Identification and characterization of lysophosphatidylcholine 14:0 as a biomarker for drug-induced lung disease.

Drug-induced interstitial lung disease (DILD) occurs when drug exposure causes inflammation of the lung interstitium. DILD can be caused by different types of drugs, and some DILD patterns results in a high mortality rate; hence, DILD poses a serious problem in clinical practice as well as drug development, and strategies to diagnose and distinguish DILD from other lung diseases are necessary. We aimed to identify novel biomarkers for DILD by performing lipidomics analysis on plasma samples from patients with acute and recovery phase DILD.

Stratifin as a novel diagnostic biomarker in serum for diffuse alveolar damage.

Among the various histopathological patterns of drug-induced interstitial lung disease (DILD), diffuse alveolar damage (DAD) is associated with poor prognosis. However, there is no reliable biomarker for its accurate diagnosis. Here, we show stratifin/14-3-3σ (SFN) as a biomarker candidate found in a proteomic analysis.

Plasma Lipid Profiling of Three Types of Drug-Induced Liver Injury in Japanese Patients: A Preliminary Study.

Drug-induced liver injury (DILI) is a major adverse event caused by drug treatment, which can be categorized into three types: hepatocellular, mixed, and cholestatic. Although nearly every class of drugs can cause DILI, an overall understanding of lipid profiles in DILI patients is lacking. We used lipidomics to analyze the plasma lipid profiles of patients to understand their hepatic pathophysiology and identify DILI biomarkers.

Outer retinal involvement in N-methyl-D-aspartate-induced inner retinal injury in rabbits assessed by optical coherence tomography.

This study was aimed to investigate morphological alteration of the retina with N-methyl-D-aspartate (NMDA)-induced injury in rabbits by optical coherence tomography (OCT). The right and left eyes of a total of 12 rabbits received single-intravitreal injection of vehicle and NMDA, respectively. Four out of the 12 animals underwent OCT and quantification of plasma microRNA repeatedly (4, 48, and 168 hr after dosing), followed by ocular histopathology at the end of the study.

S-Nitrosylation at the active site decreases the ubiquitin-conjugating activity of ubiquitin-conjugating enzyme E2 D1 (UBE2D1), an ERAD-associated protein.

S-Nitrosylation of protein cysteine thiol is a post-translational modification mediated by nitric oxide (NO). The overproduction of NO causes nitrosative stress, which is known to induce endoplasmic reticulum (ER) stress. We previously reported that S-nitrosylation of protein disulfide isomerase (PDI) and the ER stress sensor inositol-requiring enzyme 1 (IRE1) decreases their enzymatic activities.

Plasma citrulline is a sensitive safety biomarker for small intestinal injury in rats.

Plasma citrulline is decreased in cases of severe intestinal injury with apparent villus and cellular atrophy. However, the fluctuation of plasma citrulline in slight intestinal injury remains to be investigated. To clarify this, irinotecan at 30 mg/kg or 60 mg/kg was administered intravenously to rats.

TRAV7-2*02 Expressing CD8⁺ T Cells Are Responsible for Palladium Allergy.

While metallic biomaterials have led to an improvement in the quality of life, metal allergies, especially to palladium (Pd), has caused a recent increase in allergic patients. Metal allergy is known to be a T cell-mediated delayed-type hypersensitivity (DTH); however, the pathogenic T cell subsets and the specific T cell receptor (TCR) have not been identified. Therefore, we attempted to identify the pathogenic T cells responsible for Pd allergy.

Promising toxicological biomarkers for the diagnosis of liver injury types: Bile acid metabolic profiles and oxidative stress marker as screening tools in drug development.

Promising biomarkers were identified in adult male Crl:CD (SD) rats for the screening of new chemical entities for their potential to cause liver injury. We examined the serum biochemistry, liver histopathology, and bile acid profiles by LC-MS/MS, and the mRNA expression of transporters and CYPs by an RT-PCR after the following treatments to male Crl:CD (SD) rats: (a) bile duct ligation (BDL); (b) a single oral dose of 150 mg/kg α-naphthylisothiocyanate (ANIT); and (c) repeated oral doses of a novel pyrrolidinecarboxylic acid derivative (abbreviated as PCA) at 30, 300, and 1000 mg/kg. The serum total bile acid levels and bilirubin concentrations were found to be elevated in all of the groups.

Correlation between attenuation of protein disulfide isomerase activity through S-mercuration and neurotoxicity induced by methylmercury.

Methylmercury (MeHg), an environmental pollutant, causes neuronal death via endoplasmic reticulum (ER) stress; however, the precise mechanism is not fully understood. The aim of this study was to elucidate the possible mechanism of MeHg-induced neurotoxicity. Treatment with MeHg resulted in a loss of cell viability in a concentration-dependent manner accompanying the expression of ER stress marker genes in human neuroblastoma SH-SY5Y cells.

NKG2D⁺ IFN-γ⁺ CD8⁺ T cells are responsible for palladium allergy.

Nickel, cobalt, and chromium are well known to be causal agents of allergic contact dermatitis. Palladium (Pd) can also cause allergic disease and exposure results from wide use of this metal in dental restorations and jewelry. Metal allergy is categorized as a delayed-type hypersensitivity, and metal-responsive T cell clones have been isolated from allergic patients.

Nicotine- and tar-free cigarette smoke induces cell damage through reactive oxygen species newly generated by PKC-dependent activation of NADPH oxidase.

We examined cytotoxic effects of nicotine/tar-free cigarette smoke extract (CSE) on C6 glioma cells. The CSE induced plasma membrane damage (determined by lactate dehydrogenase leakage and propidium iodide uptake) and cell apoptosis {determined by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] reduction activity and DNA fragmentation}. The cytotoxic activity decayed with a half-life of approximately 2 h at 37°C, and it was abolished by N-acetyl-L-cysteine and reduced glutathione.

Function and regulation of endothelin type A receptor-operated transient receptor potential canonical channels.

The purpose of this study is to identify transient receptor potential canonical (TRPC) channels responsible for receptor-operated Ca(2+) entry (ROCE) triggered by activation of endothelin type A receptor (ET(A)R) and to clarify the importance of calmodulin (CaM) / inositol 1,4,5-trisphosphate (IP(3)) receptor binding (CIRB) domain at the C terminus of TRPC channels in ET(A)R-activated channel regulation. In HEK293 cells coexpressing ET(A)R and one of seven TRPC isoforms, ET(A)R stimulation induced ROCE through TRPC3, TRPC5, TRPC6, and TRPC7. The TRPC3- and TRPC6-mediated ROCE was inhibited by selective inhibitors of G(q) protein, phospholipase C (PLC), and CaM.

Adenylate cyclase/cAMP/protein kinase A signaling pathway inhibits endothelin type A receptor-operated Ca²⁺ entry mediated via transient receptor potential canonical 6 channels.

Receptor-operated Ca²⁺ entry (ROCE) via transient receptor potential canonical channel 6 (TRPC6) is important machinery for an increase in intracellular Ca²⁺ concentration triggered by the activation of G(q) protein-coupled receptors. TRPC6 is phosphorylated by various protein kinases including protein kinase A (PKA). However, the regulation of TRPC6 activity by PKA is still controversial.

On-off system for PI3-kinase-Akt signaling through S-nitrosylation of phosphatase with sequence homology to tensin (PTEN).

Nitric oxide (NO) physiologically regulates numerous cellular responses through S-nitrosylation of protein cysteine residues. We performed antibody-array screening in conjunction with biotin-switch assays to look for S-nitrosylated proteins. Using this combination of techniques, we found that phosphatase with sequence homology to tensin (PTEN) is selectively S-nitrosylated by low concentrations of NO at a specific cysteine residue (Cys-83).

The ECS(SPSB) E3 ubiquitin ligase is the master regulator of the lifetime of inducible nitric-oxide synthase.

The ubiquitin-proteasome pathway is an important regulatory system for the lifetime of inducible nitric-oxide synthase (iNOS), a high-output isoform compared to neuronal NOS (nNOS) and endothelial NOS (eNOS), to prevent overproduction of NO that could trigger detrimental effects such as cytotoxicity. Two E3 ubiquitin ligases, Elongin B/C-Cullin-5-SPRY domain- and SOCS box-containing protein [ECS(SPSB)] and the C-terminus of Hsp70-interacting protein (CHIP), recently have been reported to target iNOS for proteasomal degradation. However, the significance of each E3 ubiquitin ligase for the proteasomal degradation of iNOS remains to be determined.

A Phase I clinical study of cisplatin-incorporated polymeric micelles (NC-6004) in patients with solid tumours.

Background: On the basis of preclinical studies of NC-6004, a cisplatin-incorporated micellar formulation, we hypothesised that NC-6004 could show lower toxicity than cisplatin and show greater anti-tumour activity in phase I study.

Methods: A total of 17 patients were recruited in a range of advanced solid tumour types. NC-6004 was administered intravenously (i.

Regulation of inducible nitric-oxide synthase by the SPRY domain- and SOCS box-containing proteins.

Inducible nitric-oxide synthase (iNOS, NOS2) plays a prominent role in macrophage bactericidal and tumoricidal activities. A relatively large amount of NO produced via iNOS, however, also targets the macrophage itself for apoptotic cell death. To uncover the intrinsic mechanisms of iNOS regulation, we have characterized the SPRY domain- and SOCS box-containing protein 1 (SPSB1), SPSB2, and SPSB4 that interact with the N-terminal region of iNOS in a D-I-N-N-N sequence-dependent manner.

Screening systems for the identification of S-nitrosylated proteins.

S-nitrosylation is a well-characterized reaction involving the covalent binding of nitric oxide (NO) to cysteine residues (Cys) in a protein. Similar to protein phosphorylation, S-nitrosylation is a post-translational modification involved in the regulation of a large number of intracellular functions and signaling events. Moreover, like phosphorylation, S-nitrosylation is precisely regulated in time and space.

Endothelin type B receptor-induced sustained Ca2+ influx involves G(q/11)/phospholipase C-independent, p38 mitogen-activated protein kinase-dependent activation of Na+/H+ exchanger.

The mechanism for sustained Ca2+ influx activated by G protein-coupled receptors was examined. In Chinese hamster ovary cells expressing recombinant human endothelin type B receptor (ET(B)R) and endogenous P2Y receptor (P2Y-R), endothelin-1 elicited a sustained Ca2+ influx depending on G(q/11 )protein, phospholipase C (PLC), Na+/H+ exchanger (NHE), and p38 mitogen-activated protein kinase (p38MAPK), whereas P2Y-R-induced sustained Ca2+ influx was negligible. Functional studies showed that NHE activation by ET(B)R was mediated via p38MAPK but not G(q/11)/PLC, while that by P2Y-R involves only G(q/11)/PLC/p38MAPK.

Jab1 regulates levels of endothelin type A and B receptors by promoting ubiquitination and degradation.

Endothelin type A receptor (ET(A)R) plays an important role in some cardiovascular disorders where ET(A)R levels are increased. However, regulatory mechanisms for ET(A)R levels are unknown. Here, we identified Jun activation domain-binding protein 1 (Jab1) as an ET(A)R-interacting protein by yeast two-hybrid screening of human heart cDNA library using carboxyl terminal tail (C-tail) of ET(A)R as a bait.

Differential coupling of human endothelin type A receptor to G(q/11) and G(12) proteins: the functional significance of receptor expression level in generating multiple receptor signaling.

This study examines the influence of receptor expression level on signaling pathways activated via endothelin type A receptor (ET(A)R) expressed in Chinese hamster ovary cells at 32,100 (ET(A)R-high-CHO) and 893 (ET(A)R-low-CHO) fmolmg protein(-1). Endothelin-1 (ET-1) elicited a sustained increase in intracellular Ca(2+) concentration ([Ca(2+)](i)), which was dependent on G(q/11) protein, phospholipase C (PLC), Na(+)/H(+) exchanger (NHE), and p38 mitogen-activated protein kinase (p38MAPK) in ET(A)R-high-CHO, whereas the sustained [Ca(2+)](i) increase was negligible in ET(A)R-low-CHO. Functional study with Cytosensor(TM) microphysiometer showed that ET-1 evoked an NHE1-mediated increase in extracellular acidification rate (ECAR) in ET(A)R-high-CHO and ET(A)R-low-CHO.

Involvement of cytochrome P450-mediated metabolism in tienilic acid hepatotoxicity in rats.

Tienilic acid is reported to be converted into electrophilic metabolites by cytochrome P450 (CYP) in vitro. In vivo, however, the metabolites have not been detected and their effect on liver function is unknown. We previously demonstrated that tienilic acid decreased the GSH level and upregulated genes responsive to oxidative/electrophilic stresses, such as heme oxygenase-1 (Ho-1), glutamate-cysteine ligase modifier subunit (Gclm) and NAD(P)H dehydrogenase quinone 1 (Nqo1), in rat liver, as well as inducing hepatotoxicity by co-treatment with the glutathione biosynthesis inhibitor l-buthionine-(S,R)-sulfoximine (BSO).

The crucial protective role of glutathione against tienilic acid hepatotoxicity in rats.

To investigate the hepatotoxic potential of tienilic acid in vivo, we administered a single oral dose of tienilic acid to Sprague-Dawley rats and performed general clinicopathological examinations and hepatic gene expression analysis using Affymetrix microarrays. No change in the serum transaminases was noted at up to 1000 mg/kg, although slight elevation of the serum bile acid and bilirubin, and very mild hepatotoxic changes in morphology were observed. In contrast to the marginal clinicopathological changes, marked upregulation of the genes involved in glutathione biosynthesis [glutathione synthetase and glutamate-cysteine ligase (Gcl)], oxidative stress response [heme oxygenase-1 and NAD(P)H dehydrogenase quinone 1] and phase II drug metabolism (glutathione S-transferase and UDP glycosyltransferase 1A6) were noted after 3 or 6 h post-dosing.