Localization and Functional Roles of Components of the Translation Apparatus in the Eukaryotic Cell Nucleus

Components of the translation apparatus, including ribosomal proteins, have been found in cell nuclei in various organisms. Components of the translation apparatus are involved in various nuclear processes, particularly those associated with genome integrity control and the nuclear stages of gene expression, such as transcription, mRNA processing, and mRNA export. Components of the translation apparatus control intranuclear trafficking; the nuclear import and export of RNA and proteins; and regulate the activity, stability, and functional recruitment of nuclear proteins. The nuclear translocation of these components is often involved in the cell response to stimulation and stress, in addition to playing critical roles in oncogenesis and viral infection. Many components of the translation apparatus are moonlighting proteins, involved in integral cell stress response and coupling of gene expression subprocesses. Thus, this phenomenon represents a significant interest for both basic and applied molecular biology. Here, we provide an overview of the current data regarding the molecular functions of translation factors and ribosomal proteins in the cell nucleus.

Morphological Alterations and Stress Protein Variations in Lung Biopsies Obtained from Autopsies of COVID-19 Subjects

Molecular chaperones, many of which are heat shock proteins, play a role in cell stress response and regulate the immune system in various ways, such as in inflammatory/autoimmune reactions. It would be interesting to study the involvement of these molecules in the damage done to COVID-19-infected lungs. In our study, we performed a histological analysis and an immunomorphological evaluation on lung samples from subjects who succumbed to COVID-19 and subjects who died from other causes. We also assessed Hsp60 and Hsp90 distribution in lung samples to determine their location and post-translational modifications. We found histological alterations that could be considered pathognomonic for COVID-19-related lung disease. Hsp60 and Hsp90 immunopositivity was significantly higher in the COVID-19 group compared to the controls, and immunolocalization was in the plasma membrane of the endothelial cells in COVID-19 subjects. The colocalization ratios for Hsp60/3-nitrotyrosine and Hsp60/acetylate-lisine were significantly increased in the COVID-19 group compared to the control group, similar to the colocalization ratio for Hsp90/acetylate-lisine. The histological and immunohistochemical findings led us to hypothesize that Hsp60 and Hsp90 might have a role in the onset of the thromboembolic phenomena that lead to death in a limited number of subjects affected by COVID-19. Further studies on a larger number of samples obtained from autopsies would allow to confirm these data as well as discover new biomarkers useful in the battle against this disease.

Extracorporeal Shock Wave Therapy Protected the Functional and Architectural Integrity of Rodent Urinary Bladder against Ketamine-Induced Damage

This study tested the hypothesis that extracorporeal-shock-wave (ECSW) protected the functional and anatomical integrity of rat urinary-bladder against ketamine-induced damage. In in vitro study, the rat bladder smooth muscle cells (RBdSMCs) were categorized into G1 (sham-control), G2 (RBdSMCs + menadione), G3 (RBdSMCs + ECSW) and G4 (RBdSMCs + menadione + ECSW). The results showed protein expressions of oxidative-stress/mitochondrial-damaged biomarkers (NOX-1/NOX-2/oxidized protein/cytosolic-cytochrome-C/cyclophilin-D), inflammatory markers (MyD88/TRAF6/p-IKB-α/NF-κB/TNF-α/IL-6/IL-1ß/MMP-9/iNOS), and cell-stress response signalings (ASK1/p-MKK4/p-MKK7/ERK1/2//p-JNK/p-p38/p-53) were significantly increased in G2 than in G1 and G3, and those were significantly reversed in G4 (all p < 0.0001). Adult-male SD rats (n = 24) were equally categorized into group 1 (sham-control), group 2 (ketamine/30 mg/kg/daily i.p. injection for four weeks), group 3 [ketamine/30 mg/kg + ECSW/optimal energy (0.12 mJ/mm2/120 impulses/at 3 h and days 3/7/14/21/28 after ketamine administration)] and group 4 [(ketamine/30 mg/kg + ECSW/higher energy (0.16 mJ/mm2/120 impulses)] and animals were euthanized by day 42. The results showed the urine levels of pro-inflammatory cytokines (TNF-α/IL-6) were lowest in group 1, highest in group 2 and significantly higher in group 3 than in group 4 at days 1/7/14/28 (all p < 0.0001). The duration of urinary bladder contraction was lowest in group 2, highest in group 1 and significantly higher in group 4 than in group 3, whereas the maximal pressure of urinary bladder exhibited an opposite pattern of bladder contraction among the groups (all p < 0.0001). The histopathological findings of fibrosis/inflammation/keratinization and protein expressions of oxidative-stress/mitochondrial-damaged biomarkers (NOX-1/NOX-2/oxidized protein/cytosolic-cytochrome-C/cyclophilin-D), and inflammatory (TLR-2/TLR-4/MyD88/TRAF6/p-IKB-α/NF-κB/TNF-α/IL-1ß/MMP-9/iNOS) and cell-stress response (ASK1/p-MKK4/p-MKK7/ERK1/2//p-JNK/p-p38) signalings and apoptotic/fibrotic biomarkers (cleaved-caspas3/cleaved-PARB/Smad3/TFG-ß) exhibited an identical pattern of urine proinflammatory cytokine among the groups (all p < 0.0001). ECSW effectively attenuated ketamine-induced bladder damage and dysfunction.

Integrated multi-omics analysis of RB-loss identifies widespread cellular programming and synthetic weaknesses

Inactivation of RB is one of the hallmarks of cancer, however gaps remain in our understanding of how RB-loss changes human cells. Here we show that pRB-depletion results in cellular reprogramming, we quantitatively measured how RB-depletion altered the transcriptional, proteomic and metabolic output of non-tumorigenic RPE1 human cells. These profiles identified widespread changes in metabolic and cell stress response factors previously linked to E2F function. In addition, we find a number of additional pathways that are sensitive to RB-depletion that are not E2F-regulated that may represent compensatory mechanisms to support the growth of RB-depleted cells. To determine whether these molecular changes are also present in RB1−/− tumors, we compared these results to Retinoblastoma and Small Cell Lung Cancer data, and identified widespread conservation of alterations found in RPE1 cells. To define which of these changes contribute to the growth of cells with de-regulated E2F activity, we assayed how inhibiting or depleting these proteins affected the growth of RB1−/− cells and of Drosophila E2f1-RNAi models in vivo. From this analysis, we identify key metabolic pathways that are essential for the growth of pRB-deleted human cells.

Clinical Relevance of Estrogen Reactivity in the Breast Cancer Microenvironment

Background: Estrogen signals play an important role in the phenotype of estrogen receptor positive breast cancer (BC). However, comprehensive analyses of the effect of estrogen signals on the tumor microenvironment (TME) and treatment response in large cohorts of primary BC patients have been lacking. We aimed to test the hypothesis that estrogen reactivity effects gene expression and immune cell infiltration profiles in the TME and relates to response to chemotherapy (CT) and endocrine therapy (ET). Methods: A total of 3091 BC cases were analyzed; 1075 from TCGA cohort, 1904 from METABRIC cohort, and 112 from Hokkaido University hospital cohort. We divided the group into estrogen reactivity-high and estrogen reactivity-low groups utilizing estrogen response genes.Results: BC with high estrogen reactivity was related to Myc targets, Metabolism-related signaling, cell stress response, TGF-beta signaling, androgen response, and MTORC1 signaling gene sets in the TME. Low estrogen reactivity was related to immune-related proteins, IL2-STAT5 signaling, IL6-JAK-STAT3 signaling, KRAS signaling, cell cycle related gene sets, and EMT. In addition, BC with high levels of estrogen reactivity had low immune cytolytic activity, low levels of immunostimulatory cells, and high levels of immunosuppressive cells. It also had low levels of stimulatory and inhibitory factors of the cancer immunity cycle (CIC). Patients with high estrogen reactivity were also associated with a better prognosis. Regarding the effect of estrogen reactivity on treatment, patients who were treated with ET and CT but relapsed (BC with CT rec) were related with higher levels of E2F targets and G2M checkpoint, but lower levels of immunosuppressive M2 macrophages or Tregs cells. In addition, the TME in CT rec had higher levels of CIC regulators.Conclusions: We demonstrated the relationship between estrogen reactivity and the profiles of immune cells and gene expression within the TME, as well as the treatment effect of CT given in addition to ET.

Comparative therapeutic strategies for preventing aortic rupture in a mouse model of vascular Ehlers Danlos syndrome

We created a knock-in Col3a1+/G182R mouse model with spontaneous mortality caused by thoracic aortic rupture that recapitulates a rare vascular genetic disease of type III collagen, the vascular Ehlers-Danlos syndrome (vEDS). Investigation of this model showed lower survival rate in males caused by aortic rupture, thin non-inflammatory arteries and altered arterial collagen. Transcriptomic analysis of aortas showed upregulation of genes related to inflammation and cell stress response. Compared to water, survival rate of Col3a1+/G182R mice was not affected by beta-blockers (propranolol or celiprolol). Two other vasodilating anti-hypertensive agents (hydralazine, amlodipine) gave opposite results on aortic rupture and mortality rate. There was a spectacular beneficial effect of losartan, reversed by the cessation of its administration, and a marked deleterious effect of exogenous angiotensin II. These results suggest that blockade of the renin angiotensin system should be tested as a first-line medical therapy in patients with vEDS.

The chaperonin CCT8 controls proteostasis essential for T cell maturation, selection, and function

T cells rely for their development and function on the correct folding and turnover of proteins generated in response to a broad range of molecular cues. In the absence of the eukaryotic type II chaperonin complex, CCT, T cell activation induced changes in the proteome are compromised including the formation of nuclear actin filaments and the formation of a normal cell stress response. Consequently, thymocyte maturation and selection, and T cell homeostatic maintenance and receptor-mediated activation are severely impaired. In the absence of CCT-controlled protein folding, Th2 polarization diverges from normal differentiation with paradoxical continued IFN-γ expression. As a result, CCT-deficient T cells fail to generate an efficient immune protection against helminths as they are unable to sustain a coordinated recruitment of the innate and adaptive immune systems. These findings thus demonstrate that normal T cell biology is critically dependent on CCT-controlled proteostasis and that its absence is incompatible with protective immunity.

Transcriptome analysis of Escherichia coli K1 after therapy with hesperidin conjugated with silver nanoparticles

Backgrounds Escherichia coli K1 causes neonatal meningitis. Transcriptome studies are indispensable to comprehend the pathology and biology of these bacteria. Recently, we showed that nanoparticles loaded with Hesperidin are potential novel antibacterial agents against E. coli K1. Here, bacteria were treated with and without Hesperidin conjugated with silver nanoparticles, and silver alone, and 50% minimum inhibitory concentration was determined. Differential gene expression analysis using RNA-seq, was performed using Degust software and a set of genes involved in cell stress response and metabolism were selected for the study. Results 50% minimum inhibitory concentration with silver-conjugated Hesperidin was achieved with 0.5 μg/ml of Hesperidin conjugated with silver nanoparticles at 1 h. Differential genetic analysis revealed the expression of 122 genes (≥ 2-log FC, P< 0.01) in both E. coli K1 treated with Hesperidin conjugated silver nanoparticles and E. coli K1 treated with silver alone, compared to untreated E. coli K1. Of note, the expression levels of cation efflux genes (cusA and copA) and translocation of ions, across the membrane genes (rsxB) were found to increase 2.6, 3.1, and 3.3- log FC, respectively. Significant regulation was observed for metabolic genes and several genes involved in the coordination of flagella. Conclusions The antibacterial mechanism of nanoparticles maybe due to disruption of the cell membrane, oxidative stress, and metabolism in E. coli K1. Further studies will lead to a better understanding of the genetic mechanisms underlying treatment with nanoparticles and identification of much needed novel antimicrobial drug candidates.