IL-1α cleavage by inflammatory caspases of the noncanonical inflammasome controls the senescence-associated secretory phenotype

Interleukin-1 alpha (IL-1α) is a powerful cytokine that modulates immunity, and requires canonical cleavage by calpain for full activity. Mature IL-1α is produced after inflammasome activation and during cell senescence, but the protease cleaving IL-1α in these contexts is unknown. We show IL-1α is activated by caspase-5 or caspase-11 cleavage at a conserved site. Caspase-5 drives cleaved IL-1α release after human macrophage inflammasome activation, while IL-1α secretion from murine macrophages only requires caspase-11, with IL-1β release needing caspase-11 and caspase-1. Importantly, senescent human cells require caspase-5 for the IL-1α-dependent senescence-associated secretory phenotype (SASP) in vitro, while senescent mouse hepatocytes need caspase-11 for the SASP-driven immune surveillance of senescent cells in vivo. Together, we identify IL-1α as a novel substrate of noncanonical inflammatory caspases and finally provide a mechanism for how IL-1α is activated during senescence. Thus, targeting caspase-5 may reduce inflammation and limit the deleterious effects of accumulated senescent cells during disease and Aging.

Juxtacrine regulation of cellular senescence

Cellular senescence is defined as a state of stable cell cycle exit in response to various stimuli, which include both cytotoxic stress and physiological cues. In addition to the core non-proliferative aspect, senescence is associated with diverse functionalities, which contribute to the role of senescence in a wide range of pathological and physiological processes. Such functionality is often mediated by the capability of senescent cells to communicate with their surroundings. Emerging evidence suggests that senescence is not a single entity, but a dynamic and heterogeneous collective phenotype. Understanding the diverse nature of senescence should provide insights into the complexity of tissue homeostasis and its disruption, such as in aging and tumorigenesis. [BMB Reports 2019; 52(1): 3-4].

LION LBD: a literature-based discovery system for cancer biology

MOTIVATION

The overwhelming size and rapid growth of the biomedical literature make it impossible for scientists to read all studies related to their work, potentially leading to missed connections and wasted time and resources. Literature-based discovery (LBD) aims to alleviate these issues by identifying implicit links between disjoint parts of the literature. While LBD has been studied in depth since its introduction three decades ago, there has been limited work making use of recent advances in biomedical text processing methods in LBD.

RESULTS

We present LION LBD, a literature-based discovery system that enables researchers to navigate published information and supports hypothesis generation and testing. The system is built with a particular focus on the molecular biology of cancer using state-of-the-art machine learning and natural language processing methods, including named entity recognition and grounding to domain ontologies covering a wide range of entity types and a novel approach to detecting references to the hallmarks of cancer in text. LION LBD implements a broad selection of co-occurrence based metrics for analyzing the strength of entity associations, and its design allows real-time search to discover indirect associations between entities in a database of tens of millions of publications while preserving the ability of users to explore each mention in its original context in the literature. Evaluations of the system demonstrate its ability to identify undiscovered links and rank relevant concepts highly among potential connections.

AVAILABILITY AND IMPLEMENTATION

The LION LBD system is available via a web-based user interface and a programmable API, and all components of the system are made available under open licenses from the project home page http://lbd.lionproject.net.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Short-term gain, long-term pain: the senescence life cycle and cancer

Originally thought of as a stress response end point, the view of cellular senescence has since evolved into one encompassing a wide range of physiological and pathological functions, including both protumorignic and antitumorigenic features. It has also become evident that senescence is a highly dynamic and heterogenous process. Efforts to reconcile the beneficial and detrimental features of senescence suggest that physiological functions require the transient presence of senescent cells in the tissue microenvironment. Here, we propose the concept of a physiological "senescence life cycle," which has pathological consequences if not executed in its entirety.

Score-Based and Nutrient-Derived Dietary Patterns Are Associated with Depressive Symptoms in Community-Dwelling Older Japanese: A Cross-Sectional Study

OBJECTIVES

This study evaluated associations of score-based and nutrient-derived dietary patterns with depressive symptoms in community-dwelling older Japanese.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

982 community-dwelling adults aged 65 years or older.

MEASUREMENTS

Score-based pattern was assessed by using dietary variety score (DVS), which covers 10 food group items in Japanese meals. Nutrient-derived dietary patterns were identified by using reduced rank regression (RRR), with folate, vitamin C, magnesium, calcium, iron, and zinc intakes as response variables. Depressive symptoms were assessed with the Geriatric Depression Scale. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for these dietary patterns in multivariate logistic regression analyses with potential confounders. The lowest consumption category was used as the reference group.

RESULTS

The prevalence of depressive symptoms was 13.5%. Higher DVS was associated with fewer depressive symptoms (OR=0.52, 95% CI=0.27-1.03 for the highest vs the lowest DVS; P for trend=0.031). The first RRR dietary pattern score was characterized by high intakes of fish, soybean products, potatoes, most vegetables, mushrooms, seaweeds, fruits, and green tea and a low intake of rice and was inversely associated with the prevalence of depressive symptoms (OR=0.53, 95% CI=0.30-0.92; P for trend=0.030).

CONCLUSION

Greater dietary variety and a dietary pattern characterized by high intakes of fish, soybean products, potatoes, most vegetables, mushrooms, seaweeds, fruit, and green tea and a low intake of rice were consistently associated with lower prevalence of depressive symptoms in community-dwelling older Japanese. Therefore, both patterns identified the components of dietary habits essential to depression prevention.

Juxtacrine regulation of cellular senescence

Cellular senescence is defined as a state of stable cell cycle exit in response to various stimuli, which include both cytotoxic stress and physiological cues. In addition to the core non-proliferative aspect, senescence is associated with diverse functionalities, which contribute to the role of senescence in a wide range of pathological and physiological processes. Such functionality is often mediated by the capability of senescent cells to communicate with their surroundings. Emerging evidence suggests that senescence is not a single entity, but a dynamic and heterogeneous collective phenotype. Understanding the diverse nature of senescence should provide insights into the complexity of tissue homeostasis and its disruption, such as in aging and tumorigenesis. [BMB Reports 2019; 52(1): 3-4].

440. The Masqueraders Presenting a Multisystem Disease: Unusual and Atypical Clinical Features of Scrub Typhus in Fukushima, Japan

Background

Scrub typhus (ST) is endemic in Fukushima, where the highest number has been reported from 2006 to 2011 in Japan. Atypical clinical presentation of ST makes the diagnosis difficult followed by treatment delay. Despite fatal but treatable disease with early recognition, the myriad clinical features of ST have been underreported.

Methods

We reviewed the clinical features of adult patients diagnosed as ST from 2008 to 2017 at Ohta Nishinouchi General Hospital, a major teaching hospital in Fukushima, Japan.

Results

Total 55 cases (serotype Karp 24, Irie/Kawasaki 21, Hirano/Kuroki 10) of ST were confirmed by elevated specific IgM and IgG in the paired sera and real-time PCR analysis of eschars. Unusual presentations as the main clinical features of ST are found in 7/55 (13%; Karp 4 and Irie/Kawasaki 3), including cardiovascular (3 cases of paroxysmal atrial fibrillation), neurological (2 cases of syncope and one case of encephalitis) and metabolic/electrolyte disorder (one case of hyponatremia). In terms of atypical clinical features, the cases without triad (fever ≥38.0℃, rash and eschar) were found in 14/55 (25%). The cases of “eschar negative scrub typhus” were found in 6/55 (11%; Karp 1, Irie/Kawasaki 2, Hirano/Kuroki 3). The cases without fever and rash were also found in 6/55 (11%; Karp 2, Irie/Kawasaki 3, Hirano/Kuroki 1) and 4/55 (7%; Karp 2, Irie/Kawasaki 1, Hirano/Kuroki 1), respectively. Severe cases (4/55, 7%) were found with shock and disseminated intravascular coagulation including one fatal case (1/55, 1.8%; Hirano/Kuroki). Besides more than the half of ST cases with triad (30/55; 55%), unusual and atypical presentations were found in 38% (21/55) of the total number of cases.

Conclusion

The diagnosis of ST is a clinical challenge without typical features. In endemic area, unusual and atypical presentation of ST involving multi-system should be noted as the odds-on favorite differential diagnosis.

Disclosures

All authors: No reported disclosures.

A novel Atg5-shRNA mouse model enables temporal control of Autophagy in vivo

Macroautophagy/autophagy is an evolutionarily conserved catabolic pathway whose modulation has been linked to diverse disease states, including age-associated disorders. Conventional and conditional whole-body knockout mouse models of key autophagy genes display perinatal death and lethal neurotoxicity, respectively, limiting their applications for in vivo studies. Here, we have developed an inducible shRNA mouse model targeting Atg5, allowing us to dynamically inhibit autophagy in vivo, termed ATG5i mice. The lack of brain-associated shRNA expression in this model circumvents the lethal phenotypes associated with complete autophagy knockouts. We show that ATG5i mice recapitulate many of the previously described phenotypes of tissue-specific knockouts. While restoration of autophagy in the liver rescues hepatomegaly and other pathologies associated with autophagy deficiency, this coincides with the development of hepatic fibrosis. These results highlight the need to consider the potential side effects of systemic anti-autophagy therapies.

NOTCH-mediated non-cell autonomous regulation of chromatin structure during senescence

Senescent cells interact with the surrounding microenvironment achieving diverse functional outcomes. We have recently identified that NOTCH1 can drive 'lateral induction' of a unique senescence phenotype in adjacent cells by specifically upregulating the NOTCH ligand JAG1. Here we show that NOTCH signalling can modulate chromatin structure autonomously and non-autonomously. In addition to senescence-associated heterochromatic foci (SAHF), oncogenic RAS-induced senescent (RIS) cells exhibit a massive increase in chromatin accessibility. NOTCH signalling suppresses SAHF and increased chromatin accessibility in this context. Strikingly, NOTCH-induced senescent cells, or cancer cells with high JAG1 expression, drive similar chromatin architectural changes in adjacent cells through cell-cell contact. Mechanistically, we show that NOTCH signalling represses the chromatin architectural protein HMGA1, an association found in multiple human cancers. Thus, HMGA1 is involved not only in SAHFs but also in RIS-driven chromatin accessibility. In conclusion, this study identifies that the JAG1-NOTCH-HMGA1 axis mediates the juxtacrine regulation of chromatin architecture.

A case of typhoidal tularemia in a male Japanese farmer

In Japan, most tularemia cases occur after contact with hares (hunting, cooking) and involve the glandular or ulceroglandular form. Here, we present a case of typhoidal tularemia in a 72-year-old Japanese male farmer who presented with fever, fatigue, and right lower abdominal pain. Computed tomography revealed intestinal wall thickening at the ascending colon, pleural effusion, and ascites. Following an initial diagnosis of bacterial enteric infection, his symptoms deteriorated after a week-long cephalosporin treatment course. The patient lived in an area endemic for scrub typhus; the antibiotic was changed to a tetracycline on suspicion of scrub typhus infection. His symptoms rapidly improved after initiation of minocycline treatment. Later, blood tests revealed marked increases in serological tests against Francisella tularensis exclusively, and the patient was diagnosed with typhoidal tularemia. Typhoidal tularemia may be characterized by any combination of general symptoms, but does not exhibit the local manifestations associated with other forms of tularemia. The patient, in this case, had no direct contact with hares or other wild animals and did not present with local manifestations of tularemia. Physicians should consider this disease, especially when tick-borne disease is suspected in the absence of local wounds, eschar, ulcers, or lymphadenopathy.

The Power Behind the Throne: Senescence and the Hallmarks of Cancer

Cellular senescence is a state of stable proliferative arrest triggered by various stimuli, including oncogenic and other cellular stress. Senescent cells are highly metabolically active and have diverse and profound nonautonomous effects through the senescence-associated secretory phenotype (SASP). It has become increasingly evident that senescent cells can have tumour suppressive or pro-oncogenic effects on adjacent cancer cells and other players in the tumor microenvironment such as the stroma, vasculature, and immune system. Thus, the last decade or so has witnessed a huge leap forward in our understanding of the biology of senescence, promoting it from an autonomous tumor suppressor to a complex, dynamic, and interactive phenotype. It is perhaps not a coincidence that the concept of the “hallmarks of cancer” has also evolved during this period, with the latest iteration ( Hanahan & Weinberg 2011 ) focusing more on the microenvironment. Here, we suggest that cellular senescence could underpin the biology of many of the hallmarks of cancer, making it the true power behind the throne.

Notch and Senescence

Cellular senescence, previously thought of as an autonomous tumour suppressor mechanism, is emerging as a phenotype and effector present throughout the life of an organism from embryogenesis to senile decline. Senescent cells have powerful non-autonomous effects upon multiple players within their microenvironment mainly through their secretory phenotype. How senescent cells co-ordinate numerous, sometimes functionally contrasting outputs through their secretome had previously been unclear. The Notch pathway, originally identified for its involvement in Drosophila wing development, has more recently been found to underpin diverse effects in human cancer. Here we discuss recent findings that suggest that Notch is intimately involved in the development of senescence and how it acts to co-ordinate the composition and functional effects of the senescence secretome. We also highlight the complex physical and functional interplay between Notch and p53, critical to both senescence and cancer. Understanding the interplay between Notch, p53 and senescence could allow us develop the therapeutics of the future for cancer and ageing.

Effects of Low-Dose Dairy Protein Plus Micronutrient Supplementation during Resistance Exercise on Muscle Mass and Physical Performance in Older Adults: A Randomized, Controlled Trial

OBJECTIVES

To investigate whether supplementation with low-dose dairy protein plus micronutrients augments the effects of resistance exercise (RE) on muscle mass and physical performance compared with RE alone among older adults.

DESIGN

Randomized controlled trial.

SETTING

Tokyo, Japan.

PARTICIPANTS

Eighty-two community-dwelling older adults (mean age, 73.5 years) were randomly allocated to an RE plus dairy protein and micronutrient supplementation group or an RE only group (n = 41 each).

INTERVENTION

The RE plus supplementation group participants ingested supplements with dairy protein (10.5 g/day) and micronutrients (8.0 mg zinc, 12 μg vitamin B12, 200 μg folic acid, 200 IU vitamin D, and others/day). Both groups performed the same twice-weekly RE program for 12 weeks.

MEASUREMENTS

Whole-body, appendicular, and leg lean soft-tissue mass (WBLM, ALM, and LLM, respectively) with dual-energy X-ray absorptiometry, physical performance, biochemical characteristics, nutritional intake, and physical activity were measured before and after the intervention. Data were analyzed by using linear mixed-effects models.

RESULTS

The groups exhibited similar significant improvements in maximum gait speed, Timed Up-and-Go, and 5-repetition and 30-s chair stand tests. As compared with RE only, RE plus supplementation significantly increased WBLM (0.63 kg, 95% confidence interval [CI]: 0.31-0.95), ALM (0.37 kg, 95% CI: 0.16-0.58), LLM (0.27 kg, 95% CI: 0.10-0.46), and serum concentrations of 25-hydroxyvitamin D (4.7 ng/mL, 95% CI: 1.6-7.9), vitamin B12 (72.4 pg/mL, 95% CI: 12.9-131.9), and folic acid (12.9 ng/mL, 95% CI: 10.3-15.5) (all P < 0.05 for group-by-time interactions). Changes over time in physical activity and nutritional intake excluding the supplemented nutrients were similar between groups.

CONCLUSION

Low-dose dairy protein plus micronutrient supplementation during RE significantly increased muscle mass in older adults but did not further improve physical performance.

Prevalence of venous thromboembolism at a teaching hospital in Okinawa, Japan

Limited data suggest that Asian Americans may have a lower risk of venous thromboembolism (VTE) than Caucasians. However, the actual prevalence of VTE among Asians remains controversial, and has not been described in Japan. We studied all 131,060 patients hospitalized at a single medical centre in Japan (January 1987 – December 1999). Patients with VTE were identified through discharge diagnoses. Hospital records were reviewed for information on patient demographics, risk factors, and diagnostic modalities. VTE occurred in 0.11% of admissions (n=141, 95%CI 0.09–0.13%). Mean age (±SD) was 64±17 years, 70% were women, 91% had deep vein thrombosis, and 29% pulmonary embolism. Among hospitalized patients 50–69 years old, VTE was significantly more common among women than men (0.31% vs. 0.08%; OR 3.88; 95%CI 1.45–6.31). We found a low prevalence of VTE in Japan compared to that reported in the US. Future studies are needed to clarify the reasons for our findings.

Spatial and Temporal Control of Senescence

Cellular senescence is an autonomous tumor suppressor mechanism leading to stable cell cycle arrest. Senescent cells are highly secretory, driving a range of different functions through the senescence-associated secretory phenotype (SASP). Recent findings have suggested that the composition of the SASP is dynamically and spatially regulated and that the changing composition of the SASP can determine the beneficial and detrimental aspects of the senescence program, tipping the balance to either an immunosuppressive/profibrotic environment or proinflammatory/fibrolytic state. Here, we discuss the current understanding of the temporal and spatial regulation of the SASP and the novel finding of NOTCH signaling as a regulator of SASP composition.

Presence of periaortic gas in Clostridium septicum-infected aortic aneurysm aids in early diagnosis: a case report and systematic review of the literature

BACKGROUND

Clostridium septicum-infected aortic aneurysm is a fatal and rare disease. We present a fatal case of C. septicum-infected aortic aneurysm and a pertinent literature review with treatment suggestions for reducing mortality rates.

CASE PRESENTATION

A 58-year-old Japanese man with an unremarkable medical history presented with a 3-day history of mild weakness in both legs, and experienced paraplegia and paresthesia a day before admission. Upon recognition of signs of an abdominal aortic aneurysm and paraplegia, we suspected an occluded Adamkiewicz artery and performed a contrast-enhanced computed tomography scan, which revealed an aortic aneurysm with periaortic gas extending from his chest to his abdomen and both kidneys. Antibiotics were initiated followed by emergency surgery for source control of the infection. However, owing to his poor condition and septic shock, aortic repair was not possible. We performed bilateral nephrectomy as a possible source control, after which we initiated mechanical ventilation, continuous hemodialysis, and hemoperfusion. A culture of the samples taken from the infected region and four consecutive blood cultures yielded C. septicum. His condition gradually improved postoperatively; however, on postoperative day 10, massive hemorrhage due to aortic rupture resulted in his death.

CONCLUSIONS

In this patient, C. septicum was thought to have entered his blood through a gastrointestinal tumor, infected the aorta, and spread to his kidneys. However, we were uncertain whether there was an associated malignancy. A literature review of C. septicum-related aneurysms revealed the following: 6-month mortality, 79.5%; periaortic gas present in 92.6% of cases; no standard operative procedure and no guidelines for antimicrobial administration established; and C. septicum was associated with cancer in 82.5% of cases. Thus, we advocate for early diagnosis via the identification of periaortic gas, as an aortic aneurysm progresses rapidly. To reduce the risk of reinfection as well as infection of other sites, there is the need for concurrent surgical management of the aneurysm and any associated malignancy. We recommend debridement of the infectious focus and in situ vascular graft with omental coverage. Postoperatively, orally administered antibiotics must be continued indefinitely (chronic suppression therapy). We believe that these treatments will decrease mortality due to C. septicum-infected aortic aneurysms.

A 'synthetic-sickness' screen for senescence re-engagement targets in mutant cancer backgrounds

Senescence is a universal barrier to immortalisation and tumorigenesis. As such, interest in the use of senescence-induction in a therapeutic context has been gaining momentum in the past few years; however, senescence and immortalisation remain underserved areas for drug discovery owing to a lack of robust senescence inducing agents and an incomplete understanding of the signalling events underlying this complex process. In order to address this issue we undertook a large-scale morphological siRNA screen for inducers of senescence phenotypes in the human melanoma cell line A375P. Following rescreen and validation in a second cancer cell line, HCT116 colorectal carcinoma, a panel of 16 of the most robust hits were selected for further validation based on significance and the potential to be targeted by drug-like molecules. Using secondary assays for detection of senescence biomarkers p21, 53BP1 and senescence associated beta-galactosidase (SAβGal) in a panel of HCT116 cell lines carrying cancer-relevant mutations, we show that partial senescence phenotypes can be induced to varying degrees in a context dependent manner, even in the absence of p21 or p53 expression. However, proliferation arrest varied among genetic backgrounds with predominantly toxic effects in p21 null cells, while cells lacking PI3K mutation failed to arrest. Furthermore, we show that the oncogene ECT2 induces partial senescence phenotypes in all mutant backgrounds tested, demonstrating a dependence on activating KRASG13D for growth suppression and a complete senescence response. These results suggest a potential mechanism to target mutant KRAS signalling through ECT2 in cancers that are reliant on activating KRAS mutations and remain refractory to current treatments.

Calligraphy-Stroke Learning Support System Using Projector and Motion Sensor

This paper presents a newly developed calligraphy-stroke learning support system. The system incorporates the following functions: a) Displaying brushwork, trajectory, and handwriting; b) recording and playback of an expert’s calligraphy-stroke; and c) teaching a learner a calligraphy-stroke. The following features of the system demonstrate the contributions of our study. (1) The system, which consists of a sensor and projector, is simple and compact, so as to be easily introduced to the usual educational fields and practical leaning situations. (2) Three-dimensional calligraphy-stroke is instructed by presenting two-dimensional visual information. (3) A trajectory region is generated in the form of continuous squares, calculated using a brush model based on the brush position information measured by a sensor. (4) Handwriting is expressed by mapping a handwriting texture image according to ink concentration and the brush handling state. The results of the trial experiment suggest the effectiveness of the learning support function in terms of letter form and calligraphy-stroke.