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Introduction The jejunal pouch interposition (JPI) after proximal gastrectomy (PG) was proposed as a reconstructive procedure to provide a gastric reservoir substitute and prevent postgastrectomy syndrome. However, food residue remaining in some of the pouches resulted in the adverse effect of abdominal bloating, thereby body weight loss. Here, we report a rare case with an extreme dilation of the interposed jejunal pouch (JP) 8 years after PG, requiring pouch resection. Presentation of case A 65-year-old-man who had undergone PG with an inverted U-shaped JPI for early gastric cancer 8 years previously, suffered from shock after right hip joint implantation. Abdominal enhanced CT scan revealed an extremely dilated JP accompanied by portal venous gas. After 5 months of conservative therapy, he underwent resection of the JP and gastric remnant with Roux-en-Y esophagojejunostomy reconstruction. After the operation, the patient has remained in good health for over 3 years. Discussion and conclusion Long-term operative outcome following pouch operation for gastric cancer still remains controversial. Surgical intervention should be considered when we encounter patients who have refractory pouch dilatation after surgery for gastric cancer. [ABSTRACT FROM AUTHOR]

Cellular heterogeneity of aortic valves complicates the mechanistic evaluation of the calcification processes in calcific aortic valve disease (CAVD), and animal disease models are lacking. In this study, we identify a disease-driver population (DDP) within valvular interstitial cells (VICs). Through stepwise single-cell analysis, phenotype-guided omic profiling, and network-based analysis, we characterize the DDP fingerprint as CD44highCD29+CD59+CD73+CD45low and discover potential key regulators of human CAVD. These DDP-VICs demonstrate multi-lineage differentiation and osteogenic properties. Temporal proteomic profiling of DDP-VICs identifies potential targets for therapy, including MAOA and CTHRC1. In vitro loss-of-function experiments confirm our targets. Such a stepwise strategy may be advantageous for therapeutic target discovery in other disease contexts. [Display omitted] • CD44highCD29+CD59+CD73+CD45low cells are disease-driving population (DDP) VICs in CAVD • DDP-VICs possess osteogenic differentiation properties • Single-cell analysis and proteomics identified CAVD targets like MAOA and CTHRC1 • MAOA and CTHRC1 inhibition attenuate calcification in human aortic VICs Decano et al. characterize valvular interstitial cells (VICs) that are CD44highCD29+CD59+CD73+CD45low within human calcific valve disease (CAVD) as a disease-driver population (DDP) capable of osteogenic and procalcific differentiation. Phenotype-guided single-cell, multi-omic analysis identifies potential CAVD key regulators, such as MAOA and CTHRC1, validated through in vitro loss of function and histology. [ABSTRACT FROM AUTHOR]

Abstract: Lipid rafts, microdomains in the plasma membrane, are known to be involved in G protein-coupled receptor signal transduction; however, their involvement in thromboxane A2 receptor (TP) signaling remains to be clarified. We examined whether two isoforms of TP, TPα and TPβ, utilize lipid rafts for multiple G protein signal transduction. Sucrose density gradient centrifugation followed by western blotting of HEK cells expressing TPα or TPβ revealed the localization of both TPα and TPβ in lipid rafts. Furthermore, methyl-β-cyclodextrin, which destroys lipid raft structure by depleting cholesterol, influenced G protein signaling elicited by TPα and TPβ to varying degrees. Phosphatidylinositol hydrolysis and cAMP accumulation induced by TPα or TPβ stimulation was markedly inhibited by methyl-β-cyclodextrin. In contrast, treatment with methyl-β-cyclodextrin partially inhibited RhoA activation induced by TPα stimulation, but failed to affect TPβ stimulation. Furthermore, the inhibitory action of methyl-β-cyclodextrin on cAMP accumulation was specific to TPα and TPβ, because methyl-β-cyclodextrin enhanced forskolin and β-adrenergic stimulation-induced cAMP accumulation. These results indicate that TP isoforms depend on lipid rafts during Gq and Gs signaling, while G13 signaling mediated by TP isoforms does not. Moreover, TPα seems to be more lipid raft-dependent with respect to RhoA activation than TPβ. These results indicate that the two isoforms of the TP mediate multiple signal transductions with varying degrees of lipid raft dependency. Moreover, our results provide a deeper understanding of the function of lipid rafts in G protein signaling and the physiological meaning of TP isoforms. [Copyright &y& Elsevier]

Abstract: Glutathione S-transferases (GSTs) are multifunctional enzymes involved in the protection of cellular components against anti-cancer drugs or peroxidative stress. Previously we found that GST π, an isoform of the GSTs, is transported into the nucleus. In the present study, we found that GST π is present in mitochondria as well as in the cytosol and nucleus in mammalian cell lines. A construct comprising the 84 amino acid residues in the amino-terminal region of GST π and green fluorescent protein was detected in the mitochondria. The mutation of arginine to alanine at positions 12, 14, 19, 71, and 75 in full-length GST π completely abrogated the ability to distribute in the mitochondria, suggesting that arginine, a positively charged residue, is required for the mitochondrial transport of GST π. Chemicals generating reactive oxygen species, such as rotenone and antimycin A, decreased cell viability and reduced mitochondrial membrane potential. The overexpression of GST π diminished these changes. GST π-targeting siRNA abolished the protective effect of GST π on the mitochondria under oxidative stress. The findings indicate that the peptide signal is conducive to the mitochondrial localization of GST π under steady-state conditions without alternative splicing or posttranslational modifications such as proteolysis, suggesting that GST π protects mitochondria against oxidative stress. [Copyright &y& Elsevier]

Abstract: We previously found that nuclear glutathione S-transferase π (GSTπ) accumulates in cancer cells resistant to anticancer drugs, suggesting that it has a role in the acquisition of resistance to anticancer drugs. In the present study, the effect of oxidative stress on the nuclear translocation of GSTπ and its role in the protection of DNA from damage were investigated. In human colonic cancer HCT8 cells, the hydrogen peroxide (H2O2)-induced increase in nuclear condensation, the population of sub-G1 peak, and the number of TUNEL-positive cells were observed in cells pretreated with edible mushroom lectin, an inhibitor of the nuclear transport of GSTπ. The DNA damage and the formation of lipid peroxide were dependent on the dose of H2O2 and the incubation time. Immunological analysis showed that H2O2 induced the nuclear accumulation of GSTπ but not of glutathione peroxidase. Formation of the 7-(2-oxo-hepyl)-substituted 1,N2-etheno-2′-deoxyguanosine adduct by the reaction of 13-hydroperoxyoctadecadienoic acid (13-HPODE) with 2′-deoxyguanosine was inhibited by GSTπ in the presence of glutathione. The conjugation product of 4-oxo-2-nonenal, a lipid aldehyde of 13-HPODE, with GSH in the presence of GSTπ, was identified by LS/MS. These results suggested that nuclear GSTπ prevents H2O2-induced DNA damage by scavenging the formation of lipid-peroxide-modified DNA. [Copyright &y& Elsevier]

The GSH/glutaredoxin (GRX) system is involved in the redox regulation of certain enzyme activities, and this system protects cells from H2O2-induced apoptosis by regulating the redox state of Akt (Murata, H., Ihara, Y., Nakamura, H., Yodoi, J., Sumikawa, K., and Kondo, T. (2003) J. Biol. Chem. 278, 50226-50233). Estrogens, such as 17β-estradiol (E2), play an important role in development, growth, and differentiation and appear to have protective effects on oxidative stress mediated by estrogen receptor α (ERα). However, the role of the ERβ-mediated pathway in this cytoprotection and the involvement of E2 in the redox regulation are not well understood. In the present study, we demonstrated that E2 protected cardiac H9c2 cells, expressing ERβfrom H2O2-induced apoptosis concomitant with an increase in the activity of Akt. E2 induced the expression of glutaredoxin (GRX) as well as γ-glutamylcysteine synthetase, a rate-limiting enzyme for the synthesis of GSH. Inhibitors for both γ-glutamylcysteine synthetase and GRX and ICI182,780, a specific inhibitor of ERs, abolished the protective effect of E2 on cell survival as well as the activity of Akt, suggesting that ERβ is involved in the cytoprotection and redox regulation by E2. Transcription of the GRX gene was enhanced by E2. The promoter activity of GRX was up-regulated by an ERβ-dependent element. These results suggest that the GRX/GSH system is involved in the cytoprotective and genomic effects of E2 on the redox state of Akt, a pathway that is mediated, at least in part, by ERβ. This mechanism may also play an antiapoptotic role in cancer cells during carcinogenesis or chemotherapy. [ABSTRACT FROM AUTHOR]

Accumulating evidence has suggested that prion protein (PrP) is neuroprotective and that a PrP-like protein/Doppel (PrPLP/Dpl) is neurotoxic. A line of PrPdeficient mice, Ngsk Prnp[sup 0/0], ectopically expressing PrPLP/Dpl in neurons, exhibits late-onset ataxia because of Purkinje cell death that is prevented by a transgene encoding wild-type mouse PrP. To elucidate the mechanisms of neurodegeneration in these mice, we introduced five types of PrP transgene, namely one heterologous hamster, two mouse/hamster chimeric genes, and two mutants, each of which encoded PrP lacking residues 23-88 (MHM2.del23-88) or with E199K substitution (Mo.E199K), into Ngsk Prnp[sup 0/0] mice. Only MHM2.deI23-88 failed to rescue the mice from the Purkinje cell death. The transgenic mice, MHM2.del23-88/ Ngsk Prnp[sup 0/0], expressed several times more PrP than did wild-type (Prnp[sup +/+]) mice and PrPLP/Dpl at an equivalent level to Ngsk Prnp[sup 0/0] mice. Little difference was observed in the pathology and onset of ataxia between Ngsk Prnp[sup 0/0] and MHM2.del23-88/Ngsk Prnp[sup 0/0]. No detergent-insoluble PrPLP/Dpl was detectable in the central nervous system of Ngsk Prnp[sup 0/0] mice even after the onset of ataxia. Our findings provide evidence that the N-terminal residues 23-88 of PrP containing the unique octapeptide-repeat region is crucial for preventing Purkinje cell death in Prnp[sup 0/0] mice expressing PrPLP/Dpl in the neuron. [ABSTRACT FROM AUTHOR]

Advanced glycation end products (AGEs) are believed to play an important role in the development of angiopathy in diabetes mellitus. Previous reports suggested a correlation between accumulation of AGEs and production of vascular endothelial growth factor (VEGF) in human diabetic retina. However, the mechanisms involved were not revealed. In this study, we investigated the transcriptional regulation of the expression of vascular endothelial growth factor (VEGF) by AGEs, and possible involvement of reactive oxygen species (ROS) in the induction. We employed an AGE of bovine serum albumin (BSA) prepared by an incubation of BSA with D-glucose for 40 weeks and N(epsilon)-(carboxymethyl)lysine (CML), a major AGE. The expression of VEGF was induced by CML-BSA in RAW264.7 mouse macrophage-like cells. CML-BSA stimulated the DNA-binding activity of activator protein-1 (AP-1). Promoter assay showed that the induction of VEGF was dependent on AP-1. The activity of Ras/Raf-1/MEK/ERK1/2 was involved in the CML-BSA-stimulated signaling pathways to activate the AP-1 transcription with a peak at 1 h. AGE-BSA also induced VEGF mediated by AP-1, however, there was a difference of effect between AGE-BSA and CML-BSA in the activation of AP-1. AGE-BSA-stimulated AP-1 activity showed a peak at 5 h, which paralleled the formation of ROS. Reduction of AGE-BSA with NaBH4 or addition of vitamin E attenuated the AGE-BSA-stimulated signaling pathways leading to the same pattern as for CML-BSA-stimulated signals. These results suggest an important role for AGEs in stimulation of the development of angiogenesis observed in diabetic complications, and that ROS accelerates the AGE-stimulated VEGF expression. [Copyright &y& Elsevier]