Laparoscopic Partial Hepatectomy: Animal Experiments

As a first step in firmly establishing laparoscopic hepatectomy, we introduce a porcine model of laparoscopic partial hepatectomy. This procedure has been successfully performed under the normal-pressure or low-pressure pneumoperitoneum condition supported by the full-thickness abdominal wall lifting technique. An ultrasonic dissector combined with electrocautery, newly developed by Olympus Optical Corporation (Japan) was effectively utilized in facilitating safe and smooth incisions into the liver parenchyma. Although indications for this procedure seem to be limited only to peripheral lesions and not to central lesions, clinical application of this method may be useful for some patients in the near future

Molecular-targeted Therapy for Metastatic Renal Cell Carcinoma As First-line Therapy: A Single Institution 13-year Experience

We aimed to identify the role of first-line monotherapy with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKI) in patients with metastatic RCC. Eligible patients were categorized into three groups (favorable, intermediate, and poor risk) according to the International Metastatic RCC Database Consortium risk criteria. Overall survival (OS) was the primary endpoint. Survival was compared using the log-rank test. A total of 108 patients were retrospectively analyzed. The numbers of patients in the favorable-, intermediate-, and poor-risk groups were 32 (30%), 66 (61%), and 10 (9%), repestively. The median OS values in the entire cohort was 36 months (95% confidence interval [CI] 29-53). The median OS in the favorable, intermediate, and poor risk groups were 94 months (95% CI: 43-Not reached), 30 months (95% CI: 20-38), and 8 months (95% CI: 0-Not reached), respectively (p<0.05). Prior nephrectomy, clear cell histology, clinical T stage ≤2, no metastasis at the time of diagnosis, nivolumab beyond first-line therapy, and objective response to VEGFR-TKIs were factors significantly prolonging OS on univariate analysis. VEGFR-TKI monotherapy as first-line therapy was an effective treatment option for patients with metastatic clear cell RCC with favorable risk

X-ray structure of Galdieria Rubisco complexed with one sulfate ion per active site

AbstractRibulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the reactions of carboxylation and oxygenation of ribulose-1,5-bisphosphate. These reactions require that the active site should be closed by a flexible loop (loop 6) of the large subunit. Rubisco from a red alga, Galdieria partita, has the highest specificity for carboxylation reaction among the Rubiscos hitherto reported. The crystal structure of unactivated Galdieria Rubisco has been determined at 2.6 Å resolution. The electron density map reveals that a sulfate binds only to the P1 anion-binding site of the active site and the loop 6 is closed. Galdieria Rubisco has a unique hydrogen bond between the main chain oxygen of Val332 on the loop 6 and the ϵ-amino group of Gln386 of the same large subunit. This interaction is likely to be crucial to understanding for stabilizing the loop 6 in the closed state and to making a higher affinity for anionic ligands

BATTLE: Genetically Engineered Strategies for Split-Tunable Allocation of Multiple Transgenes in the Nervous System

Elucidating fine architectures and functions of cellular and synaptic connections requires development of new flexible methods. Here, we created a concept called the “battle of transgenes,” based on which we generated strategies using genetically engineered battles of multiple recombinases. The strategies enabled split-tunable allocation of multiple transgenes. We demonstrated the versatility of these strategies and technologies in inducing strong and multi-sparse allocations of multiple transgenes. Furthermore, the combination of our transgenic strategy and expansion microscopy enabled three-dimensional high-resolution imaging of whole synaptic structures in the hippocampus with simultaneous visualizations of endogenous synaptic proteins. These strategies and technologies based on the battle of genes may accelerate the analysis of whole synaptic and cellular connections in diverse life science fields

PITHD1 is essential for male fertilization

The proteasome is a protein-degrading molecular complex that is necessary for protein homeostasis and various biological functions, including cell cycle regulation, signal transduction, and immune response. Proteasome activity is finely regulated by a variety of proteasome-interacting molecules. PITHD1 is a recently described molecule that has a domain putatively capable of interacting with the proteasome. However, it is unknown as to whether PITHD1 can actually bind to proteasomes and what it does in vivo. Here we report that PITHD1 is detected specifically in the spermatids in the testis and the cortical thymic epithelium in the thymus. Interestingly, PITHD1 associates with immunoproteasomes in the testis, but not with thymoproteasomes in the thymus. Mice deficient in PITHD1 exhibit severe male infertility accompanied with morphological abnormalities and impaired motility of spermatozoa. Furthermore, PITHD1 deficiency reduces proteasome activity in the testis and alters the amount of proteins that are important for fertilization capability by the sperm. However, the PITHD1-deficient mice demonstrate no detectable defects in the thymus, including T cell development. Collectively, our results identify PITHD1 as a proteasome-interacting protein that plays a nonredundant role in the male reproductive system

BATTLE: Genetically Engineered Strategies for Split-Tunable Allocation of Multiple Transgenes in the Nervous System

Elucidating fine architectures and functions of cellular and synaptic connections requires development of new flexible methods. Here, we created a concept called the “battle of transgenes,” based on which we generated strategies using genetically engineered battles of multiple recombinases. The strategies enabled split-tunable allocation of multiple transgenes. We demonstrated the versatility of these strategies and technologies in inducing strong and multi-sparse allocations of multiple transgenes. Furthermore, the combination of our transgenic strategy and expansion microscopy enabled three-dimensional high-resolution imaging of whole synaptic structures in the hippocampus with simultaneous visualizations of endogenous synaptic proteins. These strategies and technologies based on the battle of genes may accelerate the analysis of whole synaptic and cellular connections in diverse life science fields

PITHD1 is a proteasome-interacting protein essential for male fertilization

Hiroyuki Kondo, Takafumi Matsumura, Mari Kaneko, Kenichi Inoue, Hidetaka Kosako, Masahito Ikawa, Yousuke Takahama, Izumi Ohigashi, PITHD1 is a proteasome-interacting protein essential for male fertilization, Journal of Biological Chemistry, Volume 295, Issue 6, 2020, Pages 1658-1672, ISSN 0021-9258, https://doi.org/10.1074/jbc.RA119.011144

PsyR, a transcriptional regulator in quorum sensing system, binds lux box-like sequence in psyI promoter without AHL quorum sensing molecule and activates psyI transcription with AHL in Pseudomonas syringae pv. tabaci 6605

Quorum sensing (QS) is a mechanism for bacterial cell-cell communication using QS signals. N-acyl-homoserine lactones (AHLs), QS signals in Pseudomonas syringae pv. tabaci (Pta) 6605, are synthesized by an AHL synthase (PsyI) and recognized by the cognate transcription factor PsyR. To reveal the role of PsyR in virulence, we generated a psyR mutant and complemented strains of Pta 6605 and found that the psyR mutant is remarkably reduced in AHL production and ability to cause disease and propagate in host tobacco leaves. The phenotypes of complemented strains were restored to that of the wild type (WT). Because the psyR mutant lost nearly all AHL production, we investigated the function of PsyR in the transcription of psyI and production of AHL. Electrophoretic mobility shift assays suggested that the recombinant PsyR protein binds the promoter region of psyI but not psyR without AHL. The addition of AHL did not significantly affect this binding. The binding core sequence of this region was identified as a 20-bp lux box-like sequence. To reveal the function of PsyR and AHL on psyI transcription, we constructed a psyI promoter::lacZYA chimeric reporter gene, and inserted it into the WT and psyI mutant of Pta 6605. beta-galactosidase activity increased in a bacterial density-dependent manner in the WT and also in a psyI mutant after the addition of exogenous AHL. These results indicate that the solo PsyR binds the lux box in the psyI promoter and activates transcription in the concomitant presence of AHL

Small molecule-based detection of non-canonical RNA G-quadruplex structures that modulate protein translation

Tandem repeats of guanine-rich sequences in RNA often form thermodynamically stable four-stranded RNA structures. Such RNA G-quadruplexes have long been considered to be linked to essential biological processes, yet their physiological significance in cells remains unclear. Here, we report a approach that permits the detection of RNA G-quadruplex structures that modulate protein translation in mammalian cells. The approach combines antibody arrays and RGB-1, a small molecule that selectively stabilizes RNA G-quadruplex structures. Analysis of the protein and mRNA products of 84 cancer-related human genes identified Nectin-4 and CapG as G-quadruplex-controlled genes whose mRNAs harbor non-canonical G-quadruplex structures on their 5′UTR region. Further investigations revealed that the RNA G-quadruplex of CapG exhibits a structural polymorphism, suggesting a possible mechanism that ensures the translation repression in a KCl concentration range of 25–100 mM. The approach described in the present study sets the stage for further discoveries of RNA G-quadruplexes