Departamento de Fisiología

JAK3 Is Expressed in the Nucleus of Malignant T Cells in Cutaneous T Cell Lymphoma (CTCL)

2026-04-10T07:21:24Z

JAK3 Is Expressed in the Nucleus of Malignant T Cells in Cutaneous T Cell Lymphoma (CTCL) Vadivel, Chella Krishna; Gluud, Maria; Torres Rusillo, Sara; Boding, Lasse; Willerslev-Olsen, Andreas; Buus, Terkild B.; Nielsen, Tea Kirkegaard; Persson, Jenny L.; Bonefeld, Charlotte M.; Geisler, Carsten; Krejsgaard, Thorbjorn; Fuglsang, Anja T.; Odum, Niels; Woetmann, Anders Perturbation in JAK-STAT signaling has been reported in the pathogenesis of cutaneous T cell lymphoma (CTCL). JAK3 is predominantly associated with the intra-cytoplasmic part of IL-2Rγc located in the plasma membrane of hematopoietic cells. Here we demonstrate that JAK3 is also ectopically expressed in the nucleus of malignant T cells. We detected nuclear JAK3 in various CTCL cell lines and primary malignant T cells from patients with Sézary syndrome, a leukemic variant of CTCL. Nuclear localization of JAK3 was independent of its kinase activity whereas STAT3 had a modest effect on nuclear JAK3 expression. Moreover, JAK3 nuclear localization was only weakly affected by blockage of nuclear export. An inhibitor of the nuclear export protein CRM1, Leptomycin B, induced an increased expression of SOCS3 in the nucleus, but only a weak increase in nuclear JAK3. Importantly, immunoprecipitation experiments indicated that JAK3 interacts with the nuclear protein POLR2A, the catalytic subunit of RNA Polymerase II. Kinase assays showed tyrosine phosphorylation of recombinant human Histone H3 by JAK3 in vitro-an effect which was blocked by the JAK inhibitor (Tofacitinib citrate). In conclusion, we provide the first evidence of nuclear localization of JAK3 in malignant T cells. Our findings suggest that JAK3 may have a cytokine-receptor independent function in the nucleus of malignant T cells, and thus a novel non-canonical role in CTCL.; Se ha descrito una alteración en la señalización JAK-STAT en la patogénesis del linfoma cutáneo de células T (CTCL). La JAK3 se asocia predominantemente a la parte intracitoplasmática del IL-2Rγc, situada en la membrana plasmática de las células hematopoyéticas. En este trabajo demostramos que la JAK3 también se expresa de forma ectópica en el núcleo de las células T malignas. Detectamos JAK3 nuclear en diversas líneas celulares de LCT y en células T malignas primarias de pacientes con síndrome de Sézary, una variante leucémica del LCT. La localización nuclear de JAK3 fue independiente de su actividad cinasa, mientras que STAT3 tuvo un efecto moderado sobre la expresión nuclear de JAK3. Además, la localización nuclear de JAK3 solo se vio ligeramente afectada por el bloqueo de la exportación nuclear. Un inhibidor de la proteína de exportación nuclear CRM1, la leptomicina B, indujo un aumento de la expresión de SOCS3 en el núcleo, pero solo un débil aumento de JAK3 nuclear. Es importante destacar que los experimentos de inmunoprecipitación indicaron que JAK3 interactúa con la proteína nuclear POLR2A, la subunidad catalítica de la ARN polimerasa II. Los ensayos de cinasa mostraron la fosforilación de tirosina de la histona H3 humana recombinante por JAK3 in vitro, un efecto que fue bloqueado por el inhibidor de JAK (citrato de tofacitinib). En conclusión, aportamos la primera evidencia de la localización nuclear de JAK3 en las células T malignas. Nuestros hallazgos sugieren que JAK3 podría tener una función independiente del receptor de citocinas en el núcleo de las células T malignas y, por lo tanto, un nuevo papel no canónico en el CTCL. This research was funded by LEO Foundation, The Danish Cancer Society (Kræftens Bekæmpelse), the Fight Cancer Program (Knæk Cancer), Novo Nordisk Research Foundation, Novo Nordic Foundation Tandem Program (grant number NNF14OC0012345), Lundbeck Foundation (A.W.-O.), The Danish Council for Independent Research (Danmarks Frie Forskningsfond, 2 project grants for N.O., a Sapera Aude Talent Grant (DFF-4092-00122) for T.K.), Dansk Kræftforsknings Fond and Alfonso Martín Escudero Foundation (S.T.-R.).; Supplementary Materials The following are available online at https://www.mdpi.com/2072-6694/13/2/280/s1

Vitamin D Inhibits IL-22 Production Through a Repressive Vitamin D Response Element in the il22 Promoter

2026-04-10T07:14:25Z

Vitamin D Inhibits IL-22 Production Through a Repressive Vitamin D Response Element in the il22 Promoter López, Daniel V.; Al-Jaberi, Fatima A. H.; Damas, Nkerorema D.; Weinert, Brian T.; Pus, Urska; Torres Rusillo, Sara; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte M.; Kongsbak-Wismann, Martin; Geisler, Carsten Th22 cells constitute a recently described CD4+ T cell subset defined by its production of interleukin (IL)-22. The action of IL-22 is mainly restricted to epithelial cells. IL-22 enhances keratinocyte proliferation but inhibits their differentiation and maturation. Dysregulated IL-22 production has been associated to some inflammatory skin diseases such as atopic dermatitis and psoriasis. How IL-22 production is regulated in human T cells is not fully known. In the present study, we identified conditions to generate Th22 cells that do not co-produce IL-17 from naïve human CD4+ T cells. We show that in addition to the transcription factors AhR and RORγt, the active form of vitamin D3 (1,25(OH)2D3) regulates IL-22 production in these cells. By studying T cells with a mutated vitamin D receptor (VDR), we demonstrate that the 1,25(OH)2D3-induced inhibition of il22 gene transcription is dependent on the transcriptional activity of the VDR in the T cells. Finally, we identified a vitamin D response element (VDRE) in the il22 promoter and demonstrate that 1,25(OH)2D3-VDR directly inhibits IL-22 production via this repressive VDRE.; Las células Th22 constituyen un subconjunto de células T CD4+ descrito recientemente y definido por su producción de interleucina (IL)-22. La acción de la IL-22 se limita principalmente a las células epiteliales. La IL-22 potencia la proliferación de los queratinocitos, pero inhibe su diferenciación y maduración. La producción desregulada de IL-22 se ha asociado a algunas enfermedades inflamatorias de la piel, como la dermatitis atópica y la psoriasis. No se conoce del todo cómo se regula la producción de IL-22 en las células T humanas. En el presente estudio, identificamos las condiciones para generar células Th22 que no coproducen IL-17 a partir de células T CD4+ humanas vírgenes. Demostramos que, además de los factores de transcripción AhR y RORγt, la forma activa de la vitamina D3 (1,25(OH)2D3) regula la producción de IL-22 en estas células. Mediante el estudio de células T con un receptor de vitamina D (VDR) mutado, demostramos que la inhibición de la transcripción del gen il22 inducida por 1,25(OH)2D3 depende de la actividad transcripcional del VDR en las células T. Por último, identificamos un elemento de respuesta a la vitamina D (VDRE) en el promotor de il22 y demostramos que el 1,25(OH)2D3-VDR inhibe directamente la producción de IL-22 a través de este VDRE represor. The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fimmu.2021. 715059/full#supplementary-material

Identification of sequence-specific promoters driving polycistronic transcription initiation by RNA polymerase II in trypanosomes

2026-04-10T06:49:59Z

Identification of sequence-specific promoters driving polycistronic transcription initiation by RNA polymerase II in trypanosomes Cordón-Obras, Carlos; Gómez-Liñán, Claudia; Torres Rusillo, Sara; Vidal-Cobo, Isabel; López-Farfan, Diana; Barroso-Del Jesús, Alicia; Rojas-Barros, Domingo; Carrington, Mark; Navarro, Miguel Protein-coding genes in trypanosomes occur in polycistronic transcription units (PTUs). How RNA polymerase II (Pol II) initiates transcription of PTUs has not been resolved; the current model favors chromatin modifications inducing transcription rather than sequence-specific promoters. Here, we uncover core promoters by functional characterization of Pol II peaks identified by hromatin immunoprecipitation sequencing (ChIP-seq). Two distinct promoters are located between divergent PTUs, each driving unidirectional transcription. Detailed analysis identifies a 75-bp promoter that is necessary and sufficient to drive full reporter expression and contains functional motifs. Analysis of further promoters suggests transcription initiation is regulated and promoters are either focused or dispersed. In contrast to the previous model of unregulated and promoter-independent transcription initiation, we find that sequence-specific promoters determine the initiation of Pol II transcription of protein-coding genes PTUs. These findings in Trypanosoma brucei suggest that in addition of chromatin modifications, promoter motifs-based regulation of gene expression is deeply conserved among eukaryotes.; Los genes codificadores de proteínas en los tripanosomas se presentan en unidades de transcripción policistrónicas (PTU). Aún no se ha dilucidado cómo la ARN polimerasa II (Pol II) inicia la transcripción de las PTU; el modelo actual se inclina por las modificaciones de la cromatina que inducen la transcripción, en lugar de promotores específicos de secuencia. En este trabajo, identificamos promotores centrales mediante la caracterización funcional de los picos de Pol II detectados por secuenciación de inmunoprecipitación de cromatina (ChIP-seq). Entre las PTU divergentes se localizan dos promotores distintos, cada uno de los cuales impulsa la transcripción unidireccional. Un análisis detallado identifica un promotor de 75 pb que es necesario y suficiente para impulsar la expresión completa del reportero y contiene motivos funcionales. El análisis de otros promotores sugiere que el inicio de la transcripción está regulado y que los promotores pueden estar concentrados o dispersos. En contraste con el modelo anterior de inicio de la transcripción no regulado e independiente del promotor, encontramos que los promotores específicos de secuencia determinan el inicio de la transcripción de la Pol II de los PTU de genes codificadores de proteínas. Estos hallazgos en Trypanosoma brucei sugieren que, además de las modificaciones de la cromatina, la regulación de la expresión génica basada en motivos promotores está profundamente conservada entre los eucariotas. This work was supported by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (RTI2018-098834-B-I00), Subdirección General de Redes y Centros de Investigación Cooperativa (RD12/0018/0015, RD16/0027/0019, RD16/0027/0014), and National Institutes of Health (R01AI114685). M.C. is a Wellcome Investigator 217138/Z/19/Z.

Metabolomics insights into the shared and cultivar-related mechanisms controlling postharvest cold tolerance in Cucurbita pepo L

2026-04-08T10:47:48Z

Metabolomics insights into the shared and cultivar-related mechanisms controlling postharvest cold tolerance in Cucurbita pepo L García, Alicia; Castro-Cegrí, Alejandro; García-Pérez, Pascual; Palma Martín, Francisco José; Martínez, Cecilia; Garrido Garrido, Dolores; Jamilena, Manuel; Lucini, Luigi Zucchini (Cucurbita pepo L.) is highly sensitive to chilling injury during cold storage, which leads to surface damage, quality loss, and reduced nutraceutical value. Fruits were stored at 4 °C, and samples were collected at harvest (T0), 3 days (T3), and 14 days (T14) of cold storage. To elucidate the biochemical determinants of cold tolerance, we selected five cold-tolerant and five cold-sensitive cultivars from a previous screening of 126 accessions based on differences in chilling injury index (CI), weight loss (WL), and physiological indicators of oxidative stress. Metabolomic profiling was performed on fruit exocarp tissue using an untargeted LC–MS approach. Despite genotypic variability, all cultivars displayed a shared metabolic response to cold storage characterized by the accumulation of N6,N6,N6-trimethyl-L-lysine and 6-hydroxymethyl-7,8-dihydropterin, intermediates in carnitine and folate biosynthesis. Notably, tolerant cultivars maintained higher levels of these metabolites throughout storage, suggesting the presence of a metabolic signature associated with improved cold tolerance. Beyond this shared response, tolerant cultivars exhibited distinct metabolic adjustments involving nucleotides, phenolic compounds, amino acids, phytohormones, vitamins, and cucurbitacins. Overall, these results provide new insights into metabolic responses associated with postharvest cold tolerance in zucchini and highlight candidate metabolic markers that may be useful for breeding programs aimed at improving postharvest performance and shelf life.

Food group intake and Mediterranean diet adherence among a representative sample of Spanish middle-aged and older adults. Are we still on track? The HERMEX study

2026-04-07T11:23:42Z

Food group intake and Mediterranean diet adherence among a representative sample of Spanish middle-aged and older adults. Are we still on track? The HERMEX study Nebot Valenzuela, Elena; Aparicio, Virginia A; Morán, Luis J.; De la Flor Alemany, Marta; Fernández-Bergés, Daniel; Nestares Pleguezuelo, María Teresa; Felix Redondo, Francisco J. Background and aim: To explore food group intake and adherence to the Mediterranean Diet (MD) in a representative sample of 2833 middle-aged and older adults from the HERMEX study. Methods and results: This cross-sectional study utilized a food frequency questionnaire to assess food group intake and measured MD adherence using the MD Score. Sociodemographic, anthropometric, and clinical characteristics were also analyzed. Among participants, 74 % were living with overweight or obesity, 69.9 % were non-smokers, and 88 % showed medium-high adherence to the MD. Compared to the national dietary recommendations issued by the Spanish Agency for Food Safety and Nutrition (AESAN), 76 % had carbohydrate intake below recommended levels (average intake: 35.4 %), whereas 73.5 % consumed protein at 16.6 % of total energy intake. Only 2 % of participants adhered to the fat intake recommendation (<35 % of total energy). Consumption of fruits, vegetables, cereals, potatoes, and eggs was below recommendations, while intake of legumes, nuts, fish, seafood, and dairy met or nearly met the recommendations. Meat consumption exceeded recommendations. Macronutrient intake (carbohydrates, protein, fat, and fiber) was similar across BMI groups. However, participants with obesity consumed fewer nuts, whereas those with normal weight had a higher intake of red wine compared to individuals with overweight (p < 0.05). MD adherence was similar across BMI groups (34 points on a 0–55 scale). Conclusions: Prevalence of overweight and obesity was high despite medium-high adherence to the MD. Overall, caloric intake and food consumption patterns were consistent across BMI groups, with notable differences in nut and red wine intake.