[Methylation detection of phosphatase and tensin homolog deleted on chromosome ten gene promoter in hepatocellular carcinoma samples by next-generation sequencing].

Objective: The purpose of this study is to use the next-generation sequencing (NGS) technology platform to detect the methylation rate of phosphatase and tensin homolog deleted on chromosome ten (PTEN) promoter region in hepatocellular carcinoma (HCC) tissue samples, and to analyze the clinical significance of its correlation with the prognosis of patients receiving sorafenib treatment. Methods: The 52 pairs of tumor tissue and para-cancerous tissue samples from HCC patients treated with sorafenib alone, which were collected and preserved in the Liver Tumor Diagnosis and Research Center of the former 302 Hospital of the People's Liberation Army by the National Natural Science Foundation of China Youth Project with the project batch number 81702986 in 2018, were extracted total DNA from the samples. Then the DNA samples were treated with bisulfite and specific primers were designed to amplify the PTEN promoter region. Finally, the amplified products were analyzed by second-generation sequencing. In the analysis of clinical significance of PTEN methylation, log-rank statistical analysis was used to calculate whether there was a statistical difference in survival between the patient groups. Results: The methylation rate of PTEN promoter region in tumor tissues (29.17%±9.58%) was significantly higher than that in paracancer tissues (4.17%±2.86%)(t=19.970,P<0.05). At the same time, in HCC tissues, the methylation rate of the PTEN promoter region is negatively correlated with its expression (F=47.270,P<0.000 1;Y=-1 800×X+38.03), and the PTEN methylation rate is negatively correlated with the prognosis of patients receiving the molecularly targeted drug Sorafenib (χ²=4.313,P<0.05). Conclusion: This study successfully established a new method for detecting methylation in the promoter region of PTEN, and the methylation rate of PTEN can be used as one of the targets of HCC diagnosis and targeted therapy.

[Application value of urinary IGFBP7 and TIMP-2 in acute kidney injury with decompensated hepatitis B virus-related liver cirrhosis].

Objective: To investigate the application value of new urinary biomarkers insulin-like growth factor binding protein 7 (IGFBP7) and tissue matrix metalloproteinase inhibitor-2 (TIMP-2) in acute kidney injury with decompensated hepatitis B virus-related liver cirrhosis. Methods: 45 newly hospitalized cases with decompensated hepatitis B virus-related liver cirrhosis were selected. Among them, 19 cases were combined with AKI on admission (cirrhosis-AKI group), 26 cases without AKI (cirrhosis-non-AKI group), and 12 healthy cases (normal control group). First-morning urine samples were collected and IGFBP7 and TIMP-2 were detected by enzyme-linked immunosorbent assay (ELISA). Urinary IGFBP7 and serum creatinine (SCr) were dynamically monitored after hospitalization in cirrhosis-non-AKI group. Normally distributed measurement data were compared by t-test, and non-normally distributed measurement data were compared by rank sum test. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the diagnostic accuracy of the indicators. Results: Urinary IGFBP7, IGFBP7 with TIMP-2 (IGFBP7×TIMP-2) in cirrhosis-AKI group (n = 19) were equally higher than that of the cirrhosis-non-AKI group (P < 0.05). Urinary IGFBP7, TIMP-2 and IGFBP7×TIMP-2 in cirrhosis-AKI group or cirrhosis-non-AKI group were significantly higher than those of the normal control group (P < 0.01). The AUC of urinary IGFBP7 and urinary IGFBP7×TIMP-2 for diagnosis of AKI were 0.703 (95% CI 0.547-0.860) and 0.700 (95% CI 0.541-0.859), respectively. In the liver cirrhosis-non-AKI group (n = 26), 5 cases of AKI were newly diagnosed according to the changes in SCr during hospitalization (progressive group). Urinary IGFBP7 was significantly increased 2 days before the diagnosis of AKI. The concentration of urinary IGFBP7 at admission in the progressive group (n = 5) was higher than that of the non-progressive group (n = 21) (P < 0.05). Conclusion: Urinary IGFBP7 and TIMP-2 concentrations were significantly increased in patients with decompensated hepatitis B virus-related liver cirrhosis. When AKI occurred, urinary IGFBP7 and IGFBP7×TIMP-2 was further increased. Urinary IGFBP7 is valuable for early AKI diagnosis, and may play a role in predicting AKI occurrence.

FAM196B acts as oncogene and promotes proliferation of gastric cancer cells through AKT signaling pathway.

Gastric cancer (GC) is the second leading cause of cancer-related deaths worldwide, but the mechanisms remain unknown. Here we report that family with sequence similarity 196 member B (FAM196B) is highly expressed in primary GC tissues and the expression level is correlated with the clinicopathologic characteristics of GC. In this experiment, knockdown of FAM196B suppressed GC cell proliferation and induced G1/G0 to S phase cell cycle arrest by regulating Cyclin D1, Cyclin A and CDK2 expressions. Furthermore, we investigated the molecular mechanism of FAM196B action in GC. The results showed that knockdown of FAM196B inhibited the activation of AKT signaling pathway. We further revealed that activating of AKT rescued the effect of FAM196B knockdown on cell proliferation and drove cell re-enter into the S phase of the cell cycle with SC79 (a AKT activator). Our findings demonstrated that FAM196B may promote GC cell proliferation by activating AKT signaling pathway. Taken together, this study provides a new evidence that FAM196B functions as a novel oncogene and could be a potential therapeutic target in therapy of GC.

Association between matrix metallopeptidase 1 and type 2 diabetes mellitus coexisting with coronary heart disease in a Han Chinese population.

Matrix metallopeptidase 1 (MMP-1) has been reported to be involved in the coexistence of type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). We sought to examine the association between the MMP-1 gene polymorphism and coexistence of T2DM and CHD in a Han Chinese population. We extracted genomic DNA from the peripheral blood of 794 subjects, including 378 patients with coexisting T2DM and CHD and 416 healthy controls. We selected several single nucleotide polymorphisms of the MMP-1 gene and genotyped them using the MassARRAY system, before analyzing the data with Haploview 4.0 and SPSS 20.0. A statistical difference was found in the distribution of rs1799750 genotypes between the patient and control groups (P = 0.041). The frequency of the 2G/2G genotype was 44.25 and 37.0% among patients and control subjects, respectively. Moreover, the frequency of the 2G allele was 65.9% among patients and 59.6% in the control group, and this difference was found to be significant (P = 0.010). Elevated body mass index was also associated with the 2G/2G genotype. Thus, MMP-1 rs1799750 may be involved in the development of coexisting T2DM and CHD in the Han Chinese population.

Comparisons of different myosin heavy chain types, AMPK, and PGC-1α gene expression in the longissimus dorsi muscles in Bama Xiang and Landrace pigs.

Bama Xiang and Landrace pigs are the local fatty and lean breeds, respectively, in China. We compared differences in carcass traits, meat quality traits, and myosin heavy chain (MyHC) types in the longissimus dorsi muscles between Bama Xiang and Landrace pigs. This was done in pigs of the same age, using real-time PCR, to investigate the relationship between MyHC fiber types and carcass characteristics, meat quality traits, and the key factors regulating muscle fiber type. Bama Xiang pigs exhibited smaller size and slower growth than Landrace pigs (P < 0.01). We found that the superior meat quality, especially the high intramuscular fat (IMF) content in Bama Xiang pig, was related to elevated type I oxidative muscle fiber content (P < 0.01). In contrast, Landrace pig muscle had a higher glycolytic type IIb muscle fiber content (P < 0.01). MyHC I gene expression was significantly positively correlated with backfat thickness and IMF content (P < 0.01). MyHC IIb was significantly negatively correlated with IMF content (P < 0.05), and positively correlated with carcass yield (P < 0.05). AMP-activated protein kinase and peroxisome proliferator-activated receptor-g coactivator-1a are suggested to be the two key factors regulating muscle fiber type in pigs. Our results indicate that muscle fiber composition is one of the key differences leading to the differences of meat quality between Bama Xiang and Landrace pigs. These results may provide a theoretical basis for further studies of the molecular mechanism underlying the excellent meat quality of the Bama Xiang pig.

Gene expression and enzyme activity of lipoprotein lipase correlate with intramuscular fat content in Guangxi san-huang and Arbor Acres chickens.

Lipoprotein lipase (LPL) is a key enzyme in lipid metabolism. This study investigated LPL gene expression, LPL enzyme activity, and the correlation of each with intramuscular fat (IMF) in Chinese Guangxi san-huang (GXSH) and Arbor Acres (AA) chickens. The results showed that age and breed had significant effects on LPL expression and enzyme activity. Correlation analyses showed significant positive correlations between LPL expression levels and IMF contents in the breast and thigh tissues of both GXSH (r = 0.712, P = 0.001; r = 0.792, P < 0.001, respectively) and AA (r = 0.644, P < 0.001; r = 0.545, P < 0.001, respectively) chickens. The results also indicated a significant positive correlation between LPL enzyme activity and IMF contents in the breast and thigh tissues of both GXSH (r = 0.615, P = 0.001; r = 0.685, P < 0.001, respectively) and AA (r = 0.600, P = 0.001; r = 0.528, P = 0.003, respectively) chickens. The results indicated that the LPL gene was significantly correlated with IMF in these two breeds. The results presented here could contribute to knowledge of LPL mRNA developmental expression patterns and enzyme activity, and it could facilitate further research on the molecular mechanisms underlying IMF deposition in chickens.

Qualitative Analyses of Protein Phosphorylation in Bovine Pluripotent Stem Cells Generated from Embryonic Fibroblasts.

Pluripotent stem cells (PSCs) generated from somatic cells via ectopic expression of specific transcription factors provide an unlimited cell resource for regenerative medicine and transgenic breeding. Here, we describe the successful generation of bovine induced PSCs (biPSCs) from foetal fibroblasts by lentivirus-mediated delivery of bovine pluripotency reprogramming factors (PRFs) OCT3/4, SOX2, KLF4, c-MYC, NANOG and LIN28. The generated biPSCs resembled embryonic stem cells (ESCs) in their gene expression profiles, self-renewal capabilities and proliferation, as well as maintenance of a normal karyotype and differentiation into diverse cell types of all three germ layers both in vitro and in vivo. Qualitative phosphoproteomics of biPSCs revealed a large number of phosphorylated proteins, which might be related to the control of biPSCs status. The successful generation of biPSCs and the analysis of their phosphoproteome would further our understanding of the epigenetic mechanisms underlying iPSC pluripotency, thus promoting their application in bovine transgenic breeding and marking avenues for future research.

Complete mitochondrial genome of the Cyclemys dentata and phylogenetic analysis of the major family Geoemydidae.

In the present study, the complete mitochondrial (mt) genome of Cyclemys dentata was determined using PCR reactions. The structural organization and gene order of C. dentata were equivalent to those of most other vertebrates. The mt genome was 16,489 bp in length, has rich A+T content, consisting of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region (D-loop). All protein-coding genes started with ATG, many genes have complete stop codons, except ND2, COX3, ND3, and cyt-b genes had incomplete stop codons of T. The light-strand replication origin (OL) of C. dentata might fold into a stable stem-loop secondary structure, and its loop had 2 nt less than that of the Cyclemys atripons OL sequence. The D-Loop of C. dentata contained a central domain (CD), 2 extended termination associated sequences (ETAS1, ETAS2) and 3 conserved sequence blocks (CSB1, CSB2, CSB3). The average length of 20 turtles' mt genomes was 16,692.5 bp, including 34.1% A, 27.0% T, 26.0% C and 12.9% G. The C. dentata mitochondrial genome could provide useful data for further studies on phylogenetics and conservation genetics of this species. The phylogenetic relationships of the family Geoemydidae were analyzed by maximum-likelihood (ML) and neighbor-joining (NJ) based on concatenated sequences of 13 protein-coding genes from 20 turtle species. The ML and NJ trees had homologous topologies. The results support the existing classification of the genera of Geoemydidae, that C. dentata was a sister species of C. atripons, Pyxidea nested in Cuora, and Chinemys was synonymous with Mauremys.

Decorin-induced proliferation of avian myoblasts involves the myostatin/Smad signaling pathway.

Decorin, a small leucine-rich proteoglycan as a component of the extracellular matrix, plays an important role in the skeletal muscle development. It has been reported that decorin promoted proliferation and differentiation of muscle cells by restraining myostatin activity in rodents. However, the effects and mechanisms of decorin on avian myoblast proliferation are not understood clearly. Thus, in our research, decorin overexpressing and knocking-down quail myoblast-7 (QM7) myoblasts were established to explore the effects of decorin on avian myoblast proliferation by flow cytometry. The results showed that overexpression of decorin enhanced the proliferation of QM7 myoblasts, which was accompanied by the upregulation of follistatin and primary muscle regulatory factors (i.e., myogenic factor 5, myogenic factor 1, myogenin), and downregulation of myostatin expression, as well as the decreased phosphorylation level of SMAD family member 3 (Smad3). In line with expectations, decorin RNAi displayed an opposite effect on the proliferation and gene expression pattern of QM7 cells. In conclusion, our in vitro studies suggested the decorin-mediated myostatin/Smad signaling pathway might be involved in the regulation of avian myoblast proliferation.

Effects of dietary thiazolidinedione supplementation on growth performance, intramuscular fat and related genes mRNA abundance in the longissimus dorsi muscle of finishing pigs.

The objective of this study was to investigate the effect of dietary supplementation with thiazolidinedione (TZD) on growth performance and meat quality of finishing pigs. In Experiment 1, 80 castrated finishing pigs (Large White×Landrace, BW = 54.34 kg) were randomly assigned to 2 treatments with 5 replicates of 8 pigs each. The experimental pigs in the 2 groups were respectively fed with a diet with or without a TZD supplementation (15 mg/kg). In Experiment 2, 80 castrated finishing pigs (Large White×Landrace, BW = 71.46 kg) were divided into 2 treatments as designed in Experiment 1, moreover, carcass evaluations were performed. The results from Experiment 1 showed that TZD supplementation could significantly decreased the average daily feed intake (ADFI) (p<0.05) during 0 to 28 d, without impairing the average daily gain (ADG) (p>0.05). In Experiment 2, the ADG was significantly increased by TZD supplementation during 14 to 28 d and 0 to 28 d (p<0.05) and the feed:gain ratio (F:G) was significantly decreased by TZD supplementation during 0 to 28 d (p<0.05). Compared with the control group, TZD group had significantly higher serum triglyceride (TG) concentration at 28h and serum high-density lipoprotein (HDL) levels at 14 d (p<0.05). Moreover, there was an apparent improvement in the marbling score (p<0.10) and intramuscular fat (IMF) content (p<0.10) of the longissimus dorsi muscle in pigs treated by TZD supplementation. Real-time RT-PCR analyses demonstrated that pigs of TZD group had higher mRNA abundance of PPARγ coactivator 1 (PGC-1) (p<0.05) and fatty acid-binding protein 3 (FABP3) (p<0.05) than pigs of control group. Taken together, these results suggested that dietary TZD supplementation could improve growth performance and increase the IMF content of finishing pigs through regulating the serum parameters and genes mRNA abundance involved in fat metabolism.

Effects of dietary lysine levels on apparent nutrient digestibility and serum amino Acid absorption mode in growing pigs.

Two experiments were conducted to determine the effects of different dietary lysine levels on the apparent nutrient digestibility, the serum amino acid (AA) concentration, and the biochemical parameters of the precaval and portal vein blood in growing pigs. In Experiment 1, 15 noncannulated pigs received diets with different lysine densities (0.65%, 0.95%, and 1.25% lysine) for 13 d. A total collection digestion test was performed, and blood samples were collected from the precaval vein at the end of the experiment. In Experiment 2, four cannulated pigs were fed the same diets of Experiment 1. The experiment used a self-control experimental design and was divided into three periods. On d 5 of each period, at 0.5 h before feeding and hourly up to 8 h after feeding, single blood samples were collected from catheters placed in the portal vein. In Experiment 1, some serum AAs (including lysine), serum urinary nitrogen (SUN), and total protein (TP) concentrations were significantly affected by the dietary lysine levels (p<0.05). Moreover, the 0.65% lysine treatment showed a significant lower apparent digestibility of gross energy, dry matter, crude protein, and phosphorus than the other treatments (p<0.05). In Experiment 2, serum lysine, histidine, phenylalanine, threonine, valine, isoleucine (p = 0.0588), triglyceride, and SUN (p = 0.0572) concentrations were significantly affected by the dietary lysine levels (p<0.05). Additionally, almost all of the determined serum AA and total AA concentrations reached their lowest values at 0.5 h before feeding and their highest values at 2 h after feeding (p<0.05). These findings indicate that the greatest absorption of AA occurred at 2 h after feeding and that the dynamic profile of serum AA is affected by the dietary lysine levels. Moreover, when the dietary lysine content was 0.95%, the growing pigs achieved a better nutrient digestibility and serum metabolites levels.

Active immunization of fatty acid translocase specifically decreased visceral fat deposition in male broilers.

Lipid accumulation of avian adipocytes is mainly dependent upon the fatty acid transmembrane uptake process mediated by membrane proteins, such as fatty acid translocase (FAT/CD36), fatty acid transport protein 1, and caveolin-2. To examine the effects of FAT/CD36 on spatial-specific fat deposition, 60 broiler chickens were randomly allocated to 2 groups by sex. Each male or female group contained 2 subgroups (n = 14-15) inoculated by intramuscular injection with chicken FAT/CD36 or BSA (control) immunogens at 34, 49, and 63 d. The subcutaneous and visceral fat deposits were measured, as were levels of plasma triglyceride and free fatty acid. Serum antibody titer was measured by ELISA. The mRNA expression levels of fatty acid transport-related genes in the adipose tissue of the male broilers were investigated to reveal the relationships among various fatty acid transporters. The results showed that active immunization with FAT/CD36 could significantly decrease the visceral fat of the male broilers by up to 40%, but it had no effect on subcutaneous fat stores of male broilers or on either site of fat deposition in female broilers. The concentration of plasma free fatty acids increased in the experimental groups for both male and female broilers. After the FAT/CD36 immunization, very low density lipoprotein receptor mRNA expression was upregulated in both the subcutaneous and visceral fat of male broilers, whereas peroxisome proliferator-activated receptor γ, FAT/CD36, and acyl-CoA binding protein mRNA expression levels were upregulated only in the visceral fat of male broilers. These results indicated a novel role of chicken FAT/CD36 in fat deposition, with sex- and spatial-specific effects.

Stability of the spreading in small-world network with predictive controller.

In this Letter, we apply the predictive control strategy to suppress the propagation of diseases or viruses in small-world network. The stability of small-world spreading model with predictive controller is investigated. The sufficient and necessary stability condition is given, which is closely related to the controller parameters and small-world rewiring probability p. Our simulations discover a phenomenon that, with the fixed predictive controller parameters, the spreading dynamics become more and more stable when p decreases from a larger value to a smaller one, and the suitable controller parameters can effectively suppress the spreading behaviors even when p varies within the whole spectrum, and the unsuitable controller parameters can lead to oscillation when p lies within a certain range.

Identification and gene expression of porcine fatty acid transport protein 1 isoforms.

Fatty acid transport protein 1 (FATP-1) is a membrane associated protein, which facilitates the long chain fatty acids (LCFA) transport across the plasma membrane for the LCFA utilization and storage. In this study, the cDNA structure of porcine FATP-1 was investigated and the gene expression patterns of porcine FATP-1 in different tissues were tested by RT-PCR and Southern blot analysis. The results showed that there were five pFATP-1 mRNA species, namely, FATP-1a, FATP-1aV, FATP-1b, FATP-1c and FATP-1cV and are generated by alternative splicing of primary transcript. Deduced pFATP-1a protein showed 91.6% and 87.5% identities with those of human and rat. RT-PCR and Southern blot analysis demonstrated widespread tissue distribution of each pFATP-1 isoform mRNA, most abundantly in the brain, heart, lung, jejunum, testis, pancreas and trapezius muscle. Real-time quantitative RT-PCR revealed that pFATP-1 mRNA expressions in masseter and trapezius muscles were much higher than those in longissimus, gluteus medius and adipose tissues. These results suggested a crucial physiological role of pFATP-1 in fatty acid utilization in muscles, especially red muscles tissues, rather than fat storage in adipose tissues.

Identification of porcine fatty acid translocase: high-level transcript in intramuscular fat.

Fatty acids translocase (FAT) is a transporter that facilitate long-chain fatty acids uptake as well as lipid accretion. To investigate the potential role of FAT in different adipose tissues, we investigated the cDNA structure of porcine FAT (pFAT) and analysed the tissue distribution of pFAT mRNA. The FAT mRNA expression profiles in the pre-adipocytes isolated from subcutaneous and intramuscular fat were also compared during cell differentiation. The results showed that 2389 bp porcine cDNA (DQ192230) had 87% homology with human FAT, 83% with mouse FAT, 82% with rat FAT and 67.5% with chicken FAT. Alignment of deduced amino acids sequence showed 82.4% homology with human FAT, 83.3% with mouse FAT and 85% with rat FAT. RT-PCR analysis revealed that the pFAT mRNA had a wide-spread expression in most tissues except for the brain. The higher level transcript was detected in visceral fat tissue by real-time quantitative RT-PCR. Interestingly, the pFAT mRNA expression level was dramatically increased in the primary culture pre-adipocytes derived from intramuscular fat and this consistent with the cellular lipid accretion. However, a sustained lower-level transcript was also found in the adipocytes from subcutaneous fat. The present study indicated that pFAT mRNA had a differential expression in subcutaneous, visceral and intramuscular fat depots. The data presented here provide further proof that pFAT might be involved in the modulation of the temporal and spatial fat depots.

MiRNA-26a promotes angiogenesis in a rat model of cerebral infarction via PI3K/AKT and MAPK/ERK pathway.

OBJECTIVE: To investigate the specific role of microRNA-26 (miRNA-26a) in a rat model of cerebral ischemic stroke and the underlying mechanism. MATERIALS AND METHODS: A rat model of middle cerebral artery occlusion (MCAO) was established to induce permanent cerebral infarction. Neuro-behavior was observed and scored after model establishment. The expression of miRNA-26a in brain tissue and brain microvascular endothelial cells (BMECs) of rats after cerebral ischemic stroke was detected by quantitative polymerase chain reaction (qPCR). The formation of the endothelial lumen was detected by Matrigel assay after BMECs were transfected with miR-26a mimics or inhibitors. Besides, cell proliferation after miRNA-26a transfection was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The protein levels related to PI3K/AKT and MAPK/ERK signaling pathway were detected by Western blot. RESULTS: miRNA-26a expression was elevated after cerebral infarction injury. Further investigation showed that miRNA-26a mimics could promote endothelial lumen formation and cell proliferation in BMECs, while miRNA-26a inhibitor inhibited the capacity of lumen formation and cell proliferation. Notably, we found that miRNA-26a might up-regulate the expression of HIF-1a via activating the AKT and ERK1/2 pathway, thus mediating the transcriptional activity of VEGF and promoting lumen formation and cell proliferation in BMECs. CONCLUSIONS: MiRNA-26a promotes angiogenesis in a rat model of cerebral ischemic via PI3K/AKT and MAPK/ERK pathway.

Dietary supplementation with arginine and glutamic acid modifies growth performance, carcass traits, and meat quality in growing-finishing pigs.

Sixty Duroc × Large White × Landrace pigs with an average initial BW of 77.1 ± 1.3 kg were used to investigate the effects of dietary supplementation with arginine and glutamic acid on growth performance, carcass traits, and meat quality in growing-finishing pigs. The animals were randomly assigned to 1 of 5 treatment groups (12 pigs/group, male:female ratio 1:1). The pigs in the control group were fed a basal diet (basal diet group), and those in the experimental groups were fed the basal diet supplemented with 2.05% -alanine (isonitrogenous group), 1.0% -arginine (Arg group), 1% glutamic acid + 1.44% -alanine (Glu group), or 1.0% -arginine + 1.0% glutamic acid (Arg+Glu group). After a 60-d period of supplementation, growth performance, carcass traits, and meat quality were evaluated. The results showed no significant differences ( > 0.05) in growth performance and carcass traits of the pigs in the Arg group relative to the basal diet group; however, the longissimus dorsi (LD) muscle and back fat showed a decrease ( < 0.05) in the percentage of SFA. In the Glu group, the final BW, phase 1 (d 1 to 30) and phase 2 (d 31 to 60) ADFI, and average back fat thickness of the pigs decreased ( < 0.05) by 7.14%, 23.43%, 8.03%, and 33.88%, respectively, when compared with the basal diet group. Dietary Arg+Glu supplementation had no effect ( > 0.05) on the final BW, phase 2 ADFI, and average daily weight gain in pigs but decreased ( < 0.05) their phase 1 ADFI, average back fat thickness, and percentage of SFA in the LD muscle and back fat, and increased ( < 0.05) the i.m. fat (IMF) content of the LD and biceps femoris muscles when compared with the basal diet group. Furthermore, a 16% decrease in yellowness (b* value; < 0.05) was observed in the Arg+Glu group pigs when compared with the isonitrogenous group. These findings suggest that dietary supplementation with both Arg and Glu beneficially increases the IMF deposition and improves the meat color and fatty acid composition without affecting growth performance and s.c. fat in pigs, providing a novel strategy to enhance meat quality in growing-finishing pigs.

Dietary supplementation with arginine and glutamic acid enhances key lipogenic gene expression in growing pigs.

Our previous study showed dietary supplementation with Arg and Glu increased intramuscular fat deposition and decreased back fat thickness in pigs, suggesting that the genes involved in lipid metabolism might be regulated differently in muscle and s.c. adipose (SA) tissues. Sixty Duroc × Large White × Landrace pigs with an average initial BW of 77.1 ± 1.3 kg were randomly assigned to 1 of 5 treatment groups (castrated male to female ratio = 1:1). Pigs in the control group were fed a basic diet, and those in experimental groups were fed the basic diet supplemented with 2.05% alanine (isonitrogenous group), 1.00% arginine (Arg group), 1.00% glutamic acid + 1.44% alanine (Glu group), or 1.00% arginine + 1.00% glutamic acid (Arg+Glu group). Fatty acid percentages and mRNA expression levels of the genes involved in lipid metabolism in muscle and SA tissues were examined. The percentages of C14:0 and C16:0 in the SA tissue of Glu group pigs and C14:0 in the longissimus dorsi (LD) muscle of Glu and Arg+Glu groups decreased ( < 0.05) compared to the basic diet group. The Arg+Glu group showed the highest ( < 0.05) hormone-sensitive lipase expression level in SA tissue and higher ( < 0.05) mRNA levels of in the LD muscle than the basic diet and isonitrogenous groups. Additionally, the mRNA level of fatty acid synthase in the Arg+Glu group was more upregulated ( < 0.05) than that of the Arg group. An increase in the mRNA level of in the biceps femoris muscle was also observed in the Arg+Glu group ( < 0.05) compared with the basic diet and isonitrogenous groups. Collectively, these findings suggest that dietary supplementation with Arg and Glu upregulates the expression of genes involved in adipogenesis in muscle tissues and lipolysis in SA tissues.

Critical role of miR-125b in lipogenesis by targeting stearoyl-CoA desaturase-1 (SCD-1).

Alteration of gene expression tightly regulates lipogenesis. Stearoyl-CoA desaturase-1 (SCD-1), a key enzyme in lipogenesis, catalyzes the conversion of SFA to MUFA, and inhibition of its activity impairs lipid synthesis. As posttranscriptional regulators, microRNAs are involved in many pathways of lipid metabolism; however, their effect on SCD-1 has not been reported. In this study, miR-125b was identified as a potential regulator of SCD-1 using bioinformatics analysis. Here, we validated SCD-1 as the target of miR-125b using a dual luciferase assay. During adipogenesis, a synthetic mimic or inhibitor was used to overexpress or reduce the expression of miR-125b in porcine adipocytes. Overexpression of miR-125b reduced the accumulation of lipid droplets and triglycerides concentration and repressed SCD-1 protein expression and MUFA composition. The inhibitor had the reverse effect. Small interfering RNA against tested in adipocytes further proved the direct correlation between miR-125b and SCD-1. Moreover, in vivo experiments in mice showed that injection of miR-125b expression vector decreased the hepatic triglycerides concentration relative to saline. This study indicated that miR-125b regulates lipogenesis by targeting SCD-1; therefore, miR-125b might be applied in therapy of lipid metabolism disorders.

Promoter mutation and reduced expression of BRCA1 in canine mammary tumors.

Breast cancer 1, early onset (BRCA1) is one of the most important genes in human familial breast cancer, which also plays an important role in canine mammary tumors. The objectives of this study were to determine the promoter sequence of canine BRCA1, to investigate its promoter mutation status and to describe BRCA1 expression pattern in canine mammary tumors. The promoter sequence of canine BRCA1 was acquired by aligning human BRCA1 promoter sequence with canine genomic sequence and confirmed by standard promoter activity analysis. Same as human BRCA1 promoter, the CAAT box and G/C box were found in canine BRCA1 promoter. In order to explore the mutation status of the promoter region and to investigate the expression pattern of this gene, 10 normal canine mammary tissues, 15 benign mammary tumors and 15 malignant mammary tumors were used. By sequencing, 46.7% of the malignant mammary tumors were found with a deletion of one cytosine in the promoter region. The mRNA expression of BRCA1 was significantly reduced in benign and malignant mammary tumors (P<0.05), and the protein expression of BRCA1 was significantly reduced in malignant mammary tumors (P<0.05). This study is the first time to determine the canine BRCA1 promoter sequence and to describe the promoter mutation status in canine mammary tumors.