124 research outputs found
PROTEASOME INHIBITORS MODULATE OSTEOCYTE DEATH AND AUTOPHAGY IN MULTIPLE MYELOMA.
Background: Cell death and autophagy are the main cellular processes involved in the regulation of bone remodeling by osteocytes.
Recently we have demonstrated that an increased osteocyte death is involved in multiple myeloma (MM)-induced osteolysis through
the upregulation of osteoclast recruitment.
Aims: Because proteasome inhibitors including Bortezomib (BOR) are known to be able to target osteoblasts in this study we have
investigated the potential effect of these drugs on osteocytes and their cell death and autophagy.
Methods: Firstly the effect of the proteasome inhibitors BOR and MG262 on osteocyte viability was evaluated in vitro in murine
osteocytic cell line MLO-Y4 and in the human pre-osteocytic one HOB-01. Both cell lines were co-coltured for 48 hours in the
presence or absence of the human myeloma cell lines (HMCLs) RPMI8226 and JJN3, placed in a transwell insert in the presence or
the absence of BOR or MG262. Moreover the effect of proteasome inhibitors on dexamethasone (DEX)-induced MLO-Y4 death,
obtained at high doses (10-5-10-6M), was checked in combination with PTH(1-34). To evaluate the presence of autophagy and
apoptosis in osteocytes, we checked the expression of both autophagic marker LC3 and apoptotic marker APAF-1 by confocal
microscopy in the co-colture system with MLO-Y4 and RPMI-8226. Finally we performed a retrospective histological evaluation on
bone biopsies of a cohort of 31 newly diagnosis MM underwent to different treatments including BOR-based regimen. Bone biopsies
were obtained at the diagnosis and after an average time of 12 months of treatment. Osteocyte viability was evaluated in a total of 500
lacunae per histological sections.
Results: The in vitro treatment with BOR or MG262 significantly blunted MLO-Y4 and HOB-01 cell death. Similarly, DEXinduced
MLO-Y4 death was reduced by proteasome inhibitors. Interestingly, we found that both proteasome inhibitors potentiated the
PTH (1-34) short-term effects on DEX-induced osteocyte death. Prevalence of autophagic cell death compared to apoptosis was
observed in this system. In line with these data, we showed that neither the HMCLs nor treatment with DEX increase the apoptotic
death and caspase 3 activation in both MLO-Y4 and HOB-01 cell lines. BOR treatment increased the basal level of LC3 indicating a
pro-survival and protective function of autophagy against the BOR-induce stress. On the contrary, when the cells undergo to a
stronger stress such as in the presence of HMCLs or by treatment with high dose of DEX we found that both proteasome inhibitors
blocked autophagic cell death in osteocytes. In the in vivo study we found a significant increase of the number of viable osteocytes in
MM patients treated with BOR-based regimen as compared to those treated without BOR (% median increase: +6% vs. +1.30%;
p=0.017). Patients treated with BOR alone showed the highest increase of osteocyte viability, as compared to those either treated
without BOR (+11.6% vs. +1.3%, p=0.0019) or treated with BOR plus DEX (+11.6% vs. +4.4%, p=0.01). On the other hand, any
significant difference was not observed in patients treated with Thalidomide (THAL) or Immunomodulatory drugs (IMiDs) than in
those untreated with these drugs (p= 0.7). A multiple regression non-parametric analysis showed that BOR had a significant positive
impact on osteocyte viability (p=0.042) whereas THAL/IMiDs as well as Zoledronic acid (ZOL) treatments have not (p=0.2). BOR
also counterbalanced the negative effect of DEX treatment (p=0.035).
Summary/Conclusion: Our data suggest that proteasome inhibitors blunted osteocyte cell death induced by MM cells and DEX
through the modulation of the autophagy and potentiated the effect of PTH. Overall our in vitro and in vivo data support the use of
BOR to improve bone integrity in MM patients
Erratum: Inflammatory extracellular vesicles prompt heart dysfunction via TLR4-dependent NF-ÎșB activation: Erratum.
[This corrects the article DOI: 10.7150/thno.39072.]
A Novel Micropeptide, \u3cem\u3eSlitharin\u3c/em\u3e, Exerts Cardioprotective Effects in Myocardial Infarction
Purpose: Micropeptides are an emerging class of proteins that play critical roles in cell signaling. Here, we describe the discovery of a novel micropeptide, dubbed slitharin (Slt), in conditioned media from Cardiosphere-derived cells (CDCs), a therapeutic cardiac stromal cell type.
Experimental design: We performed mass spectrometry of peptide-enriched fractions from the conditioned media of CDCs and a therapeutically inert cell type (human dermal fibrobasts). We then evaluated the therapeutic capacity of the candidate peptide using an in vitro model of cardiomyocyte injury and a rat model of myocardial infarction.
Results: We identified a novel 24-amino acid micropeptide (dubbed Slitharin [Slt]) with a non-canonical leucine start codon, arising from long intergenic non-coding (LINC) RNA 2099. Neonatal rat ventricular myocytes (NRVMs) exposed to Slt were protected from hypoxic injury in vitro compared to a vehicle or scrambled control. Transcriptomic analysis of cardiomyocytes exposed to Slt reveals cytoprotective capacity, putatively through regulation of stress-induced MAPK-ERK. Slt also exerted cardioprotective effects in rats with myocardial infarction as shown by reduced infarct size 48 h post-injury.
Conclusions and clinical relavance: Thus, Slt is a non-coding RNA-derived micropeptide, identified in the extracellular space, with a potential cardioprotective function
Positive symptoms associate with cortical thinning in the superior temporal gyrus via the ENIGMA-Schizophrenia consortium
Objective: Based on the role of the superior temporal gyrus (STG) in auditory processing, language comprehension and self-monitoring, this study aimed to investigate the relationship between STG cortical thickness and positive symptom severity in schizophrenia. Method: This prospective meta-analysis includes data from 1987 individuals with schizophrenia collected at seventeen centres around the world that contribute to the ENIGMA Schizophrenia Working Group. STG thickness measures were extracted from T1-weighted brain scans using FreeSurfer. The study performed a meta-analysis of effect sizes across sites generated by a model predicting left or right STG thickness with a positive symptom severity score (harmonized SAPS or PANSS-positive scores), while controlling for age, sex and site. Secondary models investigated relationships between antipsychotic medication, duration of illness, overall illness severity, handedness and STG thickness. Results: Positive symptom severity was negatively related to STG thickness in both hemispheres (left: ÎČstd = â0.052; P = 0.021; right: ÎČstd = â0.073; P = 0.001) when statistically controlling for age, sex and site. This effect remained stable in models including duration of illness, antipsychotic medication or handedness. Conclusion: Our findings further underline the important role of the STG in hallmark symptoms in schizophrenia. These findings can assist in advancing insight into symptom-relevant pathophysiological mechanisms in schizophrenia
Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium
Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion
Meta-analysis of genome-wide association studies for extraversion:Findings from the Genetics of Personality Consortium
Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion
Multiancestry analysis of the HLA locus in Alzheimerâs and Parkinsonâs diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes
Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinsonâs disease (PD) and Alzheimerâs disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased AÎČ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
TDO2âaugmented fibroblasts secrete EVs enriched in immunomodulatory Yâderived small RNA
Abstract Mounting evidence implicates extracellular vesicles (EVs) factors as mediators of cell therapy. Cardiosphereâderived cells are cardiacâderived cells with tissue reparative capacity. Activation of a downstream target of wnt/ÎČâcatenin signalling, tryptophan 2,3 dioxygenase (TDO2) renders therapeutically inert skin fibroblasts cardioprotective. Here, we investigate the mechanism by which concentrated conditioned media from TDO2âaugmented fibroblasts (TDO2âCCM) exert cardioprotective effects. TDO2âCCM is cardioprotective in a mouse model of MI compared to CCM from regular fibroblasts (HDFâCCM). Transcriptomic analysis of cardiac tissue at 24Â h demonstrates broad suppression of inflammatory and cell stress markers in animals given TDO2âCCM compared to HDFâCCM or vehicle. Sequencing analysis of TDO2âEV RNA demonstrated abundance of a small Yâderived small RNA dubbed âNT4â. Purification of TDO2âEVs by sizeâexclusion chromatography and RNAse protection assays demonstrated that NT4 is encapsulated inside EVs. Consistently with TDO2âCCM, macrophages exposed to NT4 showed suppression of the inflammatory and cell stress mediators, particularly p21/cdkn1a. NT4âdepleted TDO2âCCM resulted in diminished immunomodulatory capacity. Finally, administration of NT4 alone was cardioprotective in an acute model of myocardial infarction. Taken together, these findings elucidate the mechanism by which TDO2 augmentation mediates potency in secreted EVs through enrichment of NT4 which suppresses upstream cell stress mediators including p21/cdkn1a
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