Aberrant promoter methylation and tumor suppressive activity of the DFNA5 gene in colorectal carcinoma

To identify novel methylated gene promoters, we compared differential RNA expression profiles of colorectal cancer (CRC) cell lines with or without treatment of 5-aza-2'-deoxycytidine (5-aza-dC). Out of 1776 genes that were initially 'absent (that is, silenced)' by gene expression array analysis, we selected 163 genes that were increased after 5-aza-dC treatment in at least two of three CRC cell lines. The microarray results were confirmed by Reverse Transcription-PCR, and CpG island of the gene promoters were amplified and sequenced for examination of cancer-specific methylation. Among the genes identified, the deafness, autosomal dominant 5 gene, DFNA5, promoter was found to be methylated in primary tumor tissues with high frequency (65%, 65/100). Quantitative methylation-specific PCR of DFNA5 clearly discriminated primary CRC tissues from normal colon tissues (3%, 3/100). The mRNA expression of DFNA5 in four of five colon cancer tissues was significantly downregulated as compared to normal tissues. Moreover, forced expression of full-length DFNA5 in CRC cell lines markedly decreased the cell growth and colony-forming ability whereas knockdown of DFNA5 increased cell growth in culture. Our data implicate DFNA5 as a novel tumor suppressor gene in CRC and a valuable molecular marker for human cancer.

Minimal enteral nutrient requirements for intestinal growth in neonatal piglets: how much is enough?

BACKGROUND

Parenterally nourished preterm infants commonly receive minimal enteral feedings, the aim being to enhance intestinal function. Whether this regimen increases intestinal growth has not been established.

OBJECTIVE

Our objective was to determine the minimal enteral nutrient intakes necessary to stimulate and to normalize neonatal intestinal growth.

METHODS

Intestinal growth and cell proliferation were quantified in neonatal pigs given equal amounts of an elemental nutrient solution for 7 d. Different groups (n = 5-7 per group) received 0%, 10%, 20%, 40%, 60%, 80%, or 100% of total nutrient intake enterally, with the remainder given parenterally.

RESULTS

In the jejunum, wet weight, protein mass, and villus height were significantly greater at enteral intakes >40%. Stimulation of ileal protein mass required a higher enteral intake (60%). In both segments, abrupt increases in DNA mass, crypt depth, ornithine decarboxylase activity, and crypt cells in S-phase occurred between enteral intakes of 40% and 60%. Circulating concentrations of glucagon-like peptide-2 and peptide YY, but not gastrin, increased significantly between enteral intakes of 40% and 60% and closely paralleled indexes of cell proliferation.

CONCLUSIONS

The minimal enteral nutrient intake necessary to increase mucosal mass was 40% of total nutrient intake, whereas 60% enteral nutrition was necessary to sustain normal mucosal proliferation and growth. Our results imply that providing <40% of the total nutrient intake enterally does not have significant intestinal trophic effects.

Prevalence and Risk Factors for Frailty among Community-Dwelling Older People in China: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically assess the prevalence of frailty, including prefrailty, stratified prevalence according to frailty criteria, gender, age, and region, and the risk factors for frailty in China.

DESIGN

We conducted a systematic literature review and meta-analysis using articles available in 8 databases including PubMed, Cochrane Library, Web of Science, CINAHL Plus, China Knowledge Resource Integrated Database (CNKI), Wanfang Database, Chinese Biomedical Database (CBM), and Weipu Database (VIP).

SETTING

Cross-sectional and cohort data from Chinese community.

PARTICIPANTS

Community-dwelling adults aged 65 and older.

MEASUREMENTS

Two authors independently extracted data based upon predefined criteria. Where data were available we conducted a meta-analysis of frailty parameters using a random-effects model.

RESULTS

We screened 915 different articles, and 14 studies (81258 participants) were ultimately included in this analysis. The prevalence of frailty and prefrailty in individual studies varied from 5.9% to 17.4% and from 26.8% to 62.8%, respectively. The pooled prevalence of frailty and prefrailty were 10% (95% CI: 8% to 12%, I2 = 97.4%, P = 0.000) and 43% (95% CI: 37% to 50%, I2 = 98.0%, P = 0.000), respectively. The pooled frailty prevalence was 8% for the Fried frailty phenotype, 12% for the frail index, and 15% for the FRAIL scale. Age-stratified meta-analyses showed the pooled prevalence of frailty to be 6%, 15%, and 25% for those aged 65-74, 75-84, and ≥85 years old, respectively. The pooled prevalence of frailty was 8% for males and 11% for females. The pooled prevalence of frailty in Mainland China, Taiwan, and Hong Kong was 12%, 8%, and 14%, respectively. The pooled frailty prevalence was 10% in urban areas and 7% in rural areas. After controlling for confounding variables, increasing age (OR = 1.28, 95% CI: 1.2 to 1.36, I2 = 98.0%, P = 0.000), being female (OR = 1.29, 95% CI: 1.16 to 1.43, I2 =92.7%, P=0.000), activities of daily living (ADL) disability (OR = 1.72, 95% CI: 1.57 to 1.90, I2 = 99.7%, P = 0.000), and having three or more chronic diseases (OR = 1.97, 95% CI: 1.78 to 2.18, I2 = 97.5%, P = 0.000) were associated with frailty.

CONCLUSIONS

These findings of this review indicate an overall pooled prevalence of frailty among Chinese community-dwelling older people of 10%. Increasing age, being female, ADL disability, and having three or more chronic diseases were all risk factors for frailty. Further research will be needed to identify additional frailty risk factors in order to better treat and prevent frailty in the community.

Localization of peptidylarginine deiminase 4 (PADI4) and citrullinated protein in synovial tissue of rheumatoid arthritis

OBJECTIVES

Peptidylarginine deiminases (PADIs) convert peptidylarginine into citrulline via post-translational modification. Anti-citrullinated peptide antibodies are highly specific for rheumatoid arthritis (RA). Our genome-wide case-control study of single-nucleotide polymorphisms found that the PADI4 gene polymorphism is closely associated with RA. Here, we localized the expression of PADI4 and the citrullinated protein product in synovial RA tissue.

METHODS

We used immunohistochemistry, double immunofluorescent labelling and western blotting.

RESULTS

We found that PADI4 is extensively expressed in T cells, B cells, macrophages, neutrophils, fibroblast-like cells and endothelial cells in the lining and sublining areas of the RA synovium. We also found extracellular and intracellular expression of PADI4 in fibrin deposits with loose tissue structures where apoptosis was widespread. Unlike PADI4, citrullinated protein generally appeared in fibrin deposits that were abundant in the RA synovium. The citrullinated fibrin aggregate was immunoreactive against immunoglobulin (Ig) A and IgM, but not IgG and IgE. Although a little PADI4 was expressed in osteoarthritic and normal synovial tissues, significant citrullination was undetectable.

CONCLUSIONS

The results showed that PADI4 is mainly distributed in cells of various haematopoietic lineages and expressed at high levels in the inflamed RA synovium. The co-localization of PADI4, citrullinated protein and apoptotic cells in fibrin deposits suggests that PADI4 is responsible for fibrin citrullination and is involved in apoptosis. The immunoreactivity of citrullinated fibrin with IgA and IgM in the RA synovium supports the notion that citrullinated fibrin is a potential antigen of RA autoimmunity.

The cystic fibrosis mutation (delta F508) does not influence the chloride channel activity of CFTR

The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-regulated Cl- channel. In most mammalian cells, the functional consequences of the most common CF mutation, delta F508-CFTR, cannot be assessed as the mutant protein undergoes biosynthetic arrest. However, function can be studied in the baculovirus-insect cell expression system where delta F508-CFTR does not appear to undergo such arrest. Our results show that phosphorylation-regulated Cl- channel activity of delta F508-CFTR is similar to that of wild-type CFTR. This observation was confirmed in comparative studies of purified delta F508-CFTR and CFTR reconstituted in planar lipid bilayers. Therefore, we suggest that this common mutation does not result in a significant alteration in CFTR function.

Supplemental chromium for stressed and growing feeder calves

The effects of supplemental chromium (Cr) from high-Cr yeast were investigated with steer calves fed corn silage diets. One hundred eight Charolais-crossed calves, weighing 245 kg after marketing and transport, were allotted to one of four treatments during the initial 28-d stress period: control, .4 ppm of Cr in the diet, long-acting injectable oxytetracycline (LAOTC), and Cr + LAOTC. Those fed Cr received 4 mg of Cr/d for the first 3 d sprinkled onto a small amount of hay over the silage. Chromium without LAOTC increased (P less than .05) ADG by 30% (.61 vs .79 kg/d) and ADG/DMI by 27% (.123 vs .156). Oxytetracycline alone increased (P less than .05) ADG by 30% and DMI by 15%. Chromium had no effect on morbidity. However, LAOTC tended (P less than .14) to reduce morbidity (26.0 vs 14.0%) after its administration. After d 28, steers were processed. Two weeks later, they were rerandomized within Cr groups to urea-corn vs soybean meal supplementation of corn silage during a 70-d growing period. Level of Cr was reduced to .2 ppm. Jugular blood was collected from eight steers on each treatment on two occasions. Chromium had no effect on ADG or ADG/DMI. However, Cr decreased (P less than .05) serum cortisol (75.0 vs 55.6 nmol/L). Furthermore, Cr increased (P less than .05) serum immunoglobulin M and total immunoglobulins in calves fed diets with soybean meal but had no effect in calves with urea-corn supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Allosteric interactions between the two non-equivalent nucleotide binding domains of multidrug resistance protein MRP1

Membrane transporters of the adenine nucleotide binding cassette (ABC) superfamily utilize two either identical or homologous nucleotide binding domains (NBDs). Although the hydrolysis of ATP by these domains is believed to drive transport of solute, it is unknown why two rather than a single NBD is required. In the well studied P-glycoprotein multidrug transporter, the two appear to be functionally equivalent, and a strongly supported model proposes that ATP hydrolysis occurs alternately at each NBD (Senior, A. E., al-Shawi, M. K., and Urbatsch, I. L. (1995) FEBS Lett 377, 285-289). To assess how applicable this model may be to other ABC transporters, we have examined adenine nucleotide interactions with the multidrug resistance protein, MRP1, a member of a different ABC family that transports conjugated organic anions and in which sequences of the two NBDs are much less similar than in P-glycoprotein. Photoaffinity labeling experiments with 8-azido-ATP, which strongly supports transport revealed ATP binding exclusively at NBD1 and ADP trapping predominantly at NBD2. Despite this apparent asymmetry in the two domains, they are entirely interdependent as substitution of key lysine residues in the Walker A motif of either impaired both ATP binding and ADP trapping. Furthermore, the interaction of ADP at NBD2 appears to allosterically enhance the binding of ATP at NBD1. Glutathione, which supports drug transport by the protein, does not enhance ATP binding but stimulates the trapping of ADP. Thus MRP1 may employ a more complex mechanism of coupling ATP utilization to the export of agents from cells than P-glycoprotein.

Solution structures of the R6 human insulin hexamer,

The three-dimensional solution structure of the phenol-stabilized 36 kDa R6 insulin hexamer was determined by NMR spectroscopy and restrained molecular dynamics. The hexamer structures were derived using a stepwise procedure. Initially, 60 monomers were obtained by distance geometry from 665 NOE-derived distance restraints and three disulfide bridges. Subsequently, the hexamer structures were calculated by simulated annealing, using 30 hexamers constructed from the best 36 monomer structures as the starting models. The NMR data show that the aromatic ring of residue Phe(B25) can take two different orientations in the solution hexamer: one in which it points inward (molecule 1, about 90%) and one in which it points outward from the surface of the monomer (molecule 2, about 10%). Therefore, two hexamer structures were calculated: a symmetric hexamer consisting of six molecule 1 monomers and a nonsymmetric hexamer consisting of five molecule 1 monomers and one molecule 2 monomer. For each of the six monomers, the restraints used in the calculations of the hexamer structures include, in addition to the intramonomeric restraints, 25 NOEs between insulin and phenol, 23 NOEs and two hydrogen bonds across the dimer interface, nine NOEs across the trimer interface, and five intramonomeric or two intermonomeric NOEs, respectively, specifying the different orientations of the Phe(B25) ring. The coordination of the two Zn atoms was defined by eight distance restraints. Thus, a total of 4394 and 4391 distance restraints, respectively, were used in the two hexamer calculations. The NOE restraints were classified in an iterative process as intra- or intermonomeric on the basis of their consistency or inconsistency with the structure of the monomer. The assignment of the dimer- and trimer-specific NOEs was made using the crystal structure of the R6 hexamer as the starting model. For both solution hexamers, the average backbone rms deviation is 0.81 A, if the less well-defined N- and C-terminal residues are excluded. The corresponding rms deviations for all heavy atoms are 1.17 and 1.19 A for the nonsymmetric and symmetric hexamer, respectively. The overall solution structure of the R6 insulin hexamer is compact, rigid, and symmetric and resembles the corresponding crystal structure. However, the extension of the B-chain alpha-helix, which characterizes the R state, is shorter in the solution structure than in the crystal structure. Also, the study shows that the orientation of the Phe(B25) ring has no effect on the structure of the rest of the molecule, within the uncertainty of the structure determination. The importance of these findings for the current model for the insulin-receptor interaction is discussed.

Dietary plasma protein reduces small intestinal growth and lamina propria cell density in early weaned pigs

ABSTRACT We quantified the effects of a diet containing animal plasma protein on small intestinal growth and mucosal morphology in early weaned pigs. Ninety-six pigs [14 d old, 4 kg body weight (BW)] were assigned in groups of 32 to three dietary treatments as follows: 1) free access to control diet (C), 2) free access to plasma protein diet (P), and 3) plasma protein, pair-fed to C (PPF). Eight pigs from each group were killed at 2, 4, 8 or 16 d. Over a 16-d period, weight gain in the P group was 43% greater (P < 0.05) than that in C pigs; weight gain was similar in C and PPF groups. Protein intake in the P group was 33% higher (P < 0.05) than that in the PPF group; no significant difference was observed between the C and P groups. Dietary protein conversion efficiencies in both the P and PPF groups were approximately 18% greater (P < 0.05) than those in the C group. Intestinal masses in the three groups did not differ at 2, 4 and 8 d. By 16 d, the jejunal and ileal protein and DNA masses (mg/kg BW) in both the P and PPF groups were lower than those in the C group (P < 0.05). Dietary plasma protein did not affect crypt cell proliferation, crypt depth or villous height in either the jejunum or ileum. However, the intravillous lamina propria cell density in the jejunum was significantly lower (P < 0.05) in P and PPF pigs than in C pigs. Plasma urea concentrations were also 40 and 42% lower (P < 0.05) in the P and PPF groups, respectively, than in the C group. Our results indicate that dietary plasma protein reduces the cellularity of the lamina propria, but not epithelial cell surface of the small intestine. Feeding plasma protein also increased the efficiency of dietary protein utilization, in part, by decreasing amino acid catabolism.

Citrullination of fibronectin in rheumatoid arthritis synovial tissue

OBJECTIVES

Citrullination, catalysed by peptidylarginine deiminase (PAD), is the post-translational modification of peptidylarginine to citrulline, which is intimately involved in the pathogenesis of rheumatoid arthritis (RA). Fibronectin (Fn), a large glycoprotein, is expressed at high levels in arthritic joints and it mediates various physiological processes through interactions with cell-surface integrin receptors and growth factors. We investigated the citrullination of Fn and its potential contribution to the pathogenesis of RA.

METHODS

We localized Fn expression and citrullination in RA synovial tissue by immunohistochemistry, immunoprecipitation and western blotting. We also determined levels of citrullinated Fn in plasma from RA patients using sandwich enzyme-linked immunosorbent assay (ELISA). After incubating Fn with rabbit skeletal muscle PAD, we examined the binding ability of citrullinated Fn to vascular endothelial growth factor (VEGF) and integrin beta1 using a solid-phase receptor binding assay as well as the effect of the citrullinated Fn on apoptosis using cultured HL-60 cells.

RESULTS

Immunohistochemistry and western blotting analysis indicated that Fn formed extracellular aggregates that were specifically citrullinated in RA synovial tissue. No Fn deposits were observed in synovial tissues of osteoarthritis (OA). Sandwich ELISA detected higher levels of citrullinated Fn in plasma from patients with RA than from healthy controls or those with systemic lupus erythematosus. Following citrullination in vitro, the affinity of Fn for VEGF increased, but binding activity to integrin beta1 decreased and Fn no longer stimulated the apoptosis of monocytes induced from cultured HL-60 cells.

CONCLUSIONS

Our results suggest that the citrullination of Fn is a specific event for RA synovium, although others have detected citrullinated total proteins in inflamed synovial tissue of RA and non-RA patients. Citrullination of Fn could alter interactions between Fn and its receptors and growth factors, consequently contributing to mechanisms of RA pathogenesis such as perturbed angiogenesis and apoptosis.

Understanding the electric and nonelectric field components of the cation effect on the electrochemical CO reduction reaction

Electrolyte cations affect the activity of surface-mediated electrocatalytic reactions; however, understanding the modes of interaction between cations and reaction intermediates remains lacking. We show that larger alkali metal cations (excluding the thickness of the hydration shell) promote the electrochemical CO reduction reaction on polycrystalline Cu surfaces in alkaline electrolytes. Combined reactivity and in situ surface-enhanced spectroscopic investigations show that changes to the interfacial electric field strength cannot solely explain the reactivity trend with cation size, suggesting the presence of a nonelectric field strength component in the cation effect. Spectroscopic investigations with cation chelating agents and organic molecules show that the electric and nonelectric field components of the cation effect could be affected by both cation identity and composition of the electrochemical interface. The interdependent nature of interfacial species indicates that the cation effect should be considered an integral part of the broader effect of composition and structure of the electrochemical interface on electrode-mediated reactions.

Development of the bipolar inventory of symptoms scale

OBJECTIVE

Most rating scales for bipolar disorders (BDs) do not encompass the spectrum of symptomatology now established as characterizing the illness. We report the rationale, format, reliability and initial validity studies of the Bipolar Inventory of Symptoms Scale (BISS), a 44-item scale designed to encompass the spectrum of behavioral disturbances in BDs.

METHOD

Structured video interviews of 20 patients representing four bipolar syndromal subtypes were rated by nine raters.

RESULTS

Generally, high inter-rater reliability and internal consistency were established for the depression and mania subscales and the BISS total score. The BISS discriminated across subtypes of bipolar patients with depressed, manic/hypomanic, mixed manic or recovered status.

CONCLUSION

The BISS has adequate reliability, concurrent validity and is capable of discriminating between bipolar subtypes. It also provides a comprehensive scale to assess discrete behavioral components of BD.

The non-hydrolytic pathway of cystic fibrosis transmembrane conductance regulator ion channel gating

It has been suggested that the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel may utilize a novel gating mechanism in which open and closed states are not in thermodynamic equilibrium. This suggestion is based on the assumption that energy of ATP hydrolysis drives the gating cycle. We demonstrate that CFTR channel gating occurs in the absence of ATP hydrolysis and hence does not depend on an input of free energy from this source. The binding of ATP or structurally related analogues that are poorly or non-hydrolysable is sufficient to induce opening. Closing occurs on dissociation of these ligands or the hydrolysis products of those that can be cleaved. Not only can channel opening occur without ATP hydrolysis but the temperature dependence of the open probability (Po.) is reversed, i.e. Po. increases as temperature is lowered whereas under hydrolytic conditions, Po. increases as temperature is elevated. This indicates that there are different rate-limiting steps in the alternate gating pathways (hydrolytic and non-hydrolytic). These observations demonstrate that phosphorylated CFTR behaves as a conventional ligand-gated channel employing cytoplasmic ATP as a readily available cytoplasmic ligand; under physiological conditions ligand hydrolysis provides efficient reversibility of channel opening.

Enteral nutrient intake level determines intestinal protein synthesis and accretion rates in neonatal pigs

Our objective was to determine the minimum enteral intake level necessary to increase the protein accretion rate (PAR) in the neonatal small intestine. Seven-day-old piglets received an equal total daily intake of an elemental diet, with different proportions given enterally (0, 10%, 20%, 40%, 60%, 80%, and 100%). After 7 days, piglets were infused intravenously with [(2)H(3)]leucine for 6 h, and the fractional protein synthesis rate (FSR) was measured in the proximal (PJ) and distal jejunum (DJ) and the proximal (PI) and distal ileum (DI). The jejunal FSR increased from 45%/day to 130%/day between 0 and 60% enteral intake, whereas the FSR in the ileum was less sensitive to enteral intake level. At 0% enteral intake, PAR was significantly negative in the PJ, DJ, and PI (range -70 to -43 mg/day) and positive in the DI (49 mg/day), whereas intestinal protein balance occurred at 20% enteral intake. At 100% enteral intake, the PAR was greatest in the DI, even though the rates of protein turnover were 50% lower than in the PJ. We conclude that there is net intestinal protein loss at 0% enteral intake, protein balance at 20% enteral intake, and maximal intestinal protein accretion at 60% enteral intake.

Phylogenetic sequence analysis, recombinant expression, and tissue distribution of a channel catfish estrogen receptor beta

An estrogen receptor beta (ERbeta) cDNA fragment was amplified by RT-PCR of total RNA extracted from liver and ovary of immature channel catfish. This cDNA fragment was used to screen an ovarian cDNA library made from an immature female fish. A clone was obtained that contained an open reading frame encoding a 575-amino-acid protein with a deduced molecular weight of 63.9 kDa. Maximum parsimony and Neighbor Joining analyses were used to generate a phylogenetic classification of channel catfish ERbeta on the basis of 25 full-length teleost and tetrapod ER sequences. The consensus tree obtained indicated the existence of two major vertebrate ER subtypes, alpha and beta. Within each subtype, and in accordance with established phylogenetic relationships, teleost and tetrapod ER were monophyletic confirming the results of a previous analysis (Z. Xia et al., 1999, Gen. Comp. Endocrinol. 113, 360-368). Extracts of COS-7 cells transfected with channel catfish ERbeta cDNA bound estrogen with high affinity (K(d) = 0.21 nM) and specificity. The affinity of channel catfish ERbeta for estrogen was higher than previously reported for channel catfish ERalpha. As determined by qualitative RT-PCR, the tissue distributions of ERalpha and ERbeta were similar but not identical. Both ER subtypes were present in ovary and testis. ERalpha was found in all other tissues examined from juvenile and mature fish of both sexes. ERbeta was also found in most tissues except, in most cases, whole blood and head kidney. Interestingly, the pattern of expression of ER subtypes in head kidney always corresponded to the pattern in whole blood. In conclusion, we isolated a channel catfish ERbeta with ligand-binding affinity and tissue expression patterns different from ERalpha. Also, we confirmed the validity of our previously proposed general classification scheme for vertebrate ER into alpha and beta subtypes and within each subtype, into teleost and tetrapod clades.

Chelated chromium for stressed feeder calves

Using crossbred calves obtained at feeder sales in Ontario, we evaluated two different sources of organically complexed chromium (Cr) for supplementing corn silage. A preliminary trial was conducted with 12 unstressed steers with or without 1 mg kg−1 chelated Cr during a 56-d growing period. Chelated Cr markedly decreased (P < 0.05) serum cortisol and glucose levels. In the main trial, 72 calves, weighing 233 kg, were randomly allotted to four treatments: control, high-Cr yeast, chelated Cr, and chelated Cr plus chelated Zn, Cu and Mn for the initial 7 d. Morbidity was determined by visual detection followed by rectal temperature checks. One third of morbidity occurred by day 12; two thirds, by day 16. High-Cr yeast tended to reduce morbidity; however, chelated Cr was more effective, resulting in 16.5% morbidity, or less (P < 0.05) than one third of the control. Daily gain was 41% higher (P < 0.05) with chelated Cr during the first 21 d after arrival, mainly due to the marked reduction in number of sick calves. During days 21–35, compensatory gain occurred with the morbid or antibiotic-treated calves. These data indicate that early (relative to peak morbidity) supplementation of stressed feeder calves with chelated Cr markedly reduces morbidity. Key words: Chromium, stress, calves, morbidity, cortisol, steers

Localization of estrogen receptor alpha and beta RNA in germinal and nongerminal epithelia of the channel catfish testis

The germinal epithelium of the anterior region of the channel catfish testis is the site of spermatogenesis, whereas the nongerminal epithelium of the posterior region (seminal vesicle) may play a role in the regulation of seminal fluid composition. The available information indicates that estrogens play a physiological role in the regulation of spermatogenesis and seminal fluid composition in vertebrates. However, the cellular distribution of estrogen receptor (ER) gene expression in the teleost testis is poorly understood. Therefore, the objective of this study was to determine the presence and cellular distribution of ERalpha and ERbeta transcripts in germinal and nongerminal epithelia of the mature testis of channel catfish. RT-PCR of whole-testis RNA extracts showed that ERalpha and ERbeta RNAs are present in the mature testis. In situ hybridization of histological sections of the germinal epithelium showed that primary spermatocytes contain little or no ERalpha or ERbeta RNA. However, both ER transcripts were present in secondary spermatocytes and spermatids and their levels were relatively high in mature sperm. The columnar epithelium of the seminal vesicle also contained ERalpha and ERbeta RNA. The ER RNAs in epithelial cells of the seminal vesicle were not evenly distributed throughout the cytoplasm but seemed to concentrate in their apical region, near the nucleus. In conclusion, ERalpha and ERbeta genes are coexpressed in germinal and nongerminal epithelia of the mature testis of channel catfish and seem to be developmentally regulated in spermatocytes. These observations are consistent with the concept that estrogens, via interaction with ERalpha and ERbeta, participate in the regulation of male gamete development and fertility.

The inhibition of antithrombin by peptidylarginine deiminase 4 may contribute to pathogenesis of rheumatoid arthritis

OBJECTIVE

The gene for peptidylarginine deiminase 4 (PADI4) has been found to be closely associated with rheumatoid arthritis (RA). Peptidylarginine deiminase (PADI) catalyses the post-translational modification of peptidylarginine to citrulline, a reaction known as citrullination. PADI extracted from rabbit muscle has been reported to citrullinate antithrombin, a principal plasma inhibitor of thrombin. Thrombin is known to induce angiogenesis, fibrin formation and inflammation, the primary events of the RA joint. Here, we investigate whether human PADI4 can inhibit antithrombin by catalysing antithrombin citrullination and how the enzyme is involved in RA pathogenesis.

METHODS

Antithrombin was incubated with recombinant PADI4 protein, and the inactivation of antithrombin was determined by reduction of its thrombin-inhibiting activity. Citrullination of antithrombin was detected by western blotting and enzyme-linked immunosorbent assay (ELISA). In addition, the citrullination level, activity and concentration of antithrombin in RA plasma were investigated by sandwich ELISA.

RESULTS

Incubation of antithrombin with PADI4 resulted in loss of thrombin-inhibitory activity and in citrullination of antithrombin. RA plasma showed higher levels of citrullinated antithrombin than controls with non-arthritis disease and healthy individuals.

CONCLUSION

The results indicate that PADI4 could inactivate antithrombin through citrullination. The abnormal expression or activation of PADI4 in RA synovium is suggested to be responsible for the high level of citrullinated antithrombin in RA plasma. Local inhibition of antithrombin activity in RA synovium might lead to the excessive angiogenesis, fibrin deposition and inflammation of the tissue.

RNA-seq analysis of amygdala tissue reveals characteristic expression profiles in schizophrenia

The amygdala brain region has been implicated in the pathophysiology of schizophrenia through emotion processing. However, transcriptome messages in the amygdala of schizophrenia patients have not been well studied. We used RNA sequencing to investigate gene-expression profiling in the amygdala tissues, and identified 569 upregulated and 192 downregulated genes from 22 schizophrenia patients and 24 non-psychiatric controls. Gene functional enrichment analysis demonstrated that the downregulated genes were enriched in pathways such as 'synaptic transmission' and 'behavior', whereas the upregulated genes were significantly over-represented in gene ontology pathways such as 'immune response' and 'blood vessel development'. Co-expression-based gene network analysis identified seven modules including four modules significantly associated with 'synaptic transmission', 'blood vessel development' or 'immune responses'. Taken together, our study provides novel insights into the molecular mechanism of schizophrenia, suggesting that precision-tailored therapeutic approaches aimed at normalizing the expression/function of specific gene networks could be a promising option in schizophrenia.

Clinical study and PLA2G6 mutation screening analysis in Chinese patients with infantile neuroaxonal dystrophy

BACKGROUND AND PURPOSE

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder. The most typical neuropathological finding of this disease is axonal swelling. Before the identification of associated mutations in PLA2G6-encoding iPLA(2)-VIA (cytosolic Ca(2+)-independent phospholipids A(2), group VIA) in 2006, neuropathological evidence was critical for definitive diagnosis. Only five genetic studies in INAD patients have been published worldwide, wherein 44 mutations were reported. To define the clinical and genetic characteristics of Chinese patients with INAD, 10 cases were analyzed.

METHODS

For 10 cases of INAD, extensive clinical investigations, neuropathological examination, and mutation screening in PLA2G6 were performed.

RESULTS

All cases displayed typical clinical features. Axonal swelling was found in skin or sural nerve biopsy specimens in three cases. Twelve PLA2G6 mutations were identified, nine of which were novel. These novel mutations include six missense, one abolishing the normal start codon, one nonsense, and one splice-site mutation.

CONCLUSIONS

The nine novel mutations identified in this study suggest the uniqueness of the PLA2G6 mutation spectrum in Chinese patients, and greatly extends the spectrum of known mutations in INAD patients. In addition to pathological evidence, genetic analysis can inform definitive diagnosis of INAD.

Carcass characteristics and tissue-mineral contents of steers fed supplemental chromium

This study investigated the effects of supplemental chromium (Cr) (0 or 0.2 mg kg−1 from high-Cr yeast) on performance, carcass characteristics and tissue-mineral contents of growing–finishing steers fed corn silage supplemented with either urea–corn or soybean meal during the growing period and a high-grain diet during the finishing period. Ninety-six Charolais-crossed steers, divided into four treatment groups with 24 animals each, were fed for a 70-d growing period followed by a 68-d finishing period. After continuous supplemental Cr, steers were commercially slaughtered and their carcass characteristics were evaluated. Tissue samples, including loin-eye lean and rib fat, liver and kidney, were analyzed for Cr and other minerals (P, Ca, Mg, Fe, Zn and Cu). Supplemental Cr had no effects (P > 0.05) on average daily gain (ADG), dry-matter intake, (DMI), feed efficiency (ADG/DMI), and carcass characteristics, including dressing percentage, loin-eye area, backfat thickness, marbling score, kidney fat and liver weight. Proportion of lean, fat and bone in rib sections was not affected (P > 0.05) by Cr supplementation. Supplemental Cr also did not affect (P > 0.05) total-tissue Cr and other mineral concentrations. However, supplemental Cr increased (P < 0.05) the Cu level of livers in steers fed urea–corn supplements during the growing period. This study showed that continuous supplementation of Cr (0.2 mg kg−1) to unstressed growing-finishing steers had no effect on carcass composition and several minerals in various tissues. Key words: Chromium, steer, carcass, tissue

Dietary plasma protein is used more efficiently than extruded soy protein for lean tissue growth in early-weaned pigs

We compared the effects of supplementing either animal plasma or extruded soy protein in the diet based on the efficiency of dietary protein utilization for lean tissue growth in early-weaned pigs. Twenty-four 14-d-old pigs (4 kg body weight) were pair-fed (per kg body weight) either a control diet containing extruded soy protein (C; n = 12) or a diet with 10% animal plasma (P; n = 12) for 24 d. During the 24 days, protein intake was not different, yet mean daily body weight gains (+23%) and food conversion efficiencies (expressed as the ratio of body weight gain to protein intake) (+19%) were greater (P < 0.05) in the P group than in the C group. Lean body mass measured after 24 d, using both dual-energy X-ray absorptiometry and total body potassium analysis, was significantly (P < 0.05) greater (approximately 16%) in P than in C pigs. The circulating urea concentrations were 40% lower (P < 0.05) in P than in C pigs. Our results demonstrate that supplementing early-weaned pig diets with animal plasma rather than extruded soy protein increased the efficiency of dietary protein use for lean tissue growth and that this response is mediated in part by decreased amino acid catabolism.

Novel transcripts of the estrogen receptor alpha gene in channel catfish

Complementary DNA libraries from liver and ovary of an immature female channel catfish were screened with a homologous ERalpha cDNA probe. The hepatic library yielded two new channel catfish ER cDNAs that encode N-terminal ERalpha variants of different sizes. Relative to the catfish ERalpha (medium size; 581 residues) previously reported, these new cDNAs encode Long-ERalpha (36 residues longer) and Short-ERalpha (389 residues shorter). The 5'-end of Long-ERalpha cDNA is identical to that of Medium-ERalpha but has an additional 503-bp segment with an upstream, in-frame translation-start codon. Recombinant Long-ERalpha binds estrogen with high affinity (K(d) = 3. 4 nM), similar to that previously reported for Medium-ERalpha but lower than reported for catfish ERbeta. Short-ERalpha cDNA encodes a protein that lacks most of the receptor protein and does not bind estrogen. Northern hybridization confirmed the existence of multiple hepatic ERalpha RNAs that include the size range of the ERalpha cDNAs obtained from the libraries as well as additional sizes. Using primers for RT-PCR that target locations internal to the protein-coding sequence, we also established the presence of several ERalpha cDNA variants with in-frame insertions in the ligand-binding and DNA-binding domains and in-frame or out-of-frame deletions in the ligand-binding domain. These internal variants showed patterns of expression that differed between the ovary and liver. Further, the ovarian library yielded a full-length, ERalpha antisense cDNA containing a poly(A) signal and tail. A limited survey of histological preparations from juvenile catfish by in situ hybridization using directionally synthesized cRNA probes also suggested the expression of ERalpha antisense RNA in a tissue-specific manner. In conclusion, channel catfish seemingly have three broad classes of ERalpha mRNA variants: those encoding N-terminal truncated variants, those encoding internal variants (including C-terminal truncated variants), and antisense mRNA. The sense variants may encode functional ERalpha or related proteins that modulate ERalpha or ERbeta activity. The existence of ER antisense mRNA is reported in this study for the first time. Its role may be to participate in the regulation of ER gene expression.

Glucagon-like peptide-2 protects against TPN-induced intestinal hexose malabsorption in enterally refed piglets

Premature infants receiving chronic total parenteral nutrition (TPN) due to feeding intolerance develop intestinal atrophy and reduced nutrient absorption. Although providing the intestinal trophic hormone glucagon-like peptide-2 (GLP-2) during chronic TPN improves intestinal growth and morphology, it is uncertain whether GLP-2 enhances absorptive function. We placed catheters in the carotid artery, jugular and portal veins, duodenum, and a portal vein flow probe in piglets before providing either enteral formula (ENT), TPN or a coinfusion of TPN plus GLP-2 for 6 days. On postoperative day 7, all piglets were fed enterally and digestive functions were evaluated in vivo using dual infusion of enteral ((13)C) and intravenous ((2)H) glucose, in vitro by measuring mucosal lactase activity and rates of apical glucose transport, and by assessing the abundances of sodium glucose transporter-1 (SGLT-1) and glucose transporter-2 (GLUT2). Both ENT and GLP-2 pigs had larger intestine weights, longer villi, and higher lactose digestive capacity and in vivo net glucose and galactose absorption compared with TPN alone. These endpoints were similar in ENT and GLP-2 pigs except for a lower intestinal weight and net glucose absorption in GLP-2 compared with ENT pigs. The enhanced hexose absorption in GLP-2 compared with TPN pigs corresponded with higher lactose digestive and apical glucose transport capacities, increased abundance of SGLT-1, but not GLUT-2, and lower intestinal metabolism of [(13)C]glucose to [(13)C]lactate. Our findings indicate that GLP-2 treatment during chronic TPN maintains intestinal structure and lactose digestive and hexose absorptive capacities, reduces intestinal hexose metabolism, and may facilitate the transition to enteral feeding in TPN-fed infants.