Anti-NMDA-receptor encephalitis during pregnancy: A case report and literature review.

Anti-N-methyl-d-aspartate receptor (anti-NMDA-R) encephalitis is an autoimmune disorder that was first described by Dr Vitaliani in 2005. In 2007, Dalmau et al. found anti-NMDA-R antibody expressed both in the hippocampus and prefrontal nerve cell membrane, finally proposing the diagnosis of autoimmune anti-NMDA-R encephalitis. Most of the patients are female (91%), with ages ranging from 4 to 76 years. The average age is 23 years, a birth peak age, although anti-NMDA-R encephalitis is rare during pregnancy. The disorder is characterized by prominent psychosis, dyskinesias, seizures, autonomic disturbance, and central hypoventilation. We report a 24-year-old woman hospitalized at 28 gestational weeks with acute-onset psychosis. Over the course of 3 weeks, her mental status worsened until she fell into a coma. Both serum and cerebrospinal fluid anti-NMDA-R antibodies were found to be positive. At cesarean section, a healthy baby boy was born and a wedge-shaped bilateral ovarian resection was performed. Treatment with corticosteroids, intravenous immunoglobulin, and plasmapheresis can lead to improved outcomes for both mother and baby.

Dichlorvos exposure results in large scale disruption of energy metabolism in the liver of the zebrafish, Danio rerio.

BACKGROUND: Exposure to dichlorvos (DDVP), an organophosphorus pesticide, is known to result in neurotoxicity as well as other metabolic perturbations. However, the molecular causes of DDVP toxicity are poorly understood, especially in cells other than neurons and muscle cells. To obtain a better understanding of the process of non-neuronal DDVP toxicity, we exposed zebrafish to different concentrations of DDVP, and investigated the resulting changes in liver histology and gene transcription. RESULTS: Functional enrichment analysis of genes affected by DDVP exposure identified a number of processes involved in energy utilization and stress response in the liver. The abundance of transcripts for proteins involved in glucose metabolism was profoundly affected, suggesting that carbon flux might be diverted toward the pentose phosphate pathway to compensate for an elevated demand for energy and reducing equivalents for detoxification. Strikingly, many transcripts for molecules involved in ß-oxidation and fatty acid synthesis were down-regulated. We found increases in message levels for molecules involved in reactive oxygen species responses as well as ubiquitination, proteasomal degradation, and autophagy. To ensure that the effects of DDVP on energy metabolism were not simply a consequence of poor feeding because of neuromuscular impairment, we fasted fish for 29 or 50 h and analyzed liver gene expression in them. The patterns of gene expression for energy metabolism in fasted and DDVP-exposed fish were markedly different. CONCLUSION: We observed coordinated changes in the expression of a large number of genes involved in energy metabolism and responses to oxidative stress. These results argue that an appreciable part of the effect of DDVP is on energy metabolism and is regulated at the message level. Although we observed some evidence of neuromuscular impairment in exposed fish that may have resulted in reduced feeding, the alterations in gene expression in exposed fish cannot readily be explained by nutrient deprivation.

Detection of dichlorvos adducts in a hepatocyte cell line.

The toxicity of dichlorvos (DDVP), an organophosphate (OP) pesticide, classically results from modification of the serine in the active sites of cholinesterases. However, DDVP also forms adducts on unrelated targets such as transferrin and albumin, suggesting that DDVP could cause perturbations in cellular processes by modifying noncholinesterase targets. Here we identify novel DDVP-modified targets in lysed human hepatocyte-like cells (HepaRG) using a direct liquid chromatography-mass spectrometry (LC-MS) assay of cell lysates incubated with DDVP or using a competitive pull-down experiments with a biotin-linked organophosphorus compound (10-fluoroethoxyphosphinyl-N-biotinamidopentyldecanamide; FP-biotin), which competes with DDVP for similar binding sites. We show that DDVP forms adducts to several proteins important for the cellular metabolic pathways and differentiation, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and actin. We validated the results using purified proteins and enzymatic assays. The study not only identified novel DDVP-modified targets but also suggested that the modification directly inhibits the enzymes. The current approach provides information for future hypothesis-based studies to understand the underlying mechanism of toxicity of DDVP in non-neuronal tissues. The MS data have been deposited to the ProteomeXchange with identifier PXD001107.

Expression of p14(ARF), p15(INK4b), p16(INK4a) and skp2 increases during esophageal squamous cell cancer progression.

Esophageal carcinoma is the sixth most common cause of cancer-related mortality in the world. Senescence and apoptosis are assumed to be two main mechanisms that inhibit age-related carcinogenesis. p14(ARF), p15(INK4b) and p16(INK4a), which are known to induce senescence by regulating G(1) cell cycle arrest, have been identified as senescence markers. However, the mechanism by which senescence and apoptosis causes neoplasia in esophageal squamous cell carcinoma (ESCC) has not been identified. In this study, 20 cases of normal esophageal tissues, 11 cases of esophageal intraepithelial dysplasia (EID) and 60 cases of ESCC were obtained and pathologically diagnosed. Immunohistochemical staining was performed to assess the expression of p14(ARF), p15(INK4b), p16(INK4a), skp2, bcl-2 and ki-67. The senescence markers p14(ARF) and p16(INK4a) were found to be expressed in 15 and 10% of the normal tissues, 82 and 73% of the EID cases and 100 and 88% of the ESCC cases, respectively. The expression of p15(INK4b) was low in normal tissues, while 92% of the ESCC specimens were diffusely and markedly stained, involving the basal, middle and upper portion of the epithelium. The nuclear expression markers ki-67 and skp2 were highly expressed in ESCC tissues (100 and 72%, respectively). bcl-2 was expressed weakly in normal tissues (10%) and demonstrated various staining patterns in carcinoma specimens (strong in 60%, negative in 40%). MI was 0.09% in normal tissues and 0.95% in the ESCC specimens. Apart from the increased proliferation in esophageal carcinogenesis, as indicated in the ki-67 and skp2 indices, there was an increased expression of senescence-associated molecular markers in the ESCC specimens, which indicates that the senescence pathway may be activated and become a part of cancer development. Of greatest interest to us was that, when compared with clinical information, the expression of the senescence markers was markedly high in the poorly differentiated specimens with lymph node metastasis, indicating that senescence markers may have diagnostic potential in clinical settings.

Thrombin stimulation of inflammatory breast cancer cells leads to aggressiveness via the EGFR-PAR1-Pak1 pathway.

Inflammatory breast cancer (IBC) accounts for a small fraction but aggressive form of epithelial breast cancer. Although the role of thrombin in cancer is beginning to be unfolded, its impact on the biology of IBC remains unknown. The purpose of this study was to establish the role of thrombin on the invasiveness of IBC cells. The IBC SUM149 cell line was treated with thrombin in the absence or presence of the epidermal growth factor receptor (EGFR) inhibitor erlotinib and protease-activated receptor 1 (PAR1) inhibitor. The effects of pharmacological inhibitors on the ability of thrombin to stimulate the growth rate and invasiveness were examined. We found that the inhibition of putative cellular targets of thrombin action suppresses both the growth and invasiveness of SUM149 cells in a concentration-dependent manner. In addition, thrombin-mediated increased invasion of SUM149 cells was routed through EGFR phosphorylation, and in turn, stimulation of the p21-activated kinase (Pak1) activity in a EGFR-sensitive manner. Interestingly, thrombin-mediated activation of the Pak1 pathway stimulation was blocked by erlotinib and PAR1 inhibitor. For proof-of-principle studies, we found immunohistochemical evidence of Pak1 activation as well as expression of PAR1 in IBC. Thrombin utilizes EGFR to relay signals promoting SUM149 cell growth and invasion via the Pak1 pathway. The study provides the rationale for future therapeutic approaches in mitigating the invasive nature of IBC by targeting Pak1 and/or EGFR.

MTA1 coregulator regulates LPS response via MyD88-dependent signaling.

Although metastasis tumor antigen 1 (MTA1) contributes to the responsiveness of macrophages to LPS, the underlying mechanism remains unknown. Here, we investigated the role of MTA1 in the regulation of expression and function of MyD88, a proximal component of NF-κB signaling. We discovered that MTA1 targets MyD88 and that MyD88 is a NF-κB-responsive gene in LPS-stimulated macrophages. We found that MTA1 is required for MyD88-dependent stimulation of NF-κB signaling and expression of proinflammatory cytokines such as IL-1ß, MIP2, and TNF-α as MTA1 depletion leads to a substantial reduction in the expression of NF-κB target genes. In addition, LPS-mediated stimulation of MyD88 transcription was accompanied by an enhanced recruitment of MTA1, RNA polymerase II, and p65RelA complex to the NF-κB consensus sites in the MyD88 promoter. Interestingly, the recruitment of both MTA1 and MyD88 expression is effectively blocked by NF-κB inhibitor parthenolide. Selective knockdown of MyD88 by a dominant negative mutant of MyD88 or selective siRNA also impairs the ability of LPS to stimulate the NF-κB target genes. These findings reveal an inherent coregulatory role of MTA1 upon the expression of MyD88 and suggest that MTA1 regulation of MyD88 may constitute at least one of the mechanisms by which MTA1 stimulates LPS-induced NF-κB signaling in stimulated macrophages.

Chemotherapy induces macrophage chemoattractant protein-1 production in ovarian cancer.

OBJECTIVES: Tumor infiltrating macrophages play an important role in tumor progression. Macrophage chemoattractant protein-1 (MCP-1) is one of the major chemokines responsible for inducing macrophage migration. Our objective was to investigate chemotherapy-induced modulation of MCP-1 in ovarian cancer by investigating macrophage infiltration, tumor vascularity, and MCP-1 expression after chemotherapy exposure. METHODS: MA-148 ovarian cancer cells were treated with paclitaxel (43 pg/mL) and carboplatin (5 microg/mL) alone or in combination. Reverse transcription-polymerase chain reaction determined MCP-1 transcript levels and enzyme-linked immunosorbent assay evaluated MCP-1 protein production at multiple time points. The effect of kinase inhibitors on MCP-1 expression was investigated. In vivo MCP-1 production was examined in tumor-bearing mice and immunohistochemistry with fluorescein isothiocyanate conjugated anti-mouse F4/80 antibody, phycoerythrin-anti-CD31, and terminal deoxynucleotide transferase dUTP nick-end labeling assay were performed. RESULTS: Macrophage chemoattractant protein-1 transcript levels were up-regulated in MA-148 after treatment with paclitaxel and carboplatin individually and in combination. The greatest elevation was seen with combination therapy: 2.5-fold increase in the MCP-1 protein levels from baseline (P = 0.011) with the mitogen-activated protein kinase and janus kinases/signal transducers and activators of transcription pathways appearing to be involved in the regulation of MCP-1 production. In vivo mouse studies confirmed increased MCP-1 production after chemotherapy; however, there was no significant difference in macrophage, apoptosis, or vessel density. CONCLUSIONS: Macrophage chemoattractant protein-1 is up-regulated in ovarian cancer after chemotherapy in vitro and in vivo. Whether MCP-1 production is increased because of a stress-induced response or a scavenger response promoting macrophage infiltration remains unknown. Chemotherapy induction of MCP-1 in ovarian cancer suggests this chemokine plays an important role in the immune response occurring after chemotherapy exposure.

Regulation of NF-kappaB circuitry by a component of the nucleosome remodeling and deacetylase complex controls inflammatory response homeostasis.

The MTA1 coregulator (metastatic tumor antigen 1), a component of the nucleosome remodeling and deacetylase (NuRD) complex, has been intimately linked with human cancer, but its role in inflammatory responses remains unknown. Here, we discovered that MTA1 is a target of inflammation, and stimulation of macrophages with Escherichia coli lipopolysaccharide (LPS) stimulates MTA1 transcription via the NF-kappaB pathway. Unexpectedly, we found that MTA1 depletion in LPS-stimulated macrophages impairs NF-kappaB signaling and expression of inflammatory molecules. MTA1 itself acts as a transcriptional coactivator of inflammatory cytokines in LPS-stimulated macrophages, and in contrast, it acts as a corepressor in resting primary macrophages as its depletion induced cytokine expression. LPS stimulates S-nitrosylation of histone deacetylase 2 (HDAC2) and interferes with its binding to MTA1, which, in turn, resulted in the loss of corepressor behavior of MTA1.HDAC complex in activated macrophages. Consequently, the net levels of inflammatory cytokines in LPS-stimulated macrophages from MTA1(-/-) mice were high compared with wild-type mice. Accordingly, MTA1(-/-) mice were much more susceptible than control mice to septic shock induced by LPS, revealing that MTA1 protects mice from deregulated host inflammatory response. These findings reveal a previously unrecognized, critical homeostatic role of MTA1, both as a target and as a component of the NF-kappaB circuitry, in the regulation of inflammatory responses.

Sprouty1 inhibits angiogenesis in association with up-regulation of p21 and p27.

Sprouty1 (Spry1) is a conserved antagonist of FGF signaling. The goal of this study was to further explore the downstream mechanisms governing Spry1 inhibition of endothelial cell proliferation. Up-regulation of Spry1 in HUVECs inhibited tube formation on Matrigel (n = 6, P < 0.001). This was associated with decreased proliferation as measured by BrdU incorporation (n = 6, P < 0.001) and increased protein expression of the cyclin-dependent kinase inhibitor 1A (CDKN1A), p21 and cyclin-dependent kinase inhibitor 1B (CDKN1B), p27. A transcriptional analysis using a targeted human angiogenesis array following up-regulation of Spry1 demonstrated a >2-fold increase in an anti-angiogenic factor, serpin peptidase inhibitor, clad F (Serpinf1), and a >2-fold decrease in pro-angiogenic factors fms-related tyrosine kinase 1 (FLT1), angiopoietin2 (Ang-2), and placental growth factor (PGF) (n = 2). To define upstream mechanisms that may regulate endogenous Spry1, we performed a search for responsive elements upstream of the promoter region. This search resulted in the identification of multiple degenerate hypoxia responsive elements. Exposure to hypoxia resulted in a significant increase in Spry1 expression (n = 8, P < 0.01). These findings shed new light on downstream signaling pathways associated with Spry1 anti-proliferative responses, and provide new evidence that hypoxia stimulates Spry1 expression.

Stimulation of inducible nitric oxide by hepatitis B virus transactivator protein HBx requires MTA1 coregulator.

Nitric oxide has been implicated in the pathogenesis of inflammatory disorders, including hepatitis B virus-associated hepatocellular carcinoma. Transactivator protein HBx, a major regulator of cellular responses of hepatitis B virus, is known to induce the expression of MTA1 (metastasis-associated protein 1) coregulator via NF-kappaB signaling in hepatic cells. However, the underlying mechanism of HBx regulation of the inducible nitric-oxide synthase (iNOS) pathway remains unknown. Here we provide evidence that MTA1 is a positive regulator of iNOS transcription and plays a mechanistic role in HBx stimulation of iNOS expression and activity. We found that the HBx-MTA1 complex is recruited onto the human iNOS promoter in an NF-kappaB-dependent manner. Pharmacological inhibition of the NF-kappaB signaling prevented the ability of HBx to stimulate the transcription, the expression, and the activity of iNOS; nevertheless, these effects could be substantially rescued by MTA1 dysregulation. We further discovered that HBx-mediated stimulation of MTA1 is paralleled by the suppression of miR-661, a member of the small noncoding RNAs, recently shown to target MTA1. We observed that miR-661 controls of MTA1 expression contributed to the expression and activity of iNOS in HBx-expressing HepG2 cells. Accordingly, depletion of MTA1 by either miR-661 or siRNA in HBx-expressing cells severely impaired the ability of HBx to modulate the endogenous levels of iNOS and nitrite production. Together, these findings reveal an inherent role of MTA1 in HBx regulation of iNOS expression and consequently its function in the liver cancer cells.

The antitumoral effect of Paris Saponin I associated with the induction of apoptosis through the mitochondrial pathway.

Rhizoma Paridis, a traditional Chinese medicine, has shown promise in cancer prevention and therapy. In the present study, we isolated Paris Saponin I (PSI), an active component of Rhizoma paridis, and evaluated its effects on a panel of human cell lines and in a mouse model of human ovarian cancer to explore the mechanisms of its activity. PSI had more potent and selective cytotoxic effects on tumor cell lines than etoposide had, promoting dramatic G(2)-M phase arrest and apoptosis in SKOV3 cells in a time- and dose-dependent manner. Furthermore, PSI treatment increased levels of Bax, cytochrome c, activated caspase-3, active caspase-9, and cleaved poly(ADP-ribose) polymerase and decreased both Bcl-2 expression levels and extracellular signal-regulated kinase-1/2 activity. We also assessed the antitumor efficacy of i.p. and p.o. PSI administration in mice bearing SKOV3 tumors; both significantly inhibited the growth of SKOV3 cells in a subcutaneous xenograft mouse model (by 66% and 52%, respectively). These results indicate that PSI mediates its effects via mitochondrial apoptosis, mitogen-activated protein kinase pathways, and G(2)-M cell cycle arrest. Most important, the efficacy of PSI in xenografts when administered p.o. or i.p. suggests its clinical potential. Thus, PSI is a potent antitumor compound and should be developed as a natural agent for cancer therapy.

PAK thread from amoeba to mammals.

The p21-activated kinases (PAKs) are signaling nodes that play a crucial role in cellular processes including cell motility, differentiation, survival, gene transcription, and hormone signaling. PAKs are highly conserved family of serine-threonine kinases that act as effector for small GTPases Rac and Cdc42. Most of our knowledge about PAK functions has been derived from genetic approaches in lower organisms and many of these functions are similar to that seen in mammalian cells. In this review, we have summarized the extensive information generated in lower eukaryotes and very briefly discussed the current status of PAKs in humans.