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Recent years have seen advances in our understanding of the neural circuits associated with trauma-related disorders, and the development of relevant assays for these behaviors in rodents. Although inherited factors are known to influence individual differences in risk for these disorders, it has been difficult to identify specific genes that moderate circuit functions to affect trauma-related behaviors. Here, we exploited robust inbred mouse strain differences in Pavlovian fear extinction to uncover quantitative trait loci (QTL) associated with this trait. We found these strain differences to be resistant to developmental cross-fostering and associated with anatomical variation in basolateral amygdala (BLA) perineuronal nets, which are developmentally implicated in extinction. Next, by profiling extinction-driven BLA expression of QTL-linked genes, we nominated Ppid (peptidylprolyl isomerase D, a member of the tetratricopeptide repeat (TPR) protein family) as an extinction-related candidate gene. We then showed that Ppid was enriched in excitatory and inhibitory BLA neuronal populations, but at lower levels in the extinction-impaired mouse strain. Using a virus-based approach to directly regulate Ppid function, we demonstrated that downregulating BLA-Ppid impaired extinction, while upregulating BLA-Ppid facilitated extinction and altered in vivo neuronal extinction encoding. Next, we showed that Ppid colocalized with the glucocorticoid receptor (GR) in BLA neurons and found that the extinction-facilitating effects of Ppid upregulation were blocked by a GR antagonist. Collectively, our results identify Ppid as a novel gene involved in regulating extinction via functional actions in the BLA, with possible implications for understanding genetic and pathophysiological mechanisms underlying risk for trauma-related disorders.

// So-Yeon Kim 1 , Ho-Chang Jeong 1 , Soon-Ki Hong 1 , Mi-Ok Lee 2 , Seung-Ju Cho 1 and Hyuk-Jin Cha 1 1 College of Natural Sciences, Department of Life Sciences, Sogang University, Seoul 121–742, Korea 2 Stem Cell Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305–806, Korea Correspondence to: Hyuk-Jin Cha, email: hjcha@sogang.ac.kr Seung-Ju Cho, email: sjcho122108@gmail.com Keywords: quercetin, human embryonic stem cells (hESCs), reactive oxygen species (ROS), p53, cyclophilin D Received: March 30, 2016 Accepted: July 19, 2016 Published: August 05, 2016 ABSTRACT Small molecules to selectively induce cell death of undifferentiated human pluripotent stem cells (hPSCs) have been developed with the aim of lowering the risk of teratoma formation during hPSC-based cell therapy. In this context, we have reported that Quercetin (QC) induces cell death selectively in hESCs via p53 mitochondrial localization. However, the detailed molecular mechanism by which hESCs undergo selective cell death induced by QC remains unclear. Herein, we demonstrate that mitochondrial reactive oxygen species (ROS), strongly induced by QC in human embryonic stem cells (hESCs) but not in human dermal fibroblasts (hDFs), were responsible for QC-mediated hESC’s cell death. Increased p53 protein stability and subsequent mitochondrial localization by QC treatment triggered mitochondrial cell death only in hESCs. Of interest, peptidylprolyl isomerase D [ PPID , also called cyclophilin D (CypD)], which functions in mitochondrial permeability transition and mitochondrial cell death, was highly expressed in hESCs. Inhibition of CypD by cyclosporine A (CsA) clearly inhibited the QC-mediated loss of mitochondrial membrane potential and mitochondrial cell death. These results suggest that p53 and CypD in the mitochondria are critical for the QC-mediated induction of cell death in hESCs.

Background/Aims: Increased oxidative stress and decreased immune cell apoptosis have been reported to be important factors in the pathogenesis of Crohn’s disease (CD). Our aim was to characterize the genetic expression of molecules implicated in the regulation of oxidative stress and apoptosis in peripheral white mononuclear cells of 18 healthy volunteers (controls) and 20 patients at the onset of CD (active CD [aCD]): 10 who achieved remission (inactive CD [iCD]) and 10 who did not present a complete and deep response to treatment (aCD-T). Methods: mRNA expression was measured by the Agena MassARRAY quantitative gene expression analysis application. The genes analyzed were Fas-receptor (FASR), Fas-ligand (FASL), signal transducer and activator of transcription 1 (STAT1), nuclear factor kappa-light-chain-­enhancer of activated B cells (NFKB1), apoptosis signal-regulating kinase 1 (ASK1), serine/threonine-protein kinase H1 (PSKH1), ATP-binding cassette sub-family B1 (ABCB1) and peptidylprolyl isomerase D (PPID). Results: During a CD flare, we found specific upregulated expression of the genes STAT1 and PSKH1, whereas ABCB1 and FASL were downregulated. In the patients with iCD, FASR and NFKB1 were upregulated. The expression levels of NFKB1, STAT1 and ABCB1 did not show any difference in patients with aCD at the onset of the disease and after treatment (aCD-T). The expression levels of PPID and ASK1 did not show any differences in the patients with aCD, iCD and the controls. We have also reviewed the cellular function and role of these genes in CD. Conclusions: These findings contribute to improving the understanding of the pathogenesis of CD and highlight potential genes involved.

Background & Aims Little is known about the signaling pathways that initiate and promote acute pancreatitis (AP). The pathogenesis of AP has been associated with abnormal increases in cytosolic Ca 2+ , mitochondrial dysfunction, impaired autophagy, and endoplasmic reticulum (ER) stress. We analyzed the mechanisms of these dysfunctions and their relationships, and how these contribute to development of AP in mice and rats. Methods Pancreatitis was induced in C57BL/6J mice (control) and mice deficient in peptidylprolyl isomerase D (cyclophilin D, encoded by Ppid ) by administration of L-arginine (also in rats), caerulein, bile acid, or an AP-inducing diet. Parameters of pancreatitis, mitochondrial function, autophagy, ER stress, and lipid metabolism were measured in pancreatic tissue, acinar cells, and isolated mitochondria. Some mice with AP were given trehalose to enhance autophagic efficiency. Human pancreatitis tissues were analyzed by immunofluorescence. Results Mitochondrial dysfunction in pancreas of mice with AP was induced by either mitochondrial Ca 2+ overload or through a Ca 2+ overload-independent pathway that involved reduced activity of ATP synthase (80% inhibition in pancreatic mitochondria isolated from rats or mice given L-arginine). Both pathways were mediated by cyclophilin D and led to mitochondrial depolarization and fragmentation. Mitochondrial dysfunction caused pancreatic ER stress, impaired autophagy, and deregulation of lipid metabolism. These pathologic responses were abrogated in cyclophilin D-knockout mice. Administration of trehalose largely prevented trypsinogen activation, necrosis, and other parameters of pancreatic injury in mice with L-arginine AP. Tissues from patients with pancreatitis had markers of mitochondrial damage and impaired autophagy, compared with normal pancreas. Conclusions In different animal models, we find a central role for mitochondrial dysfunction, and for impaired autophagy as its principal downstream effector, in development of AP. In particular, the pathway involving enhanced interaction of cyclophilin D with ATP synthase mediates L-arginine–induced pancreatitis, a model of severe AP the pathogenesis of which has remained unknown. Strategies to restore mitochondrial and/or autophagic function might be developed for treatment of AP.

The aim was to characterise gene expression in the hypothalamus of suckled and weaned postpartum beef cows. The hypothalamus was obtained at slaughter from 12 primiparous Brahman cows (Zebu, Bos indicus) at 27 and 34 days postpartum. Six cows were weaned 7 days or 14 days before slaughter. Hypothalamic regions used for gene expression were: H1 (SC-POA, APVN, anterior hypothalamic nucleus, anterior portion of the arcuate nucleus, nearby areas of the diagonal band of Broca, and medial septum); H2 (basal hypothalamus-median eminence, ventromedial hypothalamus, posterior portion of the arcuate nucleus, and anterior part of the mammillary body). Gene expression was determined using the Agilent bovine 44k DNA microarray and differential expression (DE) was ascertained by mixed model analysis. A total of 122 genes were DE in H1 and 84 genes were DE in H2; 41 DE genes were common to H1 and H2. Functional clustering of DE genes using DAVID (www.david.abcc.ncifcrf.gov) revealed DE gene clusters in H1 associated with signalling events and ion binding, and DE gene clusters in H2 associated with hormone activity and ligand-receptor interactions. Of the DE genes, ~25% were linked with oestrogen signalling. This included oestrogen receptor-α (ESR1) that showed lower DE in H2 for weaned cows. Two modulators of steroid receptor signalling, proline-rich nuclear receptor coactivator-2 (PNRC2)1 and peptidylprolyl isomerase D (PPID)2, showed altered expression. In weaned cows, expression level of PNRC2 was lower in H1 and H2, while that of PPID was decreased in H1. The overlapped hypothalamic regions H1 and H2 are known to contain GnRH neuron terminals and kisspeptin neurons. Weaning promotes the resumption of cyclic ovarian function in postpartum cows, and the similar shifts in DE of ESR1, PNRC2 and PPID provided further evidence of a role for oestradiol at the hypothalamus in regulating postpartum reproduction. (1) Zhou D et al. 2006 Nucleic Acids Res 34:5974–86 (2) Kumar P et al. 2001 Biochem Biophys Res Commun 284:219–25