Leucine zipper protein 1 (LUZP1) regulates the constriction velocity of the contractile ring during cytokinesis

There has been a great deal of research on cell division and its mechanisms; however, its processes still have many unknowns. To find novel proteins that regulate cell division, we performed the screening using siRNAs and/or the expression plasmid of the target genes and identified leucine zipper protein 1 (LUZP1). Recent studies have shown that LUZP1 interacts with various proteins and stabilizes the actin cytoskeleton; however, the function of LUZP1 in mitosis is not known. In this study, we found that LUZP1 colocalized with the chromosomal passenger complex (CPC) at the centromere in metaphase and at the central spindle in anaphase and that these LUZP1 localizations were regulated by CPC activity and kinesin family member 20A (KIF20A). Mass spectrometry analysis identified that LUZP1 interacted with death-associated protein kinase 3 (DAPK3), one regulator of the cleavage furrow ingression in cytokinesis. In addition, we found that LUZP1 also interacted with myosin light chain 9 (MYL9), a substrate of DAPK3, and comprehensively inhibited MYL9 phosphorylation by DAPK3. In line with a known role for MYL9 in the actin-myosin contraction, LUZP1 suppression accelerated the constriction velocity at the division plane in our time-lapse analysis. Our study indicates that LUZP1 is a novel regulator for cytokinesis that regulates the constriction velocity of the contractile ring.

PDZ-binding kinase inhibitor OTS514 suppresses the proliferation of oral squamous carcinoma cells

OBJECTIVE

PDZ-binding kinase (PBK) has been reported as a poor prognostic factor and is a promising molecular target for anticancer therapeutics. Here, we aimed to investigate the effect of specific PBK inhibitor OTS514 on the survival of OSCC cells.

METHODS

Four OSCC cell lines (HSC-2, HSC-3, SAS, and OSC-19) were used to examine the effect of OTS514 on cell survival and apoptosis. DNA microarray analysis was conducted to investigate the effect of OTS514 on gene expression in OSCC cells. Gene set enrichment analysis was performed to identify molecular signatures related to the antiproliferative effect of OTS514.

RESULTS

OTS514 decreased the cell survival of OSCC cells dose-dependently, and administration of OTS514 readily suppressed the HSC-2-derived tumor growth in immunodeficient mice. Treatment with OTS514 significantly increased the number of apoptotic cells and caspase-3/7 activity. Importantly, OTS514 suppressed the expression of E2F target genes with a marked decrease in protein levels of E2F1, a transcriptional factor. Moreover, TP53 knockdown attenuated OTS514-induced apoptosis.

CONCLUSION

OTS514 suppressed the proliferation of OSCC cells by downregulating the expression of E2F target genes and induced apoptosis by mediating the p53 signaling pathway. These results highlight the clinical application of PBK inhibitors in the development of molecular-targeted therapeutics against OSCC.

ARK5 enhances cell survival associated with mitochondrial morphological dynamics from fusion to fission in human multiple myeloma cells

5' adenosine monophosphate-activated protein kinase-related kinase 5 (ARK5) is involved in mitochondrial ATP production and associated with poor prognosis of multiple myeloma (MM). However, the molecular mechanisms of ARK5 in MM remain largely unknown. This study examined the pathogenic role of ARK5 in mitochondria by using genetically modified isogenic cell clones with or without ARK5 in human myeloma cell lines, KMS-11 and Sachi, which overexpress ARK5. The biallelic knockout of ARK5 (ARK5-KO) inhibited cell proliferation, colony formation, and migration with increased apoptosis. Mitochondrial fusion was enhanced in ARK5-KO cells, unlike in ARK5 wild-type (ARK5-WT) cells, which exhibited increased mitochondrial fission. Furthermore, ARK5-KO cells demonstrated a lower phosphorylated dynamin-related protein 1 at serine 616, higher protein expression of mitofusin-1 (MFN1) and MFN2, optic atrophy 1 with a lower level of ATP, and higher levels of lactate and reactive oxygen species than ARK5-WT cells. Our findings suggest that ARK5-enhanced myeloma cells can survive associated mitochondrial fission and activity. This study first revealed the relationship between ARK5 and mitochondrial morphological dynamics. Thus, our outcomes show novel aspects of mitochondrial biology of ARK5, which can afford a more advanced treatment approach for unfavorable MM expressing ARK5.

Repeated cold stress, an animal model for fibromyalgia, elicits proprioceptor-induced chronic pain with microglial activation in mice

BACKGROUND

Fibromyalgia is characterized by chronic pain, fatigue, and other somatic symptoms. We have recently revealed that proprioceptor hyperactivation induces chronic pain in a rat model of myalgic encephalomyelitis. The present study explores whether similar proprioceptor-induced pain is elicited in a mouse model of fibromyalgia.

METHODS

Repeated cold stress (RCS) was used as a fibromyalgia model. Pain behavior was examined using the von Frey test, and neuronal activation was examined immunohistochemically as activating transcription factor (ATF)3 expression. The Atf3:BAC transgenic mouse, in which mitochondria in hyperactivated neurons are specifically labeled by green fluorescent protein, was used to trace the activated neuronal circuit. PLX3397 (pexidartinib) was used for microglial suppression.

RESULTS

RCS elicited long-lasting pain in mice. ATF3, a marker of cellular hyperactivity and injury, was expressed in the lumbar dorsal root ganglion (DRG) 2 days after RCS initiation; the majority of ATF3-expressing DRG neurons were tropomyosin receptor kinase C- and/or vesicular glutamate transporter 1-positive proprioceptors. Microglial activation and increased numbers of microglia were observed in the medial part of the nucleus proprius 5 days after RCS initiation, and in the dorsal region of the ventral horn 7 days after RCS. In the ventral horn, only a subset of motor neurons was positive for ATF3; these neurons were surrounded by activated microglia. A retrograde tracer study revealed that ATF3-positive motor neurons projected to the intrinsic muscles of the foot (IMF). Using Atf3:BAC transgenic mice, we traced hyperactivated neuronal circuits along the reflex arc. Green fluorescent protein labeling was observed in proprioceptive DRG neurons and their processes originating from the IMF, as well as in motor neurons projecting to the IMF. Microglial activation was observed along this reflex arc, and PLX3397-induced microglial ablation significantly suppressed pain behavior.

CONCLUSION

Proprioceptor hyperactivation leads to local microglial activation along the reflex arc; this prolonged microglial activation may be responsible for chronic pain in the present model. Proprioceptor-induced microglial activation might be the common cause of chronic pain in both the fibromyalgia and myalgic encephalomyelitis models, although the experimental models are different.

Flow cytometry-based quantification of genome editing efficiency in human cell lines using the L1CAM gene

CRISPR/Cas9 is a powerful genome editing system that has remarkably facilitated gene knockout and targeted knock-in. To accelerate the practical use of CRISPR/Cas9, however, it remains crucial to improve the efficiency, precision, and specificity of genome editing, particularly targeted knock-in, achieved with this system. To improve genome editing efficiency, researchers should first have a molecular assay that allows sensitive monitoring of genome editing events with simple procedures. In the current study, we demonstrate that genome editing events occurring in L1CAM, an X-chromosome gene encoding a cell surface protein, can be readily monitored using flow cytometry (FCM) in multiple human cell lines including neuroblastoma cell lines. The abrogation of L1CAM was efficiently achieved using Cas9 nucleases which disrupt exons encoding the L1CAM extracellular domain, and was easily detected by FCM using anti-L1CAM antibodies. Notably, L1CAM-abrogated cells could be quantified by FCM in four days after transfection with a Cas9 nuclease, which is much faster than an established assay based on the PIGA gene. In addition, the L1CAM-based assay allowed us to measure the efficiency of targeted knock-in (correction of L1CAM mutations) accomplished through different strategies, including a Cas9 nuclease-mediated method, tandem paired nicking, and prime editing. Our L1CAM-based assay using FCM enables rapid and sensitive quantification of genome editing efficiencies and will thereby help researchers improve genome editing technologies.

Deep palm burn treated with enzymatic debridement followed by autologous skin cell suspension: a case study

Despite improvements in treatment methods and outcomes, burns remain one of the principal causes of mortality and morbidity worldwide. Burns involving the hands are estimated to occur in >80% of people with burns. Hand burns have also been associated with long-term social, psychological and physical consequences that can impede a patient's full reintegration to the community and decrease their overall quality of life. Clinically, when the trajectory towards complete re-epithelialisation stalls in deep burn wounds of the hand, skin grafting is indicated, but cosmetic problems often remain. A recent publication highlighted common complications for burns involving the hand such as scar disturbances (26%) and scar contractures (14%). Innovative approaches with the potential to reduce the occurrence of complicating scar disturbances and contractures are sought by healthcare providers specialising in burns. This case report describes a novel approach to wound closure using a topical concentrate of proteolytic enzymes followed by the application of an autologous skin cell suspension. This combination was effective in achieving early and complete re-epithelialisation of a deep burn of the palm of a 28-year-old male patient, while potentially affording a favourable impact on hypertrophic scarring or scar contracture.

CAMK2D: a novel molecular target for BAP1-deficient malignant mesothelioma

Malignant mesothelioma (MMe) is a rare but aggressive malignancy. Although the molecular genetics of MMe is known, including BRCA1-associated protein-1 (BAP1) gene alterations, the prognosis of MMe patients remains poor. Here, we generated BAP1 knockout (BAP1-KO) human mesothelial cell clones to develop molecular-targeted therapeutics based on genetic alterations in MMe. cDNA microarray and quantitative RT-PCR (qRT-PCR) analyses revealed high expression of a calcium/calmodulin-dependent protein kinase type II subunit delta (CAMK2D) gene in the BAP1-KO cells. CAMK2D was highly expressed in 70% of the human MMe tissues (56/80) and correlated with the loss of BAP1 expression, making it a potential diagnostic and therapeutic target for BAP1-deficient MMe. We screened an anticancer drugs library using BAP1-KO cells and successfully identified a CaMKII inhibitor, KN-93, which displayed a more potent and selective antiproliferative effect against BAP1-deficient cells than cisplatin or pemetrexed. KN-93 significantly suppressed the tumor growth in mice xenografted with BAP1-deficient MMe cells. This study is the first to provide a potential molecular-targeted therapeutic approach for BAP1-deficient MMe.

CD206+ macrophages transventricularly infiltrate the early embryonic cerebral wall to differentiate into microglia

The relationships between tissue-resident microglia and early macrophages, especially their lineage segregation outside the yolk sac, have been recently explored, providing a model in which a conversion from macrophages seeds microglia during brain development. However, spatiotemporal evidence to support such microglial seeding in situ and to explain how it occurs has not been obtained. By cell tracking via slice culture, intravital imaging, and Flash tag-mediated or genetic labeling, we find that intraventricular CD206+ macrophages, which are abundantly observed along the inner surface of the mouse cerebral wall, frequently enter the pallium at embryonic day 12. Immunofluorescence of the tracked cells show that postinfiltrative macrophages in the pallium acquire microglial properties while losing the CD206+ macrophage phenotype. We also find that intraventricular macrophages are supplied transepithelially from the roof plate. This study demonstrates that the "roof plate→ventricle→pallium" route is an essential path for microglial colonization into the embryonic mouse brain.

Protein Tyrosine Phosphatase 1B Deficiency Improves Glucose Homeostasis in Type 1 Diabetes Treated With Leptin

Leptin, a hormone secreted by adipocytes, exhibits therapeutic potential for the treatment of type 1 diabetes (T1D). Protein tyrosine phosphatase 1B (PTP1B) is a key enzyme that negatively regulates leptin receptor signaling. Here, the role of PTP1B in the treatment of T1D was investigated using PTP1B-deficient (knockout [KO]) mice and a PTP1B inhibitor. T1D wild-type (WT) mice induced by streptozotocin showed marked hyperglycemia compared with non-T1D WT mice. KO mice displayed significantly improved glucose metabolism equivalent to non-T1D WT mice, whereas peripheral or central administration of leptin partially improved glucose metabolism in T1D WT mice. Peripheral combination therapy of leptin and a PTP1B inhibitor in T1D WT mice improved glucose metabolism to the same level as non-T1D WT mice. Leptin was shown to act on the arcuate nucleus in the hypothalamus to suppress gluconeogenesis in liver and enhance glucose uptake in both brown adipose tissue and soleus muscle through the sympathetic nervous system. These effects were enhanced by PTP1B deficiency. Thus, treatment of T1D with leptin, PTP1B deficiency, or a PTP1B inhibitor was shown to enhance leptin activity in the hypothalamus to improve glucose metabolism. These findings suggest a potential alternative therapy for T1D.

BCL6 inhibition ameliorates resistance to ruxolitinib in CRLF2-rearranged acute lymphoblastic leukemia

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is an intractable disease and most cases harbor genetic alterations that activate JAK or ABL signaling. The commonest subtype of Ph-like ALL exhibits a CRLF2 gene rearrangement that brings about JAK1/2-STAT5 pathway activation. However, JAK1/2 inhibition alone is insufficient as a treatment, so combinatorial therapies targeting multiple signals are needed. To better understand the mechanisms underlying the insufficient efficacy of JAK inhibition, we explored gene expression changes upon treatment with a JAK1/2 inhibitor (ruxolitinib) and found that elevated BCL6 expression was one such mechanism. Upregulated BCL6 suppressed the expression of TP53 along with its downstream cell cycle inhibitor p21 (CDKN2A) and pro-apoptotic molecules, such as FAS, TNFRSF10B, BID, BAX, BAK, PUMA, and NOXA, conferring cells some degree of resistance to therapy. BCL6 inhibition (with FX1) alone was able to upregulate TP53 and restore the TP53 expression that ruxolitinib had diminished. In addition, ruxolitinib and FX1 concertedly downregulated MYC. As a result, FX1 treatment alone had growth-inhibitory and apoptosis- sensitizing effects, but the combination of ruxolitinib and FX1 more potently inhibited leukemia cell growth, enhanced apoptosis sensitivity, and prolonged the survival of xenografted mice. These findings provide one mechanism for the insufficiency of JAK inhibition for the treatment of CRLF2-rearranged ALL and indicate BCL6 inhibition as a potentially helpful adjunctive therapy combined with JAK inhibition.

Correction of a CD55 mutation to quantify the efficiency of targeted knock-in via flow cytometry

BACKGROUND

Targeted knock-in assisted by the CRISPR/Cas9 system is an advanced technology with promising applications in various research fields including medical and agricultural sciences. However, improvements in the efficiency, precision, and specificity of targeted knock-in are prerequisites to facilitate the practical application of this technology. To improve the efficiency of targeted knock-in, it is necessary to have a molecular system that allows sensitive monitoring of targeted knock-in events with simple procedures.

METHODS AND RESULTS

We developed an assay, named CD55 correction assay, with which to monitor CD55 gene correction accomplished by targeted knock-in. To create the reporter clones used in this assay, we initially introduced a 7.7-kb heterozygous deletion covering CD55 exons 2-5, and then incorporated a truncating mutation within exon 4 of the remaining CD55 allele in human cell lines. The resultant reporter clones that lost the CD55 protein on the cell membrane were next transfected with Cas9 constructs along with a donor plasmid carrying wild-type CD55 exon 4. The cells were subsequently stained with fluorescence-labeled CD55 antibody and analyzed by flow cytometry to detect CD55-positive cells. These procedures allow high-throughput, quantitative detection of targeted gene correction events occurring in an endogenous human gene.

CONCLUSIONS

The current study demonstrated the utility of the CD55 correction assay to sensitively quantify the efficiency of targeted knock-in. When used with the PIGA correction assay, the CD55 correction assay will help accurately determine the efficiency of targeted knock-in, precluding possible experimental biases caused by cell line-specific and locus-specific factors.

Influence of concurrent and staggered dosing of semi-solid nutrients on the pharmacokinetics of orally administered carbamazepine in rats

In the present study, we examined the effects of concurrent and staggered dosing of PG-soft ace-MP TM (PG), novel semi-solid enteral nutrients, on the pharmacokinetics of orally administered carbamazepine (CBZ) in rats due to the high possibility of drug interaction during the absorption process. The pharmacokinetic behavior of CBZ was considerably altered when administered concurrently with PG. The maximum serum CBZ concentration (C_max) significantly decreased and the mean residence time (MRT) significantly increased. The elimination constant (k_e) also significantly increased, but there were no significant changes in the area under the serum CBZ concentration versus time curve (AUC) and the time to reach C_max (T_max). However, these changes in the pharmacokinetic parameters were eliminated by waiting 20 min, the time interval equivalent to the T_max described above, between CBZ administration and PG dosing. This study suggested that PG interferes with CBZ absorption from the digestive tract, although staggered administration of CBZ and PG prevented their interaction.

Phagocytic astrocytes: Emerging from the shadows of microglia

Elimination of dead or live cells take place in both a healthy and diseased central nervous system (CNS). Dying or dead cells are quickly cleared by phagocytosis for the maintenance of a healthy CNS or for recovery after injury. Live cells or parts thereof, such as the synapses and myelin, are appropriately eliminated by phagocytosis to maintain or refine neural networks during development and adulthood. Microglia, the specific population of resident macrophages in the CNS, are classically considered as primary phagocytes; however, astrocytes have also been highlighted as phagocytes in the last decade. Phagocytic targets and receptors are reported to be mostly common between astrocytes and microglia, which raises the question of how astrocytic phagocytosis differs from microglial phagocytosis, and how these two phagocytic systems cooperate. In this review, we address the consequences of astrocytic phagocytosis, particularly focusing on these elusive points.

Progesterone receptor membrane component 2 expression leads to erlotinib resistance in lung adenocarcinoma cells

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) provide a favorable treatment outcome in patients with EGFR mutation-positive non-small cell lung cancer. However, most of such patients become resistant to EGFR-TKIs within a year. Thus, clarifying the mechanism of acquired resistance to EGFR-TKIs has been a research focus. Here, we demonstrated that the expression of progesterone receptor membrane component 2 (PGRMC2) was upregulated in an erlotinib-resistant cell line, PC9/ER, compared with the parental PC9 lung cancer cells. Our previous study showed that PGRMC1 is responsible for acquired resistance to erlotinib; however, PGRMC2 has not been discussed yet. Thus, the aim of this study was to determine the role of PGRMC2 in acquired resistance to erlotinib. Transfection with PGRMC2 siRNA significantly enhanced the sensitivity to erlotinib in PC9/ER cells. Furthermore, knockdown of PGRMC2 reduced the expression of p21, which is known as cell-cycle inhibitor and antiproliferative effector. These results suggest that PGRMC2 partially contributes to erlotinib resistance in PC9/ER cells, and that investigation into the effect of PGRMC2 on apoptosis and the cell cycle are warranted.

Experimental strategies to achieve efficient targeted knock-in via tandem paired nicking

Tandem paired nicking (TPN) is a method of genome editing that enables precise and relatively efficient targeted knock-in without appreciable restraint by p53-mediated DNA damage response. TPN is initiated by introducing two site-specific nicks on the same DNA strand using Cas9 nickases in such a way that the nicks encompass the knock-in site and are located within a homologous region between a donor DNA and the genome. This nicking design results in the creation of two nicks on the donor DNA and two in the genome, leading to relatively efficient homology-directed recombination between these DNA fragments. In this study, we sought to identify the optimal design of TPN experiments that would improve the efficiency of targeted knock-in, using multiple reporter systems based on exogenous and endogenous genes. We found that efficient targeted knock-in via TPN is supported by the use of 1700-2000-bp donor DNAs, exactly 20-nt-long spacers predicted to be efficient in on-target cleavage, and tandem-paired Cas9 nickases nicking at positions close to each other. These findings will help establish a methodology for efficient and precise targeted knock-in based on TPN, which could broaden the applicability of targeted knock-in to various fields of life science.

A study of quality assessment in SARS-CoV-2 pathogen nucleic acid amplification tests performance; from the results of external quality assessment survey of clinical laboratories in the Tokyo Metropolitan Government external quality assessment program in 2020

Introduction

The Tokyo Metropolitan Government (TMG) conducted an external quality assessment (EQA) survey of pathogen nucleic acid amplification tests (NAATs) as a TMG EQA program for SARS-CoV-2 for clinical laboratories in Tokyo.

Methods

We diluted and prepared a standard product manufactured by Company A to about 2,500 copies/mL to make a positive control and distribute it with a negative control. The participants reported the use of the NAATs methods for SARS-CoV-2, the name of the real-time RT-PCR kit, the name of the detection device, the target gene(s), nucleic acid extraction kit, Threshold Cycle value in the case of RT-PCR and the Threshold time value and Differential calculation value in the case of Loop-Mediated Isothermal Amplification (LAMP) method.

Results

As a result, 17 laboratories using fully automated equipment and 34 laboratories using the RT-PCR method reported generally appropriate results in this EQA survey. On the other hand, among the laboratories that adopted the LAMP method, there were a plurality of laboratories that judged positive samples to be negative.

Conclusion

The false negative result is considered to be due to the fact that the amount of virus genome contained in the quality control reagent used this time was below the detection limit of the LAMP method combined with the rapid extraction reagent for influenza virus. On the other hand, false positive results are considered to be due to the non-specific reaction of the NAATs. The EQA program must be continued for the proper implementation of the pathogen NAATs.

Morphology, localization, and postnatal development of dural macrophages

The dura mater contains abundant macrophages whose functions remain largely elusive. Recent studies have demonstrated the origin, as well as the gene expression pattern, of dural macrophages (dMΦs). However, their histological features have not been explored yet. In this study, we performed immunohistochemistry and electron microscopy to elucidate their precise morphology, localization, and postnatal development in mice. We found that the morphology, as well as the localization, of dMΦs changed during postnatal development. In neonatal mice, dMΦ exhibited an amoeboid morphology. During postnatal development, their cell bodies elongated longitudinally and became aligned along dural blood vessels. In adulthood, nearly half of the dMΦs aligned along blood vessel networks. However, most of these cells were not directly attached to vessels; pericytes and fibroblasts interposed between dMΦs and vessels. This morphological information may provide further indications for the functional significance of dMΦs.

Reduced cytotoxicity in doxorubicin-exposed HepG2 cells pretreated with menthol due to upregulation of P-glycoprotein

The aim of the present study was to examine changes in the expression and activity of P-glycoprotein (P-gp) in human hepatocellular carcinoma HepG2 cells after exposure to menthol, and their relationship to the cytotoxicity of and apoptotic responses to doxorubicin (DOX), a substrate of P-gp, in the cells. The expression of P-gp in HepG2 cells was significantly increased by menthol treatment. Intracellular accumulation of DOX in HepG2 cells was significantly lower in the menthol-treated group than in the control group, but this phenomenon was abolished in the presence of verapamil. Decreased cell viability by DOX was significantly attenuated by 24-h menthol treatment prior to DOX exposure, which coincided with the changes in mRNA expression of Bcl-xl and caspase-3. These results demonstrate that menthol causes hepatocellular carcinoma cells to acquire resistance to DOX by increasing its efflux through the upregulation of P-gp.

Downregulation of organic cation transporter 1 and breast cancer resistance protein with the induction of Pregnane X receptor in rat kidney impaired by doxorubicin

Transporters expressed in the kidney play an important role in the excretion of endogenous substances and chemical drugs. The Pregnane X receptor (PXR) has been reported to be involved in regulating the expression of numerous transporters. In the present study, we examined the alteration in expression level of PXR, organic cation transporter 1 (OCT1) and breast cancer resistance protein (BCRP) in renal cell lines of rat origin and the kidney of rats when damaged by doxorubicin (DOX). The expression level of PXR in renal tubular epithelium NRK-52E cells was significantly increased by DOX at a concentration confirmed to cause cellular damage. The expression levels of OCT1 and BCRP were significantly lower in the DOX-treated cells than in the untreated cells. In model rats with DOX-induced nephrotoxicity, the alterations in renal expression of PXR, OCT1 and BCRP were similar to those in NRK-52E cells, although there was a difference in the degree of the changes.

Astrocytic phagocytosis is a compensatory mechanism for microglial dysfunction

Microglia are the principal phagocytes that clear cell debris in the central nervous system (CNS). This raises the question, which cells remove cell debris when microglial phagocytic activity is impaired. We addressed this question using Siglech^dtr mice, which enable highly specific ablation of microglia. Non‐microglial mononuclear phagocytes, such as CNS‐associated macrophages and circulating inflammatory monocytes, did not clear microglial debris. Instead, astrocytes were activated, exhibited a pro‐inflammatory gene expression profile, and extended their processes to engulf microglial debris. This astrocytic phagocytosis was also observed in Irf8‐deficient mice, in which microglia were present but dysfunctional. RNA‐seq demonstrated that even in a healthy CNS, astrocytes express TAM phagocytic receptors, which were the main astrocytic phagocytic receptors for cell debris in the above experiments, indicating that astrocytes stand by in case of microglial impairment. This compensatory mechanism may be important for the maintenance or prolongation of a healthy CNS.

Novel Interleukin-6 Inducible Gene PDZ-Binding Kinase Promotes Tumor Growth of Multiple Myeloma Cells

Multiple myeloma (MM) remains an intractable hematological malignancy, despite recent advances in anti-MM drugs. Here, we show that role of PDZ binding kinase (PBK) in MM tumor growth. We identified that interleukin-6 (IL-6) readily increases PBK expression. Kaplan–Meier analysis showed that the MM patients with higher expression of PBK have a significant shorter survival time compared with those with moderate/lower expression of PBK. Knockout of PBK dramatically suppressed in vivo tumor growth in MM cells, while genome editing of PBK changing from asparagine to serine substitution (rs3779620) slightly suppresses the tumor formation. Mechanistically, loss of PBK increased the number of apoptotic cells with concomitant decrease in the phosphorylation level of Stat3 as well as caspase activities. A novel PBK inhibitor OTS514 significantly decreased KMS-11-derived tumor growth. These findings highlight the novel oncogenic role of PBK in tumor growth of myeloma, and it might be a novel therapeutic target for the treatment of patients with MM.

Targeting MEF2D-fusion Oncogenic Transcriptional Circuitries in B-cell Precursor Acute Lymphoblastic Leukemia

The cellular context that integrates gene expression, signaling, and metabolism dictates the oncogenic behavior and shapes the treatment responses in distinct cancer types. Although chimeric fusion proteins involving transcription factors (TF) are hallmarks of many types of acute lymphoblastic leukemia (ALL), therapeutically targeting the fusion proteins is a challenge. In this work, we characterize the core regulatory circuitry (CRC; interconnected autoregulatory loops of TFs) of B-ALL involving MEF2D-fusions and identify MEF2D-fusion and SREBF1 TFs as crucial CRC components. By gene silencing and pharmacologic perturbation, we reveal that the CRC integrates the pre-B-cell receptor (BCR) and lipid metabolism to maintain itself and govern malignant phenotypes. Small-molecule inhibitors of pre-BCR signaling and lipid biosynthesis disrupt the CRC and silence the MEF2D fusion in cell culture and show therapeutic efficacy in xenografted mice. Therefore, pharmacologic disruption of CRC presents a potential therapeutic strategy to target fusion protein-driven leukemia.

SIGNIFICANCE

Cancer type-specific gene expression is governed by transcription factors involved in a highly interconnected autoregulatory loop called CRC. Here, we characterized fusion protein-driven CRC and identified its pharmacologic vulnerabilities, opening therapeutic avenues to indirectly target fusion-driven leukemia by disrupting its CRC.See related commentary by Sadras and Müschen, p. 18. This article is highlighted in the In This Issue feature, p. 5.

Biallelic loss of FAM46C triggers tumor growth with concomitant activation of Akt signaling in multiple myeloma cells

Loss of heterozygosity or mutation of the family with sequence similarity 46, member C (FAM46C) gene on chromosome band 1p12 is associated with shorter overall survival of patients with multiple myeloma (MM). In this study, using human MM cell lines (KMS‐11, OCI‐My5, and ANBL‐6), we generated FAM46C^−/− cell clones and examined the effect of disruption of FAM46C on cell survival and cellular signaling. Cell proliferation assays showed increased clonogenicity of FAM46C^−/− KMS‐11 cells compared to WT cells. Xenograft experiments showed significantly shorter overall survival of mice harboring the FAM46C^−/− cell‐derived tumors than mice with the FAM46C^WT cell‐derived tumors. Notably, levels of phosphorylated Akt and its substrates increased both in vitro and in vivo in the FAM46C^−/− cells compared to WT cells. In addition, caspase activities decreased in the FAM46C^−/− cells. Results of gene set enrichment analysis showed that loss of FAM46C significantly activated serum‐responsive genes while inactivating phosphatase and tensin homolog (PTEN)‐related genes. Mechanistically, loss of FAM46C decreased the PTEN activity, number of apoptotic cells, and caspase activities. PF‐04691502, a selective PI3K inhibitor, suppressed the augmented phosphorylation of Akt and its substrate FoxO3a. Treatment with afuresertib (a specific Akt inhibitor) in combination with bortezomib additively decreased FAM46C^−/− MM cell survival. Collectively, this study is the first to report that loss of FAM46C triggers the concomitant activation of the PI3K‐Akt signaling pathway, which might be a therapeutic target for MM with abnormalities in the FAM46C gene.

Discovery of novel molecular characteristics and cellular biological properties in ameloblastoma

Ameloblastoma is a rare odontogenic benign tumor accounting for less than 1% of head and neck tumors. Advanced next generation sequencing (NGS) analyses identified high frequency of BRAF V600E and SMO L412F mutations in ameloblastoma. Despite the existence of whole genomic sequence information from patients with ameloblastoma, entire molecular signature of and the characteristics of ameloblastoma cells are still obscure. In this study, we sought to uncover the molecular basis of ameloblastoma and to determine the cellular phenotype of ameloblastoma cells with BRAF mutations. Our comparative cDNA microarray analysis and gene set enrichment analysis (GSEA) showed that ameloblastoma exhibited a distinct gene expression pattern from the normal tissues: KRAS-responsive gene set is significantly activated in ameloblastoma. Importantly, insulin like growth factor 2 (IGF2), a member of KRAS-responsive genes, enhances the proliferation of an ameloblastoma cell line AMU-AM1 with BRAF mutation. In addition, Toll-like receptor 2 (TLR2) knockdown readily inactivated KRAS-responsive gene sets as well as increases caspase activities, suggesting that TLR2 signaling may mediate cell survival signaling in ameloblastoma cells. Collectively, the findings may help to further clarify the pathophysiology of ameloblastoma and lead to the development of precision medicine for patients with ameloblastoma.

Dual microglia effects on blood brain barrier permeability induced by systemic inflammation

Microglia survey brain parenchyma, responding to injury and infections. Microglia also respond to systemic disease, but the role of blood-brain barrier (BBB) integrity in this process remains unclear. Using simultaneous in vivo imaging, we demonstrated that systemic inflammation induces CCR5-dependent migration of brain resident microglia to the cerebral vasculature. Vessel-associated microglia initially maintain BBB integrity via expression of the tight-junction protein Claudin-5 and make physical contact with endothelial cells. During sustained inflammation, microglia phagocytose astrocytic end-feet and impair BBB function. Our results show microglia play a dual role in maintaining BBB integrity with implications for elucidating how systemic immune-activation impacts neural functions.

124Impact of intimal tracking for recanalization of CTO lesions on long-term clinical outcomes

Background

For recanalization of coronary chronic total occlusion (CTO) lesions, subintimal guidewire tracking in both antegrade and retrograde approaches are commonly used.

Purpose

This study aimed to assess the impact of subintimal tracking on long-term clinical outcomes after recanalization of CTO lesions.

Methods

Between January 2009 and December 2016, 474 CTO lesions (434patients) were successfully recanalized in our center. After guidewire crossing in a CTO lesion, those lesions were divided into intimal tracking group (84.6%, n=401) and subintimal tracking group (15.4%, n=73) according to intravascular ultrasound (IVUS) findings. Long-term clinical outcomes including death, target lesion revascularization (TLR), target vessel revascularization (TVR) were compared between the two groups. In addition, the rate of re-occlusion after successful revascularization was also evaluated.

Results

The median follow-up period was 4.7 years (interquartile range, 2.8–6.1). There was no significant difference of the rate of cardiac death between the two groups (intimal tracking vs. subintimal tracking: 7.0% vs. 4.1%; hazard ratio, 0.61; 95% confidence interval [CI], 0.19 to 2.00; p=0.41), TLR (14.3% vs. 16.2%; hazard ratio, 1.34; 95% CI, 0.71 to 2.53; p=0.37), and TVR (17.5% vs. 20.3%; hazard ratio, 1.27; 95% CI, 0.72 to 2.23; p=0.42). However, the rate of re-occlusion was significantly higher in the subintimal tracking group than intimal tracking group at 3-years re-occlusion (4.2% vs. 14.5%; log-rank test, p=0.002, Figure). In the multivariate COX regression, subintimal guidewire tracking was an independent predictor of re-occlusion after CTO recanalization (HR: 5.40; 95% CI: 2.11–13.80; p<0.001).

Figure 1

Conclusions

Subintimal guidewire tracking for recanalization of coronary CTO was associated with significantly higher incidence of target lesion re-occlusion during long-term follow-up period.

Safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies

PURPOSE

Immune checkpoint inhibitors (ICIs) show promising clinical activity in advanced cancers. However, the safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies (ANA) are unclear.

METHODS

191 patients treated with nivolumab, pembrolizumab, atezolizumab, or durvalumab for unresectable advanced cancers between September 2014 and December 2018 were identified retrospectively. Patients were divided into positive (ANA titers ≥ 1:160) and negative ANA groups (ANA titers < 1:160). Development of immune-related adverse events (irAEs), the overall response rate (ORR), and disease control rate (DCR) were monitored.

RESULTS

Positive ANA titers were seen in 9 out of 191 patients. Four patients in the positive ANA group and 69 patients in the negative group developed irAEs of any grade without a significant difference between the groups. The development of endocrine, pulmonary, and cutaneous irAEs was not significant, whereas positive ANA was significantly higher in patients who developed colitis (2/9) than in patients who did not (3/182, P = 0.0002). DCR in the positive and negative ANA group was 37.5% and 67.5%, respectively, and was not statistically significant, but had better efficacy in patients without ANA (P = 0.08). ANA-related autoimmune diseases such as SLE, Sjögren's syndrome, MCTD, scleroderma, dermatomyositis, and polymyositis was not induced in either group. However, one patient with preexisting dermatomyositis had a flare up after initiation of atezolizumab.

CONCLUSION

Further studies to identify predictive factors for the development of irAEs are required to provide relevant patient care and maximize the therapeutic benefits of ICIs.

Necroptosis of Intestinal Epithelial Cells Induces Type 3 Innate Lymphoid Cell-Dependent Lethal Ileitis

A short form of cellular FLICE-inhibitory protein encoded by CFLARs promotes necroptosis. Although necroptosis is involved in various pathological conditions, the detailed mechanisms are not fully understood. Here we generated transgenic mice wherein CFLARs was integrated onto the X chromosome. All male CFLARs Tg mice died perinatally due to severe ileitis. Although necroptosis was observed in various tissues of CFLARs Tg mice, large numbers of intestinal epithelial cells (IECs) died by apoptosis. Deletion of Ripk3 or Mlkl, essential genes of necroptosis, prevented both necroptosis and apoptosis, and rescued lethality of CFLARs Tg mice. Type 3 innate lymphoid cells (ILC3s) were activated and recruited to the small intestine along with upregulation of interleukin-22 (Il22) in CFLARs Tg mice. Deletion of ILC3s or Il22 rescued lethality of CFLARs Tg mice by preventing apoptosis, but not necroptosis of IECs. Together, necroptosis-dependent activation of ILC3s induces lethal ileitis in an IL-22-dependent manner.

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CFLARs Tg mice develop severe ileitis in utero

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Intestinal epithelial cells die by apoptosis and necroptosis in CFLARs Tg mice

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Blockade of necroptosis rescues lethality of CFLARs Tg mice

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Necroptosis activates type 3 innate lymphoid cells, resulting in severe ileitis

GPR34 in spinal microglia exacerbates neuropathic pain in mice

Background

Neuropathic pain is caused by sensory nerve injury, but effective treatments are currently lacking. Microglia are activated in the spinal dorsal horn after sensory nerve injury and contribute to neuropathic pain. Accordingly, molecules expressed by these cells are considered potential targets for therapeutic strategies. Our previous gene screening study using a mouse model of motor nerve injury showed that the G-protein-coupled receptor 34 gene (GPR34) is induced by nerve injury. Because GPR34 is now considered a microglia-enriched gene, we explored the possibility that it might be involved in microglial activation in the dorsal horn in a mouse model of neuropathic pain.

Methods

mRNA expression of GPR34 and pro-inflammatory molecules was determined by quantitative real-time PCR in wild-type and GPR34-deficient mice with L4 spinal nerve injury. In situ hybridization was used to identify GPR34 expression in microglia, and immunohistochemistry with the microglial marker Iba1 was performed to examine microglial numbers and morphology. Mechanical sensitivity was evaluated by the von Frey hair test. Liquid chromatography–tandem mass spectrometry quantified expression of the ligand for GPR34, lysophosphatidylserine (LysoPS), in the dorsal horn, and a GPR34 antagonist was intrathecally administrated to examine the effect of inhibiting LysoPS-GPR34 signaling on mechanical sensitivity.

Results

GPR34 was predominantly expressed by microglia in the dorsal horn after L4 nerve injury. There were no histological differences in microglial numbers or morphology between WT and GPR34-deficient mice. However, nerve injury-induced pro-inflammatory cytokine expression levels in microglia and pain behaviors were significantly attenuated in GPR34-deficient mice. Furthermore, the intrathecal administration of the GPR34 antagonist reduced neuropathic pain.

Conclusions

Inhibition of GPR34-mediated signal by GPR34 gene deletion reduced nerve injury-induced neuropathic pain by suppressing pro-inflammatory responses of microglia without affecting their morphology. Therefore, the suppression of GPR34 activity may have therapeutic potential for alleviating neuropathic pain.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1458-8) contains supplementary material, which is available to authorized users.

Establishment and characterization of CRISPR/Cas9-mediated NF2-/- human mesothelial cell line: Molecular insight into fibroblast growth factor receptor 2 in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM), a highly refractory tumor, is currently incurable due to the lack of an early diagnosis method and medication, both of which are urgently needed to improve the survival and/or quality of life of patients. NF2 is a tumor suppressor gene and is frequently mutated in MPM. Using a CRISPR/Cas9 system, we generated an NF2‐knockout human mesothelial cell line, MeT‐5A (NF2‐KO). In NF2‐KO cell clones, cell growth, clonogenic activity, migration activity, and invasion activity significantly increased compared with those in NF2‐WT cell clones. Complementary DNA microarray analysis clearly revealed the differences in global gene expression profile between NF2‐WT and NF2‐KO cell clones. Quantitative PCR analysis and western blot analysis showed that the upregulation of fibroblast growth factor receptor 2 (FGFR2) was concomitant with the increases in phosphorylation levels of JNK, c‐Jun, and retinoblastoma (Rb) in NF2‐KO cell clones. These increases were all abrogated by the exogenous expression of NF2 in the NF2‐KO clone. In addition, the disruption of FGFR2 in the NF2‐KO cell clone suppressed cell proliferation as well as the phosphorylation levels of JNK, c‐Jun, and Rb. Notably, FGFR2 was found to be highly expressed in NF2‐negative human mesothelioma tissues (11/12 cases, 91.7%) but less expressed in NF2‐positive tissues. Collectively, these findings suggest that NF2 deficiency might play a role in the tumorigenesis of human mesothelium through mediating FGFR2 expression; FGFR2 would be a candidate molecule to develop therapeutic and diagnostic strategies for targeting MPM with NF2 loss.

Microglial TREM2/DAP12 Signaling: A Double-Edged Sword in Neural Diseases

Microglia are activated after neuronal injury and in neurodegenerative diseases, and trigger neuroinflammation in the central nervous system (CNS). Microglia-derived neuroinflammation has both beneficial and detrimental effects on neurons. Because the timing and magnitude of microglial activation is thought to be a critical determinant of neuronal fate, understanding the molecular mechanisms underlying microglial activation is required to enable establishment of microglia-targeted therapies for neural diseases. Plasma membrane receptors play primary roles as activators of microglia and in this review, we focus on a receptor complex involving triggering receptor expressed on myeloid cells 2 (TREM2) and DNAX-activating protein of 12 kDa (DAP12), both of which are causative genes for Nasu-Hakola disease, a dementia with bone cysts. Recent transcriptome approaches demonstrated TREM2/DAP12 signaling as the principal regulator that transforms microglia from a homeostatic to a neural disease-associated state. Furthermore, animal model studies revealed critical roles for TREM2/DAP12 in the regulation of microglial activity, including survival, phagocytosis, and cytokine production, not only in Alzheimer's disease but also in other neural diseases, such as Parkinson's disease, demyelinating disease, ischemia, and peripheral nerve injury. Intriguingly, while TREM2/DAP12-mediated microglial activation is detrimental for some diseases, including peripheral nerve injury, it is beneficial for other diseases. As the role of activated microglia differs among disease models, TREM2/DAP12 signaling may result in different outcomes in different diseases. In this review we discuss recent perspectives on the role of TREM2/DAP12 in microglia and their contribution to neural diseases.

Novel combined Ato-C treatment synergistically suppresses proliferation of Bcr-Abl-positive leukemic cells in vitro and in vivo

Chronic myelogenous leukemia (CML) accounts for 15-20% of all leukemias affecting adults. Despite recent advances in the development of specific Bcr-Abl tyrosine kinase inhibitors (TKIs), some CML patients suffer from relapse due to TKI resistance. Here, we assessed the efficacy of a novel combinatorial arsenic trioxide (ATO) and cisplatin (CDDP) treatment (Ato-C) in human Bcr-Abl-positive leukemic cells. Combination index analyses revealed that a synergistic interaction of ATO and CDDP elicits a wide range of effects in K562, KU-812, MEG-A2, and KCL-22 cells. Notably, Ato-C synergistically enhanced apoptosis and decreased the survival of both acquired TKI-resistant CML cells and the cells expressing mutant Bcr-Abl^T315I. In addition, Ato-C dramatically decreased the phosphorylation level of forkhead transcription factor FOXO1/3a and STAT5 as well as c-Myc protein level. Interestingly, results of gene set enrichment analysis showed that Ato-C significantly downregulates the expression of MYC- and/or E2F1-target genes. Furthermore, Ato-C significantly suppressed the proliferation of MEG-A2-derived tumor when compared with that following monotherapy in vivo. Collectively, these results suggest that combined Ato-C treatment could be a promising alternative to the current therapeutic regime in CML.

Inhibition of NADPH oxidase 2 induces apoptosis in osteosarcoma: The role of reactive oxygen species in cell proliferation

Osteosarcomas (OS) are aggressive tumors that are characterized by dysregulated growth and resistance to apoptosis. Reactive oxygen species (ROS) are thought to be important signal transduction molecules in the regulation of cell growth. ROS-generating nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes have previously been suggested to be involved in neoplastic proliferation. To examine whether NOX-mediated generation of intracellular ROS confers anti-apoptotic activity, and thus a growth advantage, the current study first analyzed the mRNA expression of NOX family members by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in five human OS cell lines. RT-PCR analysis revealed that NOX2 and NOX4 mRNAs were expressed in all the OS cell lines examined, whereas little or no NOX1 and NOX3 mRNAs were detected. By RT-qPCR, NOX2 mRNA expression levels were demonstrated to be higher than NOX4 mRNA expression levels. The viability of OS cells decreased in a dose-dependent manner with treatment of diphenylene iodonium (DPI), an inhibitor of flavoprotein-dependent oxidase. DPI treatment was observed to reduce intracellular ROS levels by ~50%, and increase the frequency of apoptosis by 30%. Notably, small interfering RNAs (siRNAs) targeting NOX2 significantly suppressed ROS generation; ROS depletion by DPI or NOX2 siRNAs induced apoptosis in OS cells. Together, the results of the present study indicate that NOX2-mediated ROS generation promotes cell survival and ROS depletion leads to apoptosis, thus highlighting the NOX2-ROS signaling pathway as a potential therapeutic target for OS treatment.

Long-term clinical impact of serum albumin in coronary artery disease patients with preserved renal function

BACKGROUND AND AIMS

Low serum albumin level is reportedly associated with worse clinical outcomes in patients with chronic kidney disease (CKD). However, associations between decreased serum albumin level and outcomes in non-CKD patients with coronary artery disease (CAD) remain unclear. Therefore, we aimed to evaluate the prognostic value of serum albumin concentrations in stable CAD patients with preserved renal function.

METHODS AND RESULTS

We studied 1316 patients with CAD and preserved renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m²) who underwent their first PCI between 2000 and 2011 and had data available for pre-procedural serum albumin. Patients were assigned to quartiles based on pre-procedural albumin concentrations. The incidence of major adverse cardiac events (MACE), including all-cause death and non-fatal myocardial infarction, was evaluated. Mean albumin concentration was 4.1 ± 0.4 g/dL. During the median follow-up of 7.5 years, 181 events occurred (13.8%). Kaplan-Meier curves revealed that patients with decreased serum albumin concentrations showed a higher event rate for MACE (log-rank, p < 0.0001). Using the highest tertiles (>4.3 g/dL) as reference, adjusted hazard ratios were 1.97 (95% CI, 1.12-3.55), 1.77 (95% CI, 0.99-3.25), and 1.19 (95% CI, 0.68-2.15) for serum albumin concentrations of <3.9, 3.9-4.0, and 4.1-4.3 g/dL, respectively. Decreased serum albumin concentration was associated with MACE even after adjusting for other independent variables (HR, 2.21 per 1-g/dL decrease; 95% CI, 1.37-3.56, p = 0.001).

CONCLUSION

Decreased serum albumin concentration independently predicted worse long-term prognosis in non-CKD patients after PCI. Pre-procedural serum albumin concentration could offer a useful predictor for patients with CAD and preserved renal function.

Lack of Fgf18 causes abnormal clustering of motor nerve terminals at the neuromuscular junction with reduced acetylcholine receptor clusters

FGF receptor 2 is involved in the formation of the neuromuscular junction (NMJ), but its in vivo ligand remains to be determined. Laser capture microdissection of the mouse spinal motor neurons (SMNs) revealed that Fgf18 mRNA is highly expressed in SMNs in adults. Expression of Fgf18 mRNA was the highest in the spinal cord at embryonic day (E) 15.5, which gradually decreased to postnatal day 7. FGF18 protein was localized at the NMJs of the tibialis anterior muscle at E18.5 and in adults. Fgf18−/− mice at E18.5 showed decreased expressions of the NMJ-specific Chrne and Colq genes in the diaphragm. In Fgf18−/− diaphragms, the synaptophysin-positive areas at the nerve terminals and the acetylcholine receptor (AChR)-positive areas at the motor endplates were both approximately one-third of those in wild-type embryos. Fgf18−/− diaphragms ultrastructurally showed abnormal aggregation of multiple nerve terminals making a gigantic presynapse with sparse synaptic vesicles, and simplified motor endplates. In Fgf18−/− diaphragms, miniature endplate potentials were low in amplitude with markedly reduced frequency. In C2C12 myotubes, FGF18 enhanced AChR clustering, which was blocked by inhibiting FGFRs or MEK1. We propose that FGF18 plays a pivotal role in AChR clustering and NMJ formation in mouse embryogenesis.

Agonists for G-protein-coupled receptor 84 (GPR84) alter cellular morphology and motility but do not induce pro-inflammatory responses in microglia

Background

Several G-protein-coupled receptors (GPCRs) have been shown to be important signaling mediators between neurons and glia. In our previous screening for identification of nerve injury-associated GPCRs, G-protein-coupled receptor 84 (GPR84) mRNA showed the highest up-regulation by microglia after nerve injury. GPR84 is a pro-inflammatory receptor of macrophages in a neuropathic pain mouse model, yet its function in resident microglia in the central nervous system is poorly understood.

Methods

We used endogenous, natural, and surrogate agonists for GPR84 (capric acid, embelin, and 6-OAU, respectively) and examined their effect on mouse primary cultured microglia in vitro.

Results

6-n-Octylaminouracil (6-OAU), embelin, and capric acid rapidly induced membrane ruffling and motility in cultured microglia obtained from C57BL/6 mice, although these agonists failed to promote microglial pro-inflammatory cytokine expression. Concomitantly, 6-OAU suppressed forskolin-induced increase of cAMP in cultured microglia. Pertussis toxin, an inhibitor of Gi-coupled signaling, completely suppressed 6-OAU-induced microglial membrane ruffling and motility. In contrast, no 6-OAU-induced microglial membrane ruffling and motility was observed in microglia from DBA/2 mice, a mouse strain that does not express functional GPR84 protein due to endogenous nonsense mutation of the GPR84 gene.

Conclusions

GPR84 mediated signaling causes microglial motility and membrane ruffling but does not promote pro-inflammatory responses. As GPR84 is a known receptor for medium-chain fatty acids, those released from damaged brain cells may be involved in the enhancement of microglial motility through GPR84 after neuronal injury.

Perioperative outcomes of single-port mediastinoscope-assisted transhiatal esophagectomy for thoracic esophageal cancer

We developed an en bloc lymphadenectomy method in the upper mediastinum with a single-port mediastinoscopic cervical approach. This study was designed to evaluate the safety and efficacy of single-port mediastinoscope-assisted transhiatal esophagectomy for thoracic esophageal cancer. The perioperative outcomes of 60 patients with thoracic esophageal cancer who underwent this operation between March 2014 and June 2016 were retrospectively analyzed. The upper mediastinal dissection including lymphadenectomy along the left recurrent laryngeal nerve, using a left cervical approach, was performed with a single-port mediastinoscopic technique, which was used to improve the visibility and handling in the deep mediastinum around the aortic arch. The lymphadenectomy along the right recurrent laryngeal nerve was performed under direct vision using a right cervical approach. Bilateral cervical approaches were followed by hand-assisted laparoscopic transhiatal esophagectomy with en bloc lymphadenectomy in the middle and lower mediastinum. Tumors were mainly located in the middle thoracic esophagus (n = 33), and most tumors were squamous cell carcinoma (n = 58). Pretreatment diagnoses were stage I, 19; II, 13; III, 24; IV, 4. Preoperative chemotherapy was performed for 40 patients. The median operation time and blood loss were 363 minutes and 235 mL, respectively. There were two patients who underwent conversion to thoracotomy. Perioperative complications were evaluated and graded according to the Clavien-Dindo (CD) and the Esophagectomy Complications Consensus Group (ECCG) classifications. Postoperatively, pneumonia was observed in four patients (CD, Grade II, 2; Grade IIIb, 2), although vocal cord palsy was more frequent (ECCG, Type I, 12; Type III, 8). The median number of thoracic lymph nodes resected was 21, and the R0 resection rate was 95%. Single-port mediastinoscope-assisted transhiatal esophagectomy is feasible, in terms of perioperative outcomes, for a radical surgery for thoracic esophageal cancer, although its safety needs to be further demonstrated.

Novel ATP-competitive Akt inhibitor afuresertib suppresses the proliferation of malignant pleural mesothelioma cells

Malignant pleural mesothelioma (MPM), an asbestos-related occupational disease, is an aggressive and incurable tumor of the thoracic cavity. Despite recent advances in MPM treatment, overall survival of patients with MPM is very low. Recent studies have implicated that PI3K/Akt signaling is involved in MPM cell survival and development. To investigate the effects of Akt inhibitors on MPM cell survival, we examined the effects of nine selective Akt inhibitors, namely, afuresertib, Akti-1/2, AZD5363, GSK690693, ipatasertib, MK-2206, perifosine, PHT-427, and TIC10, on six MPM cell lines, namely, ACC-MESO-4, Y-MESO-8A, MSTO-211H, NCI-H28, NCI-H290, and NCI-H2052, and a normal mesothelial cell line MeT-5A. Comparison of IC₅₀ values of the Akt inhibitors showed that afuresertib, an ATP-competitive specific Akt inhibitor, exerted tumor-specific effects on MPM cells. Afuresertib significantly increased caspase-3 and caspase-7 activities and apoptotic cell number among ACC-MESO-4 and MSTO-211H cells. Moreover, afuresertib strongly arrested the cell cycle in the G₁ phase. Western blotting analysis showed that afuresertib increased the expression of p21^WAF1/CIP1 and decreased the phosphorylation of Akt substrates, including GSK-3β and FOXO family proteins. These results suggest that afuresertib-induced p21 expression promotes G₁ phase arrest by inducing FOXO activity. Furthermore, afuresertib significantly enhanced cisplatin-induced cytotoxicity. Interestingly, results of gene set enrichment analysis showed that afuresertib modulated the expression E2F1 and MYC, which are associated with fibroblast core serum response. Together, these results suggest that afuresertib is a useful anticancer drug for treating patients with MPM.

Microbial acceleration of aerobic pyrite oxidation at circumneutral pH

Pyrite (FeS₂ ) is the most abundant sulfide mineral on Earth and represents a significant reservoir of reduced iron and sulfur both today and in the geologic past. In modern environments, oxidative transformations of pyrite and other metal sulfides play a key role in terrestrial element partitioning with broad impacts to contaminant mobility and the formation of acid mine drainage systems. Although the role of aerobic micro-organisms in pyrite oxidation under acidic-pH conditions is well known, to date there is very little known about the capacity for aerobic micro-organisms to oxidize pyrite at circumneutral pH. Here, we describe two enrichment cultures, obtained from pyrite-bearing subsurface sediments, that were capable of sustained cell growth linked to pyrite oxidation and sulfate generation at neutral pH. The cultures were dominated by two Rhizobiales species (Bradyrhizobium sp. and Mesorhizobium sp.) and a Ralstonia species. Shotgun metagenomic sequencing and genome reconstruction indicated the presence of Fe and S oxidation pathways in these organisms, and the presence of a complete Calvin-Benson-Bassham CO₂ fixation system in the Bradyrhizobium sp. Oxidation of pyrite resulted in thin (30-50 nm) coatings of amorphous Fe(III) oxide on the pyrite surface, with no other secondary Fe or S phases detected by electron microscopy or X-ray absorption spectroscopy. Rates of microbial pyrite oxidation were approximately one order of magnitude higher than abiotic rates. These results demonstrate the ability of aerobic microbial activity to accelerate pyrite oxidation and expand the potential contribution of micro-organisms to continental sulfide mineral weathering around the time of the Great Oxidation Event to include neutral-pH environments. In addition, our findings have direct implications for the geochemistry of modern sedimentary environments, including stimulation of the early stages of acid mine drainage formation and mobilization of pyrite-associated metals.