Biology subjects

Guillen, E.

Publications and source records attributed to Guillen, E..

7 recordsLinked to original sources

bioRxiv2025

Therapy to Teratology: Chronic Paternal Antioxidant Supplementation Alters Offspring Placental Architecture and Craniofacial Morphogenesis in a Mouse Model

Oxidative stress plays a significant role in regulating the mammalian epigenome, with emerging evidence suggesting imbalances in the cellular redox state trigger stress-responsive epigenetic modifications that drive various human diseases. However, it remains unclear whether, like worms, epigenetic changes caused by redox imbalance or mitochondrial stress can move through the mammalian germline, potentially affecting the health of future generations. Antioxidant therapies are commonly used to reduce oxidative damage and are widely employed in cases of male infertility, where high-dose supplementation is often recommended to enhance sperm quality and overall measures of male reproductive health. Interestingly, in non-stressed, ostensibly healthy males, recent research suggests that antioxidants may have a negative influence on sperm epigenetic markers, indicating a potential epigenetic liability. However, whether male antioxidant treatment can induce paternal effects on offspring growth and development remains unknown. Here, we employed micro-CT imaging and geometric morphometrics to determine whether chronic antioxidant supplementation in healthy male mice affects placental growth and craniofacial development in their offspring. Adult C57BL/6J male mice were given a six-week preconception regimen of N-acetyl-L-cysteine (NAC; 400 mg/kg/day) and selenium (0.04 mg/kg/day), which continued throughout breeding with treatment-naive females. Although we observed modest alterations to the histological patterning of the female placenta, placental weights and efficiency remained unchanged. In contrast, we observed significant changes in facial shape and symmetry in both male and female offspring, with female offspring exhibiting significant reductions in eye spacing and head area. These changes occurred without any macro changes in paternal metabolic health, indicating that antioxidant-induced shifts in redox balance may disrupt developmental programming in the male germline independent of changes in overall health. Our findings emphasize the need for caution when using antioxidants as preconception interventions and broadly suggest that modulation of the paternal redox axis may result in altered developmental programming and teratogenic effects.

developmental biology↗

bioRxiv2025

Role of NLRP3 activation in salt sensitive blood pressure regulation, effect of ND-13

Background and ObjectivesHigh salt intake is a major contributor to the development and exacerbation of hypertension, partly by inducing an inflammatory response through immune cell dysfunction. Inflammasomes, key components of the innate immune response, may influence blood pressure regulation. The renal DJ-1 protein is known for its antioxidant and anti-inflammatory properties. To explore novel pharmacological applications of renal DJ-1 pathway, we developed ND-13, a peptide consisting of 13 highly conserved amino acids derived from the DJ-1 sequence. In this study, we investigated the effects of ND-13 and MCC950, a specific NLRP3 inflammasome inhibitor, on blood pressure regulation in C57BL/6J mice on a high-salt diet. MethodsC57BL/6J mice were fed a high-salt diet (HS) for one week and then treated with ND-13 or MCC950, an NLRP3 inflammasome inhibitor. Subsequently, gene expression by qPCR, staining of immune cells, Sirius Red and Periodic Acid-Schiff (PAS) staining were determined in the mice kidneys, as well as the inflammasome activity in peritoneal cells. ResultsOne week of HS resulted increased in blood pressure, that was prevented by both ND-13 and MCC950 treatments. These treatments also prevented the increase in proteinuria that was accompanied by tubular protein deposits. Renal expression of inflammatory genes, immune cell infiltration, and renal collagen deposition were not observed in the HS group. Peritoneal macrophages isolated from HS treated mice exhibited enhanced IL-1{beta} release upon LPS+ATP stimulation, suggesting activation of the NLRP3 inflammasome. Treatment with ND-13 and MCC950 normalized this activity. Furthermore, ND-13 reduced IL-1{beta} mRNA expression in peritoneal macrophages. ConclusionsOur findings highlight the critical role of the NLRP3 inflammasome in salt-sensitive blood pressure regulation and suggest that ND-13 may serve as a potential therapeutic agent for preventing hypertension and associated inflammatory alterations induced by a high salt intake.

physiology↗

bioRxiv2025

ND-13, a DJ-1 derived peptide, as a novel pharmacological approach in the prevention of NLRP3 inflammasome activity in Diabetic Nephropathy

Diabetic nephropathy is the most important cause of renal failure worldwide and is characterized by sustained inflammation regulated in part by NLRP3 Inflammasome. Attenuation of inflammation is a major priority to prevent renal damage. Our previous publications show that DJ-1 has antioxidant and anti-inflammatory properties in the kidney. ND-13 is a short peptide consisting of 13 amino acids of the DJ-1-protein, which could increase DJ-1 pathway activation. The aim of these studies was to determine the role of NLRP3 in the pathogenesis of diabetic nephropathy and to study the possible renal protective effects of the DJ-1 pathway in diabetic mice and on inflammasome regulation. Bone marrow derived macrophages were treated with ND-13 and cultivated in high and low glucose. Diabetes was induced in C57Bl/6 mice via injection of streptozotocin and treated with ND-13 and MCC950, an inhibitor of the NLRP3 inflammasome. Peripheral mononuclear cells were isolated from human with diabetes, diabetic nephropathy and healthy donors and were plated, pretreated with ND-13 and stimulated with LPS+ATP. IL-1{beta} concentration in the medium of bone marrow derived macrophages increased by NLRP3 inflammasome stimulation by LPS+ATP, and decreased in macrophages pre-treated with ND-13, however, in the presence of LPS+Nigericin no effect was found. Peritoneal macrophages from diabetic mice were obtained and plated. Streptozotocin-induced diabetic C57BL/6 mice have increased the peritoneal cells IL-1{beta} production compared with control mice, suggesting that inflammasome may be activated in macrophages during diabetes and that ND-13 treatment normalized its activity. ND-13 and MCC950 decreased histologic evidence of tubular injury in STZ-induced diabetes in mice, additionally, significantly increased the mRNA expression of Col-I, Col-II, Tgf-{beta}, Il-6, Tnf- and P2x7 in the renal cortex, which was partially prevented by ND-13 and MCC950 pre-treatment. P2x7 mRNA expression was also increased in peritoneal macrophages obtained from diabetic mice, and its expression was attenuated by ND-13 pre-treatment. Peripheral mononuclear cells isolated from patients blood were plated and stimulated with LPS+ATP. Patients with diabetic nephropathy presented a significant increase of IL-1{beta} release compared to diabetic individuals and ND-13 could has a role in the prevention of inflammasome activation in healthy patients. Our results demonstrate that activation of the DJ-1 pathway is a promising approach to prevent renal inflammation and fibrosis during diabetes, by ameliorating inflammasome activation in peripheral immune cells. Thus, ND-13 could be a promising new therapeutic approach to attenuating inflammation and renal damage in diabetic nephropathy.

cell biology↗

bioRxiv2022

Loss of the MLL3 tumor suppressor accelerates breast tumor onset via HIF1a-induced CCL2-mediated recruitment of CCR2+ regulatory T cells

While essential gatekeepers of immune homeostasis, Foxp3+ regulatory T (Treg) cells infiltrating tumors acquire distinct phenotypes and become highly immunosuppressive, promoting tumor immune escape and growth. How this occurs and relates to tumor-driver mutations is largely uncharacterized. Herein, we created a mouse mammary stem cell-based tumor model using CRISPR gene editing in which we introduced known human cancer-driver mutations. These included functional loss of the MLL3 histone methyltransferase and p53, and constitutive PI3-kinase activation, recapitulating the genetic makeup of aggressive breast cancers. We show that MLL3 loss fosters tumorigenesis by promoting the rapid establishment of an immunosuppressive microenvironment through induction of HIF1, which increases the secretion of the chemokine CCL2 by tumor cells and the recruitment of higher numbers of Foxp3+ Treg cells via CCR2. Greater infiltration of Treg cells also correlates with MLL3 downregulation and mutations in human breast cancer biopsies. Interestingly, HIF1 enforces the differentiation of tumor-infiltrating Treg cells into highly immunosuppressive ICOShiGITRhi Blimp-1hi effector Treg cells that enable rapid tumor escape. Monoclonal antibody targeting of ICOS or GITR inhibits tumorigenesis in most mice even two months after the cessation of treatment as well as the growth of established tumors, suggesting possible therapeutic opportunities for MLL3-mutant breast cancers.

immunology↗

bioRxiv2021

T cell receptor and IL-2 signaling strength control memory CD8+ T cell functional fitness via chromatin remodeling

Cognate antigen signal controls CD8+ T cell priming, expansion size and effector versus memory cell fates, but it is not known if and how it modulates the functional features of memory CD8+ T cells. Here we show that the strength of T cell receptor (TCR) signaling determines the requirement for interleukin-2 (IL-2) signals to form a pool of memory CD8+ T cells that competitively re-expand upon secondary antigen encounter. Combining strong TCR and intact IL-2 signaling synergistically induces genome-wide chromatin accessibility in regions targeting a wide breadth of biological processes, consistent with their greater functional fitness. Chromatin accessibility in promoters of genes encoding for stem cell, cell cycle and calcium-related proteins correlated with faster intracellular calcium accumulation, initiation of cell cycle and more robust expansion. High-dimensional flow-cytometry analysis also highlights higher subset diversity and phenotypes. These results formally establish that epitope selection in vaccine design strongly impacts memory CD8+ T cell epigenetic programming and functions. One Sentence SummaryThe strength of antigenic and interleukin 2 signals received by CD8+ T cells during vaccination epigenetically programs their ability to form functional memory.

immunology↗

bioRxiv2021

Memory CD8+ T cells mediate early pathogen-specific protection through localized delivery of chemokines and IFNγ to clusters of inflammatory monocytes

While cognate antigen drives clonal expansion of memory CD8+ T cells to achieve sterilizing immunity in immunized hosts, not much is known on how cognate antigen contributes to early mechanisms of protection before clonal expansion occurs. Herein, using distinct models of immunization, we establish that cognate antigen recognition by CD8+ TM cells on dendritic cells initiates their rapid and coordinated production of a burst of CCL3, CCL4 and XCL1 chemokines under the transcriptional control of IRF4. Using intravital microscopy imaging and in vivo monoclonal antibody labelling, we reveal that memory CD8+ T cells undergo antigen-mediated arrest in splenic red pulp clusters of CCR2+ monocytes where they locally deliver both IFN{gamma}- and chemokine-potentiating microbicidal activities to achieve early protection. Thus, rapid and effective memory CD8+ T cell responses require a complex series of spatially and temporally coordinated stepwise molecular and cellular events that quickly restrict microbial pathogen growth and optimize the local delivery of effector molecules before clonal expansion occurs.

immunology↗

bioRxiv2020

Blockade of LAG-3 in PD-L1-deficient mice enhances clearance of blood stage malaria independent of humoral responses

T cells expressing high levels of inhibitory receptors such as PD-1 and LAG-3 are a hallmark of chronic infections and cancer. Checkpoint blockade therapies targeting these receptors have been largely validated as promising strategies to restore exhausted T cell functions and clearance of chronic infections and tumors. The inability to develop long-term natural immunity in malaria-infected patients has been proposed to be at least partially accounted for by sustained expression of high levels of inhibitory receptors on T and B lymphocytes. While blockade or lack of PD-1/PD-L1 and/or LAG-3 was reported to promote better clearance of Plasmodium parasites in mice, how exactly these pathways contributes to protection is not known. Herein, using a mouse model of non-lethal P. yoelii (Py) infection, we reveal that the kinetics of blood parasitemia is indistinguishable between PD-1-/-, PD-L1-/- and WT mice. Yet, monoclonal antibody (mAb) blockade of LAG-3 in PD-L1-/- mice promoted accelerated control of blood parasite growth and clearance. We also report that i) the majority of LAG-3+ cells are T cells, ii) selective depletion of CD8+ T cells did not prevent anti-LAG-3-mediated protection, and iii) production of effector cytokines by CD4+ T cells is increased in anti-LAG-3-treated versus control mice. In addition, parasite-specific Ab serum titers and their ability to transfer protection from both groups of mice was comparable and depletion of CD4+ T cells prevented protection. Thus, taken together, these results are consistent with a model in which disruption of PD-L1 and LAG-3 on parasite-specific CD4+ T cells unleashes their ability to effectively clear blood parasites, independently from humoral responses. Author SummaryMalaria, caused by Plasmodium parasites, is a global burden for which an efficacious vaccine is urgently needed. The development of long-term immunity against malaria is unclear, but we know that both T and B (that produce antibodies, Ab) lymphocytes, that are subsets of white blood cells, are required. Studies in mouse models of malaria have suggested that sets of inhibitory receptors, namely LAG-3 and PD-1, expressed on cytotoxic and helper T lymphocytes hamper the development of effective immunity against malaria. Therapeutic blockade of these receptors was reported to enhance blood parasite clearance through the development of more protective parasite-specific helper T lymphocytes and Abs. Herein, we reveal that, while mice genetically deficient for the PD-1 pathway fail to clear blood parasites better than WT counterparts, anti-LAG-3 treatment does. Importantly, we found comparable parasite-specific Ab responses between all mouse groups, and Ab transfers conferred similar protection to newly infected mice. We also show that LAG-3 is mostly expressed on T lymphocytes, and that cytotoxic T lymphocytes are not involved in anti-LAG-3 accelerated clearance of parasites. Our results suggest that LAG-3 blockade acts on helper T lymphocytes to unleash their effector responses and enhance the control of blood-stage malaria, independently from parasite-specific Abs.

immunology↗