Emerging Role of Exosomal Long Non-coding RNAs in Spaceflight-Associated Risks in Astronauts

During spaceflight, astronauts are exposed to multiple unique environmental factors, particularly microgravity and ionizing radiation, that can cause a range of harmful health consequences. Over the past decades, increasing evidence demonstrates that the space environment can induce changes in gene expression and RNA processing. Long non-coding RNA (lncRNA) represent an emerging area of focus in molecular biology as they modulate chromatin structure and function, the transcription of neighboring genes, and affect RNA splicing, stability, and translation. They have been implicated in cancer development and associated with diverse cardiovascular conditions and associated risk factors. However, their role on astronauts’ health after spaceflight remains poorly understood. In this perspective article, we provide new insights into the potential role of exosomal lncRNA after spaceflight. We analyzed the transcriptional profile of exosomes isolated from peripheral blood plasma of three astronauts who flew on various Shuttle missions between 1998–2001 by RNA-sequencing. Computational analysis of the transcriptome of these exosomes identified 27 differentially expressed lncRNAs with a Log2 fold change, with molecular, cellular, and clinical implications.

CTIM-09. PHASE I STUDY OF PD-L1 INHIBITION WITH AVELUMAB AND LASER INTERSTITIAL THERMAL THERAPY IN PATIENTS WITH RECURRENT GLIOBLASTOMA

BACKGROUND The treatment of glioblastoma (GBM) poses many challenges. The use of immune checkpoint inhibition (ICI) has been disappointing as GBM is characterized by a low mutational burden and low infiltration by T cells. The combination of ICI with other treatment modalities may improve efficacy. METHODS Patients with recurrent GBM were treated with 800 mg avelumab, a human IgG1 antibody directed against PD-L1, either alone (in part A) or within a week after MRI-guided laser interstitial thermal therapy (LITT, in part B) and by-weekly thereafter (NCT03341806). To spare steroid use, bevacizumab was allowed to be combined with avelumab. The primary objective was to characterize the tolerability and safety of the regimen. The secondary objectives included overall survival, progression-free survival, and signature of plasma analytes. RESULTS A total of 12 patients (median age 64, range 37 - 73) enrolled from June 2018 to November 2019, 5 in part A and 7 in part B. Three serious adverse events (SAE) occurred in the same patient, not leading to death. There were 94 AEs reported, 5 grade 3, 28 grade 2, and 61 grade 1. The median PFS was 16.7 weeks (range 7.4-56.7) for patients in Part A and 30.9 weeks (range 8.5-77.7) for patients in Part B. The median survival for patients in part A was 11 months and 13.5 months for part B. The risk ratio of death by combining bevacizumab was 0.573 (p=0.258) with significantly decreased levels of peripheral blood plasma inflammatory markers such as EGF, CXCL5, VEGFA, LAP.TGβ1, ANGPT2 in women. CONCLUSIONS Avelumab was generally well-tolerated, and the combination with LITT had a manageable safety profile and increased survival in a subset of patients. The addition of bevacizumab may increase survival by lowering cytokine expression in a gender-dependent manner. These results warrant further investigation in the next phase study.

CHEMOKINES CCL17 AND CCL22 IN SARCOIDOSIS

Various immune cells as well as related cytokines are involved in immunopathogenesis of sarcoidosis and mechanisms of granuloma development. Currently, a role for chemokines in sarcoidosis has been extensively investigated, which is paralleled with a search for key molecules necessary for recruiting immune cells to intrusion site and granuloma formation as well as affecting outcome of the latter. Our study was aimed for determining level of plasma CCL17/TARC and CCL22/MDC chemokines in patients with sarcoidosis who received no immunosuppressive therapy is of high priority for clarifying some aspects in underlying immunopathogenesis as well as seeking out for secure clinical and laboratory criteria for assessing activity and disease prognosis. We studied peripheral blood plasma samples of the patients with sarcoidosis (n = 52). In 37% (19/52), they exhibited acute clinical manifestations, and 63% (33/52) had chronic sarcoidosis. The control group included peripheral blood samples from healthy volunteers (n = 22). The chemokine concentrations (pg/ml) were determined by multiplex analysis using xMAP technology (Luminex), and Milliplex MAP test system (Millipore, USA). In the patients with sarcoidosis, significantly higher levels of chemokines were shown relative to healthy volunteers: CCL17 – 78.24 pg/ml vs 26.24 pg/ml, p < 0.001; CCL22 – 660.60 pg/ml vs 405.00 pg/ml, p < 0.001. Evaluation of clinical and laboratory diagnostic characteristics for plasma chemokine levels in sarcoidosis patients allowed to assess their sensitivity and specificity. The respective values were as follows: in acute sarcoidosis: for CCL17 – 63% and 78%, CCL22 – 63% and 91%; in chronic sarcoidosis: CCL17 – 58% and 83%, CCL22 – 67% and 86%, respectively. In chronic sarcoidosis the levels of this chemokine correlated with the activity of angiotensin-converting enzyme (ACE), for CCL17 (r = 0.530; p = 0.003), for CCL22 (r = 0.446; p = 0.014). Patients with systemic lesions vs no systemic lesions (sarcoidosis of the respiratory system only) had significantly elevated CCL17 level: 102.82 pg/ml vs 32.72 pg/ml, p = 0.011. The concentration of chemokine CCL17 was significantly increased in patients with vs without signs of hepatomegaly: 130.73 pg/ml vs 51.60 pg/ml, p = 0.022. Levels of chemokines was significantly increased in patients with vs without ultrasound signs of splenomegaly comprising: for CCL17 – 249.18 pg/ml vs 46.87 pg/ml, p = 0.002; for CCL22 – 1271.40 pg/ml vs 660.63 pg/ml, p = 0.003. Thus, it should be noted that the peripheral blood plasma level of chemokines CCL17 and CCL22 may be used as additional prognostic markers in chronic sarcoidosis with varying scoring of clinical signs including with/without systemic disease manifestations.

Concentration of Circulating Cell-Free DNA in the Peripheral Blood Plasma of Patients with Acute Endogenous and Exogenous Etiology Psychoses

Introduction: cell-free plasma DNA (cfDNA) is used as a marker refl ecting the level of apoptosis in the human body under stress. Acute psychosis caused by endogenous (schizophrenia) and exogenous (alcohol intoxication) factors in the patient’s body is associated with oxidative stress. Presumably, cfDNA concentration in the blood plasma of patients with acute psychoses of endogenous and exogenous etiology is increased. The purpose of the study: comparative analysis of the cfDNA concentration in the blood plasma of treated and untreated patients with paranoid schizophrenia during the disease exacerbation, patients with alcoholic psychosis and healthy volunteers. Patients and methods: the concentration of cfDNA was determined in the blood plasma samples of 476 people: control group (n = 95); patients with schizophrenia in the acute stage of the disease (n = 334); patients with alcoholic psychosis (n = 47). Results: the concentrations of cfDNA in the plasma of patients with schizophrenia (median 931 ng/ml) is 2.2 times higher than in the control group (median 428 ng/ml) and 1.8 times higher than in the patients with alcoholic psychosis (504 ng/ml). For the patients with schizophrenia with high PANSS, we found the highest values of the cfDNA concentration in the blood plasma during psychosis, which indicates a more pronounced systemic process, which is accompanied by the cell death level increase. Conclusions: the concentration of cfDNA in the blood plasma could be used as a biochemical marker that refl ects the severity of the schizophrenia patient’ state upon admission to the hospital.

Autoantibody profiles associated with clinical features in psychotic disorders

Autoimmune processes are suspected to play a role in the pathophysiology of psychotic disorders. Better understanding of the associations between auto-immunoglobulin G (IgG) repertoires and clinical features of mental illness could yield novel models of the pathophysiology of psychosis, and markers for biological patient stratification. We undertook cross-sectional detection and quantification of auto-IgGs in peripheral blood plasma of 461 people (39% females) with established psychotic disorder diagnoses. Broad screening of 24 individuals was carried out on group level in eight clinically defined groups using planar protein microarrays containing 42,100 human antigens representing 18,914 proteins. Autoantibodies indicated by broad screening and in the previous literature were measured using a 380-plex bead-based array for autoantibody profiling of all 461 individuals. Associations between autoantibody profiles and dichotomized clinical characteristics were assessed using a stepwise selection procedure. Broad screening and follow-up targeted analyses revealed highly individual autoantibody profiles. Females, and people with family histories of obesity or of psychiatric disorders other than schizophrenia had the highest overall autoantibody counts. People who had experienced subjective thought disorder and/or were treated with clozapine (trend) had the lowest overall counts. Furthermore, six autoantibodies were associated with specific psychopathology symptoms: anti-AP3B2 (persecutory delusions), anti-TDO2 (hallucinations), anti-CRYGN (initial insomnia); anti-APMAP (poor appetite), anti-OLFM1 (above-median cognitive function), and anti-WHAMMP3 (anhedonia and dysphoria). Future studies should clarify whether there are causal biological relationships, and whether autoantibodies could be used as clinical markers to inform diagnostic patient stratification and choice of treatment.

May critical molecular cross-talk between indoleamine 2,3-dioxygenase (IDO) and arginase during human aging be targets for immunosenescence control?

Background This study aimed to identify novel plasma metabolic signatures with possible clinical relevance during the aging process. A biochemical quantitative phenotyping platform, based on targeted electrospray ionization tandem mass spectrometry technology, was used for the identification of any eventual perturbed biochemical pathway by the aging process in prospectively collected peripheral blood plasma from 166 individuals representing the population of São Paulo city, Brazil. Results Indoleamine 2,3-dioxygenase (IDO) activity (Kyn/Trp) was significantly elevated with age, and among metabolites most associated with elevations in IDO, one of the strongest correlations was with arginase (Orn/Arg), which could also facilitate the senescence process of the immune system. Hyperactivity of IDO was also found to correlate with increased blood concentrations of medium-chain acylcarnitines, suggesting that deficiencies in beta-oxidation may also be involved in the immunosenescence process. Finally, our study provided evidence that the systemic methylation status was significantly increased and positively correlated to IDO activity. Conclusions In the present article, besides identifying elevated IDO activity exhibiting striking parallel association with the aging process, we additionally identified increased arginase activity as an underlying biochemical disturbance closely following elevations in IDO. Our findings support interventions to reduce IDO or arginase activities in an attempt to preserve the functionality of the immune system, including modulation of myeloid-derived suppressor cells (MDSCs), T cells, macrophages, and dendritic cells’ function, in old individuals/patients.

Blood Platelets as an Important but Underrated Circulating Source of TGFβ

When treating diseases related primarily to tissue remodeling and fibrosis, it is desirable to regulate TGFβ concentration and modulate its biological effects. The highest cellular concentrations of TGFβ are found in platelets, with about 40% of all TGFβ found in peripheral blood plasma being secreted by them. Therefore, an understanding of the mechanisms of TGFβ secretion from platelets may be of key importance for medicine. Unfortunately, despite the finding that platelets are an important regulator of TGFβ levels, little research has been carried out into the development of platelet-directed therapies that might modulate the TGFβ-dependent processes. Nevertheless, there are some very encouraging reports suggesting that platelet TGFβ may be specifically involved in cardiovascular diseases, liver fibrosis, tumour metastasis, cerebral malaria and in the regulation of inflammatory cell functions. The purpose of this review is to briefly summarize these few, extremely encouraging reports to indicate the state of current knowledge in this topic. It also attempts to better characterize the influence of TGFβ on platelet activation and reactivity, and its shaping of the roles of blood platelets in haemostasis and thrombosis.

Radiation Can Regulate the Expression of miRNAs Associated with Osteogenesis and Oxidation in Exosomes from Peripheral Blood Plasma

Objectives. Radiotherapy is a common therapy in head and neck tumors, which may cause a side effect radiation bone injury (RBI). Furthermore, it has been investigated that microRNA (miRNA) expression levels were altered after radiotherapy. Exosomes play a role in bone formation as miRNA containers, while radiation affects exosomes composition, secretion, and function. So, our objective is to explore changes in miRNA levels during bone formation after radiotherapy and identify the differentially expressed miRNAs (DE-miRs) in plasma exosomes during the process of osteogenesis related to irradiation. Materials and Methods. In this study, we analyzed nine samples from three rabbits exposed twice to radiation (15 Gy each) and detected DE-miRs from irradiated plasma exosomes during the process of osteogenesis by RNA sequencing. Further, we identified DE-miRs with significant differences and predicted their target genes via the bioinformatics analysis tools Targetscan v7.2 and miRPathDB v2.0. Finally, we identified radiation-responsive miRNAs and predicted their target genes during osteogenesis. Results. Taken together, we have identified some DE-miRs in irradiated plasma exosomes, which were involved in several vital signaling pathways related to bone physiology, such as the Wnt pathway, MAPK cascade, and calcium modulating pathway. Conclusions. We have found that plasma exosomes are one of the ways by which radiation can affect bone metabolism and regeneration. However, the specific mechanisms of how these plasma exosomal miRNAs mediate the osteogenesis pathways must be further investigated. Clinical Relevance. Radiotherapy may cause radiation bone injury, and miRNA expression levels in rabbit plasma exosomes are altered after radiotherapy. High-throughput RNA sequencing can identify the differentially expressed miRNAs in irradiated plasma exosomes during the process of osteogenesis. These findings make sense to develop novel therapeutic strategies for treating radiation-induced bone injury disorders.