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Archivos de Bronconeumologia Sep 2022The clinical and epidemiological implications of abnormal immune responses in COVID-19 for latent tuberculosis infection (LTBI) screening are unclear. (Review)
Review
Clinical and Epidemiological Correlates of Low IFN-Gamma Responses in Mitogen Tube of QuantiFERON Assay in Tuberculosis Infection Screening During the COVID-19 Pandemic: A Population-Based Marker of COVID-19 Mortality?
BACKGROUND
The clinical and epidemiological implications of abnormal immune responses in COVID-19 for latent tuberculosis infection (LTBI) screening are unclear.
METHODS
We reviewed QuantiFERON TB Gold Plus (QFT-Plus) results (36,709 patients) from July 2016 until October 2021 in Asturias (Spain). We also studied a cohort of ninety hospitalized patients with suspected/confirmed COVID-19 pneumonia and a group of elderly hospitalized patients with COVID-19 who underwent serial QFT-Plus and immune profiling testing.
RESULTS
The indeterminate QFT-Plus results rate went from 1.4% (July 2016 to November 2019) to 4.2% during the COVID-19 pandemic. The evolution of the number of cases with low/very low interferon-gamma (IFN-gamma) response in the mitogen tube paralleled the disease activity and number of deaths during the pandemic waves in our region (from March 2020 to October 2021). The percentages of positive QFT-plus patients did not significantly change before and during the pandemic (13.9% . 12.2%). Forty-nine patients from the suspected/confirmed COVID-19 pneumonia cohort (54.4%) had low/very low IFN-gamma response to mitogen, 22 of them (24.4%) had severe and critical pneumonia. None received immunosuppressants prior to testing. Abnormal radiological findings (P = 0.01) but not COVID-19 severity was associated with low mitogen response. Immune profiling showed a reduction of CD8 + T cells and a direct correlation between the number of EMRA CD8 + T-cells and IFN-gamma response to mitogen (P = 0.03).
CONCLUSION
Low IFN-gamma responses in mitogen tube of QFT-Plus often occur in COVID-19 pneumonia, which is associated with a low number of an effector CD8 + T-cell subset and does not seem to affect LTBI screening; however, this abnormality seems to parallel the dynamics of COVID-19 at the population level and its mortality.
Topics: Aged; Biomarkers; COVID-19; Humans; Interferon-gamma; Interferon-gamma Release Tests; Latent Tuberculosis; Mitogens; Mycobacterium tuberculosis; Pandemics; Tuberculin Test
PubMed: 35185258
DOI: 10.1016/j.arbres.2022.01.011 -
Nature Communications Nov 2023Cyclin-dependent kinases 4 and 6 (CDK4/6) are critical for initiating cell proliferation by inactivating the retinoblastoma (Rb) protein. However, mammalian cells can...
Cyclin-dependent kinases 4 and 6 (CDK4/6) are critical for initiating cell proliferation by inactivating the retinoblastoma (Rb) protein. However, mammalian cells can bypass CDK4/6 for Rb inactivation. Here we show a non-canonical pathway for Rb inactivation and its interplay with external signals. We find that the non-phosphorylated Rb protein in quiescent cells is intrinsically unstable, offering an alternative mechanism for initiating E2F activity. Nevertheless, this pathway incompletely induces Rb-protein loss, resulting in minimal E2F activity. To trigger cell proliferation, upregulation of mitogenic signaling is required for stabilizing c-Myc, thereby augmenting E2F activity. Concurrently, stress signaling promotes Cip/Kip levels, competitively regulating cell proliferation with mitogenic signaling. In cancer, driver mutations elevate c-Myc levels, facilitating adaptation to CDK4/6 inhibitors. Differentiated cells, despite Rb-protein loss, maintain quiescence through the modulation of c-Myc and Cip/Kip levels. Our findings provide mechanistic insights into an alternative model of cell-cycle entry and the maintenance of quiescence.
Topics: Animals; Cyclin-Dependent Kinase 4; Cell Cycle; Cell Division; Phosphorylation; Signal Transduction; Cell Cycle Proteins; Retinoblastoma Protein; Mitogens; Mammals
PubMed: 38030655
DOI: 10.1038/s41467-023-43716-y -
Neuro-oncology Nov 2023Pediatric low-grade gliomas (pLGGs) are the most common brain tumor in young children. While they are typically associated with good overall survival, children with...
Pediatric low-grade gliomas (pLGGs) are the most common brain tumor in young children. While they are typically associated with good overall survival, children with these central nervous system tumors often experience chronic tumor- and therapy-related morbidities. Moreover, individuals with unresectable tumors frequently have multiple recurrences and persistent neurological symptoms. Deep molecular analyses of pLGGs reveal that they are caused by genetic alterations that converge on a single mitogenic pathway (MEK/ERK), but their growth is heavily influenced by nonneoplastic cells (neurons, T cells, microglia) in their local microenvironment. The interplay between neoplastic cell MEK/ERK pathway activation and stromal cell support necessitates the use of predictive preclinical models to identify the most promising drug candidates for clinical evaluation. As part of a series of white papers focused on pLGGs, we discuss the current status of preclinical pLGG modeling, with the goal of improving clinical translation for children with these common brain tumors.
Topics: Child; Humans; Child, Preschool; Glioma; Brain Neoplasms; Mutation; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Tumor Microenvironment
PubMed: 37738646
DOI: 10.1093/neuonc/noad125 -
Cell Reports Jul 2021Contact inhibition of cell proliferation regulates tissue size and prevents uncontrolled cell expansion. When cell density increases, contact inhibition can force...
Contact inhibition of cell proliferation regulates tissue size and prevents uncontrolled cell expansion. When cell density increases, contact inhibition can force proliferating cells into quiescence. Here we show that the variable memory of local cell density experienced by a mother cell controls the levels of the cyclin-dependent kinase (CDK) activator cyclin D1 and inhibitor p27 in newborn daughters, which direct cells to proliferation or quiescence. Much of this regulation can be explained by rapid suppression of ERK activity by high cell density in mothers, which leads to lower cyclin D1 and higher p27 levels in daughters. Strikingly, cell density and mitogen signals compete by shifting the ratio of cyclin D1/p27 levels below or above a single sharp threshold that controls the proliferation decision. Thus, the history of competing cell density and mitogen signals experienced by mothers is funneled into a precise activator-inhibitor balance that decides the fate of daughter cells.
Topics: Cell Count; Cell Cycle; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Female; Humans; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Mitogens; Models, Biological; Phosphorylation; Retinoblastoma Protein
PubMed: 34320337
DOI: 10.1016/j.celrep.2021.109436 -
Frontiers in Immunology 2023Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy...
INTRODUCTION
Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3-7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less.
METHODS
Three potential assays were examined-assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2-72 h.
RESULTS
Suppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h.
DISCUSSION
Takeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2-6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h.
Topics: Humans; T-Lymphocytes; Leukocytes, Mononuclear; Tumor Necrosis Factor-alpha; Mitogens; Immunosuppression Therapy; Mesenchymal Stem Cells; Intercellular Signaling Peptides and Proteins; Caspases
PubMed: 37822938
DOI: 10.3389/fimmu.2023.1225047 -
The Prostate May 2022Prostate cancer (PC) is the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in males. The disease is initially treated with...
BACKGROUND
Prostate cancer (PC) is the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in males. The disease is initially treated with methods that inhibit androgen receptor (AR) signal transduction. Laboratory-based and clinical studies have identified alternative pathways that cause the failure of AR signal inhibition and consequent development of castration-resistant prostate cancer (CRPC). Glucocorticoid receptor (GR) signaling is activated in certain PC patients and promotes the emergence of CRPC, although by as yet incompletely understood mechanisms. We have previously demonstrated that ubiquitous βarrestin1 (βArr1) expression levels are linked to PC progression. Here, we consider the possibility that βArr1 interacts with and activates GR in model CRPC cells.
METHODS
Bioinformatic analysis of tumor xenograft and human PC datasets was used to correlate the expression of βArr1 and GR. Western blot, immunohistochemistry and immunofluorescence microscopy, and subcellular fractionation were used to determine protein expression level and localization. Immunoprecipitation was applied to detect protein-protein interactions. RNA expression levels were determined using quantitative reverse transcription-polymerase chain reaction. Prostate sphere analysis was used to assess the rate of growth and invasion. The xenograft tumor implantation method was used to determine the tumor growth rate, local invasion, and metastasis.
RESULTS
Elevated expression of βArr1 positively correlated with increased GR expression and function in CRPC xenograft and in human PC patients. βArr1 is expressed in the cell cytosol and nucleus, and it formed a complex with GR in the nucleus and not cytosol. Depletion of βArr1 in AR-null CRPC cells inhibited GR function and CRPC growth and invasion in both in vitro and in vivo settings.
CONCLUSIONS
βArr1 binds GR that initiates mitogenic signaling cascades involved in the progression of PC to CRPC. The targeting of the βArr1-GR axis may provide a new opportunity to better manage the CRPC disease.
Topics: Androgens; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Humans; Male; Mitogens; Prostatic Neoplasms, Castration-Resistant; Receptors, Androgen; Receptors, Glucocorticoid; Signal Transduction; beta-Arrestin 1
PubMed: 35226379
DOI: 10.1002/pros.24324 -
International Journal of Molecular... Sep 2023The prevalence of autoimmune hepatitis (AIH) is increasing, yet specific pharmacotherapies remain to be explored. The present study aimed to investigate the effects of...
The prevalence of autoimmune hepatitis (AIH) is increasing, yet specific pharmacotherapies remain to be explored. The present study aimed to investigate the effects of sophoricoside (SOP), a bioactive component of medical herbs, on AIH and to elucidate the underlying mechanisms. Bioinformatic approaches were used to predict the potential targets and underlying regulatory mechanisms of SOP on AIH. The effects of SOP on AIH were evaluated by determining the expression levels of inflammatory cytokines, histological liver injury and hepatic fibrosis in an improved chronic cytochrome P450 2D6 (CYP2D6)‑AIH mouse model and in a model of concanavalin‑A (ConA)‑induced acute immune‑mediated liver injury. The antioxidant activity of SOP was detected in and experiments. The selected signal targeted by SOP in AIH was further confirmed using western blot analysis and immunofluorescence staining. The results of bioinformatic analysis revealed that the targets of SOP in AIH were related to oxidative stress and the NF‑κB gene set. The NF‑κB transcription factor family is a key player that controls both innate and adaptive immunity. The activation of the NF‑κB signaling pathway is often associated with autoimmune disorders. In the animal experiments, SOP attenuated CYP2D6/ConA‑induced AIH, as evidenced by a significant reduction in the levels of hepatic enzymes in serum, inflammatory cytokine expression and histological lesions in the liver. The oxidative response in AIH was also significantly inhibited by SOP, as evidenced by a decrease in the levels of hepatic malondialdehyde, and elevations in the total antioxidant capacity and glutathione peroxidase levels. The results of the and experiments revealed that SOP significantly reduced the enhanced expression and nuclear translocation of phosphorylated p65 NF‑κB in the livers of mice with AIH and in lipopolysaccharide‑stimulated AML12 cells. On the whole, the present study demonstrates the protective role of SOP in AIH, which may be mediated by limiting the oxidative response and the activation of the NF‑κB signaling pathway in hepatocytes.
Topics: Mice; Animals; NF-kappa B; Cytochrome P-450 CYP2D6; Liver; Hepatitis, Autoimmune; Signal Transduction; Oxidative Stress; Cytokines; Antioxidants; Concanavalin A
PubMed: 37477163
DOI: 10.3892/ijmm.2023.5281 -
The International Journal of... Jan 2021Eukaryotic cells perform a range of complex processes, some essential for life, others specific to cell type, all of which are governed by post-translational... (Review)
Review
Eukaryotic cells perform a range of complex processes, some essential for life, others specific to cell type, all of which are governed by post-translational modifications of proteins. Among the repertoire of dynamic protein modifications, ubiquitination is arguably the most arcane and profound due to its complexity. Ubiquitin conjugation consists of three main steps, the last of which involves a multitude of target-specific ubiquitin ligases that conjugate a range of ubiquitination patterns to protein substrates with diverse outcomes. In contrast, ubiquitin removal is catalysed by a relatively small number of de-ubiquitinating enzymes (DUBs), which can also display target specificity and impact decisively on cell function. Here we review the current knowledge of the intriguing ubiquitin-specific protease 17 (USP17) family of DUBs, which are expressed from a highly copy number variable gene that has been implicated in multiple cancers, although available evidence points to conflicting roles in cell proliferation and survival. We show that key USP17 substrates populate two pathways that drive cell cycle progression and that USP17 activity serves to promote one pathway but inhibit the other. We propose that this arrangement enables USP17 to stimulate or inhibit proliferation depending on the mitogenic pathway that predominates in any given cell and may partially explain evidence pointing to both oncogenic and tumour suppressor properties of USP17.
Topics: Animals; Carcinogenesis; Cell Cycle; Deubiquitinating Enzymes; Endopeptidases; Humans; Neoplasms; Protein Processing, Post-Translational; Ubiquitin
PubMed: 33227393
DOI: 10.1016/j.biocel.2020.105886 -
Biomacromolecules Nov 2019Asymmetrically branched precision glycooligomers are synthesized by solid-phase polymer synthesis for studying multivalent carbohydrate-protein interactions. Through the...
Asymmetrically branched precision glycooligomers are synthesized by solid-phase polymer synthesis for studying multivalent carbohydrate-protein interactions. Through the stepwise assembly of Fmoc-protected oligo(amidoamine) building blocks and Fmoc/Dde-protected lysine, straightforward variation of structural parameters such as the number and length of arms, as well as the number and position of carbohydrate ligands, is achieved. Binding of 1-arm and 3-arm glycooligomers toward lectin receptors langerin and concanavalin A (ConA) was evaluated where the smallest 3-arm glycooligomer shows the highest binding toward langerin, and stepwise elongation of one, two, or all three arms leads to decreased binding. When directly comparing binding toward langerin and ConA, we find that structural variation of the scaffold affects glycomimetic ligand binding differently for the different targets, indicating the potential to tune such ligands not only for their avidity but also for their selectivity toward different lectins.
Topics: Antigens, CD; Carbohydrates; Concanavalin A; Glycoproteins; Humans; Lectins, C-Type; Ligands; Mannose-Binding Lectins; Protein Binding; Protein Conformation; Proteins; Receptors, Mitogen
PubMed: 31600054
DOI: 10.1021/acs.biomac.9b00906 -
International Journal of Molecular... May 2021Genome expansion, whole genome and gene duplication events during metazoan evolution produced an extensive family of genes whose members express transcription factors... (Review)
Review
Genome expansion, whole genome and gene duplication events during metazoan evolution produced an extensive family of genes whose members express transcription factors with a conserved winged helix-turn-helix DNA-binding domain. Unravelling their biological roles has proved challenging with functional redundancy manifest in overlapping expression patterns, a common consensus DNA-binding motif and responsiveness to mitogen-activated protein kinase signalling. Key determinants of the cellular repertoire of ETS proteins are their stability and turnover, controlled largely by the actions of selective E3 ubiquitin ligases and deubiquitinases. Here we discuss the known relationships between ETS proteins and enzymes that determine their ubiquitin status, their integration with other developmental signal transduction pathways and how suppression of ETS protein ubiquitination contributes to the malignant cell phenotype in multiple cancers.
Topics: Animals; Humans; Neoplasms; Proto-Oncogene Proteins c-ets; Ubiquitin; Ubiquitination
PubMed: 34066106
DOI: 10.3390/ijms22105119