TP53-induced glycolysis and apoptosis regulator (TIGAR) inhibits glycolysis and increases the flow of pentose phosphate pathway (PPP), which generates NADPH and pentose. We hypothesized that TIGAR plays a neuroprotective role in brain ischemia as neurons do not rely on glycolysis but are vulnerable to oxidative stress. We found that TIGAR was highly expressed in brain neurons and was rapidly upregulated in response to ischemia/reperfusion insult in a TP53-independent manner. Overexpression of TIGAR in normal mice with lentivirus reduced ischemic neuronal injury, whereas lentivirus-mediated TIGAR knockdown aggravated it. In cultured primary neurons, increasing TIGAR expression reduced oxygen and glucose deprivation (OGD)/reoxygenation-induced injury, whereas decreasing its expression worsened the injury. The glucose 6-phosphate dehydrogenase was upregulated in mouse and cellular models of stroke, and its upregulation was further enhanced by overexpression of TIGAR. Supplementation of NADPH also reduced ischemia/reperfusion brain injury and alleviated TIGAR knockdown-induced aggravation of ischemic injury. In animal and cellular stroke models, ischemia/ reperfusion increased mitochondrial localization of TIGAR. OGD/reoxygenation-induced elevation of ROS, reduction of GSH, dysfunction of mitochondria, and activation of caspase-3 were rescued by overexpression of TIGAR or supplementation of NADPH, while knockdown of TIGAR aggravated these changes. Together, our results show that TIGAR protects ischemic brain injury via enhancing PPP flux and preserving mitochondria function, and thus may be a valuable therapeutic target for ischemic brain injury.

No abstract

No abstract

J. Neurochem. (2012) 121, 1007–1013. Abstract Previous studies have demonstrated that a natural coumarin compound esculetin (Esc) possesses antioxidant, anti‐tumor, and anti‐inflammation activities and rescues cultured primary neurons from NMDA toxicity. In this study, we investigated the neuroprotective effects of Esc on cerebral ischemia/reperfusion (I/R) injury in a middle cerebral artery occlusion model in mice. Esc (20 μg) was administered intracerebroventricularly at 30 min before ischemia. We found that Esc significantly reduced infarct volume and decreased neurological deficit scores after 75 min of ischemia and 24 h of reperfusion. Post‐treatment of Esc still provided neuroprotection even when Esc was administered after 4 h of reperfusion. Our data also indicated that intraperitoneal administration of Esc showed protective effects on cerebral I/R injury in a dose‐dependent manner. We further explored the protective mechanisms of Esc on cerebral I/R injury and found that Esc decreased cleaved caspase 3 level, a marker of apoptosis. Finally, our data demonstrated that Esc exerted its anti‐apoptotic activity by up‐regulating the expression of Bcl‐2 and down‐regulating the expression of Bax, two apoptosis‐related proteins. Because of its clinical use as an anticoagulant and its safety profile, Esc may have a therapeutic potential for the treatment of stroke in the future clinical trials.

(18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has become useful for the detection and diagnosis of inflammatory conditions, including rheumatic diseases, immunoglobulin (Ig) G4-related disease and giant cell arteritis. However, few articles based on small sample sizes (n = 7) diagnosed as adult-onset Still's disease (AOSD) have been published. The study aim was to observe the reliable characteristics and usefulness of (18)F-FDG PET/CT for the evaluation of consecutive patients with AOSD. Eligible patients were selected from among those who had undergone (18)F-FDG PET/CT between May 2007 and June 2014. Twenty-six consecutive AOSD patients were recruited retrospectively according to criteria set by Yamaguchi et al. All patients underwent evaluation by (18)F-FDG PET/CT. The characteristics and usefulness of (18)F-FDG PET/CT for evaluation of consecutive patients with AOSD were evaluated. All 26 patients had (18)F-FDG-avid lesion(s) related to their particular disease. Diffuse and homogeneous accumulation of (18)F-FDG was seen in the bone marrow (26/26; 100 %; maximum standardized uptake (SUVmax), 2.10-6.73) and spleen (25/26; 96.15 %). The SUVmax of affected lymph nodes was 1.3-9.53 (mean ± SD, 4.12 ± 2.24). The SUVmax and size factors (maximum diameter and areas) of affected lymph nodes were significantly different (P = 0.033 and P = 0.012, respectively). (18)F-FDG PET/CT showed the general distribution of (18)F-FDG accumulation. This factor helped to exclude malignant disease and aided the diagnosis of AOSD (42.3 %) in 11 cases when combined with clinical features and aided decisions regarding appropriate biopsy sites, such as the lymph nodes (n = 9) and bone marrow (n = 13). (18)F-FDG PET/CT is a unique imaging method for the assessment of metabolic activity throughout the body in subjects with AOSD. Characteristics or patterns of AOSD observed on (18)F-FDG PET/CT can be used for the indication and diagnosis or to guide the clinical management of ASOD.

The present study investigated the underlying role of growth arrest-specific transcript 5 (GAS5) in epithelial ovarian cancer (EOC), which is the main cause of death in women with malignant tumor of the genital system. In vivo GAS5 expression in 60 EOC specimens was evaluated by quantitative reverse transcription (qRT)-PCR, which was used to study the differences of GAS5 expression between EOC tissues and normal ovarian epithelium. In vitro GAS5 overexpression was applied to discover the biological functions in EOC cell lines. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide and colony formation assays were employed to investigate the effect on proliferation. The function of apoptosis was assessed by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick-end labeling, and JC-1 probe staining, and migration and invasion were detected by Transwell assay. The data show that no significant differences of GAS5 expression were observed between normal ovarian epithelium and benign epithelial lesions; however, GAS5 expression was lower in EOC tissues compared with normal ovarian epithelial tissues (6.44-fold), which was closely related to lymph node metastasis (P=0.025) and tumor node metastasis stage (P=0.035). Moreover, exogenous GAS5-inhibited proliferation promoted apoptosis and decreased migration and invasion in ovarian cancer cells. Finally, through mitochondrial potential and western blot analyses, GAS5 could disrupt mitochondrial membrane potential and promote BAX, BAK, cleaved-caspase 3 and cleaved-caspase 9 expression. Taken together, the findings of the present study revealed that GAS5 is downregulated in EOC specimens, and GAS5 inhibits EOC cell proliferation, migration and invasion, and promotes cell apoptosis. GAS5 can serve as a novel therapeutic target in patients with EOC.

A series of quinazolinone derivatives were synthesized based on a hit compound identified from a high-throughput screening campaign targeting the human formyl peptide receptor-like 1 (FPRL1). Based on structure-activity relationship analysis, we found that substitution on the para position of the 2-phenyl group of the quinazolinone backbone could alter the pharmacological properties of the compound. The methoxyl substitution produced an agonist 4-butoxy-N-[2-(4-methoxy-phenyl)-4-oxo-1,4-dihydro-2H-quinazolin-3-yl]-benzamide (Quin-C1; C1), whereas a hydroxyl substitution resulted in a pure antagonist, Quin-C7 (C7). Several partial agonists were derived from other substitutions on the para position. C7 partially displaced3 H]N-formyl-Met-Leu-Phe to formyl peptide receptor. In functional assays using FPRL1-expressing RBL-2H3 cells, C7 inhibited calcium mobilization and chemotaxis induced by WKYMVm and C1 and degranulation elicited by C1. C7 also suppressed C1-induced extracellular signal-regulated kinase phosphorylation and reduced arachidonic acid-induced ear edema in mice. This study represents the first characterization of a nonpeptidic antagonist for FPRL1 and suggests the prospect of using low molecular weight compounds as modulators of chemoattractant receptors in vitro and in vivo.The human formyl peptide receptor (FPR) family of chemoattractant receptors consists of FPR, formyl peptide receptor-like 1 (FPRL1), and FPRL2. These receptors are expressed primarily in neutrophils and monocytes and exert important functions in inflammation and immunity (Le et al., 2002). The FPRL1 gene was initially cloned in 1992 for its homology with FPR cDNA (Bao et al., 1992;Murphy et al., 1992;Ye et al., 1992). The prototype of chemotactic peptide N-formyl-Met-Leu-Phe (fMLF), an agonist for FPR, can also activate FPRL1 with a reduced affinity (Quehenberger et al., 1993). Stimulation of FPRL1 elicits a cascade of host defense reactions against pathogens, including chemotaxis, superoxide generation, and exocytosis in human neutrophils. In addition, it was reported that FPRL1 attenuates HIV-1 infection by desensitizing and down-regulating the chemokine receptors CCR5 and CXCR4, which serve as major coreceptors for HIV-1, on monocyte surfaces (Li et al., 2001). A recent study showed that the expression of FPRL1 in mouse C26 cells markedly reduced tumorigenicity in syngeneic mice and resulted in high levels of humoral immune response to both FPRL1-containing and wild-type C26 cells . The data indicate that FPRL1 also plays a key role in specific antitumor response. The expression of FPRL1 in activated microglial cells and its function as a receptor for A␤(1-42), a 42-amino acid form of the ␤-amyloid peptide, suggest that FPRL1 is closely related to neurodegenerative disorders . Investigation in ligand binding, signal transduction, and functional properties of FPRL1 is expected to facilThis project was supported in part by grants from the Ministry

Cyclosporin A (CsA) is a fungus-derived cyclic undecapeptide with potent immunosuppressive activity. Its analog, cyclosporin H (CsH), lacks immunosuppressive function but can act as an antagonist for the human formyl peptide receptor (FPR). More recent studies have shown that CsA also inhibits fMLF-induced degranulation in differentiated HL-60 promyelocytic leukemia cells. However, it is unclear whether CsA interferes with ligand-receptor interaction, G protein activation, or other downstream signaling events. In this study we used human neutrophils, differentiated HL-60 cells, and rat basophilic leukemia (RBL)-2H3 cells expressing human FPR (RBL-FPR) to identify the action site of CsA. In functional assays, CsA inhibited fMLF-stimulated degranulation, chemotaxis, calcium mobilization, and phosphorylation of the MAPKs ERK 1/2 and the serine/threonine protein kinase Akt. CsA also blocked Trp-Lys-Tyr-Met-Val-d-Met (WKYMVm)-induced functions in RBL-FPR cells. Concentrations for half-maximal inhibition with CsA are generally 6- to 50-fold higher than that of CsH. CsA was compared with another immunosuppressant, ascomycin, relative to the inhibitory effects on FPR-mediated chemotaxis, calcium mobilization, and degranulation. In these experiments, ascomycin produced no inhibitory effects at low micromolar concentrations (1–4 μM), whereas the inhibitory effects of CsA were prominent at comparable concentrations. Finally, CsA dose-dependently inhibited the uptake of fNle-Leu-Phe-Nle-Tyr-Lys-fluoresceine and [3H]fMLF or [125I]WKYMVm binding to FPR. However, CsA and CsH did not show any obvious inhibitory effect on FPR-like 1-mediated cellular functions. These results demonstrate that CsA is a selective antagonist of FPR and that its inhibition of fMLF-stimulated leukocyte activation is at the level of cognate ligand binding.