A comparative analysis of Spanish Clinical encoder-based models on NER and classification tasks.

OBJECTIVES: This comparative analysis aims to assess the efficacy of encoder Language Models for clinical tasks in the Spanish language. The primary goal is to identify the most effective resources within this context. IMPORTANCE: This study highlights a critical gap in NLP resources for the Spanish language, particularly in the clinical sector. Given the vast number of Spanish speakers globally and the increasing reliance on electronic health records, developing effective Spanish language models is crucial for both clinical research and healthcare delivery. Our work underscores the urgent need for specialized encoder models in Spanish that can handle clinical data with high accuracy, thus paving the way for advancements in healthcare services and biomedical research for Spanish-speaking populations. MATERIALS AND METHODS: We examined 17 distinct corpora with a focus on clinical tasks. Our evaluation centered on Spanish Language Models and Spanish Clinical Language models (both encoder-based). To ascertain performance, we meticulously benchmarked these models across a curated subset of the corpora. This extensive study involved fine-tuning over 3000 models. RESULTS: Our analysis revealed that the best models are not clinical models, but general-purpose models. Also, the biggest models are not always the best ones. The best-performing model, RigoBERTa 2, obtained an average F1 score of 0.880 across all tasks. DISCUSSION: Our study demonstrates the advantages of dedicated encoder-based Spanish Clinical Language models over generative models. However, the scarcity of diverse corpora, mostly focused on NER tasks, underscores the need for further research. The limited availability of high-performing models emphasizes the urgency for development in this area. CONCLUSION: Through systematic evaluation, we identified the current landscape of encoder Language Models for clinical tasks in the Spanish language. While challenges remain, the availability of curated corpora and models offers a foundation for advancing Spanish Clinical Language models. Future efforts in refining these models are essential to elevate their effectiveness in clinical NLP.

Elevated levels of cell-free NKG2D-ligands modulate NKG2D surface expression and compromise NK cell function in severe COVID-19 disease.

Introduction: It is now clear that coronavirus disease 19 (COVID-19) severity is associated with a dysregulated immune response, but the relative contributions of different immune cells is still not fully understood. SARS CoV-2 infection triggers marked changes in NK cell populations, but there are contradictory reports as to whether these effector lymphocytes play a protective or pathogenic role in immunity to SARS-CoV-2. Methods: To address this question we have analysed differences in the phenotype and function of NK cells in SARS-CoV-2 infected individuals who developed either very mild, or life-threatening COVID-19 disease. Results: Although NK cells from patients with severe disease appeared more activated and the frequency of adaptive NK cells was increased, they were less potent mediators of ADCC than NK cells from patients with mild disease. Further analysis of peripheral blood NK cells in these patients revealed that a population of NK cells that had lost expression of the activating receptor NKG2D were a feature of patients with severe disease and this correlated with elevated levels of cell free NKG2D ligands, especially ULBP2 and ULBP3 in the plasma of critically ill patients. In vitro, culture in NKG2DL containing patient sera reduced the ADCC function of healthy donor NK cells and this could be blocked by NKG2DL-specific antibodies. Discussion: These observations of reduced NK function in severe disease are consistent with the hypothesis that defects in immune surveillance by NK cells permit higher levels of viral replication, rather than that aberrant NK cell function contributes to immune system dysregulation and immunopathogenicity.

Determination of De Novo Suberin-Lignin Ferulate Deposition in Xylem Tissue Upon Vascular Pathogen Attack.

Plant vascular pathogens use different ways to reach the xylem vessels and cause devastating diseases in plants. Resistant and tolerant plants have evolved various defense mechanisms against vascular pathogens. Inducible physico-chemical structures, such as the formation of tyloses and wall reinforcements with phenolic polymers, are very effective barriers that confine the pathogen and prevent colonization. Here, we use a combination of classical histochemistry along with bright-field and fluorescence microscopy and two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy to visualize and characterize wall reinforcements containing phenolic wall polymers, namely, lignin, ferulates, and suberin, which occur in different xylem vasculature in response to pathogen attack.

Renal Transplant Artery Stenosis and Kinking: An Unusual Association.

Renal artery stenosis of the kidney allograft associated with kinking is not a frequent finding. As a correctable cause of graft dysfunction, it is important to diagnose it as soon as possible to avoid further graft damage and improve graft and patient survival. As pulsed wave Doppler ultrasound mapping of the graft's renal arteries is essential to diagnose possible alterations, point of care ultrasound (POCUS) is a highly useful tool for early diagnosis. We present a case in which nephrologists performed this examination promptly allowing a timely diagnosis and treatment plan.

The Tomato Feruloyl Transferase FHT Promoter Is an Accurate Identifier of Early Development and Stress-Induced Suberization.

As a wall polymer, suberin has a multifaceted role in plant development and stress responses. It is deposited between the plasma membrane and the primary cell wall in specialized tissues such as root exodermis, endodermis, phellem, and seed coats. It is formed de novo in response to stresses such as wounding, salt injury, drought, and pathogen attack and is a complex polyester mainly consisting of fatty acids, glycerol, and minor amounts of ferulic acid that are associated to a lignin-like polymer predominantly composed of ferulates. Metabolomic and transcriptomic studies have revealed that cell wall lignification precedes suberin deposition. The ferulic acid esterified to ω-hydroxy fatty acids, synthetized by the feruloyl transferase FHT (or ASFT), presumably plays a role in coupling both polymers, although the precise mechanism is not understood. Here, we use the promoter of tomato suberin feruloyl transferase (FHT/ASFT) fused to GUS (ß-glucuronidase) to demonstrate that ferulate deposition agrees with the site of promoter FHT activation by using a combination of histochemical staining and UV microscopy. Hence, FHT promoter activation and alkali UV microscopy can be used to identify the precise localization of early suberizing cells rich in ferulic acid and can additionally be used as an efficient marker of early suberization events during plant development and stress responses. This line can be used in the future as a tool to identify emerging suberization sites via ferulate deposition in tomato plants, which may contribute to germplasm screening in varietal improvement programs.

Objective hand eczema severity assessment with automated lesion anatomical stratification.

Hand eczema (HE) is one of the most frequent dermatoses, known to be both relapsing and remitting. Regular and precise evaluation of the disease severity is key for treatment management. Current scoring systems such as the hand eczema severity index (HECSI) suffer from intra- and inter-observer variance. We propose an automated system based on deep learning models (DLM) to quantify HE lesions' surface and determine their anatomical stratification. In this retrospective study, a team of 11 experienced dermatologists annotated eczema lesions in 312 HE pictures, and a medical student created anatomical maps of 215 hands pictures based on 37 anatomical subregions. Each data set was split into training and test pictures and used to train and evaluate two DLMs, one for anatomical mapping, the other for HE lesions segmentation. On the respective test sets, the anatomy DLM achieved average precision and sensitivity of 83% (95% confidence interval [CI] 80-85) and 85% (CI 82-88), while the HE DLM achieved precision and sensitivity of 75% (CI 64-82) and 69% (CI 55-81). The intraclass correlation of the predicted HE surface with dermatologists' estimated surface was 0.94 (CI 0.90-0.96). The proposed method automatically predicts the anatomical stratification of HE lesions' surface and can serve as support to evaluate hand eczema severity, improving reliability, precision and efficiency over manual assessment. Furthermore, the anatomical DLM is not limited to HE and can be applied to any other skin disease occurring on the hands such as lentigo or psoriasis.

BCG-activation of leukocytes is sufficient for the generation of donor-independent innate anti-tumor NK and γδ T-cells that can be further expanded in vitro.

Bacillus Calmette-Guérin (BCG), the nonpathogenic Mycobacterium bovis strain used as tuberculosis vaccine, has been successfully used as treatment for non-muscle invasive bladder cancer for decades, and suggested to potentiate cellular and humoral immune responses. However, the exact mechanism of action is not fully understood. We previously described that BCG mainly activated anti-tumor cytotoxic NK cells with upregulation of CD56 and a CD16+ phenotype. Now, we show that stimulation of human peripheral blood mononuclear cells with iBCG, a preparation based on BCG-Moreau, expands oligoclonal γδ T-cells, with a cytotoxic phenotype, together with anti-tumor CD56high CD16+ NK cells. We have used scRNA-seq, flow cytometry, and functional assays to characterize these BCG-activated γδ T-cells in detail. They had a high IFNγ secretion signature with expression of CD27+ and formed conjugates with bladder cancer cells. BCG-activated γδ T-cells proliferated strongly in response to minimal doses of cytokines and had anti-tumor functions, although not fully based on degranulation. BCG was sufficient to stimulate proliferation of γδ T-cells when cultured with other PBMC; however, BCG alone did not stimulate expansion of purified γδ T-cells. The characterization of these non-donor restricted lymphocyte populations, which can be expanded in vitro, could provide a new approach to prepare cell-based immunotherapy tools.

Quantification of Efflorescences in Pustular Psoriasis Using Deep Learning.

OBJECTIVES: Pustular psoriasis (PP) is one of the most severe and chronic skin conditions. Its treatment is difficult, and measurements of its severity are highly dependent on clinicians' experience. Pustules and brown spots are the main efflorescences of the disease and directly correlate with its activity. We propose an automated deep learning model (DLM) to quantify lesions in terms of count and surface percentage from patient photographs. METHODS: In this retrospective study, two dermatologists and a student labeled 151 photographs of PP patients for pustules and brown spots. The DLM was trained and validated with 121 photographs, keeping 30 photographs as a test set to assess the DLM performance on unseen data. We also evaluated our DLM on 213 unstandardized, out-of-distribution photographs of various pustular disorders (referred to as the pustular set), which were ranked from 0 (no disease) to 4 (very severe) by one dermatologist for disease severity. The agreement between the DLM predictions and experts' labels was evaluated with the intraclass correlation coefficient (ICC) for the test set and Spearman correlation (SC) coefficient for the pustular set. RESULTS: On the test set, the DLM achieved an ICC of 0.97 (95% confidence interval [CI], 0.97-0.98) for count and 0.93 (95% CI, 0.92-0.94) for surface percentage. On the pustular set, the DLM reached a SC coefficient of 0.66 (95% CI, 0.60-0.74) for count and 0.80 (95% CI, 0.75-0.83) for surface percentage. CONCLUSIONS: The proposed method quantifies efflorescences from PP photographs reliably and automatically, enabling a precise and objective evaluation of disease activity.

Detecting racism and xenophobia using deep learning models on Twitter data: CNN, LSTM and BERT.

With the growth that social networks have experienced in recent years, it is entirely impossible to moderate content manually. Thanks to the different existing techniques in natural language processing, it is possible to generate predictive models that automatically classify texts into different categories. However, a weakness has been detected concerning the language used to train such models. This work aimed to develop a predictive model based on BERT, capable of detecting racist and xenophobic messages in tweets written in Spanish. A comparison was made with different Deep Learning models. A total of five predictive models were developed, two based on BERT and three using other deep learning techniques, CNN, LSTM and a model combining CNN + LSTM techniques. After exhaustively analyzing the results obtained by the different models, it was found that the one that got the best metrics was BETO, a BERT-based model trained only with texts written in Spanish. The results of our study show that the BETO model achieves a precision of 85.22% compared to the 82.00% precision of the mBERT model. The rest of the models obtained between 79.34% and 80.48% precision. On this basis, it has been possible to justify the vital importance of developing native transfer learning models for solving Natural Language Processing (NLP) problems in Spanish. Our main contribution is the achievement of promising results in the field of racism and hate speech in Spanish by applying different deep learning techniques.

High-throughput RNA sequencing transcriptome analysis of ABC-DLBCL reveals several tumor evasion strategies.

Activated B-cell (ABC) lymphoma, a distinct molecular entity within diffuse large B-cell lymphoma (DLBCL), remains highly incurable, showing a worse response to standard immunochemotherapy. The discouraging results obtained in several clinical trials using proteasome inhibitors, tyrosine kinase inhibitors, or immunomodulators, lead to an intense search for new, potentially druggable biomarkers in DLBCL. In this study, we designed an experimental strategy for DLBCL to discover high- and low-abundance RNA-seq-derived transcripts involved in the oncogenic phenotype in patients diagnosed with ABC-DLBCL. Based on the results of a comparative analysis, 79 DE genes and two enriched gene sets related to metabolism and immunity were selected. Genes related to drug resistance, anti-inflammatory response, and tumor-cell dissemination were found to be up-regulated, while tumor suppressor genes were down-regulated. Then, we searched for the perturbagens most suitable for gene expression profiling (GEP) by iLINCS-CMap. Herein, we present a novel experimental approach that connects the omics signature of DLBCL with potential drugs for more accurate treatments.

Cross-reactive cellular, but not humoral, immunity is detected between OC43 and SARS-CoV-2 NPs in people not infected with SARS-CoV-2: Possible role of cTFH cells.

Multiple questions about SARS-CoV-2 humoral and cellular immunity remain unanswered. One key question is whether preexisting memory T or B cells, specific for related coronaviruses in SARS-CoV-2-unexposed individuals, can recognize and suppress COVID-19, but this issue remains unclear. Here, we demonstrate that antibody responses to SARS-CoV-2 antigens are restricted to serum samples from COVID-19 convalescent individuals. In contrast, cross-reactive T cell proliferation and IFN-γ production responses were detected in PBMCs of around 30% of donor samples collected prepandemic, although we found that these prepandemic T cell responses only elicited weak cTFH activation upon stimulation with either HCoV-OC43 or SARS-CoV-2 NP protein. Overall, these observations confirm that T cell cross-reactive with SARS-CoV-2 antigens are present in unexposed people, but suggest that the T cell response to HCoV-OC43 could be deficient in some important aspects, like TFH expansion, that might compromise the generation of cross-reactive TFH cells and antibodies. Understanding these differences in cellular responses may be of critical importance to advance in our knowledge of immunity against SARS-CoV-2.

Induced ligno-suberin vascular coating and tyramine-derived hydroxycinnamic acid amides restrict Ralstonia solanacearum colonization in resistant tomato.

Tomato varieties resistant to the bacterial wilt pathogen Ralstonia solanacearum have the ability to restrict bacterial movement in the plant. Inducible vascular cell wall reinforcements seem to play a key role in confining R. solanacearum into the xylem vasculature of resistant tomato. However, the type of compounds involved in such vascular physico-chemical barriers remain understudied, while being a key component of resistance. Here we use a combination of histological and live-imaging techniques, together with spectroscopy and gene expression analysis to understand the nature of R. solanacearum-induced formation of vascular coatings in resistant tomato. We describe that resistant tomato specifically responds to infection by assembling a vascular structural barrier formed by a ligno-suberin coating and tyramine-derived hydroxycinnamic acid amides. Further, we show that overexpressing genes of the ligno-suberin pathway in a commercial susceptible variety of tomato restricts R. solanacearum movement inside the plant and slows disease progression, enhancing resistance to the pathogen. We propose that the induced barrier in resistant plants does not only restrict the movement of the pathogen, but may also prevent cell wall degradation by the pathogen and confer anti-microbial properties, effectively contributing to resistance.

In planta vs viral expression of HCPro affects its binding of nonplant 21-22 nucleotide small RNAs, but not its preference for 5'-terminal adenines, or its effects on small RNA methylation.

Previous studies have found a correlation between the abilities of PVX vector-expressed HCPro variants to bind small RNAs (sRNAs), and to suppress silencing. Moreover, HCPro preferred to bind viral sRNAs of 21-22 nucleotides (nt) containing 5'-terminal adenines. This would require such viral sRNAs to have either different access to the suppressor than those of plant sequences, or different molecular properties. To investigate this preference further, we have used suppressor-competent or suppressor-deficient HCPro variants, expressed from either T-DNAs or potyvirus constructs. Then, the sRNAs generated in plants and associated with the purified HCPro variants were characterized. Marked differences were observed in the ratios of sRNAs of plant vs nonplant origin that bound to suppressor-competent HCPro, depending on the mode of its expression. Regardless of the means of expression, HCPro retained the same preference among the nonplant sRNAs of 21-22 nt for those with 5'-terminal adenines. Relative methylation levels of individual sRNAs were assessed, and the nonplant sRNAs were found to be significantly less methylated in the presence of the suppressor. Targeted binding of sRNAs based on size, 5'-terminal sequence and origin, together with affecting their methylation, could explain how HCPro counteracts silencing.

[Renal allograft transplant vascular complications. Diagnostic and treatment.] / Complicaciones vasculares del trasplante renal. Diagnóstico y tratamiento.

Vascular complications remain common after renal transplantation, occurring in 3% to 15% of patients. These complications can compromise graft function,with graft loss rates ranging from 12.6 to 66.7%.Vascular abnormalities of the graft, specifically the presence of multiple vessels, represent the most frequently studied risk factor for the development of vascular complications. Other risk factors identified for the development of vascular complications are linked to the characteristics of the recipient, or thromboembolic diseasesharing atherosclerosis and/or hypercoagulant state aspathogenic features.Although the most frequent vascular complication is renal artery stenosis, we will also address the complications according to their early or late on set in order to highlightthe potentially more severe complications that may affectgraft survival during the follow-up period.Early vascular complications include mainly arterial and venous thrombosis and lacerations or disruptions of artery and/or vein, as well as arterio-venous fistulas or intrarenal pseudoaneurysms. In contrast, late-onset complications include stenosis or kinking of the renal artery-and less commonly of the renal vein-, as well as extrinsic compression as a consequence of the presence of perigraft fluid collections. Finally, extrarenal pseudoaneurysm is a potentially severe complication in the late post-transplant period.Finally, this article explores special transplant situations such as complications derived from the paediatric donor in adult recipients, transplantation in the paediatric recipient and emerging techniques like robotic renal transplantation.

Las complicaciones vasculares siguen siendo frecuentes después del trasplante renal, ocurriendo entre el 3% y el 15% de los pacientes. Estas complicaciones pueden comprometer la función del injerto,con unas tasas de pérdida del injerto que varían entreel 12,6 ­ 66,7%.Las anomalías vasculares del injerto, y concretamente la presencia de múltiples vasos, representan el factor de riesgo más frecuente y estudiado para el desarrollo de complicaciones vasculares. Otros factores de riesgo de complicaciones vasculares se han relacionado con las características del receptor, o la enfermedad tromboembólica, compartiendo como características patogénicas la aterosclerosis y/o el estado hipercoagulante. Aunque la complicación vascular más frecuente está constituida por la estenosis de la arteria renal, expondremos las complicaciones en función de su presentación clínica temprana o tardía en un intento de destacar para el lector las complicaciones potencialmente más severas y que en cada momento del tiempo pueden condicionar la supervivencia del injerto.Las complicaciones de presentación preferentemente perioperatoria incluyen fundamentalmente la trombosis arterial y venosa y las laceraciones o disrupciones de arteria y/o vena, así como las fístulas arterio-venosas opseudoaneurismas intrarrenales. Por el contrario, otras complicaciones tienen comúnmente una presentación clínica más tardía. En este grupo incluimos la estenosiso acodamiento de la arteria renal y excepcionalmente de la vena renal, así como la compresión extrínseca de los vasos del injerto como consecuencia de la presencia de colecciones peri-injerto. Finalmente, una complicación severa que puede manifestarse de forma tardía enla evolución del receptor, es el pseudoaneurisma extrarrenal. Finalmente, haremos brevemente referencia a situaciones especiales del trasplante como las complicaciones derivadas del donante pediátrico en receptores adultos,del trasplante en el receptor pediátrico y de técnicas emergentes como el trasplante renal robótico.

Complicaciones vasculares del trasplante renal. Diagnóstico y tratamiento / Vascular complications of kidney transplantation. Diagnosis and treatment

Existen diferentes técnicas quirúrgicaspara la reconstrucción del tracto urinario en el trasplanterenal. Sin embargo es frecuente la aparición de complicaciones urinarias en el postoperatorio, siendo el uréterla localización frecuente de las mismas. Esto implicaun alto gasto sanitario, aumentando la morbimortalidaddel paciente y pudiendo llegar a desencadenar la pérdida del injerto. Por ello es importante la prevención, elcorrecto diagnóstico y su tratamiento.El objetivo de esta revisión es describir las técnicas quirúrgicas más usadas en el trasplante renal para la ureteroneocistostomía. Analizar las ventajas y desventajas decada una de ellas y comparar sus complicaciones. Porotro lado se resume la literatura reciente sobre las cuatrocomplicaciones urinarias más frecuentes en el postoperatorio del trasplante. Se exponen las posibles causas ytratamiento de la fuga urinaria, la obstrucción ureteral,la hematuria y el reflujo ureterovesical.(AU)

There are different surgical techniques forreconstruction of the urinary tract in kidney transplant.However, urinary complications are frequent in the postoperative period, being the ureter the frequent locationof these complications. This results in high health carecosts, increasing patient morbimortality and sometimesgraft loss. For this reason, prevention, correct diagnosisand treatment are important.The aim of this review is to describe the surgical techniques most commonly used in kidney transplant forureteroneocystostomy. To analyze the advantages anddisadvantages of each of them and to compare theircomplications. On the other hand, we summarize therecent literature on the four most frequent urinary complications in the postoperative period after transplantation.The possible causes and treatment of urine leak, uretericobstruction, hematuria and vesicoureteral reflux are presented.(AU)

Molecular diagnosis of polycystic ovary syndrome in obese and non-obese women by targeted plasma miRNA profiling.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is diagnosed based on the clinical signs, but its presentation is heterogeneous and potentially confounded by concurrent conditions, such as obesity and insulin resistance. miRNA have recently emerged as putative pathophysiological and diagnostic factors in PCOS. However, no reliable miRNA-based method for molecular diagnosis of PCOS has been reported. The aim of this study was to develop a tool for accurate diagnosis of PCOS by targeted miRNA profiling of plasma samples, defined on the basis of unbiased biomarker-finding analyses and biostatistical tools. METHODS: A case-control PCOS cohort was cross-sectionally studied, including 170 women classified into four groups: non-PCOS/lean, non-PCOS/obese, PCOS/lean, and PCOS/obese women. High-throughput miRNA analyses were performed in plasma, using NanoString technology and a 800 human miRNA panel, followed by targeted quantitative real-timePCR validation. Statistics were applied to define optimal normalization methods, identify deregulated biomarker miRNAs, and build classification algorithms, considering PCOS and obesity as major categories. RESULTS: The geometric mean of circulating hsa-miR-103a-3p, hsa-miR-125a-5p, and hsa-miR-1976, selected among 125 unchanged miRNAs, was defined as optimal reference for internal normalization (named mR3-method). Ten miRNAs were identified and validated after mR3-normalization as differentially expressed across the groups. Multinomial least absolute shrinkage and selection operator regression and decision-tree models were built to reliably discriminate PCOS vs non-PCOS, either in obese or non-obese women, using subsets of these miRNAs as performers. CONCLUSIONS: We define herein a robust method for molecular classification of PCOS based on unbiased identification of miRNA biomarkers and decision-tree protocols. This method allows not only reliable diagnosis of non-obese women with PCOS but also discrimination between PCOS and obesity. CAPSULE: We define a novel protocol, based on plasma miRNA profiling, for molecular diagnosis of PCOS. This tool not only allows proper discrimination of the condition in non-obese women but also permits distinction between PCOS and obesity, which often display overlapping clinical presentations.

Determining Factors in the Use of Urban Parks That Influence the Practice of Physical Activity in Children: A Systematic Review.

The design and/or remodelling of urban parks is a good health strategy to alleviate the lack of physical activity (PA) in children and, consequently, the different health problems derived from this. The main objective of the present study was to obtain a systematic review of the design features and characteristics that influence users' visits to urban parks and the PA engagement in them. A literature search was carried out in the Web of Science (WOS) and Scopus databases during the months of June and July 2020. After considering and applying inclusion criteria, the final review sample was formed of 31 scientific papers published between 2010-2020. The results obtained in the review lead us to conclude that the needs of the population (children and family members who care for them) and socio-economic context of the area in which they are built must be considered when constructing and/or remodelling parks. Involving community members in playground renovations can have a positive effect on park use and PA engagement in children.

Effect of Fe-N Codoping on the Optical Properties of TiO2 for Use in Photoelectrolysis of Water.

TiO2 nanoparticles were synthesized by green chemistry where organic solvents are replaced by an aqueous extract solution of lemongrass leaves that act as a reducer and growth-stopper agent. The nanoparticles were codoped with N-Fe to modify the absorption range in the electromagnetic spectrum and were characterized by Fourier-transform infrared (FTIR), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), and UV-vis/diffuse reflectance spectroscopy (DRS). The modified samples with Fe and N resulted in smaller nanoparticle size values than pure TiO2. Similarly, the band-gap energy for doped nanoparticles decreased to 2.22 eV in relation to the value of 3.09 eV for pure TiO2, due to the introduction of new energy levels.

Knockout of PRDX6 induces mitochondrial dysfunction and cell cycle arrest at G2/M in HepG2 hepatocarcinoma cells.

Peroxiredoxin 6 (PRDX6) has been associated with tumor progression and cancer metastasis. Its acting on phospholipid hydroperoxides and its phospholipase-A2 activity are unique among the peroxiredoxin family and add complexity to its action mechanisms. As a first step towards the study of PRDX6 involvement in cancer, we have constructed a human hepatocarcinoma HepG2PRDX6-/- cell line using the CRISPR/Cas9 technique and have characterized the cellular response to lack of PRDX6. Applying quantitative global and redox proteomics, flow cytometry, in vivo extracellular flow analysis, Western blot and electron microscopy, we have detected diminished respiratory capacity, downregulation of mitochondrial proteins and altered mitochondrial morphology. Autophagic vesicles were abundant while the unfolded protein response (UPR), HIF1A and NRF2 transcription factors were not activated, despite increased levels of p62/SQSTM1 and reactive oxygen species (ROS). Insulin receptor (INSR), 3-phosphoinositide-dependent protein kinase 1 (PDPK1), uptake of glucose and hexokinase-2 (HK2) decreased markedly while nucleotide biosynthesis, lipogenesis and synthesis of long chain polyunsaturated fatty acids (LC-PUFA) increased. 254 Cys-peptides belonging to 202 proteins underwent significant redox changes. PRDX6 knockout had an antiproliferative effect due to cell cycle arrest at G2/M transition, without signs of apoptosis. Loss of PLA2 may affect the levels of specific lipids altering lipid signaling pathways, while loss of peroxidase activity could induce redox changes at critical sensitive cysteine residues in key proteins. Oxidation of specific cysteines in Proliferating Cell Nuclear Antigen (PCNA) could interfere with entry into mitosis. The GSH/Glutaredoxin system was downregulated likely contributing to these redox changes. Altogether the data demonstrate that loss of PRDX6 slows down cell division and alters metabolism and mitochondrial function, so that cell survival depends on glycolysis to lactate for ATP production and on AMPK-independent autophagy to obtain building blocks for biosynthesis. PRDX6 is an important link in the chain of elements connecting redox homeostasis and proliferation.