Significance
Many important biological processes occur within biomolecular condensates. Unlike many organelles, these condensates lack a surrounding membrane but are formed by phase separation due to ...interactions of their molecular components. Although the important role of intrinsically disordered protein regions (IDRs) in condensates is appreciated and contributing amino acids have been identified, experimentally derived site-specific information reporting on interactions between IDRs in condensed phases is lacking. Using a suite of NMR experiments with improved resolution and sensitivity for studies of condensed phases, we have obtained quantitative and site-specific information on interactions and hot spots that govern phase separation of the C-terminal IDR of CAPRIN1 and how phase separation can be modulated by posttranslational modifications, mutations, and interactions with ATP.
The role of biomolecular condensates in regulating biological function and the importance of dynamic interactions involving intrinsically disordered protein regions (IDRs) in their assembly are increasingly appreciated. While computational and theoretical approaches have provided significant insights into IDR phase behavior, establishing the critical interactions that govern condensation with atomic resolution through experiment is more difficult, given the lack of applicability of standard structural biological tools to study these highly dynamic large-scale associated states. NMR can be a valuable method, but the dynamic and viscous nature of condensed IDRs presents challenges. Using the C-terminal IDR (607 to 709) of CAPRIN1, an RNA-binding protein found in stress granules, P bodies, and messenger RNA transport granules, we have developed and applied a variety of NMR methods for studies of condensed IDR states to provide insights into interactions driving and modulating phase separation. We identify ATP interactions with CAPRIN1 that can enhance or reduce phase separation. We also quantify specific side-chain and backbone interactions within condensed CAPRIN1 that define critical sequences for phase separation and that are reduced by
O
-GlcNAcylation known to occur during cell cycle and stress. This expanded NMR toolkit that has been developed for characterizing IDR condensates has generated detailed interaction information relevant for understanding CAPRIN1 biology and informing general models of phase separation, with significant potential future applications to illuminate dynamic structure–function relationships in other biological condensates.
Abstract
Introduction
Noncombat injuries (“injuries”) greatly impact soldier health and United States (U.S.) Army readiness; they are the leading cause of outpatient medical encounters (more than two ...million annually) among active component (AC) soldiers. Noncombat musculoskeletal injuries (“MSKIs”) may account for nearly 60% of soldiers’ limited duty days and 65% of soldiers who cannot deploy for medical reasons. Injuries primarily affect readiness through increased limited duty days, decreased deployability rates, and increased medical separation rates. MSKIs are also responsible for exorbitant medical costs to the U.S. government, including service-connected disability compensation. A significant subset of soldiers develops chronic pain or long-term disability after injury; this may increase their risk for chronic disease or secondary health deficits potentially associated with MSKIs. The authors will review trends in U.S. Army MSKI rates, summarize MSKI readiness-related impacts, and highlight the importance of standardizing surveillance approaches, including injury definitions used in injury surveillance.
Materials/Methods
This review summarizes current reports and U.S. Department of Defense internal policy documents. MSKIs are defined as musculoskeletal disorders resulting from mechanical energy transfer, including traumatic and overuse injuries, which may cause pain and/or limit function. This review focuses on various U.S. Army populations, based on setting, sex, and age; the review excludes combat or battle injuries.
Results
More than half of all AC soldiers sustained at least one injury (MSKI or non-MSKI) in 2017. Overuse injuries comprise at least 70% of all injuries among AC soldiers. Female soldiers are at greater risk for MSKI than men. Female soldiers’ aerobic and muscular fitness performances are typically lower than men’s performances, which could account for their higher injury rates. Older soldiers are at greater injury risk than younger soldiers. Soldiers in noncombat arms units tend to have higher incidences of reported MSKIs, more limited duty days, and higher rates of limited duty days for chronic MSKIs than soldiers in combat arms units. MSKIs account for 65% of medically nondeployable AC soldiers. At any time, 4% of AC soldiers cannot deploy because of MSKIs. Once deployed, nonbattle injuries accounted for approximately 30% of all medical evacuations, and were the largest category of soldier evacuations from both recent major combat theaters (Iraq and Afghanistan). More than 85% of service members medically evacuated for MSKIs failed to return to the theater. MSKIs factored into (1) nearly 70% of medical disability discharges across the Army from 2011 through 2016 and (2) more than 90% of disability discharges within enlisted soldiers’ first year of service from 2010 to 2015. MSKI-related, service-connected (SC) disabilities account for 44% of all SC disabilities (more than any other body system) among compensated U.S. Global War on Terrorism veterans.
Conclusions
MSKIs significantly impact soldier health and U.S. Army readiness. MSKIs also figure prominently in medical disability discharges and long-term, service-connected disability costs. MSKI patterns and trends vary between trainees and soldiers in operational units and among military occupations and types of operational units. Coordinated injury surveillance efforts are needed to provide standardized metrics and accurately measure temporal changes in injury rates.
Cancer patients have an increased risk of thrombosis. The development of cancer thrombosis is dependent on a number of factors including cancer type, stage, various biologic markers, and the use of ...central venous catheters. In addition, cancer treatment itself may increase thrombotic risk. Tamoxifen increases the risk of venous thromboembolism (VTE) by two- to sevenfold, while an impact on risk of arterial thrombosis is uncertain. Immunomodulatory imide drugs (IMiDs) such as thalidomide and lenalidomide increase the risk of VTE in patients with multiple myeloma (MM) by about 10-40% when given in combination with glucocorticoids or other chemotherapy agents; the risk of VTE in MM patients treated with IMiD-containing regimens necessitates that such patients receive thromboprophylaxis with aspirin, low-molecular-weight heparin, or warfarin. Among cytotoxic chemotherapy agents, cisplatin, and to a lesser extent fluorouracil, has been described in association with thrombosis. L-asparaginase in treatment of acute lymphoblastic leukemia is significantly associated with increased thrombosis particularly affecting the CNS, which may be due to acquired antithrombin deficiency; at some centers, plasma infusions or antithrombin replacement is used to mitigate this. Bevacizumab, an inhibitor of vascular endothelial growth factor, increases arterial and possibly venous thrombotic risk, although the literature is conflicting about the latter. Supportive care agents in cancer care, such as erythropoiesis-stimulating agents, granulocyte colony stimulating factor, and steroids, also have some impact on thrombosis. This review summarizes the mechanisms by which these and other therapies modulate thrombotic risks and how such risks may be managed.
Background
Ghrelin is a potential therapy for cachexia due to its orexigenic properties and anabolic effects on muscle and fat. However, its clinical use is limited by the short half‐life of active ...(acylated) ghrelin (~11 min in humans). EXT418 is a novel long‐acting, constitutively active ghrelin analog created by covalently linking it to a vitamin D derivative. Here, we evaluated the effects and mechanisms of action of EXT418 on Lewis lung carcinoma (LLC)‐induced cachexia in mice.
Methods
Male C57BL/6J mice (5‐ to 7‐month‐old) were implanted with 1 × 106 heat‐killed (HK) or live LLC cells. When the tumour was palpable, mice were injected with vehicle (T + V) or EXT418 daily (T + 418 Daily, 0.25 mg/kg/day) or every other day (T + 418 EOD, 0.5 mg/kg/EOD) for up to 14 days, whereas HK‐treated mice were given vehicle (HK + V). Subsets of T + 418 Daily or EOD‐treated mice were pair‐fed to the T + V group. Body composition and grip strength were evaluated before tumour implantation and at the end of the experiment. Molecular markers were probed in muscles upon termination.
Results
In tumour‐bearing mice, administration of EXT418 daily or EOD partially prevented weight loss (T + V vs. T + 418 Daily, P = 0.030; and vs. T + 418 EOD, P = 0.020). Similar effects were observed in whole body fat and lean body mass. Grip strength in tumour‐bearing mice was improved by EXT418 daily (P = 0.010) or EOD (P = 0.008) administration compared with vehicle‐treated mice. These effects of EXT418 on weight and grip strength were partially independent of food intake. EXT418 daily administration also improved type IIA (P = 0.015), IIB (P = 0.037) and IIX (P = 0.050) fibre cross‐sectional area (CSA) in tibialis anterior (TA) and EXT418 EOD improved CSA of IIB fibres in red gastrocnemius (GAS; P = 0.005). In skeletal muscles, tumour‐induced increases in atrogenes Fbxo32 and Trim63 were ameliorated by EXT418 treatments (TA and GAS/plantaris, PL), which were independent of food intake. EXT418 administration decreased expression of the mitophagy marker Bnip3 (GAS/PL; P ≤ 0.010). Similar effects of EXT418 EOD were observed in p62 (GAS/PL; P = 0.039). In addition, EXT418 treatments ameliorated the tumour‐induced elevation in muscle Il6 transcript levels (TA and GAS/PL), independently of food intake. Il‐6 transcript levels in adipose tissue and circulating IL‐10 were elevated in response to the tumour but these increases were not significant with EXT418 administration. Tumour mass was not altered by EXT418.
Conclusions
EXT418 mitigates LLC‐induced cachexia by attenuating skeletal muscle inflammation, proteolysis, and mitophagy, without affecting tumour mass and partially independent of food intake.
The COVID-19 pandemic has laid bare the devastating truth about pervasive health inequity in the United States. As the virus swept through the country, underserved racial and ethnic minority ...populations disproportionately bore the brunt of the hospitalizations, severe illness, and fatalities. The devastation among these groups far outstripped their privileged counterparts due to convergence of disadvantages that created a perfect storm of exposures. We used empirical evidence incorporated into a theoretical framework analyzing vulnerabilities that have long plagued these communities. These exposures were further exacerbated by the rapid transmission of this virus and impaired the capability of these communities to escape illness and death due to a lack of adequate public health and medical responses. Will the aftermath of this coronavirus prove to be a reckoning for how American society addresses the conditions of most vulnerable populations or another ignored data-point? We suggest some policy steps to address the problem.
Background
Ghrelin may ameliorate cancer cachexia (CC) by preventing anorexia, muscle, and fat loss. However, the mechanisms mediating these effects are not fully understood. This study characterizes ...the pathways involved in muscle mass and strength loss in the Lewis lung carcinoma (LLC)‐induced cachexia model, and the effects of ghrelin in mice with or without its only known receptor: the growth hormone secretagogue receptor‐1a ((GHSR‐1a), Ghsr+/+ and Ghsr−/−).
Methods
Five to 7‐month‐old male C57BL/6J Ghsr+/+ and Ghsr−/− mice were inoculated with 1 × 106 heat‐killed (HK) or live LLC cells (tumour implantation, TI). When tumours were palpable (7 days after TI), tumour‐bearing mice were injected with vehicle (T + V) or ghrelin twice/day for 14 days (T + G, 0.8 mg/kg), while HK‐treated mice were given vehicle (HK + V). Body weight and grip strength were evaluated before TI and at termination (21 days after TI). Hindlimb muscles were collected for analysis.
Results
Less pronounced body weight (BW) loss (87.70 ± 0.98% vs. 83.92 ± 1.23%, percentage of baseline BW in tumour‐bearing Ghsr+/+ vs. Ghsr−/−, P = 0.008), and lower upregulation of ubiquitin‐proteasome system (UPS, MuRF1/Trim63, 5.71 ± 1.53‐fold vs. 9.22 ± 1.94‐fold‐change from Ghsr+/+ HK + V in tumour‐bearing Ghsr+/+ vs. Ghsr‐/‐, P = 0.036) and autophagy markers (Becn1, Atg5, Atg7, tumour‐bearing Ghsr+/+ < Ghsr−/−, all P < 0.02) were found in T + V Ghsr+/+ vs. Ghsr−/− mice. Ghrelin attenuated LLC‐induced UPS marker upregulation in both genotypes, Trim63 was decreased from 5.71 ± 1.53‐fold to 1.96 ± 0.47‐fold in Ghsr+/+ (T + V vs. T + G: P = 0.032) and 9.22 ± 1.94‐fold to 4.72 ± 1.06‐fold in Ghsr−/− (T + V vs. T + G: P = 0.008). Only in Ghsr+/+ mice ghrelin ameliorated LLC‐induced grip strength loss improved from 89.24 ± 3.48% to 97.80 ± 2.31% of baseline (T + V vs. T + G: P = 0.042), mitophagy markers Bnip3 was decreased from 2.28 ± 0.56 to 1.38 ± 0.14‐fold (T + V vs. T + G: P ≤ 0.05), and impaired mitochondrial respiration State 3u improved from 698.23 ± 73.96 to 934.37 ± 95.21 pmol/min (T + V vs. T + G: P ≤ 0.05), whereas these markers were not improved by ghrelin Ghsr−/−. Compared with Ghsr+/+, Ghsr−/− tumour‐bearing mice also showed decreased response to ghrelin in BW T + G‐treated Ghsr+/+ vs. Ghsr −/−: 91.75 ± 1.05% vs. 86.18 ± 1.13% of baseline BW, P < 0.001), gastrocnemius (T + G‐treated Ghsr+/+ vs. Ghsr−/−: 96.9 ± 2.08% vs. 88.15 ± 1.78% of Ghsr+/+ HK + V, P < 0.001) and quadriceps muscle mass (T + G‐treated Ghsr+/+ vs. Ghsr−/−: 96.12 ± 2.31% vs. 88.36 ± 1.94% of Ghsr+/+ HK + V, P = 0.01), and gastrocnemius type IIA (T + G‐treated Ghsr+/+ vs. Ghsr−/−: 1250.49 ± 31.72 vs. 1017.62 ± 70.99 μm2, P = 0.027) and IIB fibre cross‐sectional area (T + G‐treated Ghsr+/+ vs. Ghsr−/−: 2496.48 ± 116.88 vs. 2183.04 ± 103.43 μm2, P = 0.024).
Conclusions
Growth hormone secretagogue receptor‐1a mediates ghrelin's effects on attenuating LLC‐induced weakness but not muscle mass loss by modulating the autophagy‐lysosome pathway, mitophagy, and mitochondrial respiration.
Diffuse idiopathic skeletal hyperostosis (DISH) is an incompletely defined disease process with no known unifying pathophysiological mechanism.
To our knowledge, no genetic studies have been ...performed in a North American population. To summarize genetic findings from previous studies and to comprehensively test for these associations in a novel and diverse, multi-institutional population.
Cross-sectional, single nucleotide polymorphism (SNP) analysis was performed in 55 of 121 enrolled patients with DISH. Baseline demographic data were available on 100 patients. Based on allele selection from previous studies and related disease conditions, sequencing was performed on COL11A2, COL6A6, fibroblast growth factor 2 gene, LEMD3, TGFB1, and TLR1 genes and compared with global haplotype rates.
Consistent with previous studies, older age (mean 71 years), male sex predominance (80%), a high frequency of type 2 diabetes (54%), and renal disease (17%) were observed. Unique findings included high rates of tobacco use (11% currently smoking, 55% former smoker), a higher predominance of cervical DISH (70%) relative to other locations (30%), and an especially high rate of type 2 diabetes in patients with DISH and ossification of the posterior longitudinal ligament (100%) relative to DISH alone (100% vs 47%, P < .001). Compared with global allele rates, we found higher rates of SNPs in 5 of 9 tested genes ( P < .05).
We identified 5 SNPs in patients with DISH that occurred more frequently than a global reference. We also identified novel environmental associations. We hypothesize that DISH represents a heterogeneous condition with both multiple genetic and environmental influences.
Abstract
BACKGROUND
Novel methods in predicting survival in patients with spinal metastases may help guide clinical decision-making and stratify treatments regarding surgery vs palliative care.
...OBJECTIVE
To evaluate whether the frailty/sarcopenia paradigm is predictive of survival and morbidity in patients undergoing surgery for spinal metastasis.
METHODS
A total of 271 patients from 4 tertiary care centers who had undergone surgery for spinal metastasis were identified. Frailty/sarcopenia was defined by psoas muscle size. Survival hazard ratios were calculated using multivariate analysis, with variables from demographic, functional, oncological, and surgical factors. Secondary outcomes included improvement of neurological function and postoperative morbidity.
RESULTS
Patients in the smallest psoas tertile had shorter overall survival compared to the middle and largest tertile. Psoas size (PS) predicted overall mortality more strongly than Tokuhashi score, Tomita score, and Karnofsky Performance Status (KPS). PS predicted 90-d mortality more strongly than Tokuhashi score, Tomita score, and KPS. Patients with a larger PS were more likely to have an improvement in deficit compared to the middle tertile. PS was not predictive of 30-d morbidity.
CONCLUSION
In patients undergoing surgery for spine metastases, PS as a surrogate for frailty/sarcopenia predicts 90-d and overall mortality, independent of demographic, functional, oncological, and surgical characteristics. The frailty/sarcopenia paradigm is a stronger predictor of survival at these time points than other standards. PS can be used in clinical decision-making to select which patients with metastatic spine tumors are appropriate surgical candidates.
Graphical Abstract
Graphical Abstract
Toca 511 (vocimagene amiretrorepvec) is an investigational nonlytic, retroviral replicating vector (RRV) that delivers a yeast cytosine deaminase, which converts subsequently administered courses of ...the investigational prodrug Toca FC (extended-release 5-fluorocytosine) into the antimetabolite 5-fluorouracil. Forty-five subjects with recurrent or progressive high-grade glioma were treated. The end points of this phase 1, open-label, ascending dose, multicenter trial included safety, efficacy, and molecular profiling; survival was compared to a matching subgroup from an external control. Overall survival for recurrent high-grade glioma was 13.6 months (95% confidence interval, 10.8 to 20.0) and was statistically improved relative to an external control (hazard ratio, 0.45; P = 0.003). Tumor samples from subjects surviving more than 52 weeks after Toca 511 delivery disproportionately displayed a survival-related mRNA expression signature, identifying a potential molecular signature that may correlate with treatment-related survival rather than being prognostic. Toca 511 and Toca FC show excellent tolerability, with RRV persisting in the tumor and RRV control systemically. The favorable assessment of Toca 511 and Toca FC supports confirmation in a randomized phase 2/3 trial (NCT02414165).
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