Effects of adding bile acids to dietary storage japonica brown rice on growth performance, meat quality, and intestinal microbiota of growing-finishing Min pigs.

Introduction: This study investigated the effects of storage japonica brown rice (SJBR) and bile acids (BA) on the growth performance, meat quality, and intestinal microbiota of growing-finishing Min pigs. Methods: A total of 24 healthy Min pigs with a similar body weight of 42.25 ± 2.13 kg were randomly divided into three groups with eight replicates of one pig each. The groups were as follows: CON (50% corn), SJBR (25% corn +25% SJBR), and SJBR + BA (25% corn +25% SJBR +0.025% hyodeoxycholic acid). The experimental period lasted from day 90 (the end of the nursery phase) to day 210 (the end of the finishing phase). Results: The results showed the following: (1) Compared with the CON group, there was no significant difference in the average daily gain (ADG) and average daily feed intake (ADFI) of the SJBR and SJBR + BA groups, and the feed conversion ratio (FCR) was significantly decreased (p < 0.05). (2) Compared with the CON group, the total protein (TP) content in the serum was significantly increased, and the blood urea nitrogen (BUN) content was significantly decreased (p < 0.05) in the SJBR and SJBR + BA groups; moreover, HDL-C was significantly higher by 35% (p < 0.05) in the SJBR + BA group. (3) There were no significant differences in carcass weight, carcass length, pH, drip loss, cooking loss, and shear force among the groups; the eye muscle area was significantly increased in the SJBR group compared with the CON group (p < 0.05); back fat thickness was significantly decreased in the SJBR + BA group compared with the SJBR group (p < 0.05); and the addition of SJBR significantly increased the mRNA expression of MyHC I in the longissimus dorsi (LD) muscle of growing-finishing Min pigs (p < 0.05). (4) The cecal bacteria were detected using 16S rDNA, and the proportion of Lactobacillus was increased gradually at the genus level, but there was no significant difference among the different groups. Conclusion: In conclusion, 25% SJBR can improve the growth performance and increase the abundance of intestinal beneficial bacteria, and based on this, adding bile acids can reduce the back fat thickness of growing-finishing Min pigs.

Integrated Microbiome and Metabolomics Analysis of the Effects of Dietary Supplementation with Corn-Steep-Liquor-Derived Candida utilis Feed on Black Pigs.

In this experiment, glucose master liquor and corn steep liquor were used as carbon and nitrogen sources, and Candida utilis was used as a strain to ferment yeast feed. The OD value and number of yeast cells were used as response values to optimize the medium components of the yeast feed through a response surface methodology. The optimal medium components were a glucose master liquor concentration of 8.3%, a corn steep liquor concentration of 1.2%, and a KH2PO4 concentration of 0.14%. Under this condition of fermentation, the OD value was 0.670 and the number of yeast cells was 2.72 × 108/mL. Then, we fed Candida utilis feed to Dongliao black piglets, and the effects of the yeast feed on the piglets' growth performance, fecal microbiota, and plasma metabolic levels were investigated through 16S rDNA sequencing and metabolomics. In total, 120 black piglets with an average initial weight of 6.90 ± 1.28 kg were randomly divided into two groups. One group was fed the basic diet (the CON group), and the other was supplemented with 2.5% Candida utilis add to the basic diet (the 2.5% CU group). After a pre-feeding period, the formal experiments were performed for 21 days. The results showed that the addition of Candida utilis to the diet did not affect growth performance compared with the control group. Meanwhile, no significant differences were observed in the serum biochemical indices. However, piglets in the 2.5% CU group had a significantly altered fecal microbiota, with an increased abundance of Clostridium_sensu_stricto_1, Lactobacillus, and Muribaculaceae_unclassified. Regarding the plasma metabolome, the 12 differential metabolites detected were mainly enriched in the histidine, tryptophan, primary bile acid, and caffeine metabolic pathways. Regarding the integrated microbiome-metabolome analysis, differential metabolites correlated with fecal flora to variable degrees, but most of them were beneficial bacteria of Firmicutes. Collectively, dietary Candida utilis feed had no adverse effect on growth performance; however, it played an important role in regulating fecal flora and maintaining metabolic levels.

Lipid-mRNA nanoparticles landscape for cancer therapy.

Intracellular delivery of message RNA (mRNA) technique has ushered in a hopeful era with the successive authorization of two mRNA vaccines for the Coronavirus disease-19 (COVID-19) pandemic. A wide range of clinical studies are proceeding and will be initiated in the foreseeable future to treat and prevent cancers. However, efficient and non-toxic delivery of therapeutic mRNAs maintains the key limited step for their widespread applications in human beings. mRNA delivery systems are in urgent demand to resolve this difficulty. Recently lipid nanoparticles (LNPs) vehicles have prospered as powerful mRNA delivery tools, enabling their potential applications in malignant tumors via cancer immunotherapy and CRISPR/Cas9-based gene editing technique. This review discusses formulation components of mRNA-LNPs, summarizes the latest findings of mRNA cancer therapy, highlights challenges, and offers directions for more effective nanotherapeutics for cancer patients.

Dietary Aronia melanocarpa Pomace Supplementation Enhances the Expression of ZO-1 and Occludin and Promotes Intestinal Development in Pigs.

A fruit juice production byproduct, Aronia melanocarpa pomace (AMP) is rich in natural polyphenol antioxidant components. The objectives of this study were to study the effects of dietary AMP supplementation on the feeding outcome and intestinal barrier function of pigs. In total, 27 growing pigs (Duroc × Landrace × Yorkshire, ~60 days, average weight of 27.77 ± 2.87 kg, males and females included at random) were randomly allotted to 3 treatment groups, with 3 repetitions per group and 3 pigs per repetition. At the experiment completion, 2 pigs (close to the average body weight of all experimental pigs) per replicate were slaughtered. The control group (CON group) was fed a basic diet, and the experimental groups were fed 4% (4% AMP group) and 8% (8% AMP group) AMP in the basic diet. These pigs were prefed for 3 days, and the formal experiments were performed for 7 weeks. The results showed that compared with the CON diet, the 4% AMP supplementation significantly increased the average daily gain of pigs (P < 0.05). Regarding intestinal development, 4% AMP significantly increased the jejunal villus height/crypt depth ratio (P < 0.05), and different AMP levels had no significant effect on the pig cecum morphology. Different AMP levels significantly decreased the relative abundance of Proteobacteria (P < 0.05). Regarding other microbial genera, 4% AMP supplementation significantly increased the levels of Lachnospira, Solobacterium, Romboutsia and other beneficial microorganisms (P < 0.05). Different AMP levels significantly decreased the relative abundances of the opportunistic pathogens Escherichia-Shigella and Pseudoscardovia (P < 0.05) and increased the contents of acetic acid and butyric acid in the pig cecal contents (P < 0.05). Compared with the CON treatment, 4% AMP supplementation significantly downregulated the jejunal gene expression of porcine proinflammatory factors (IL-1ß, IL-6, IL-8 and TNF-α) and significantly upregulated the jejunal gene expression of ZO-1, Occludin and Claudin-1 (P < 0.05). In conclusion, 4% AMP supplementation in feed is beneficial to overall pig health and growth.

Curcumin Alleviates LPS-Induced Oxidative Stress, Inflammation and Apoptosis in Bovine Mammary Epithelial Cells via the NFE2L2 Signaling Pathway.

Lipopolysaccharide (LPS) is an endotoxin, which may cause immune response and inflammation of bovine mammary glands. Mastitis impairs animal health and results in economic loss. Curcumin (CUR) is a naturally occurring diketone compound, which has attracted widespread attention as a potential anti-inflammatory antioxidant. The purpose of this study is to investigate whether CUR can reduce the damage of bovine mammary epithelial cells (MAC-T) induced by LPS and its underlying molecular mechanism. The MAC-T cell line was treated with different concentrations of LPS and CUR for 24 h. The results showed that CUR rescued the decrease of MAC-T cell viability and cell damage induced by LPS. At the same time, 10 µM CUR and 100 µg/mL LPS were used to treat the cells in the follow-up study. The results showed CUR treatment reduced the accumulation of reactive oxygen species (ROS), the expression of inflammatory cytokines (tumor necrosis factor-a (TNF-α), interleukin-8 (IL-8), IL-6 and IL-1ß) and the rate of apoptosis induced by LPS. These effects were associated with the activation of the nuclear factor E2-related factor 2 (NFE2L2)-antioxidant response element (ARE) pathway coupled with inactivation of the nuclear factor-κB (NF-κB) inflammatory and caspase/Bcl2 apoptotic pathways.

Polydatin Protects Bovine Mammary Epithelial Cells Against Zearalenone-Induced Apoptosis By Inhibiting Oxidative Responses and Endoplasmic Reticulum Stress.

Zearalenone (ZEA) is a mycotoxin of the Fusarium genus that can cause endoplasmic reticulum (ER) stress and Apoptosis in bovine mammary epithelial cells (MAC-T). Polydatin (PD), a glycoside purified from Polygonum cuspidatum, has antioxidant properties. This study aimed to explore whether PD can alleviate ZEA-induced damage on bovine mammary epithelial cells (MAC-T). We found that incasing the concentration of ZEA (0, 7.5, 15, 30, 60, 90, 120, and 240 µM) gradually decreased the cell viability. PD treatment alone at 5, 10, and 20 µM did not affect cell viability. Follow-up studies then applied 30 µM of ZEA and 5 µM of PD to treat cells; the results showed that the ZEA + PD treatment group effectively reduced cell oxidative damage compared with the ZEA treatment group. The qPCR analysis showed that ZEA treatment significantly up-regulated the expression of ER stress-related genes, relative to the control. However, adding PD significantly down-regulated the expression of ER stress-related genes. The cell apoptosis detection results showed that, compared with the ZEA treatment group, the ZEA + PD treatment group down-regulated the Bax gene and up-regulated the Bcl-2 gene expressions, which reduced the cell apoptosis rate and Caspase-3 activity. Taken together, these results indicate that PD reduces ZEA-induced apoptosis by inhibiting oxidative damage and ER stress.

Pterostilbene inhibits deoxynivalenol-induced oxidative stress and inflammatory response in bovine mammary epithelial cells.

More and more studies have showed that tricothecene mycotoxin, deoxynivalenol (DON) caused cytotoxicity in mammary alveolar cells-large T antigen cells (MAC-T). Therefore, research on reducing the cytotoxicity of DON has gradually attracted attention. In this study, we aim to explore the potential of pterostilbene (PTE) to protect MAC-T cells from DON-induced oxidative stress and inflammatory response. MAC-T cells were treated with 0.25 µg/mL DON or 2.0504 µg/mL PTE or 0.25 µg/mL DON and 2.0504 µg/mL PTE together, incubated for 9 h. PTE effectively improved cell viability, cell proliferation and total antioxidant capacity (T-AOC), reduced reactive oxygen species (ROS) production and malondialdehyde (MDA), and improved glutathione (GSH) depletion. Moreover, PTE effectively regulated the mRNA levels of nuclear factor erythroid-2-related factor 2 (Nrf2), kelch-like ech-associated protein 1 (Keap1), superoxide dismutase 1 (SOD1) and superoxide dismutase 2 (SOD2). PTE significantly inhibited nuclear factor kappa-B P65 (NF-κB P65), nuclear factor kappa-B P50 (NF-κB P50), cyclooxygenase-2 (COX-2), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and monocyte chemotactic protein 1 (MCP-1) mRNA levels in DON-induced MAC-T cells. PTE also significantly reduced inducible nitric oxide synthase (iNOS) and nitric oxide (NO) levels in DON-induced MAC-T cells. Additionally, ELISA revealed that PTE inhibited the expression of tumor necrosis factor-α (TNF-α) and IL-6 proteins produced in DON-induced MAC-T cells. These findings together provided strong evidence to support that PTE can effectively alleviate the damage to cells caused by DON, and it may be used as an effective anti-inflammatory and antioxidant to prevent the damage of mycotoxins to the animal body.

Effects of dietary grape pomace on the intestinal microbiota and growth performance of weaned piglets.

Grape pomace (GP) is an abundant by-product from wine production and is rich in phenolic compounds, unsaturated fatty acids, dietary fibre and beneficial bacteria. In this study, weaned piglets were fed a basic diet supplemented with 5% GP for 4 weeks. Compared with those in the control (CON) group, it was found that the proportion of Lactobacillus delbrueckii, Olsenella umbonata and Selenomonas bovis in the caecum and the villus height and villus height/crypt depth ratio (VCR) of the jejunum were both significantly increased in the GP group (p < 0.05). Meanwhile, at the mRNA expression level, several proinflammatory cytokines (IL-1ß, IL-8, IL-6 and TNF-α) were significantly downregulated (p < 0.05) in piglet caecal tissue, and the short-chain fatty acid receptors (GPR41 and GPR43) were not significantly upregulated. In contrast, the levels of IgG was significantly increased (p < 0.05) in the sera of weaned piglets in the GP group. However, no difference in growth performance between the two groups of piglets was detected. These results show that GP had no adverse effects on the growth performance of piglets, but GP can promote the content of some beneficial bacteria in the caecum; this effect is conducive to improving the disease resistance potential of piglets.

Transcriptional profiling of zearalenone-induced inhibition of IPEC-J2 cell proliferation.

Mounting evidence has shown that zearalenone (ZEA) can have toxic effects on the intestinal epithelial cells (IECs) of mammals and humans, but the mechanism of ZEA-induced toxicity on IECs is unclear. The aim of this study was to reveal the mechanism of action of ZEA on intestinal epithelial cells via RNA-seq technology. We measured the effects of ZEA on the viability and lactate dehydrogenase (LDH) activity of the pig intestinal epithelial cell line J2 (IPEC-J2). The results showed ZEA can decrease the IPEC-J2 cell viability and increase LDH activity. Appropriate treatment concentrations were determined (40 µM ZEA) to study the toxic effect of ZEA on IPEC-J2. The results showed that 40 µM ZEA significantly inhibited IPEC-J2 proliferation and arrested the cell cycle at the G2/M phase. A total of 783 differentially expressed genes (DEGs) were identified after ZEA treatment. KEGG pathway analysis revealed that PERK regulates gene expression, Toll-like receptor cascades signaling pathway, mitosis, mitotic metaphase and anaphase, DNA replication and G2/M checkpoints, were involved in the cell cycle pathway. Eleven key genes involved in G2/M checkpoints were validated by qPCR. Thus, these data highlighted that ZEA caused abnormalities in the G2/M transition in IPEC-J2 cells by altering the cell cycle signaling pathway, thereby inhibiting cell proliferation and inducing injury in IECs. And the study will contribute to get the molecular mechanisms of ZEA inhibition of IECs cell proliferation.

Zearalenone induces apoptosis in bovine mammary epithelial cells by activating endoplasmic reticulum stress.

Zearalenone (ZEA) is a common mycotoxin produced by fungi within the genus Fusarium. However, few studies have examined the direct effects of the toxin on the mammary glands. In the present study, the effects of ZEA treatment on bovine mammary epithelial cells (MAC-T) from dairy cows were investigated. The cells were treated with different concentrations of ZEA to evaluate the effect of the toxin on cell viability, intracellular reactive oxygen species (ROS) concentrations, mitochondrial membrane potential, endoplasmic reticulum (ER) stress, and the expression of apoptosis-related genes. The results indicated that different concentrations (5, 10, 15, 20, 25, 30, 50, 60, or 100 µM) of ZEA were able to inhibit growth of MAC-T cells. After exposing the MAC-T cells to 30 µM ZEA, compared with the control group, ROS levels increased, mitochondrial membrane potential decreased, and mRNA expression of the ER-specific stress-related genes GRP78, HSP70, ATF6, EIF2A, ASK1, and CHOP was upregulated in the ZEA-treated group. Further, we analyzed the increase in apoptotic rate by flow cytometry. At the mRNA level, compared with the control group, the expression of the apoptosis-promoting gene BAX was increased in the ZEA-treated group, the expression of the inhibitory gene BCL2 decreased, and the expression of the gene CASP3 increased. We observed a significant increase in caspase-3 activity in ZEA-treated MAC-T cells. Furthermore, the apoptotic rate of the cells in the ZEA group treated with 4-phenylbutyric acid (ER stress inhibitor) decreased and the mRNA expression levels of ER stress markers GRP78 and CHOP decreased. Compared with the ZEA treatment group, the mRNA expression level of the apoptosis-related gene BAX was decreased and the expression level of BCL2 was increased in the ZEA + 4-phenylbutyric acid cotreatment group. These findings indicate that ZEA-induced ER stress increases apoptosis in MAC-T cells. The treatment of MAC-T cells with ZEA reduced cell viability, increased ROS content, decreased mitochondrial membrane potential, increased ER stress marker expression, and induced apoptosis.

Deoxynivalenol induces oxidative stress, inflammatory response and apoptosis in bovine mammary epithelial cells.

Deoxynivalenol (DON) is a toxic secondary metabolite produced by Fusarium graminearum. It is one of the most common feed contaminants that poses a serious threat to the health and performance of dairy cows. This study investigated the in vitro cytotoxicity of DON on bovine mammary epithelial cells (MAC-T). DON at different concentrations (0.25, 0.3, 0.5, 0.8, 1 or 2 µg/ml) inhibited the growth of MAC-T cells after 24 hr of exposure (p < .001). DON at 0.25 µg/ml increased lactate dehydrogenase (LDH) leakage (p < .05); decreased glutathione (GSH) levels (p < .001), total superoxide dismutase (T-SOD) activity and total antioxidant capacity (T-AOC; p < .01); and increased malondialdehyde (MDA) concentration (p < .01) in MAC-T cells after 24 hr of exposure. We also observed that DON increased reactive oxygen species (ROS) levels in cells incubated for 9, 15 and 24 hr (p < .001). DON at 0.25 µg/ml triggered oxidative damage in MAC-T cells. Furthermore, it induced an inflammatory response in the cells incubated for 9, 15 and 24 hr (p < .05) by increasing the mRNA expression levels of nuclear factor kappa B, myeloid differentiation factor 88 (MyD88), tumour necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6, cyclooxygenase-2 and IL-8. We further examined the effect of DON on apoptosis. DON prevented normal proliferation of MAC-T cells by blocked cell cycle progression in 24 hr (p < .001). In addition, the apoptosis rate measured using annexin V-FITC significantly increased (p < .05) with increase in the mRNA expression level of Bax (p < .01) and increase in the Bax/Bcl-2 ratio (p < .01) in cells incubated for 24 hr. In summary, DON exerts toxic effects in MAC-T cells by causing oxidative stress, inducing an inflammatory response, affecting cell cycle and leading to apoptosis.

Resveratrol inhibits aflatoxin B1-induced oxidative stress and apoptosis in bovine mammary epithelial cells and is involved the Nrf2 signaling pathway.

Aflatoxins are widely occurring food contaminants that are particularly harmful to dairy products and cows. The plant polyphenol resveratrol has been reported to have a good effect on increasing the resistance of cells toward toxins. Therefore, we measured the effects of aflatoxin B1 and resveratrol on the viability of the MAC-T cow mammary epithelial cell line. The appropriate treatment concentrations were assayed (12.81 µM aflatoxin B1 and 43.81 µM resveratrol) to verify the protective effect of resveratrol toward mammary epithelial cells. The results showed that resveratrol alleviates aflatoxin B1-induced cytotoxicity, including the increase in ROS and the decrease in mitochondrial membrane potential (MMP) and apoptosis in MAC-T cells. The expression of mRNA transcripts (including Nrf2, Keap1, NQO1, HO-1, SOD2 and HSP70) for components of the Nrf2 signaling pathway was evaluated by real-time fluorescent quantitative PCR, with resveratrol also exhibiting a good regulatory effect. Thus, resveratrol was shown to have an ameliorating effect on aflatoxin toxicity in MAC-T cells.

The Modification and Design of Antimicrobial Peptide.

The antimicrobial peptides (AMPs) are a group of unique naturally occurring anti-microbial compounds with around 50 amino acids. It represents promising therapeutic agents to the infectious disease without concerning about drug resistance. However, commercial development of these peptides for even the simplest application has been hindered by the limitations of sources, instability, toxicity and bioavailability. To improve the properties of the artificial synthesized AMPs, the modification and design are the hotspots of the AMPs research. In fact, more than half of the known AMPs are naturally modified. In this review, two types of modification strategies, biochemical modification and chemical modification were summarized. Although, the chemical modification is versatile and direct, the manufacturing cost is greatly increased compared to the antibiotics. With the recent progress of the protein modification enzyme, the biochemical modification of the antimicrobial peptide followed by heterologous expression has great application prospects.

Identification and characterization of the cDNA sequence encoding amelogenin in rabbit (Oryctolagus cuniculus).

Amelogenins, the most abundant proteins in tooth enamel extracellular matrix (ECM), are essential for tooth amelogenesis. The nucleotide sequence of amelogenin gene (AMEL) for rabbit, as an important member of mammals and good continuously growing incisor model, is important for comparative and evolutional study. Previous studies about rabbit amelogenin proteins got no consensus yet even as to their existence or size. In this study, with combined usage of in silico and molecular cloning technologies, we identified sequences of two transcripts of rabbit amelogenin, resulting from the alternative splicing of the 45-bp exon 4. The coding regions of the two transcripts are of 567- and 522-bp, encoding 188 and 173 amino acids including a 17-residue signal peptide, respectively. Sequence analysis revealed that rabbit amelogenin features in extremely high GC-content in nucleotide sequence and Alanine content in protein sequence. Detailed comparison of amino acid sequence with other mammals showed that the rabbit amelogenin protein is conserved in the sites and regions important for protein functions. Overall, our results uncovered the mysteries about rabbit amelogenin and revealed its sequence peculiarities.

Depressed hippocampal MEK/ERK phosphorylation correlates with impaired cognitive and synaptic function in zinc-deficient rats.

An experiment was performed to observe changes of mitogen-activated protein kinase ERK (MEK)/extracellular signal-regulated kinase (ERK) signaling pathways in the hippocampus of zinc-deficient (ZD) rats and the correlation with cognitive dysfunction. Forty-four male weanling Wistar rats were randomly assigned to ZD (n = 22) and control (pair-fed, n = 22) groups. After a 4-week treatment, Y-maze was used to test the spatial memory of the rats. The long-term potentiation (LTP) in rat hippocampal dentate gyrus was observed simultaneously. pMEK, pERK1/2, and pCREB protein levels were examined by Western blot assays. The results demonstrated that the latency period in Y-maze was significantly shorter for the ZD rats. LTP amplitude in the ZD group decreased significantly compared with the control group. pMEK, pERK1/2, and pCREB protein expression of hippocampus in the ZD group decreased significantly. The results implicated a possibility that zinc deficiency-induced cognitive and synaptic impairment may be relevant to the MEK/ERK signaling pathway.

Identification and characterization of myeloma-associated antigens in Trichinella spiralis.

To investigate the presence of myeloma-associated antigens in Trichinella spiralis and their anti-tumor effect, cross-immune responses between antigens of the myeloma cell SP2/0 versus positive sera to T. spiralis, and antigens of T. spiralis versus positive sera to myeloma cell SP2/0 were determined using T. spiralis and myeloma specific enzyme-linked immunosorbent assays (ELISA). The myeloma-associated antigens in T. spiralis were separated by ultrafiltration and 2-D electrophoresis, and the amino acid sequences and molecular weights were determined by spectrometry. An obvious reaction was found between a 33 kDa antigen and positive sera, and the major component of the antigen was tropomyosin (TM), which is an surface acidic protein with 284 amino acids. Mice were immunized with TM to determine the anti-tumor effect in vivo. The results showed that CD4(+), CD8(+) T lymphocyte, and CD19(+) B lymphocyte were significantly increased (P<0.05). The anti-tumor effects were significantly different between mice immunized with the antigens or adjuvant alone (P<0.05), while the difference between mice immunized with antigens and whole T. spiralis was not significant (P>0.05). The results indicated that TM identified in this study may play a role in eliciting cross-protective immunity.

Proteomic analysis reveals changes in the hippocampus protein pattern of rats exposed to dietary zinc deficiency.

An experiment was performed to observe protein changes in the hippocampus of zinc-deficient (ZD) rats. Twenty-four male weanling Wistar rats were randomly assigned to ZD (n=12) and control groups (n=12). After 4-wk treatment, we used 2-DE and MALDI-TOF-MS to analyze the proteomes of hippocampus in the two groups. One of the important differential proteins, ubiquitin C-terminal hydrolase L1 (Uch-L1), was confirmed by Western blot assays. The results demonstrated that compared with the controls, ZD rats had significantly reduced plasma zinc concentration and alkaline phosphatase activity. The latency period in passive avoidance performance was also significantly shorter for the ZD rats. Nine proteins were differentially expressed between the two groups. Eight of them were identified. Tubulin beta chain and voltage-dependent anion channel 1 were upregulated, while mitochondrial aldehyde dehydrogenase, alpha-enolase, dimethylarginine dimethylaminohydrolase 1, F-actin capping protein alpha-2 subunit, pyruvate dehydrogenase beta and Uch-L1 were downregulated, respectively. Importantly, some of the identified proteins (e.g. Uch-L1) are known to be involved in cognitive impairment. Western blot analysis of hippocampus Uch-L1 expression confirmed the proteomic findings. The data indicated that there may be common mechanisms or pathways in cognitive dysfunction between neurodegenerative diseases and zinc deficiency.

Depletion of intracellular zinc down-regulates expression of Uch-L1 mRNA and protein, and CREB mRNA in cultured hippocampal neurons.

Zinc deficiency has been associated with impaired learning and memory function in animals and human beings. However, the molecular mechanisms remain obscure. In light of evidence that ubiquitin C-terminal hydrolase L1 (Uch-L1) and cAMP-responsive element-binding protein (CREB) are required for synaptic and memory function and the possible regulation of CREB by Uch-L1, this present study was conducted to investigate the effect of zinc depletion on Uch-L1 protein expression and on Uch-L1 and CREB mRNA expression in cultured hippocampal neurons. Cultured hippocampal neurons were exposed to a cell membrane-permeant zinc chelator TPEN (2 microM), and to TPEN plus zinc sulphate (5 microM) for 24 h. Cultures were then processed to detect neuronal injury by lactate dehydrogenase (LDH) assay, Uch-L1 protein levels by Western blot, and Uch-L1 and CREB mRNAs levels by RT-PCR. The LDH release rate in TPEN-incubated neurons was notably increased compared to non-treated controls. Significant down-regulation of Uch-L1 protein level and mRNA levels for Uch-L1 and CREB were observed in TPEN-treated neurons. Co-addition of zinc almost completely reversed TPEN-induced neuronal injury and the alterations in Uch-L1 and CREB expression. The results demonstrated that zinc modulated the expression of Uch-L1 and CREB at the protein and/or transcription levels in hippocampal neurons, which implies that down-regulation of both Uch-L1 and CREB might participate in memory dysfunction induced by zinc deficiency.

[A survey on serum homocysteine levels and cognitive function of the middle-aged and elderly persons in Tianjin city].

OBJECTIVE: To explore the serum homocysteine levels and cognitive function status of the middle-aged and elderly persons in Tianjin city in order to provide fundamental data for the nutritional intervention trial. METHODS: The subjects between the ages of 55 and 94 years were randomly recruited in the study. The cognitive function of the subjects were evaluated by the Mini Mental State Examination (MMSE), and then screened the subjects with cognitive impairment (CI). Total homocysteine (tHcy) levels in fasting serum were measured by enzyme transition method, the correlation between tHcy levels and the cognitive function were statistically analyzed. RESULTS: The mean of serum tHcy levels were (15.95 +/- 7.29) micromol/L, the prevalence of hyperhomocysteinemia (HHE) was 45.4%; and man had a higher rates than woman ( P < 0.001); the mean MMSE scores were (26.74 +/- 2.71) points, the prevalence of CI was 26.0%, and there were no significant differences between man and woman in CI prevalence. Cognitive function status was positively correlated with education and negatively correlated with age. CONCLUSION: It was remarkable that higher prevalence of HHE and CI existed in the middle-aged and elderly persons.

[Changes of cognition and micronutrient levels in rats treated by beta amyloid protein].

OBJECTIVE: To observe the changes of the cognition and micronutrient level in rats treated by beta amyloid protein. METHODS: Thirty male Sprague-Dawley rats were randomly divided into control group, beta amyloid group (Abeta) and saline group. The rats were injected Abeta and saline by bilateral intrahippocampus (10 microg per lateral) in Abeta group and saline group separately. The experiment lasted 2 weeks.The cognition was identified by water maze and step through test. The contents of serum micronutrients were examined by atomic absorption spectrometry and fluorescence spectrometry. RESULTS: Declined cognition and prolonged latency were observed in Abeta group. The contents of serum vitamin C and iron in Abeta group were significantly lower than those of the control group and saline group (P < 0.05). There was no significant difference among the three groups in other indicators. CONCLUSION: It was seemed that impaired cognition and decreases of serum vitamin C and iron level could be observed in rats treated by beta amyloid protein.