ROSics: chemistry and proteomics of cysteine modifications in redox biology

Post-translational modifications (PTMs) occurring in proteins determine their functions and regulations. Proteomic tools are available to identify PTMs and have proved invaluable to expanding the inventory of these tools of nature that hold the keys to biological processes. Cysteine (Cys), the least abundant (1-2%) of amino acid residues, are unique in that they play key roles in maintaining stability of protein structure, participating in active sites of enzymes, regulating protein function and binding to metals, among others. Cys residues are major targets of reactive oxygen species (ROS), which are important mediators and modulators of various biological processes. It is therefore necessary to identify the Cys-containing ROS target proteins, as well as the sites and species of their PTMs. Cutting edge proteomic tools which have helped identify the PTMs at reactive Cys residues, have also revealed that Cys residues are modified in numerous ways. These modifications include formation of disulfide, thiosulfinate and thiosulfonate, oxidation to sulfenic, sulfinic, sulfonic acids and thiosulfonic acid, transformation to dehydroalanine (DHA) and serine, palmitoylation and farnesylation, formation of chemical adducts with glutathione, 4-hydroxynonenal and 15-deoxy PGJ2, and various other chemicals. We present here, a review of relevant ROS biology, possible chemical reactions of Cys residues and details of the proteomic strategies employed for rapid, efficient and sensitive identification of diverse and novel PTMs involving reactive Cys residues of redox-sensitive proteins. We propose a new name, "ROSics," for the science which describes the principles of mode of action of ROS at molecular levels.

Mechanism of 1-Cys type methionine sulfoxide reductase A regeneration by glutaredoxin

Glutaredoxin (Grx), a major redox regulator, can act as a reductant of methionine sulfoxide reductase A (MsrA). However, the biochemical mechanisms involved in MsrA activity regeneration by Grx remain largely unknown. In this study, we investigated the regeneration mechanism of 1-Cys type Clostridium oremlandii MsrA (cMsrA) lacking a resolving Cys residue in a Grx-dependent assay. Kinetic analysis showed that cMsrA could be reduced by both monothiol and dithiol Grxs as efficiently as by in vitro reductant dithiothreitol. Our data revealed that the catalytic Cys sulfenic acid intermediate is not glutathionylated in the presence of the substrate, and that Grx instead directly formed a complex with cMsrA. Mass spectrometry analysis identified a disulfide bond between the N-terminal catalytic Cys of the active site of Grx and the catalytic Cys of cMsrA. This mixed disulfide bond could be resolved by glutathione. Based on these findings, we propose a model for regeneration of 1-Cys type cMsrA by Grx that involves no glutathionylation on the catalytic Cys of cMsrA. This mechanism contrasts with that of the previously known 1-Cys type MsrB.

Measurement of vital sign in chick embryo using multi-channel diffuse speckle contrast analysis

In poultry industry which is avian breeding program, the determination whether chick embryos survive in the artificial incubation periods or not is essential to reduce the financial resources. We developed the multi-channel diffuse speckle contrast analysis (DSCA) system composed of four optical fiber detectors enabling to achieve in-vivo measurements of deep tissue flow noninvasively. The system could confirm vital sign of the chick embryo in early incubation stage. Moreover, it demonstrates the change of relative blood flow index and depth information with simplicity, low cost, and flexibility.

Sulfhydryl-specific probe for monitoring protein redox sensitivity

Reactive oxygen species (ROS) regulate various biological processes by modifying reactive cysteine residues in the proteins participating in the relevant signaling pathways. Identification of ROS target proteins requires specific reagents that identify ROS-sensitive cysteine sulfhydryls that differ from the known alkylating agents, iodoacetamide and N-ethylmaleimide, which react nonspecifically with oxidized cysteines including sulfenic and sulfinic acid. We designed and synthesized a novel reagent, methyl-3-nitro-4-(piperidin-1-ylsulfonyl)benzoate (NPSB-1), that selectively and specifically reacts with the sulfhydryl of cysteines in model compounds. We validated the specificity of this reagent by allowing it to react with recombinant proteins followed by peptide sequencing with nanoUPLC-ESI-q-TOF tandem mass spectrometry (MS/MS), and mutant studies employed it to identify cellular proteins containing redox-sensitive cysteine residues. We also obtained proteins from cells treated with various concentrations of hydrogen peroxide, labeled them with biotinylated NPSB-1 (NPSB-B), pulled them down with streptavidin beads, and identified them with MS/MS. We grouped these proteins into four families: (1) those having reactive cysteine residues easily oxidized by hydrogen peroxide, (2) those with cysteines reactive only under mild oxidative stress, (3) those with cysteines reactive only after exposure to oxidative stress, and (4) those with cysteines that are reactive regardless of oxidative stress. These results confirm that NPSBs can serve as novel chemical probes for specifically capturing reactive cysteine residues and as powerful tools for measuring their oxidative sensitivity and can help to understand the function of cysteine modifications in ROS-mediated signaling pathways.

Differential impact of unrecognised brain infarction on stroke outcome in non-valvular atrial fibrillation

There has been little information regarding the impact of unrecognised brain infarctions (UBIs) on stroke outcome in patients with non-valvular atrial fibrillation (NVAF). By using volumetric analysis of ischaemic lesions, we evaluated the potential impact of UBIs on clinical outcome according to their presence and categorised type. This study enrolled 631 patients with NVAF having no clinical stroke history. UBIs were categorised into three types as territorial, lacunar, or subcortical. We collected stroke severity, functional outcome at three months, and the total volume of UBIs and acute infarction lesions. We investigated the association between clinical outcome and the type or volume of UBI, using a linear mixed model and logistic regression analysis. UBIs were detected in 285 (45.2 %) patients; territorial UBIs were observed in 24.4 % of patients (154/631), lacunar UBIs in 25 % (158/631), and subcortical UBIs in 15.7 % (99/631). Although initial stroke severity was not different between patients with UBIs and those without, those with UBIs had less improvement during hospitalisation, leading to poorer outcome at three months. Among the three types of UBIs, only territorial UBIs were associated with poor outcome, especially in patients with relatively smaller acute infarction volume. UBIs, in particular, territorial UBIs, may be considered as predictors for poor outcome after ischaemic stroke in patients with NVAF. Our results suggest that the impact of UBIs on clinical outcome differs according to the type of UBIs and the acute stroke severity.

N-terminal truncated UCH-L1 prevents Parkinson's disease associated damage

Ubiquitin C-terminal hydrolase-L1 (UCH-L1) has been proposed as one of the Parkinson's disease (PD) related genes, but the possible molecular connection between UCH-L1 and PD is not well understood. In this study, we discovered an N-terminal 11 amino acid truncated variant UCH-L1 that we called NT-UCH-L1, in mouse brain tissue as well as in NCI-H157 lung cancer and SH-SY5Y neuroblastoma cell lines. In vivo experiments and hydrogen-deuterium exchange (HDX) with tandem mass spectrometry (MS) studies showed that NT-UCH-L1 is readily aggregated and degraded, and has more flexible structure than UCH-L1. Post-translational modifications including monoubiquitination and disulfide crosslinking regulate the stability and cellular localization of NT-UCH-L1, as confirmed by mutational and proteomic studies. Stable expression of NT-UCH-L1 decreases cellular ROS levels and protects cells from H₂O₂, rotenone and CCCP-induced cell death. NT-UCH-L1-expressing transgenic mice are less susceptible to degeneration of nigrostriatal dopaminergic neurons seen in the MPTP mouse model of PD, in comparison to control animals. These results suggest that NT-UCH-L1 may have the potential to prevent neural damage in diseases like PD.

Local application of periodontal ligament stromal cells promotes soft tissue regeneration

OBJECTIVES

To test the potential stimulatory effect of local application of periodontal ligament (PDL) stromal cells on soft tissue regeneration.

MATERIALS AND METHODS

Fluorescently labeled PDL cells outgrown from extracted human premolars or phosphate-buffered saline were locally injected to the cutaneous wounds created on mice. Soft tissue regeneration was evaluated for 14 days using photographs and histomorphometry. PDL cell engraftment was tracked with confocal microscopy. To detect the paracrine effect of the PDL cells on soft tissue regeneration, PDL cell-conditioned medium (CM) was evaluated for the concentration of secretory factors, transforming growth factor-beta 1 (TGFβ1). The effect of PDL CM on the proliferation and migration of dermal fibroblast and keratinocyte was tested using MTT assay and migration assay.

RESULTS

The application of PDL cells significantly promoted soft tissue regeneration compared with the application of PBS. Self-replicating PDL cells were engrafted into the hair follicles of the host tissue. Dermal fibroblast proliferation and keratinocyte migration were significantly enhanced by the treatment with PDL CM. Physiologically significant amount of TGFβ1 was secreted from PDL cells into the CM.

CONCLUSION

Local injection of PDL cells promoted soft tissue regeneration in part by the enhancement of fibroblast proliferation and keratinocyte migration through a paracrine mechanism.

Differential protective effects of exenatide, an agonist of GLP-1 receptor and Piragliatin, a glucokinase activator in beta cell response to streptozotocin-induced and endoplasmic reticulum stresses

Background

Agonists of glucagon-like peptide-1 receptor (GLP-1R) and glucokinase activators (GKA) act as antidiabetic agents by their ability protect beta cells, and stimulate insulin secretion. Oxidative and endoplasmic reticulum (ER) stresses aggravate type 2 diabetes by causing beta cell loss. It was shown that GLP-1R agonists protect beta cells from oxidative and ER stresses. On the other hand, little is known regarding how GKAs protect beta cells. We hypothesized that GKAs protect beta cells by mechanisms distinct from those underlying GLP-1R agonist and tested our hypothesis by comparing the molecular effects of exenatide, a GLP-1R agonist, and piragliatin, a GKA, on INS-1 cells under oxidative and ER-induced stresses.

Methods

Beta cells were treated with streptozotocin (STZ) to induce oxidative stress and with palmitate or thapsigargin (Tg) to induce ER stress respectively, and the effects of exenatide and piragliatin on these cells were investigated by: a) characterizing the kinases involved employing specific kinase inhibitors, and b) by identifying the differentially regulated proteins in response to stresses with proteomic analysis.

Results

Exenatide protected INS-1 cells from both ER and STZ-induced death. In contrast, piragliatin rescued the cells only from STZ-induced stress. Akt activation by exenatide appeared to contribute to its protective effects of beta cells while enhanced glucose utilization was the contributing factor in the case of piragliatin. Also, exenatide, not piragliatin, blocked changes in proteins 14-3-3β, ε and θ, and preserved the 14-3-3θ levels under the ER stress. Isoform-specific modifications of 14-3-3, and the reduction of 14-3-3θ, commonly associated with beta cell death were assessed.

Conclusions

Exenatide and piragliatin exert distinct effects on beta cell survival and thus on type 2 diabetes. This study which confirmed our hypothesis is also the first to observe specific modulation of 14-3-3 isoform in stress-induced beta cell death associated with progressive deterioration of type 2 diabetes.

Protective effects of peroxiredoxin 6 overexpression on amyloid β-induced apoptosis in PC12 cells

Oxidative stress triggered by amyloid beta (Aβ) accumulation contributes substantially to the pathogenesis of Alzheimer's disease (AD). In the present study, we examined the involvement of the antioxidant activity of peroxiredoxin 6 (Prdx 6) in protecting against Aβ25-35-induced neurotoxicity in rat PC12 cells. Treatment of PC12 cells with Aβ25-35 resulted in a dose- and time-dependent cytotoxicity that was associated with increased accumulation of intracellular reactive oxygen species (ROS) and mitochondria-mediated apoptotic cell death, including activation of Caspase 3 and 9, inactivation of poly ADP-ribosyl polymerse (PARP), and dysregulation of Bcl-2 and Bax. This apoptotic signaling machinery was markedly attenuated in PC12 cells that overexpress wild-type Prdx 6, but not in cells that overexpress the C47S catalytic mutant of Prdx 6. This indicates that the peroxidase activity of Prdx 6 protects PC12 cells from Aβ25-35-induced neurotoxicity. The neuroprotective role of the antioxidant Prdx 6 suggests its therapeutic and/or prophylactic potential to slow the progression of AD and limit the extent of neuronal cell death caused by AD.

A strong magnetic field around the supermassive black hole at the centre of the Galaxy

Earth's nearest candidate supermassive black hole lies at the centre of the Milky Way. Its electromagnetic emission is thought to be powered by radiatively inefficient accretion of gas from its environment, which is a standard mode of energy supply for most galactic nuclei. X-ray measurements have already resolved a tenuous hot gas component from which the black hole can be fed. The magnetization of the gas, however, which is a crucial parameter determining the structure of the accretion flow, remains unknown. Strong magnetic fields can influence the dynamics of accretion, remove angular momentum from the infalling gas, expel matter through relativistic jets and lead to synchrotron emission such as that previously observed. Here we report multi-frequency radio measurements of a newly discovered pulsar close to the Galactic Centre and show that the pulsar's unusually large Faraday rotation (the rotation of the plane of polarization of the emission in the presence of an external magnetic field) indicates that there is a dynamically important magnetic field near the black hole. If this field is accreted down to the event horizon it provides enough magnetic flux to explain the observed emission--from radio to X-ray wavelengths--from the black hole.

Structure of Nm23-H1 under oxidative conditions

Nm23-H1/NDPK-A, a tumour metastasis suppressor, is a multifunctional housekeeping enzyme with nucleoside diphosphate kinase activity. Hexameric Nm23-H1 is required for suppression of tumour metastasis and it is dissociated into dimers under oxidative conditions. Here, the crystal structure of oxidized Nm23-H1 is presented. It reveals the formation of an intramolecular disulfide bond between Cys4 and Cys145 that triggers a large conformational change that destabilizes the hexameric state. The dependence of the dissociation dynamics on the H2O2 concentration was determined using hydrogen/deuterium-exchange experiments. The quaternary conformational change provides a suitable environment for the oxidation of Cys109 to sulfonic acid, as demonstrated by peptide sequencing using nanoUPLC-ESI-q-TOF tandem MS. From these and other data, it is proposed that the molecular and cellular functions of Nm23-H1 are regulated by a series of oxidative modifications coupled to its oligomeric states and that the modified cysteines are resolvable by NADPH-dependent reduction systems. These findings broaden the understanding of the complicated enzyme-regulatory mechanisms that operate under oxidative conditions.

Effect of DA-9701, a novel prokinetic agent, on stress-induced delayed gastric emptying and hormonal changes in rats

BACKGROUND

DA-9701 is a novel prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber. This study aimed to evaluate the effect of DA-9701 on stress-induced delay in gastric emptying and changes in plasma adrenocorticotropic hormone and ghrelin levels in rats.

METHODS

Changes in gastric emptying in response to different durations of stress were evaluated. Gastric emptying was compared between the following groups: (i) nonstressed vehicle- or DA-9701-treated group, (ii) nonstressed vehicle- or mosapride-treated group, (iii) 2-h stressed vehicle- or DA-9701-treated group, and (iv) 2-h stressed vehicle- or mosapride-treated group. Water immersion restraint stress was used as the stressor. DA-9701 or mosapride at 3 mg kg(-1) was administered to the rats after subjecting them to 2-h stress, and then gastric emptying was measured using the phenol red method.

KEY RESULTS

Gastric emptying was significantly delayed in the 2-h stressed group compared with the nonstressed group. Mosapride administration resulted in significant recovery from the stress-induced delay in gastric emptying. Gastric emptying in the rats that underwent 2-h stress followed by DA-9701 administration was not significantly different from that in the nonstressed group. The plasma adrenocorticotropic hormone and active ghrelin levels in the 2-h stressed group were significantly higher than those in the nonstressed group. These increases were significantly inhibited by DA-9701.

CONCLUSIONS & INFERENCES

The administration of DA-9701 improved delayed gastric emptying and inhibited the hormonal changes induced by stress, suggesting that DA-9701 can be used as a gastroprokinetic agent for the treatment of delayed gastric emptying, particularly that associated with stress.

Complex of Fas-associated factor 1 (FAF1) with valosin-containing protein (VCP)-Npl4-Ufd1 and polyubiquitinated proteins promotes endoplasmic reticulum-associated degradation (ERAD)

Fas-associated factor 1 (FAF1) is a ubiquitin receptor containing multiple ubiquitin-related domains including ubiquitin-associated (UBA), ubiquitin-like (UBL) 1, UBL2, and ubiquitin regulatory X (UBX). We previously showed that N-terminal UBA domain recognizes Lys(48)-ubiquitin linkage to recruit polyubiquitinated proteins and that a C-terminal UBX domain interacts with valosin-containing protein (VCP). This study shows that FAF1 interacts only with VCP complexed with Npl4-Ufd1 heterodimer, a requirement for the recruitment of polyubiquitinated proteins to UBA domain. Intriguingly, VCP association to C-terminal UBX domain regulates ubiquitin binding to N-terminal UBA domain without direct interaction between UBA and UBX domains. These interactions are well characterized by structural and biochemical analysis. VCP-Npl4-Ufd1 complex is known as the machinery required for endoplasmic reticulum-associated degradation. We demonstrate here that FAF1 binds to VCP-Npl4-Ufd1 complex via UBX domain and polyubiquitinated proteins via UBA domain to promote endoplasmic reticulum-associated degradation.

Comprehensive identification of novel post-translational modifications in cellular peroxiredoxin 6

Peroxiredoxin 6 (PRDX6), a 1-Cys peroxiredoxin, is a bifunctional enzyme acting both as a glutathione peroxidase and a phospholipase A2. However, the underlying mechanisms and their regulation mechanisms are not well understood. Because post-translational modifications (PTMs) have been shown to play important roles in the function of many proteins, we undertook, in this study, to identify the PTMs in PRDX6 utilizing proteomic tools including nanoUPLC-ESI-q-TOF MS/MS employing selectively excluded mass screening analysis (SEMSA) in conjunction with MOD(i) and MODmap algorithm. We chose PRDX6 obtained from liver tissues from two inbred mouse strains, C57BL/6J and C3H/HeJ, which vary in their susceptibility to high-fat diet-induced obesity and atherosclerosis, and a B16F10 melanoma cell line for this study. When PRDX6 protein samples were separated on 2D-PAGE based on pI, several PRDX6 spots appeared. They were purified and the low abundant PTMs in each PRDX6 spot were analyzed. Unexpected mass shifts (Δm = -34, +25, +64, +87, +103, +134, +150, +284 Da) observed at active site cysteine residue (Cys47) were quantified using precursor ion intensities. Mass differences of -34, +25, and +64 Da are presumed to reflect the conversion of cysteine to dehydroalanine, cyano, and Cys-SO(2) -SH, respectively. We also detected acrylamide adducts of sulfenic and sulfinic acids (+87 and +103 Da) as well as unknown modifications (+134, +150, +284 Da). Comprehensive analysis of these PTMs revealed that the PRDX6 exists as a heterogeneous mixture of molecules containing a multitude of PTMs. Several of these modifications occur at cysteine residue in the enzyme active site. Other modifications observed, in PRDX6 from mouse liver tissues included, among others, mono- and dioxidation at Trp and Met, acetylation at Lys, and deamidation at Asn and Gln. Comprehensive identification of the diverse PTMs occurring in this bifunctional PRDX6 enzyme should help understand how PRDX6 plays key roles in oxidative stresses.

Monoisotopic mass determination algorithm for selenocysteine-containing polypeptides from mass spectrometric data based on theoretical modeling of isotopic peak intensity ratios

Selenoproteins, containing selenocysteine (Sec, U) as the 21st amino acid in the genetic code, are well conserved from bacteria to human, except yeast and higher plants that miss the Sec insertion machinery. Determination of Sec association is important to find substrates and to understand redox action of selenoproteins. While mass spectrometry (MS) has become a common and powerful tool to determine an amino acid sequence of a protein, identification of a protein sequence containing Sec was not easy using MS because of the limited stability of Sec in selenoproteins. Se has six naturally occurring isotopes, ⁷⁴Se, ⁷⁶Se, ⁷⁷Se, ⁷⁸Se, ⁸⁰Se, and ⁸²Se, and ⁸⁰Se is the most abundant isotope. These characteristics provide a good indicator for selenopeptides but make it difficult to detect selenopeptides using software analysis tools developed for common peptides. Thus, previous reports verified MS scans of selenopeptides by manual inspection. None of the fully automated algorithms have taken into account the isotopes of Se, leading to the wrong interpretation for selenopeptides. In this paper, we present an algorithm to determine monoisotopic masses of selenocysteine-containing polypeptides. Our algorithm is based on a theoretical model for an isotopic distribution of a selenopeptide, which regards peak intensities in an isotopic distribution as the natural abundances of C, H, N, O, S, and Se. Our algorithm uses two kinds of isotopic peak intensity ratios: one for two adjacent peaks and another for two distant peaks. It is shown that our algorithm for selenopeptides performs accurately, which was demonstrated with two LC-MS/MS data sets. Using this algorithm, we have successfully identified the Sec-Cys and Sec-Sec cross-linking of glutaredoxin 1 (GRX1) from mass spectra obtained by UPLC-ESI-q-TOF instrument.

Ubiquitin-associated (UBA) domain in human Fas associated factor 1 inhibits tumor formation by promoting Hsp70 degradation

Human Fas associated factor 1 (hFAF1) is a pro-apoptotic scaffolding protein containing ubiquitin-associating (UBA), ubiquitin like 1 and 2 (UBL1, UBL2), and ubiquitin regulatory X (UBX) domains. hFAF1 interacts with polyubiquitinated proteins via its N-terminal UBA domain and with valosin containing protein (VCP) via its C-terminal UBX domain. Overexpression of hFAF1 or its N-terminal UBA domain significantly increases cell death by increasing the degradation of polyubiquitinated proteins. In this study, we investigated whether hFAF1, whose expression level is reduced in cervical cancer, plays a role in tumor formation. We found that HeLa cells overexpressing full-length hFAF1 or the hFAF1 UBA domain alone, significantly suppressed the anchorage independent tumor growth in soft agar colony formation, increased cell death, and activated JNK and caspase 3. Employing UBA-specific tandem immunoprecipitation, we identified moieties specifically interacting with UBA domain of hFAF1, and found that polyubiquitinated Hsp70s are recruited to UBA domain. We also demonstrated that hFAF1 overexpression promotes Hsp70 degradation via the proteasome. We further found that mutating the UBA domain (I41N), as well as knocking down hFAF1 with specific RNAi, abolishs its ability to increase the proteasomal degradation of Hsp70. These findings suggest that hFAF1 inhibits tumor formation by increasing the degradation of Hsp70 mediated via its UBA domain.

Proteomic characterization of Kunitz trypsin inhibitor variants, Tia and Tib, in soybean [Glycine max (L.) Merrill]

The soybean Kunitz trypsin inhibitor (KTi) has several polymorphic variants. Of these, Tia and Tib, which differ by nine amino acids, are the two main types. In this study, differences in KTi proteome between Tia and Tib were investigated using three soybean cultivars and three mutant lines. Two cultivars, Baekwoon (BW) and Paldal (PD), and one mutant line, SW115-24, were Tia type, whereas one soybean cultivar, Suwon115 (SW115), and two mutant lines, BW-7-2 and PD-5-10, were Tib type. Protein from the six soybean lines was extracted and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), non-denaturing polyacrylamide gel electrophoresis (non-denaturing PAGE), and two-dimensional polyacrylamide gel electrophoresis (2-DE). By SDS-PAGE, there was no difference between soybean cultivars and mutant lines, except for SW115-24. Western blot analysis revealed that, in comparison with Tia, Tib type accumulated relatively low amounts of KTi. By non-denaturing PAGE, the three soybean lines of Tib type were characterized by slower mobility than the three soybean lines of Tia type. Zymography detected eight distinct zones of trypsin inhibitory activity among which Tia and Tib lacked the fifth and sixth zone, respectively. By two-dimensional native polyacrylamide gel electrophoresis (2-DN), the spots related to trypsin inhibitory activity showed different mobilities, whereas only one KTi (21.5 kDa) spot was resolved by 2-DE. By two-dimensional zymography (2-DZ), Tib showed a broader activity zone (pI 4-7) in comparison with Tia (pI 4-5). The results indicate that the genotypes with a different type of KTi present different proteomic profiles and trypsin inhibitory activities.

Peroxiredoxin 3 is a key molecule regulating adipocyte oxidative stress, mitochondrial biogenesis, and adipokine expression

AIMS

Increased oxidative stress and mitochondrial dysfunction in obese adipocytes contribute to adipokine dysregulation, inflammation, and insulin resistance.

RESULTS

Through an advanced proteomic analysis, we found that peroxiredoxin 3 (Prx3), a thioredoxin-dependent mitochondrial peroxidase, is highly expressed in 3T3-L1 adipocytes compared to preadipocytes. Interestingly, in obese db/db mice and human subjects, adipose Prx3 levels were significantly decreased, indicating its association with obesity. We therefore employed Prx3 knockout (KO) mice and transfected 3T3-L1 cells to examine the role of endogenous Prx3 in adipocyte metabolism. Prx3 KO mice had increased fat mass compared to wild-type due to adipocyte hypertrophy. Increased adipogenic transcription factors and lipogenic gene expression during differentiation of adipose tissue-derived stem cells from Prx3-deficient mice confirmed that these adipocytes are likely to accumulate fat. Mitochondrial protein carbonylation in Prx3 KO adipose tissue and mitochondrial superoxide level in Prx3 knockdown 3T3-L1 cells were increased showing aberrant regulation of oxidative stress. Proteomic analysis and gene expression analysis of Prx3 KO mice adipocytes also showed defect in mitochondria biogenesis along with enzymes involved in glucose/lipid metabolism and oxidative phosphorylation. In addition, expression level of adiponectin was downregulated and plasminogen activator inhibitor-1 was upregulated in Prx3 KO adipocytes. Impaired glucose tolerance and insulin resistance further implied metabolic dysregulation in Prx3 KO mice.

INNOVATION AND CONCLUSION

These data suggest that endogenous Prx3 may play an essential role in maintaining normal characteristics of adipocytes and that defect in Prx3 alters mitochondrial redox state and function, and adipokine expression in adipocytes leading to metabolic alteration.

Efficacy of ramosetron in the treatment of male patients with irritable bowel syndrome with diarrhea: a multicenter, randomized clinical trial, compared with mebeverine

BACKGROUND

The 5-HT(3) receptor antagonists are known to be effective for the treatment of diarrhea-predominant irritable bowel syndrome (IBS), but not widely used yet. The aim of this study was to compare the efficacy and safety of ramosetron, a 5-HT(3) receptor antagonist, and mebeverine in male patients with IBS with diarrhea (IBS-D).

METHODS

This study was performed in a multicenter, randomized, open-label design. Data of 343 male patients with IBS-D who were randomized to either a 4-week treatment of ramosetron 5μg once daily or a 4-week treatment of mebeverine 135 mg three times daily were analyzed by the intent-to-treat analysis. The primary efficacy parameter was the proportion of patients with adequate relief of IBS symptoms at the last week of treatment. The secondary endpoints were changes in each symptom score and the safety profiles.

KEY RESULTS

The responder rates for global IBS symptoms, abdominal pain/discomfort and abnormal bowel habits in the ramosetron and mebeverine groups significantly increased during the treatment period. The severity scores of abdominal pain/discomfort and urgency, the stool form score, and the stool frequency in both treatment arms were significantly reduced, compared with the baselines. There were no significant differences in the responder rates (37%vs 38% on ITT analysis) and adverse event profiles between the ramosetron and mebeverine groups. Neither severe constipation nor ischemic colitis was reported by ramosetron-treated patients.

CONCLUSIONS & INFERENCES

Ramosetron 5μg once daily is as effective as mebeverine three times daily in male patients with IBS-D.

Prognostic factors for idiopathic pulmonary fibrosis: clinical, physiologic, pathologic, and molecular aspects

BACKGROUND

Previous studies identified clinical and physiologic factors of idiopathic pulmonary fibrosis (IPF) that are related to an increased risk of mortality. But there are few studies about histologic and molecular approach.

OBJECTIVE

We investigated whether the C-reactive protein (CRP), fibroblastic foci, phosphorylated Smad2/3 (p-Smad2/3), tumor growth factor-beta (TGF-beta), TGF-beta receptor II (TbetaRII), and the polymorphism of the TGF-beta1 codon 10 are associated with the progression of IPF patients.

DESIGN

Eighty-six IPF patients who underwent surgical lung biopsies were examined. For each patient, clinical and physiologic parameters were investigated, and we performed immunohistochemical staining for p-Smad2/3 and TbetaRII, and genotyping of the TGF-beta1 codon 10 polymorphism.

RESULTS

Age at diagnosis, gender, symptom duration, and smoking status did not show a significant association. However, the amount of smoking (p = 0.002), severe reduction in the percentages of predicted forced vital capacity (p = 0.013) and diffusion lung capacity of carbon monoxide (p = 0.023), CRP (p = 0.009) at diagnosis, and fibroblastic foci (p = 0.026) were associated with a poor prognosis. Cellularity, fibrosis, expression level of p-Smad2/3 and TbetaRII, and genotype of the TGF-beta1 codon 10 polymorphism did not have a statistically significant association with the prognosis.

CONCLUSION

This study confirmed the amount of smoking, abrupt decrease in follow-up pulmonary function parameters, fibroblastic foci, and increased levels of CRP concentration at diagnosis were significantly associated with poor survival. Larger studies are required to confirm all prognostic factors including CRP.

Adenosine derived from Staphylococcus aureus-engulfed macrophages functions as a potent stimulant for the induction of inflammatory cytokines in mast cells

In this study, we attempted to isolate novel mast cell-stimulating molecules from Staphylococcus aureus. Water-soluble extract of S. aureus cell lysate strongly induced human interleukin- 8 in human mast cell line-1 and mouse interleukin-6 in mouse bone marrow-derived mast cells. The active molecule was purified to homogeneity through a C(18) reverse phase HPLC column. By determination of its structure by MALDITOF and (1)H- and (13)C-NMR, adenosine was revealed to be responsible for the observed cytokine induction activities. Further studies using 8-sulfophenyl theophylline, a selective adenosine receptor blocker, verified that purified adenosine can induce interleukin-8 production via adenosine receptors on mast cells. Moreover, adenosine was purified from S. aureusengulfed RAW264.7 cells, a murine macrophage cell line, used to induce phagocytosis of S. aureus. These results show a novel view of the source of exogenous adenosine in vivo and provide a mechanistic link between inflammatory disease and bacterial infection.

EHR/EMR: "Meaningful use," stimulus money, and the Serenity Prayer

Theologian Reinhold Niebuhr said, “God, grant me the serenity to accept the things I cannot change; courage to change the things I can; and wisdom to know the difference.”

Meaningful use of electronic health records in otolaryngology: recommendations from the American Academy of Otolaryngology--Head and Neck Surgery Medical Informatics Committee

Under the Health Information Technology for Economic and Clinical Health (HITECH) Act, passed as a part of the American Recovery and Reinvestment Act of 2009, the US Congress implemented new regulations to encourage the adoption of electronic health records (EHRs). The federal government will expend up to $27 billion in incentive payments to physicians and hospitals to increase adoption and implement "meaningful use" of EHRs. Otolaryngologists may receive as much as $44,000 under Medicare or $63,750 under Medicaid as part of this law. In July 2010, the US Department of Health and Human Services announced final rules to support "meaningful use." This commentary discusses recommendations from the American Academy of Otolaryngology--Head and Neck Surgery Medical Informatics Committee for implementing "meaningful use" of EHRs to improve safety, quality, and efficiency of patient care and receiving incentive payments as defined by these new regulations.