ALLO-1- and IKKE-1-dependent positive feedback mechanism promotes the initiation of paternal mitochondrial autophagy.

Allophagy is responsible for the selective removal of paternally inherited organelles, including mitochondria, in Caenorhabditis elegans embryos, thereby facilitating the maternal inheritance of mitochondrial DNA. We previously identified two key factors in allophagy: an autophagy adaptor allophagy-1 (ALLO-1) and TBK1/IKKε family kinase IKKE-1. However, the precise mechanisms by which ALLO-1 and IKKE-1 regulate local autophagosome formation remain unclear. In this study, we identify two ALLO-1 isoforms with different substrate preferences during allophagy. Live imaging reveals a stepwise mechanism of ALLO-1 localization with rapid cargo recognition, followed by ALLO-1 accumulation around the cargo. In the ikke-1 mutant, the accumulation of ALLO-1, and not the recognition of cargo, is impaired, resulting in the failure of isolation membrane formation. Our results also suggest a feedback mechanism for ALLO-1 accumulation via EPG-7/ATG-11, a worm homolog of FIP200, which is a candidate for IKKE-1-dependent phosphorylation. This feedback mechanism may underlie the ALLO-1-dependent initiation and progression of autophagosome formation around paternal organelles.

MARC-3, a membrane-associated ubiquitin ligase, is required for fast polyspermy block in Caenorhabditis elegans.

In many sexually reproducing organisms, oocytes are fundamentally fertilized with one sperm. In Caenorhabditis elegans, chitin layer formation after fertilization by the EGG complex is one of the mechanisms of polyspermy block, but other mechanisms remain unknown. Here, we demonstrate that MARC-3, a membrane-associated RING-CH-type ubiquitin ligase that localizes to the plasma membrane and cortical puncta in oocytes, is involved in fast polyspermy block. During polyspermy, the second sperm entry occurs within approximately 10 s after fertilization in MARC-3-deficient zygotes, whereas it occurs approximately 200 s after fertilization in egg-3 mutant zygotes defective in the chitin layer formation. MARC-3 also functions in the selective degradation of maternal plasma membrane proteins and the transient accumulation of endosomal lysine 63-linked polyubiquitin after fertilization. The RING-finger domain of MARC-3 is required for its in vitro ubiquitination activity and polyspermy block, suggesting that a ubiquitination-mediated mechanism sequentially regulates fast polyspermy block and maternal membrane protein degradation during the oocyte-to-embryo transition.

Predictors of life-space mobility in patients with fracture 3 months after discharge from convalescent rehabilitation ward: a prospective longitudinal study.

[Purpose] To identify predictors of life-space mobility in patients with fracture three months after discharge from convalescent rehabilitation ward. [Participants and Methods] This is a prospective longitudinal study that included patients aged 65 or older with a fracture who were scheduled for discharge home from the convalescent rehabilitation ward. Baseline measurements included sociodemographic variables (age, gender, and disease), the Falls Efficacy Scale-International, maximum walking speed, the Timed Up & Go test, the Berg Balance Scale, the modified Elderly Mobility Scale, the Functional Independence Measure, the revised version of Hasegawa's Dementia Scale, and the Vitality Index up to two weeks before discharge. As a follow-up, the life-space assessment was measured three months after discharge. In the statistical analysis, multiple linear and logistic regression analyses were performed with the life-space assessment score and the life-space level of "places outside your town" as dependent variables. [Results] The Falls Efficacy Scale-International, the modified Elderly Mobility Scale, age, and gender were selected as predictors in the multiple linear regression analysis, whereas in the multiple logistic regression analysis, the Falls Efficacy Scale-International, age, and gender were selected as predictors. [Conclusion] Our study emphasized the importance of fall-related self-efficacy and motor function for life-space mobility. The findings of this study suggest that when considering post-discharge living, therapists should conduct an appropriate assessment and adequate planning.

Autophagy regulates plastid reorganization during spermatogenesis in the liverwort Marchantia polymorpha.

Autophagy is a highly conserved system that delivers cytoplasmic components to lysosomes/vacuoles. Plastids are also degraded through autophagy for nutrient recycling and quality control; however, the involvement of autophagic degradation of plastids in plant cellular differentiation remains unclear. Here, we investigated whether spermiogenesis, the differentiation of spermatids into spermatozoids, in the liverwort Marchantia polymorpha involves autophagic degradation of plastids. Spermatozoids of M. polymorpha possess one cylindrical plastid at the posterior end of the cell body. By fluorescently labeling and visualizing plastids, we detected dynamic morphological changes during spermiogenesis. We found that a portion of the plastid was degraded in the vacuole in an autophagy-dependent manner during spermiogenesis, and impaired autophagy resulted in defective morphological transformation and starch accumulation in the plastid. Furthermore, we found that autophagy was dispensable for the reduction in plastid number and plastid DNA elimination. These results demonstrate a critical but selective role of autophagy in plastid reorganization during spermiogenesis in M. polymorpha.

Dexmedetomidine for dyspnoea.

Dexmedetomidine is a selective α2-adrenoreceptor agonist with a broad range of effects, including easily controllable sedation, analgesia and anxiolysis. Because of these favorable features, it has replaced traditional sedatives, such as benzodiazepines, and is becoming the first-line sedative for the patients in intensive care units. Terminally ill patients often need sedatives for symptom management, especially for dyspnoea. However, the use of dexmedetomidine in a palliative care setting has rarely been recognised to date. We experienced a patient nearing the end of life due to uncontrollable pulmonary haemorrhage on ventilator, whose dyspnoea was successfully managed by dexmedetomidine in addition to continuous intravenous infusion of oxycodone.

Inorganic arsenic exposure-induced premature senescence and senescence-associated secretory phenotype (SASP) in human hepatic stellate cells.

Exposure to inorganic arsenic has been known to induce cancers in various organs, however, the underlying mechanisms remain unclear. Premature senescence refers to the irreversible growth arrest induced by stress stimuli. The senescence-associated secretory phenotype (SASP), particularly in fibroblasts, has been shown to promote cancer development. In this study, we examined whether arsenite exposure causes premature senescence and induction of SASP in liver fibroblasts using the human hepatic stellate cell line, LX-2. Exposure of LX-2 cells to 5 or 7.5 µM of sodium arsenite for 144 h induced the features of senescence in the cells, including morphological changes, growth inhibition, increased senescence-associated ß-galactosidase activity, increased P21 gene expression, and decreased LAMINB1 gene expression. The mRNA expressions of SASP factors, such as MMP1, MMP3, IL-8, IL-1ß, and CXCL1, were also highly upregulated. The wound healing assay revealed that the conditioned medium from LX-2 cells with arsenite-induced senescence increased the migration activity of cells of the human hepatoma cell line, Huh-7. Gene expression data of liver cancer samples from the Human Protein Atlas showed that high expression levels of the SASP factors that were upregulated in the cells with arsenite-induced senescence were strongly associated with a poor prognosis. In addition, the cellular levels of γ-H2AX, a DNA double-strand break marker, were increased by arsenite exposure, suggesting that DNA damage could contribute to premature senescence induction. These results show that arsenite exposure induces premature senescence in hepatic stellate cells and suggest that the SASP factors from the senescent cells promote hepatic carcinogenesis.

Dynamic rearrangement and autophagic degradation of mitochondria during spermiogenesis in the liverwort Marchantia polymorpha.

Mitochondria change their morphology in response to developmental and environmental cues. During sexual reproduction, bryophytes produce spermatozoids with two mitochondria in the cell body. Although intensive morphological analyses have been conducted, how this fixed number of mitochondria is realized remains poorly understood. Here, we investigate how mitochondria are reorganized during spermiogenesis in Marchantia polymorpha. We find that the mitochondrial number is reduced to one through fission followed by autophagic degradation during early spermiogenesis, and then the posterior mitochondrion arises by fission of the anterior mitochondrion. Autophagy is also responsible for the removal of other organelles, including peroxisomes, but these other organelles are removed at distinct developmental stages from mitochondrial degradation. We also find that spermiogenesis involves nonautophagic organelle degradation. Our findings highlight the dynamic reorganization of mitochondria, which is regulated distinctly from that of other organelles, and multiple degradation mechanisms operate in organelle remodeling during spermiogenesis in M. polymorpha.

PD-1 blockade therapy augments the antitumor effects of lymphodepletion and adoptive T cell transfer.

Lymphodepleting cytotoxic regimens enhance the antitumor effects of adoptively transferred effector and naïve T cells. Although the mechanisms of antitumor immunity augmentation by lymphodepletion have been intensively investigated, the effects of lymphodepletion followed by T cell transfer on immune checkpoints in the tumor microenvironment remain unclear. The current study demonstrated that the expression of immune checkpoint molecules on transferred donor CD4+ and CD8+ T cells was significantly decreased in lymphodepleted tumor-bearing mice. In contrast, lymphodepletion did not reduce immune checkpoint molecule levels on recipient CD4+ and CD8+ T cells. Administration of anti-PD-1 antibodies after lymphodepletion and adoptive transfer of T cells significantly inhibited tumor progression. Further analysis revealed that transfer of both donor CD4+ and CD8+ T cells was responsible for the antitumor effects of a combination therapy consisting of lymphodepletion, T cell transfer and anti-PD-1 treatment. Our findings indicate that a possible mechanism underlying the antitumor effects of lymphodepletion followed by T cell transfer is the prevention of donor T cell exhaustion and dysfunction. PD-1 blockade may reinvigorate exhausted recipient T cells and augment the antitumor effects of lymphodepletion and adoptive T cell transfer.

Syntaxin 17, an ancient SNARE paralog, plays different and conserved roles in different organisms.

Mammalian syntaxin 17 (Stx17) has several roles in processes other than membrane fusion, including in mitochondrial division, autophagosome formation and lipid droplet expansion. In contrast to conventional syntaxins, Stx17 has a long C-terminal hydrophobic region with a hairpin-like structure flanked by a basic amino acid-enriched C-terminal tail. Although Stx17 is one of the six ancient SNAREs and is present in diverse eukaryotic organisms, it has been lost in multiple lineages during evolution. In the present study, we compared the localization and function of fly and nematode Stx17s expressed in HeLa cells with those of human Stx17. We found that fly Stx17 predominantly localizes to the cytosol and mediates autophagy, but not mitochondrial division. Nematode Stx17, on the other hand, is predominantly present in mitochondria and facilitates mitochondrial division, but is irrelevant to autophagy. These differences are likely due to different structures in the C-terminal tail. Non-participation of fly Stx17 and nematode Stx17 in mitochondrial division and autophagy, respectively, was demonstrated in individual organisms. Our results provide an insight into the evolution of Stx17 in metazoa. This article has an associated First Person interview with the first author of the paper.

Degradation of paternal mitochondria via mitophagy.

BACKGROUND: In most sexually reproducing organisms, mitochondrial DNA (mtDNA) is inherited maternally. SCOPE OF REVIEW: In this review, we summarise recent knowledge on how paternal mitochondria and their mtDNA are selectively eliminated from embryos. MAJOR CONCLUSIONS: Studies based on Caenorhabditis elegans have revealed that paternal mitochondria and their mtDNA are selectively degraded in embryos via mitophagy. Thus, mitophagy functions as the mechanisms of maternal inheritance of mtDNA. The mitophagy of paternal mitochondria is conserved in other species, and the underlying molecular mechanisms have begun to be elucidated. In addition to mitophagy, autophagy-independent digestion of paternal mtDNA before and after fertilization serves as another mechanism for maternal inheritance of mtDNA. GENERAL SIGNIFICANCE: Maternal inheritance of mtDNA is strictly controlled via multistep mechanisms. These studies also demonstrate a physiological role of mitophagy during animal development.

Molecular mechanisms and physiological functions of mitophagy.

Degradation of mitochondria via a selective form of autophagy, named mitophagy, is a fundamental mechanism conserved from yeast to humans that regulates mitochondrial quality and quantity control. Mitophagy is promoted via specific mitochondrial outer membrane receptors, or ubiquitin molecules conjugated to proteins on the mitochondrial surface leading to the formation of autophagosomes surrounding mitochondria. Mitophagy-mediated elimination of mitochondria plays an important role in many processes including early embryonic development, cell differentiation, inflammation, and apoptosis. Recent advances in analyzing mitophagy in vivo also reveal high rates of steady-state mitochondrial turnover in diverse cell types, highlighting the intracellular housekeeping role of mitophagy. Defects in mitophagy are associated with various pathological conditions such as neurodegeneration, heart failure, cancer, and aging, further underscoring the biological relevance. Here, we review our current molecular understanding of mitophagy, and its physiological implications, and discuss how multiple mitophagy pathways coordinately modulate mitochondrial fitness and populations.

Combination therapy of cisplatin with cilastatin enables an increased dose of cisplatin, enhancing its antitumor effect by suppression of nephrotoxicity.

Cisplatin, one of the most active anticancer agents, is widely used in standard chemotherapy for various cancers. Cisplatin is more poorly tolerated than other chemotherapeutic drugs, and the main dose-limiting toxicity of cisplatin is its nephrotoxicity, which is dose-dependent. Although less toxic methods of cisplatin administration have been established, cisplatin-induced nephrotoxicity remains an unsolved problem. Megalin is an endocytic receptor expressed at the apical membrane of proximal tubules. We previously demonstrated that nephrotoxic drugs, including cisplatin, are reabsorbed through megalin and cause proximal tubular cell injury. We further found that cilastatin blocked the binding of cisplatin to megalin in vitro. In this study, we investigated whether cilastatin could reduce cisplatin-induced nephrotoxicity without influencing the antitumor effects of cisplatin. Nephrotoxicity was decreased or absent in mice treated with cisplatin and cilastatin, as determined by kidney injury molecule-1 staining and the blood urea nitrogen content. Combined with cilastatin, a twofold dose of cisplatin was used to successfully treat the mice, which enhanced the antitumor effects of cisplatin but reduced its nephrotoxicity. These findings suggest that we can increase the dose of cisplatin when combined with cilastatin and improve the outcome of cancer patients.

ERdj8 governs the size of autophagosomes during the formation process.

In macroautophagy, membrane structures called autophagosomes engulf substrates and deliver them for lysosomal degradation. Autophagosomes enwrap a variety of targets with diverse sizes, from portions of cytosol to larger organelles. However, the mechanism by which autophagosome size is controlled remains elusive. We characterized a novel ER membrane protein, ERdj8, in mammalian cells. ERdj8 localizes to a meshwork-like ER subdomain along with phosphatidylinositol synthase (PIS) and autophagy-related (Atg) proteins. ERdj8 overexpression extended the size of the autophagosome through its DnaJ and TRX domains. ERdj8 ablation resulted in a defect in engulfing larger targets. C. elegans, in which the ERdj8 orthologue dnj-8 was knocked down, could perform autophagy on smaller mitochondria derived from the paternal lineage but not the somatic mitochondria. Thus, ERdj8 may play a critical role in autophagosome formation by providing the capacity to target substrates of diverse sizes for degradation.

Temporal Trends in Atherosclerotic Risk Factors in School Children　- Findings From 20-Year Surveillance.

BACKGROUND: Although it has been discussed which measures against atherosclerotic diseases should be started in childhood, the current situation in Japan is unclear.Methods and Results:We conducted a health management survey of all 12-year-old children in a local town for 20 years. The body mass index tended to decrease over time. Although the serum low-density lipoprotein cholesterol level did not change, the levels of serum high-density lipoprotein cholesterol and serum triglycerides significantly increased over time. CONCLUSIONS: The serum triglyceride levels in school children increased significantly, probably through lifestyle changes, and the health management system should be reviewed.

Retrospective analysis of antitumor effects and biomarkers for nivolumab in NSCLC patients with EGFR mutations.

Although the blockade of programmed cell death 1 (PD-1)/PD-ligand (L) 1 has demonstrated promising and durable clinical responses for non-small-cell lung cancers (NSCLCs), NSCLC patients with epidermal growth factor receptor (EGFR) mutations responded poorly to PD-1/PD-L1 inhibitors. Previous studies have identified several predictive biomarkers, including the expression of PD-L1 on tumor cells, for PD-1/PD-L1 blockade therapies in NSCLC patients; however, the usefulness of these biomarkers in NSCLCs with EGFR mutations has not been elucidated. The present study was conducted to evaluate the predictive biomarkers for PD-1/PD-L1 inhibitors in EGFR-mutated NSCLCs. We retrospectively analyzed 9 patients treated with nivolumab for EGFR-mutated NSCLCs. All but one patient received EGFR-tyrosine kinase inhibitors before nivolumab treatment. The overall response rate and median progression-free survival were 11% and 33 days (95% confidence interval (CI); 7 to 51), respectively. Univariate analysis revealed that patients with a good performance status (P = 0.11; hazard ratio (HR) 0.183, 95% CI 0.0217 to 1.549), a high density of CD4+ T cells (P = 0.136; HR 0.313, 95% CI 0.045 to 1.417) and a high density of Foxp3+ cells (P = 0.09; HR 0.264, 95% CI 0.0372 to 1.222) in the tumor microenvironment tended to have longer progression-free survival with nivolumab. Multivariate analysis revealed that a high density of CD4+ T cells (P = 0.005; HR<0.001, 95% CI <0.001 to 0.28) and a high density of Foxp3+ cells (P = 0.003; HR<0.001, 95% CI NA) in tumor tissues were strongly correlated with better progression-free survival. In contrast to previous studies in wild type EGFR NSCLCs, PD-L1 expression was not associated with the clinical benefit of anti-PD-1 treatment in EGFR-mutated NSCLCs. The current study indicated that immune status in the tumor microenvironment may be important for the effectiveness of nivolumab in NSCLC patients with EGFR mutations.

[A Case of Drug-Induced Organizing Pneumonia Caused by Dasatinib].

A 52-year-old man with chronic myelogenous leukemia (CML) received dasatinib after the failure of imatinib and nilotinib therapy. Two years after the initiation of dasatinib, he developed shortness of breath that gradually worsened. Chest X-ray and computed tomography scan showed pulmonary infiltrative shadows and bilateral pleural effusion. We performed a transbronchial lung biopsy and diagnosed organizing pneumonia caused by dasatinib treatment. Corticosteroid therapy was initiated after the discontinuation of dasatinib and all his symptoms were significantly improved. Because of the exacerbation of CML, the patient was treated with imatinib and then nilotinib; however, these drugs failed to decrease the leukemic cells. Re - administration of dasatinib in combination with corticosteroid therapy successfully controlled CML without recurrence of organizing pneumonia.

[Methods of coping with musculoskeletal pain among community-dwelling elderly individuals].

Objectives　Musculoskeletal pain impairs vital function and results in a requirement for long-term care. According to studies in other countries, a program that aims at reducing pain through instructions for pain-coping should be implemented. In Japan, a study on pain-coping has recently been initiated; however, the methods of coping with pain that are implemented by community-dwelling elderly individuals have not been evaluated. This study aimed to clarify the methods currently used for coping with musculoskeletal pain and to examine their association with the state of pain among community-dwelling elderly individuals.Methods　A survey was performed by sending questionnaires by mail to 2,281 community-dwelling elderly individuals. Responses were obtained from 1,835 people. The survey items consisted of questions about basic attributes and pain. A total of 16 questionnaire items regarding the methods of coping with pain were used for measuring pain-coping that community-dwelling elderly individuals use. The methods of coping with pain were classified into various types by factor analysis. The scores were calculated by type and their association with the state of pain was analyzed using one-way analysis of variance.Results　As a result of the factor analysis, methods of coping with pain were classified into five categories: "treatment in hospitals," "daily active coping," "restriction of daily behavior," "self-therapy," and "rest." From one-way analysis of variance for the site of pain, there was a significant difference between the "treatment in hospitals" and "restriction of daily behavior" categories. Among both scores, a higher score was observed in subjects with pain in both the lower back and the knee, compared to those with only pain in the lower back or the knee. Among the number of the sites, there was a significant difference between the "treatment in hospitals," "restriction of daily behavior," and "self-therapy" categories; subjects exhibiting two or more sites of pain showed a higher score than those exhibiting one site of pain. For pain duration, there was a significant difference between the "treatment in hospitals," "restriction of daily behavior," and "self-therapy" categories; subjects who had experienced pain for 5 years or longer had a higher score than those who had experienced pain for less than 6 months.Conclusion　We found that five types of methods of coping with pain ("treatment in hospitals," "daily active coping," "restriction of daily behavior," "self-therapy," and "rest") were used by community-dwelling elderly individuals and that "treatment in hospitals" and "restriction of daily behavior" were the most common strategies among elderly individuals with pain.

SFT-4/Surf4 control ER export of soluble cargo proteins and participate in ER exit site organization.

Lipoproteins regulate the overall lipid homeostasis in animals. However, the molecular mechanisms underlying lipoprotein trafficking remain poorly understood. Here, we show that SFT-4, a Caenorhabditis elegans homologue of the yeast Erv29p, is essential for the endoplasmic reticulum (ER) export of the yolk protein VIT-2, which is synthesized as a lipoprotein complex. SFT-4 loss strongly inhibits the ER exit of yolk proteins and certain soluble cargo proteins in intestinal cells. SFT-4 predominantly localizes at ER exit sites (ERES) and physically interacts with VIT-2 in vivo, which suggests that SFT-4 promotes the ER export of soluble proteins as a cargo receptor. Notably, Surf4, a mammalian SFT-4 homologue, physically interacts with apolipoprotein B, a very-low-density lipoprotein core protein, and its loss causes ER accumulation of apolipoprotein B in human hepatic HepG2 cells. Interestingly, loss of SFT-4 and Surf4 reduced the number of COPII-positive ERES. Thus, SFT-4 and Surf4 regulate the export of soluble proteins, including lipoproteins, from the ER and participate in ERES organization in animals.