MAPK, but not altered significantly the phosphorylated protein level of extracellular signaling-regulated kinase (ERK) and c-Jun aminoterminal kinase (JNK). The blocking of AMPKα signaling attenuated acetate-induced lipid accumulation, but not that of p38 MAPK signaling. In conclusion, our findings suggest that AMPKα signaling pathway is associated with acetate-induced lipogenesis.

Dietary Copper Supplementation Increases Growth Performance by Increasing Feed Intake, Digestibility, and Antioxidant Activity in Rex Rabbits.

Copper is often used as a growth promoter, at the same time copper is one of the most important essential trace elements for fur animals, especially Rex rabbits. However, too much copper added to the diet may harm animal health, and copper excreted in feces can pollute the environment. In this study, 3-month-old Rex rabbits were randomly divided into four groups and fed a basal diet containing 0, 30, 60, or 120 mg/kg Cu for 5 weeks. The diet supplemented with 30 mg/kg Cu significantly increased (P < 0.05) the average daily feed intake (ADFI) and the average daily gain (ADG) and also the activity of serum Cu-Zn (zinc) superoxide dismutase and the digestibility of ether extract. Supplemental Cu up to 120 mg/kg did not significantly adversely affect the Zn metabolism of growing Rex rabbits. Overall, the data in this study indicate that 30 mg/kg is the optimal level of Cu supplementation in the diet of growing Rex rabbits. The results will provide a reference to improve the breeding of Rex rabbits and possibly other animals. In follow-up studies, the amount of copper in the diet should be reduced as much as possible from the baseline of 30 mg/kg copper.

Comparison of Gut Microbiota and Metabolic Status of Sows With Different Litter Sizes During Pregnancy.

The experiment was conducted to compare the differences of gut microbiota and metabolic status of sows with different litter sizes on days 30 and 110 of gestation, and uncover the relationship between the composition of maternal gut microbiota during gestation and sow reproductive performance. Twenty-six Large White × Landrace crossbred multiparous sows (2nd parity) with similar back fat thickness and body weight were assigned to two groups [high-reproductive performance group (HP group) and low-reproductive performance group (LP group)] according to their litter sizes and fed a common gestation diet. Results showed that compared with LP sows, HP sows had significantly lower plasma levels of triglyceride (TG) on gestation d 30 (P < 0.05), but had significantly higher plasma levels of TG, non-esterified fatty acid, tumor necrosis factor-α, and immunoglobulin M on gestation d 110 (P < 0.05). Consistently, HP sows revealed increased alpha diversity and butyrate-producing genera, as well as fecal butyrate concentration, on gestation d 30; HP sows showed significantly different microbiota community structure with LP sows (P < 0.05) and had markedly higher abundance of Firmicutes (genera Christensenellaceae_R-7_group and Terrisporobacter) which were positively related with litter size on gestation d 110 than LP sows (P < 0.05). In addition, plasma biochemical parameters, plasma cytokines, and fecal microbiota shifted dramatically from gestation d 30 to d 110. Therefore, our findings demonstrated that microbial abundances and community structures differed significantly between sows with different litter sizes and gestation stages, which was associated with changes in plasma biochemical parameters, inflammatory factors, and immunoglobulin. Moreover, these findings revealed that there was a significant correlation between litter size and gut microbiota of sows, and provided a microbial perspective to improve sow reproductive performance in pig production.

Effects of dietary-fiber levels on RANK/RANKL/OPG expression in the appendix of weanling rabbits.

BACKGROUND/PURPOSE: The dietary fiber can regulate the intestinal mucosal immunity, and the M cell is the portal for initiating mucosal immunity. We investigated the effects of dietary fiber on the transport of Escherichia coli to assess the function of microfold (M) cells in the appendix. METHOD: A total of 150 New Zealand rabbits were fed three diets (high fiber (HF): 31.72%; control: 37.36%; low dietary fiber (LF): 41.84%; neutral detergent fiber (NDF). An infection model was established in vivo using E. coli containing green fluorescent protein as the indicator in appendix loops. Samples were collected before and after inoculation with indicator for 10, 30, or 60 min. The M cells number, differentiation-related genes and proteins were monitored by respectively using immunofluorescence, Q-PCR and Western-blot. RESULTS: The number of M cells in HF group was significantly higher than that of LF group before and at 10 min, 30 min post injection with E.coli (P < 0.01), which has an opposite at 60 min. The number of fluorescent E. coli transported across the appendix was significantly increased in the HF group (P < 0.01) compared with the LF group at 30 min (P < 0.001); expression of RANKL gene and protein levels were no difference between HF and LF group. The variation tendency of RANK, OPG genes and proteins were consistent with the change of M cell transport indicator number in different time points. CONCLUSION: Our study showed that a high-fiber diet can increase number of M cells and speed up antigen transfer under regulation of ANKL/OPG/RANK system.

Acetate Affects the Process of Lipid Metabolism in Rabbit Liver, Skeletal Muscle and Adipose Tissue.

Short-chain fatty acids (SCFAs) (a microbial fermentation production in the rabbit gut) have an important role in many physiological processes, which may be related to the reduced body fat of rabbits. In the present experiment, we study the function of acetate (a major SCFA in the rabbit gut) on fat metabolism. Ninety rabbits (40 days of age) were randomly divided into three groups: a sham control group (injection of saline for four days); a group experiencing subcutaneous injection of acetate for four days (2 g/kg BM per day, one injection each day, acetate); and a pair-fed sham treatment group. The results show that acetate-inhibited lipid accumulation by promoting lipolysis and fatty acid oxidation and inhibiting fatty acid synthesis. Activated G protein-coupled receptor 41/43, adenosine monophosphate activated protein kinase (AMPK) and extracellular-signal-regulated kinase (ERK) 1/2 signal pathways were likely to participate in the regulation in lipid accumulation of acetate. Acetate reduced hepatic triglyceride content by inhibiting fatty acid synthesis, enhancing fatty acid oxidation and lipid output. Inhibited peroxisome proliferator-activated receptor α (PPARα) and activated AMPK and ERK1/2 signal pathways were related to the process in liver. Acetate reduced intramuscular triglyceride level via increasing fatty acid uptake and fatty acid oxidation. PPARα was associated with the acetate-reduced intracellular fat content.

Dietary addition of garlic straw improved the intestinal barrier in rabbits1.

Weanling rabbits frequently exhibit diarrhea or flatulence. Our experiment was conducted to investigate the effect of garlic straw on the performance and intestinal barrier of rabbits. Hyla rabbits (60 d, n = 160) with similar body weight were divided into 4 groups (4 replicates per group and 10 rabbits per replicate): fed a basal diet (control) or fed an experimental diet with 5%, 10%, or 15% garlic straw powder supplement. The results showed that the dietary addition of garlic straw increased significantly the average daily gain and average daily feed intake. Compared with the control, dietary addition of 10% and 15% garlic straw decreased significantly the death rate of rabbit. Rabbits in 10% garlic straw group had a higher secretory immunoglobulins A and immunoglobulins G concentration in jejunum and ileum than control while lower tumor necrosis factor α (TNFα) concentration in jejunum. Compared with the control, dietary addition of 10% garlic straw increased significantly genes expression of zonula occluden protein 2 (ZO2) in jejunum and ileum and mucin4 in ileum while did not alter the genes expression of junctional adhesion molecule 2 (JAM2), JAM3, ZO1, occluding, claudin1, mucin1, mucin6, and toll-like receptor 4 in jejunum and ileum and mucin4 in jejunum. In conclusion, dietary supplement of garlic straw modulates immune responses and enhances intestinal barrier, meanwhile inhibits the synthesis of pro-inflammatory cytokine of TNFα. Besides, our experiment offers positive evidence in improving rabbit health of garlic instead of antibiotics.

The Functional Role of the 3' Untranslated Region and Poly(A) Tail of Duck Hepatitis A Virus Type 1 in Viral Replication and Regulation of IRES-Mediated Translation.

The duck hepatitis A virus type 1 (DHAV-1) is a member of Picornaviridae family, the genome of the virus contains a 5' untranslated region (5' UTR), a large open reading frame that encodes a polyprotein precursor and a 3' UTR followed by a poly(A) tail. The translation initiation of virus proteins depends on the internal ribosome-entry site (IRES) element within the 5' UTR. So far, little information is known about the role of the 3' UTR and poly(A) tail during the virus proliferation. In this study, the function of the 3' UTR and poly(A) tail of DHAV-1 in viral replication and IRES-mediated translation was investigated. The results showed that both 3' UTR and poly(A) tail are important for maintaining viral genome RNA stability and viral genome replication. During DHAV-1 proliferation, at least 20 adenines were required for the optimal genome replication and the virus replication could be severely impaired when the poly (A) tail was curtailed to 10 adenines. In addition to facilitating viral genome replication, the presence of 3' UTR and poly(A) tail significantly enhance IRES-mediated translation efficiency. Furthermore, 3' UTR or poly(A) tail could function as an individual element to enhance the DHAV-1 IRES-mediated translation, during which process, the 3' UTR exerts a greater initiation efficiency than the poly(A)25 tail.

Effect of light intensity on ovarian gene expression, reproductive performance and body weight of rabbit does.

The objective of the experiment was to find the minimum light intensity which could improve reproduction by examining its effect on ovarian gene expression, reproductive performance and body weight of rabbit does with three different light intensities: 60 (L), 80 (M), and 100 (H)lx. A total of 144 Rex-rabbits submitted to a 49-day reproductive regimen were used in this study. Ovaries were collected and relative abundance of mRNA for ovarian proteins of interest was examined with real-time PCR. Amount of protein for proteins of interest was examined by immunohistochemistry. Reproductive performance and doe bodyweight of the first three consecutive reproductive periods after initiation of the light intensity treatments were evaluated. The results provided evidence that light intensity had no effect on relative abundance of estradiol receptor-α (ER-α), follicle stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), gonadotropin releasing hormone receptor 1 (GnRHR1) and progesterone receptor (PGR) mRNA. The relative abundance of growth hormone receptor (GHR) mRNA was, however, greater in Group L than M and H (P<0.05). No difference was observed for all reproductive indices as a result of submission to the three light intensities (P>0.05). The bodyweight of the does in Group L was greater than the other two groups at first insemination, second insemination and the second postpartum period (P<0.05). There was no difference in bodyweight after the second postpartum period (P>0.05). These observations suggest that light intensity between 60 and 100lx has no effect on the reproductive performance of rabbit does, however, the amounts of GHR mRNA and growth hormone (GH) protein were affected and the greater light intensity had a negative effect on bodyweight between the time of the first insemination and the second partum period.