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Recent evidence suggests that regulatory pathways might control sustained high levels of FOXP3 in regulatory CD4+CD25hi T (Treg) cells. Based on transcriptional profiling of ex vivo activated Treg and helper CD4+CD25− T (Th) cells we have identified GARP (glycoprotein-A repetitions predominant), LGALS3 (lectin, galactoside-binding, soluble, 3) and LGMN (legumain) as novel genes implicated in human Treg cell function, which are induced upon T-cell receptor stimulation. Retroviral overexpression of GARP in antigen-specific Th cells leads to an efficient and stable re-programming of an effector T cell towards a regulatory T cell, which involves up-regulation of FOXP3, LGALS3, LGMN and other Treg-associated markers. In contrast, overexpression of LGALS3 and LGMN enhance FOXP3 and GARP expression, but only partially induced a regulatory phenotype. Lentiviral down-regulation of GARP in Treg cells significantly impaired the suppressor function and was associated with down-regulation of FOXP3. Moreover, down-regulation of FOXP3 resulted in similar phenotypic changes and down-regulation of GARP. This provides compelling evidence for a GARP-FOXP3 positive feedback loop and provides a rational molecular basis for the known difference between natural and transforming growth factor-β induced Treg cells as we show here that the latter do not up-regulate GARP. In summary, we have identified GARP as a key receptor controlling FOXP3 in Treg cells following T-cell activation in a positive feedback loop assisted by LGALS3 and LGMN, which represents a promising new system for the therapeutic manipulation of T cells in human disease. [ABSTRACT FROM AUTHOR]

Epithelial cells express genes whose products signal the presence of pathogenic microorganisms to the immune system. Pathogenicity factors of enteric bacteria modulate host cell gene expression. Using microarray technology we have profiled epithelial cell gene expression upon interaction with Yersinia enterocolitica. Yersinia enterocolitica wild-type and isogenic mutant strains were used to identify host genes modulated by invasin protein (Inv), which is involved in enteroinvasion, and Yersinia outer protein P (YopP) which inhibits innate immune responses. Among 22 283 probesets (14 239 unique genes), we found 193 probesets (165 genes) to be regulated by Yersinia infection. The majority of these genes were induced by Inv, whose recognition leads to expression of NF-κB-regulated factors such as cytokines and adhesion molecules. Yersinia virulence plasmid (pYV)-encoded factors counter regulated Inv-induced gene expression. Thus, YopP repressed Inv-induced NF-κB regulated genes at 2 h post infection whereas other pYV-encoded factors repressed host cell genes at 4 and 8 h post infection. Chromosomally encoded factors of Yersinia, other than Inv, induced expression of genes known to be induced by TGF-β receptor signalling. These genes were also repressed by pYV-encoded factors. Only a few host genes were exclusively induced by pYV-encoded factors. We hypothesize that some of these genes may contribute to pYV-mediated silencing of host cells. In conclusion, the data demonstrates that epithelial cells express a limited number of genes upon interaction with enteric Yersinia. Both Inv and YopP appear to modulate gene expression in order to subvert epithelial cell functions involved in innate immunity. [ABSTRACT FROM AUTHOR]

• Stenotrophomonas bentonitica showed high U removal potential up to 96%. • Membrane proteins, transporters and phosphatase were up-regulated gene expressions. • Cell surface and extracellular U-phosphate mineral formation were observed. • Resistance of BII-R7 to U(VI) is mediated by a multisystem combined process. The potential use of microorganisms in the bioremediation of U pollution has been extensively described. However, a lack of knowledge on molecular resistance mechanisms has become a challenge for the use of these technologies. We reported on the transcriptomic and microscopic response of Stenotrophomonas bentonitica BII-R7 exposed to 100 and 250 μM of U. Results showed that exposure to 100 μM displayed up-regulation of 185 and 148 genes during the lag and exponential phases, respectively, whereas 143 and 194 were down-regulated, out of 3786 genes (>1.5-fold change). Exposure to 250 μM of U showed up-regulation of 68 genes and down-regulation of 290 during the lag phase. Genes involved in cell wall and membrane protein synthesis, efflux systems and phosphatases were up-regulated under all conditions tested. Microscopic observations evidenced the formation of U-phosphate minerals at membrane and extracellular levels. Thus, a biphasic process is likely to occur: the increased cell wall would promote the biosorption of U to the cell surface and its precipitation as U-phosphate minerals enhanced by phosphatases. Transport systems would prevent U accumulation in the cytoplasm. These findings contribute to an understanding of how microbes cope with U toxicity, thus allowing for the development of efficient bioremediation strategies. [ABSTRACT FROM AUTHOR]

The reverse transcriptase subunit of telomerase, TERT, is frequently activated in high-grade dysplasia and invasive cancers of the uterine cervix. Telomerase activation through hypomethylation of the TERT promoter holds promise as a biomarker for cervical cancer progression, however, specific CpG sites involved in cervical cancer risk remain to be fully defined. A recent genome-wide association study on cervical cancer identified genetic polymorphisms at 5p13.33 (close to TERT-CLPTM1L) but the underlying mechanisms are undetermined. We investigated 529 CpG sites within the TERT promoter region and 3 CpG islands nearby, and 21 CpG sites within CLPTM1L in 190 bisulfite-converted cervical tumor DNA samples from BioRAIDs (NCT02428842). We identified eight CpG sites within TERT intron 2 where methylation was significantly associated with the genotypes of cervical cancer risk variants rs27070 and rs459961 in cervical tumors after multiple testing correction (p < 9.4 × 10E-5). Hypermethylation at chr5:1289663 correlated with decreased TERT mRNA levels. In an independent series of 188 normal or dysplastic cervical tissues, rare alleles of rs27070 and rs459961 were associated with low basal CLPTM1L levels and with the absence of TERT mRNA in HPV-negative samples, consistent with their proposed role as protective variants for cervical cancer. HPV infection was associated with increased CLPTM1L and TERT levels. Collectively, our results provide a link between cervical cancer risk variants, methylation, and gene expression and implicate both TERT and CLPTM1L as genes modulated by genomic background and HPV infection during cervical cancer development., (© 2024 Wiley Periodicals LLC.)

Coagulation factor XII (FXII) conveys various functions as an active protease that promotes thrombosis and inflammation, and as a zymogen via surface receptors like urokinase-type plasminogen activator receptor (uPAR). While plasma levels of FXII are increased in diabetes mellitus and diabetic kidney disease (DKD), a pathogenic role of FXII in DKD remains unknown. Here we show that FXII is locally expressed in kidney tubular cells and that urinary FXII correlates with kidney dysfunction in DKD patients. F12-deficient mice (F12 -/- ) are protected from hyperglycemia-induced kidney injury. Mechanistically, FXII interacts with uPAR on tubular cells promoting integrin β1-dependent signaling. This signaling axis induces oxidative stress, persistent DNA damage and senescence. Blocking uPAR or integrin β1 ameliorates FXII-induced tubular cell injury. Our findings demonstrate that FXII-uPAR-integrin β1 signaling on tubular cells drives senescence. These findings imply previously undescribed diagnostic and therapeutic approaches to detect or treat DKD and possibly other senescence-associated diseases., (© 2024. The Author(s).)

DNA-binding protein-A (DbpA; gene: Ybx3) belongs to the cold shock protein family with known functions in cell cycling, transcription, translation, and tight junction communication. In chronic nephritis, DbpA is upregulated. However, its activities in acute injury models, such as kidney ischemia/reperfusion injury (IRI), are unclear. To study this, mice harboring Ybx3 +/+ , Ybx3 +/- or the Ybx3 -/- genotype were characterized over 24 months and following experimental kidney IRI. Mitochondrial function, number and integrity were analyzed by mitochondrial stress tests, MitoTracker staining and electron microscopy. Western Blot, immunohistochemistry and flow cytometry were performed to quantify tubular cell damage and immune cell infiltration. DbpA was found to be dispensable for kidney development and tissue homeostasis under healthy conditions. Furthermore, endogenous DbpA protein localizes within mitochondria in primary tubular epithelial cells. Genetic deletion of Ybx3 elevates the mitochondrial membrane potential, lipid uptake and metabolism, oxygen consumption rates and glycolytic activities of tubular epithelial cells. Ybx3 -/- mice demonstrated protection from IRI with less immune cell infiltration, endoplasmic reticulum stress and tubular cell damage. A presumed protective mechanism was identified via upregulated antioxidant activities and reduced ferroptosis, when Ybx3 was deleted. Thus, our studies reveal DbpA acts as a mitochondrial protein with profound adverse effects on cell metabolism and highlights a protective effect against IRI when Ybx3 is genetically deleted. Hence, preemptive DbpA targeting in situations with expected IRI, such as kidney transplantation or cardiac surgery, may preserve post-procedure kidney function., (Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)