Inducible Transcription Factor Research Articles

Research progress in Estrogen-related receptor gamma (ERRγ) agonists and inverse agonists.

Estrogen-related receptor gamma (ERRγ), one of three members of the ERR family, is an inducible transcription factor. ERRγ has dual functions in different tissues. The decreased expression of ERRγ in the brain, stomach, prostate, and fat cells can cause neuropsychological dysfunction, gastric cancer, prostate cancer, and obesity. However, when ERRγ is present in the liver, pancreas, and thyroid follicular cells, ERRγ overexpression is related to liver cancer, type II diabetes, oxidative liver injury, and anaplastic thyroid carcinoma. Signaling pathway studies have confirmed that ERRγ agonists or inverse agonists can regulate ERRγ expression to treat related diseases. The collision between residue Phe435 and the modulator is a key factor determining the activation or inhibition of ERRγ. Although more than 20 agonists and inverse agonists of ERRγ have been reported, no clinical studies have been found in the literature. This review summarizes the important relationship between ERRγ-related signaling pathways and diseases, research progress, and the structure-activity relationship of modulators. These findings provide guidance for further study on new ERRγ modulators.

Exploring Aluminum Tolerance Mechanisms in Plants with Reference to Rice and Arabidopsis: A Comprehensive Review of Genetic, Metabolic, and Physiological Adaptations in Acidic Soils.

Aluminum (Al) makes up a third of the Earth's crust and is a widespread toxic contaminant, particularly in acidic soils. It impacts crops at multiple levels, from cellular to whole plant systems. This review delves into Al's reactivity, including its cellular transport, involvement in oxidative redox reactions, and development of specific metabolites, as well as the influence of genes on the production of membrane channels and transporters, alongside its role in triggering senescence. It discusses the involvement of channel proteins in calcium influx, vacuolar proton pumping, the suppression of mitochondrial respiration, and the initiation of programmed cell death. At the cellular nucleus level, the effects of Al on gene regulation through alterations in nucleic acid modifications, such as methylation and histone acetylation, are examined. In addition, this review outlines the pathways of Al-induced metabolic disruption, specifically citric acid metabolism, the regulation of proton excretion, the induction of specific transcription factors, the modulation of Al-responsive proteins, changes in citrate and nucleotide glucose transporters, and overall metal detoxification pathways in tolerant genotypes. It also considers the expression of phenolic oxidases in response to oxidative stress, their regulatory feedback on mitochondrial cytochrome proteins, and their consequences on root development. Ultimately, this review focuses on the selective metabolic pathways that facilitate Al exclusion and tolerance, emphasizing compartmentalization, antioxidative defense mechanisms, and the control of programmed cell death to manage metal toxicity.

Stat3 Regulates Developmental Hematopoiesis and Impacts Myeloid Cell Function via Canonical and Non-Canonical Modalities

Introduction: Signal transducer and activator of transcription (STAT) 3 is extensively involved in the development, homeostasis, and function of immune cells, with STAT3 disruption associated with human immune-related disorders. The roles ascribed to STAT3 have been assumed to be due to its canonical mode of action as an inducible transcription factor downstream of multiple cytokines, although alternative noncanonical functional modalities have also been identified. The relative involvement of each mode was further explored in relevant zebrafish models. Methods: Genome editing with CRISPR/Cas9 was used to generate mutants of the conserved zebrafish Stat3 protein: a loss of function knockout (KO) mutant and a mutant lacking C-terminal sequences including the transactivation domain (ΔTAD). Lines harboring these mutations were analyzed with respect to blood and immune cell development and function in comparison to wild-type zebrafish. Results: The Stat3 KO mutant showed perturbation of hematopoietic lineages throughout primitive and early definitive hematopoiesis. Neutrophil numbers did not increase in response to lipopolysaccharide (LPS) or granulocyte colony-stimulating factor (G-CSF) and their migration was significantly diminished, the latter correlating with abrogation of the Cxcl8b/Cxcr2 pathway, with macrophage responses perturbed. Intriguingly, many of these phenotypes were not shared by the Stat3 ΔTAD mutant. Indeed, only neutrophil and macrophage development were disrupted in these mutants with responsiveness to LPS and G-CSF maintained, and neutrophil migration actually increased. Conclusion: This study has identified roles for zebrafish Stat3 within hematopoietic stem cells impacting multiple lineages throughout primitive and early definitive hematopoiesis, myeloid cell responses to G-CSF and LPS and neutrophil migration. Many of these roles showed conservation, but notably several involved noncanonical modalities, providing additional insights for relevant diseases.

Administration of Gas6 attenuates lung fibrosis via inhibition of the epithelial-mesenchymal transition and fibroblast activation

The epithelial-mesenchymal transition (EMT) and fibroblast activation are major events in idiopathic pulmonary fibrosis pathogenesis. Here, we investigated whether growth arrest-specific protein 6 (Gas6) plays a protective role in lung fibrosis via suppression of the EMT and fibroblast activation. rGas6 administration inhibited the EMT in isolated mouse ATII cells 14 days post-BLM treatment based on morphologic cellular alterations, changes in mRNA and protein expression profiles of EMT markers, and induction of EMT-activating transcription factors. BLM-induced increases in gene expression of fibroblast activation-related markers and the invasive capacity of primary lung fibroblasts in primary lung fibroblasts were reversed by rGas6 administration. Furthermore, the hydroxyproline content and collagen accumulation in interstitial areas with damaged alveolar structures in lung tissue were reduced by rGas6 administration. Targeting Gas6/Axl signaling events with specific inhibitors of Axl (BGB324), COX-2 (NS-398), EP1/EP2 receptor (AH-6809), or PGD2 DP2 receptor (BAY-u3405) reversed the inhibitory effects of rGas6 on EMT and fibroblast activation. Finally, we confirmed the antifibrotic effects of Gas6 using Gas6−/− mice. Therefore, Gas6/Axl signaling events play a potential role in inhibition of EMT process and fibroblast activation via COX-2-derived PGE2 and PGD2 production, ultimately preventing the development of pulmonary fibrosis.

Engineering Material Properties of Transcription Factor Condensates to Control Gene Expression in Mammalian Cells and Mice.

Phase separation of biomolecules into condensates is a key mechanism in the spatiotemporal organization of biochemical processes in cells. However, the impact of the material properties of biomolecular condensates on important processes, such as the control of gene expression, remains largely elusive. Here, the material properties of optogenetically induced transcription factor condensates are systematically tuned, and probed for their impact on the activation of target promoters. It is demonstrated that transcription factors in rather liquid condensates correlate with increased gene expression levels, whereas stiffer transcription factor condensates correlate with the opposite effect, reduced activation of gene expression. The broad nature of these findings is demonstrated in mammalian cells and mice, as well as by using different synthetic and natural transcription factors. These effects are observed for both transgenic and cell-endogenous promoters. The findings provide a novel materials-based layer in the control of gene expression, which opens novel opportunities in optogenetic engineering and synthetic biology.

Abstract 1704: Interplay of MITF and NCOA3 in orchestrating oncogenic transcriptional network in uveal melanoma

Abstract Uveal melanoma (UM) originates from melanocytes residing in the uveal tract of an eye. Despite effective local control, 50% of patients develop metastatic disease responding poorly to chemotherapy, targeted therapy, and immunotherapy. The molecular basis of events leading to initiation of UM is related to mutations in G alpha proteins GNAQ or GNA11, rendering them constitutively active and activating downstream PKC, ERK and AKT pathways sustaining cell proliferation. In our previous work, we showed that NCOA3 regulates proliferation of UM cells in vitro and the growth of UM xenografts in vivo downstream of GNAQ or GNA11. The critical role of NCOA3 in UM is manifested by transcriptional regulation of proliferation-related genes that are massively suppressed by NCOA3 knockout or knockdown. Here, we interrogated transcription factors that NCOA3 interacts with in UM to execute oncogenic programs and identified Melanocyte inducing transcription factor (MITF) as its critical partner. Chromatin immunoprecipitation (ChIP) using an NCOA3 recognizing antibody followed by sequencing was performed to determine NCOA3 binding sites in the human genome. The known transcription binding motifs within NCOA3 peaks were discovered using HOMER algorithm. Co-immunoprecipitation was performed to examine direct NCOA3 and MITF interaction. ChIP sequencing for MITF was performed to determine co-localization of NCOA3 and MITF at chromatin. Proliferation of UM cells after inhibition of MITF by either siRNA mediated knockdown or MITF inhibitor ML329 was evaluated using MTT assay. Functional enrichment analysis of transcriptome was used to identify classes of genes regulated by MITF, with specific attention to the subset regulated by MITF partnered with NCOA3. NCOA3 chromatin peaks are highly enriched in MITF binding motifs, and 77% of the NCOA3 peaks co-localizes with the MITF peaks. NCOA3 co-immunoprecipitates with MITF. Among transcriptional programs regulated by MITF in UM are those related to melanocyte biology, differentiation, and melanin production, but also those related to melanoma growth, especially cell division, DNA replication, myc response, purine and pyrimidine metabolism, and mTOR signaling. Strong suppression of these transcriptional signatures by inhibition of MITF using siRNA-mediated knockdown or pharmacological inhibition correlates with dramatic loss of cell viability. Clinical data indicate that higher expression of MITF-positively regulated genes correlates with lower survival rates of UM patients. Importantly, the transcriptional programs regulated by MITF cooperating with NCOA3 were related to TGF beta signaling, cell adhesion, ECM interaction and actin cytoskeleton. Importance of MITF as an oncogene is manifested in uveal melanoma cell lines and clinical data. Oncogenic function of MITF is partially dependent on its interaction with a transcription co-activator NCOA3. Citation Format: Aleksandra Rusin, Maria E. Echartea, Sai P. Manikonda, Darlene G. Skapura, Christel M. Davis, Erik A. Ehli, Sandra L. Grimm, Cristian Coarfa, Salma Kaochar. Interplay of MITF and NCOA3 in orchestrating oncogenic transcriptional network in uveal melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1704.

Abstract 3024: HIF1A and HIF2A differentially contribute to early and adaptive changes following in vivo Vhl inactivation in the kidney

Abstract The von Hippel Lindau (VHL) tumor suppressor gene is a classical tumor suppressor whose biallelic inactivation is a truncal event in clear cell renal cell carcinoma (ccRCC) evolution. VHL is best characterized as the recognition component of an E3 ubiquitin ligase complex that targets hypoxia inducible transcription factors (HIF1A and HIF2A) for conditional oxygen-dependent degradation. HIF activation following VHL inactivation is an early event in ccRCC progression. While the functions of HIF1A and HIF2A in ccRCC biology and progression have been studied, those in VHL-null non-neoplastic cells of the renal tubular epithelium (RTE) and their contribution to tumorigenesis have not been fully explored. Here, using a combination of lineage marking and single-cell RNA sequencing (scRNA-seq), we provide the first description of HIF1A- and/or HIF2A-dependent and -independent consequences of in vivo Vhl inactivation in the RTE with single-cell resolution. We have previously reported on the development of a novel mouse model designed to mark and track cells that have undergone Vhl inactivation in vivo. Using this model, we have shown that Vhl inactivation has extensive, cell-type specific effects on gene expression in cells of the RTE within 3 weeks of recombination. Furthermore, we have shown that over a course of 4-8 months after Vhl inactivation, Vhl-null cells undergo specific adaptive changes in gene expression that encompass genes not regulated early after Vhl inactivation. In the work reported here, we have coupled this mouse model to a tamoxifen-inducible RTE-specific Pax8-CreERT2 and conditional alleles for Hif1a and/or Epas1 (codes for HIF2A). We have analyzed ‘marked’ recombined cells at early (1-3 weeks) or late (4-8 months) timepoints after recombination and compared these cells to time-matched Vhl-null cells using immunohistochemistry, in situ RNA hybridization and scRNA-seq. We found that though both HIF isoforms were present in Vhl-null cells at the early timepoint, expression of genes regulated early after Vhl inactivation was affected more by Hif1a inactivation than Epas1 inactivation. In contrast, expression of genes that are regulated in Vhl-null cells over time was drastically impacted by Epas1 deletion but was unaffected by Hif1a deletion. Interestingly, most of these Epas1-dependent, time-dependent changes in Vhl-null cells involved genes that have not been identified as direct transcriptional targets of HIF. Collectively, our work suggests that HIF1A and HIF2A have temporally distinct contributions to gene expression in Vhl-null cells in the RTE. We are currently analyzing the cell-type specificity of these contributions and ascertaining their relevance to the adoption of ccRCC-associated gene expression profiles. Citation Format: Samvid Kurlekar, Joanna Lima, Ayslan B. Barros, Norma Masson, Sophia Zhai, Christopher W. Pugh, Julie Adam, Peter J. Ratcliffe. HIF1A and HIF2A differentially contribute to early and adaptive changes following in vivo Vhl inactivation in the kidney [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3024.

Expansion of memory Vδ2 T cells following SARS-CoV-2 vaccination revealed by temporal single-cell transcriptomics

γδ T cells provide rapid cellular immunity against pathogens. Here, we conducted matched single-cell RNA-sequencing and γδ-TCR-sequencing to delineate the molecular changes in γδ T cells during a longitudinal study following mRNA SARS-CoV-2 vaccination. While the first dose of vaccine primes Vδ2 T cells, it is the second administration that significantly boosts their immune response. Specifically, the second vaccination uncovers memory features of Vδ2 T cells, shaped by the induction of AP-1 family transcription factors and characterized by a convergent central memory signature, clonal expansion, and an enhanced effector potential. This temporally distinct effector response of Vδ2 T cells was also confirmed in vitro upon stimulation with SARS-CoV-2 spike-peptides. Indeed, the second challenge triggers a significantly higher production of IFNγ by Vδ2 T cells. Collectively, our findings suggest that mRNA SARS-CoV-2 vaccination might benefit from the establishment of long-lasting central memory Vδ2 T cells to confer protection against SARS-CoV-2 infection.

A histone deacetylase, FaSRT1-2, plays multiple roles in regulating fruit ripening, plant growth and stresses resistance of cultivated strawberry.

Sirtuins (SRTs) are a group of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that target both histone and nonhistone proteins. The biological function of SRT in horticultural plants has been rarely studied. In this study, FaSRT1-2 was identified as a key member of the 8 FaSRTs encoded in cultivated strawberry genome. Transient overexpression of FaSRT1-2 in strawberry fruit accelerated ripening, increased the content of anthocyanins and sugars, enhanced ripening-related gene expression. Moreover, stable transformation of FaSRT1-2 in strawberry plants resulted in enhanced vegetative growth, increased sensitivity to heat stress and increased susceptibility to Botrytis cinerea infection. Interestingly, knocking out the homologous gene in woodland strawberry had the opposite effects. Additionally, we found the content of stress-related hormone abscisic acid (ABA) was decreased, while the growth-related gibberellin (GA) concentration was increased in FaSRT1-2 overexpression lines. Gene expression analysis revealed induction of heat shock proteins, transcription factors, stress-related and antioxidant genes in the FaSRT1-2-overexpressed plants while knocked-out of the gene had the opposite impact. In conclusion, our findings demonstrated that FaSRT1-2 could positively promote strawberry plant vegetative growth and fruit ripening by affecting ABA and GA pathways. However, it negatively regulates the resistance to heat stress and B. cinerea infection by influencing the related gene expression.

Mechanisms of AML1-ETO Induced Transcription Factor Dysregulation, Epigenetic Modification, and Immune System Evasion in Pre-Leukemic Stem Cells

Mechanisms of AML1-ETO Induced Transcription Factor Dysregulation, Epigenetic Modification, and Immune System Evasion in Pre-Leukemic Stem Cells

Regulation of a Metabolic Gene Signature in Response to Respiratory Viruses and Type I Interferon Signaling

Respiratory viruses are the causative agents responsible for seasonal epidemics and occasional pandemic outbreaks and are a leading cause of death worldwide. Type I interferon (IFNα/β) signaling in the lung epithelial cells plays a major role in the innate immunity to respiratory viruses. Gene signatures are a set of differentially expressed genes in a particular disease or condition and are used to diagnose, monitor, and predict disease progression. These signatures can be used to identify regulatory modules and gene regulatory networks (GRNs) in mammalian signal transduction pathways. Considerable progress has been made in the identification of type I interferon-regulated gene signatures in the host response to respiratory viruses, including antiviral, immunomodulatory, apoptosis, and transcription factor signatures. Respiratory virus infections and host defenses require a dramatic change in the metabolic flux of macromolecules involved in nucleotide, lipid, and protein metabolism. The profiling of IFN-stimulated metabolic genes induced in the host response to several respiratory viruses led to the identification of a common gene signature in human lung epithelial cells and in the lungs of mouse models of respiratory virus infection. The regulation of the metabolic gene signature was correlated with the induction of IFN-beta (IFN-β) and IFN-inducible transcription factors at the RNA level in lung epithelial cells. Furthermore, the gene signature was also detected in response to bacterial lipopolysaccharide-induced acute lung injury. A protein interaction network analysis revealed that metabolic enzymes interact with IFN-regulated transcription factors and members of the unfolded protein response (UPR) to form a module and potentially regulate type I interferon signaling, constituting a feedback loop. In addition, components of the metabolic gene expression signature were differentially regulated in the lung tissues of COVID-19 patients compared with healthy controls. These results suggest that the metabolic gene signature is a potential therapeutic target for the treatment of respiratory virus infections and inflammatory diseases.

Deterministic nuclear reprogramming of mammalian nuclei to a totipotency-like state by Amphibian meiotic oocytes for stem cell therapy in humans.

The ultimate aim of nuclear reprogramming is to provide stem cells or differentiated cells from unrelated cell types as a cell source for regenerative medicine. A popular route towards this is transcription factor induction, and an alternative way is an original procedure of transplanting a single somatic cell nucleus to an unfertilized egg. A third route is to transplant hundreds of cell nuclei into the germinal vesicle (GV) of a non-dividing Amphibian meiotic oocyte, which leads to the activation of silent genes in 24 h and robustly induces a totipotency-like state in almost all transplanted cells. We apply this third route for potential therapeutic use and describe a procedure by which the differentiated states of cells can be reversed so that totipotency and pluripotency gene expression are regained. Differentiated cells are exposed to GV extracts and are reprogrammed to form embryoid bodies, which shows the maintenance of stemness and could be induced to follow new directions of differentiation. We conclude that much of the reprogramming effect of eggs is already present in meiotic oocytes and does not require cell division or selection of dividing cells. Reprogrammed cells by oocytes could serve as replacements for defective adult cells in humans.

Elucidation of the mechanism of elicitation of edible sprouts using UV-C radiation

The major aim of this study was to demonstrate the influence of UV-C radiation exposure of the edible sprouts on their redox status and the mechanism of production of selected phytochemicals in them. The study has shown that UV-C irradiation of broccoli sprouts and red cabbage for 5 min, and alfalfa for 15 min activates mechanisms involved in the antioxidant protection of the cell, resulting in an increase in the level of low-molecular antioxidants, i.e. polyphenols and glutathione. It was proven that sprouts irradiated with UV-C were characterised by higher MAPK expression, as well as higher level of ABA (ROS-dependent) which contributed to the induction of transcription factors (MYB) and consequently, to increased expression of proteins involved in antioxidants biosynthesis (PAL, CHS, γ-GCS, GS) and antioxidant enzymes (MnSOD, CAT). Moreover, UV-C increased mitochondrial activity, which was observed by higher concentration of ATP, as well as increased expression of SnRK1 protein.

Hypoxia-inducible factor induces cysteine dioxygenase and promotes cysteine homeostasis in Caenorhabditis elegans

Dedicated genetic pathways regulate cysteine homeostasis. For example, high levels of cysteine activate cysteine dioxygenase, a key enzyme in cysteine catabolism in most animal and many fungal species. The mechanism by which cysteine dioxygenase is regulated is largely unknown. In an unbiased genetic screen for mutations that activate cysteine dioxygenase (cdo-1) in the nematode Caenorhabditis elegans, we isolated loss-of-function mutations in rhy-1 and egl-9, which encode proteins that negatively regulate the stability or activity of the oxygen-sensing hypoxia inducible transcription factor (hif-1). EGL-9 and HIF-1 are core members of the conserved eukaryotic hypoxia response. However, we demonstrate that the mechanism of HIF-1-mediated induction of cdo-1 is largely independent of EGL-9 prolyl hydroxylase activity and the von Hippel-Lindau E3 ubiquitin ligase, the classical hypoxia signaling pathway components. We demonstrate that C. elegans cdo-1 is transcriptionally activated by high levels of cysteine and hif-1. hif-1-dependent activation of cdo-1 occurs downstream of an H2S-sensing pathway that includes rhy-1, cysl-1, and egl-9. cdo-1 transcription is primarily activated in the hypodermis where it is also sufficient to drive sulfur amino acid metabolism. Thus, the regulation of cdo-1 by hif-1 reveals a negative feedback loop that maintains cysteine homeostasis. High levels of cysteine stimulate the production of an H2S signal. H2S then acts through the rhy-1/cysl-1/egl-9 signaling pathway to increase HIF-1-mediated transcription of cdo-1, promoting degradation of cysteine via CDO-1.

Hypoxia-inducible factor induces cysteine dioxygenase and promotes cysteine homeostasis in Caenorhabditis elegans.

Dedicated genetic pathways regulate cysteine homeostasis. For example, high levels of cysteine activate cysteine dioxygenase, a key enzyme in cysteine catabolism in most animal and many fungal species. The mechanism by which cysteine dioxygenase is regulated is largely unknown. In an unbiased genetic screen for mutations that activate cysteine dioxygenase (cdo-1) in the nematode Caenorhabditis elegans, we isolated loss-of-function mutations in rhy-1 and egl-9, which encode proteins that negatively regulate the stability or activity of the oxygen-sensing hypoxia inducible transcription factor (hif-1). EGL-9 and HIF-1 are core members of the conserved eukaryotic hypoxia response. However, we demonstrate that the mechanism of HIF-1-mediated induction of cdo-1 is largely independent of EGL-9 prolyl hydroxylase activity and the von Hippel-Lindau E3 ubiquitin ligase, the classical hypoxia signaling pathway components. We demonstrate that C. elegans cdo-1 is transcriptionally activated by high levels of cysteine and hif-1. hif-1-dependent activation of cdo-1 occurs downstream of an H2S-sensing pathway that includes rhy-1, cysl-1, and egl-9. cdo-1 transcription is primarily activated in the hypodermis where it is also sufficient to drive sulfur amino acid metabolism. Thus, the regulation of cdo-1 by hif-1 reveals a negative feedback loop that maintains cysteine homeostasis. High levels of cysteine stimulate the production of an H2S signal. H2S then acts through the rhy-1/cysl-1/egl-9 signaling pathway to increase HIF-1-mediated transcription of cdo-1, promoting degradation of cysteine via CDO-1.

Establishment of African pygmy mouse induced pluripotent stem cells using defined doxycycline inducible transcription factors

Mus minutoides is one of the smallest mammals worldwide; however, the regulatory mechanisms underlying its dwarfism have not been examined. Therefore, we aimed to establish M. minutoides induced pluripotent stem cells (iPSCs) using the PiggyBac transposon system for applications in developmental engineering. The established M. minutoides iPSCs were found to express pluripotency markers and could differentiate into neurons. Based on in vitro differentiation analysis, M. minutoides iPSCs formed embryoid bodies expressing marker genes in all three germ layers. Moreover, according to the in vivo analysis, these cells contributed to the formation of teratoma and development of chimeric mice with Mus musculus. Overall, the M. minutoides iPSCs generated in this study possess properties that are comparable to or closely resemble those of naïve pluripotent stem cells (PSCs). These findings suggest these iPSCs have potential utility in various analytical applications, including methods for blastocyst completion.

Glutamine transporter SLC38A3 promotes breast cancer metastasis via Gsk3β/β-catenin/EMT pathway

Breast cancer is the leading cancer-related cause of death in women. Here we show that solute carrier family 38-member 3 (SLC38A3) is overexpressed in breast cancer, particularly in triple-negative breast cancer (TNBC) cells and tissues. Our study reveals that SLC38A3 regulates cellular glutamine, glutamate, asparagine, aspartate, alanine, and glutathione (GSH) levels in breast cancer cells. Our data demonstrate that SLC38A3 enhances cell viability, cell migration and invasion in vitro, and promotes tumor growth and metastasis in vivo, while reducing apoptosis and oxidative stress. Mechanistically, we show that SLC38A3 suppresses the activity of glycogen synthase kinase 3-β (Gsk3β), a negative regulator of β-catenin, and increases protein levels of β-catenin, leading to the upregulation of epithelial-to-mesenchymal-transition (EMT)-inducing transcription factors and EMT markers in breast cancer. In summary, we show that SLC38A3 is overexpressed in breast cancer and promotes breast cancer metastasis via the GSK3β/β-catenin/EMT pathway, presenting a novel therapeutic target to explore for breast cancer.

ΔFosB is part of a homeostatic mechanism that protects the epileptic brain from further deterioration.

Activity induced transcription factor ΔFosB plays a key role in different CNS disorders including epilepsy, Alzheimer's disease, and addiction. Recent findings suggest that ΔFosB drives cognitive deficits in epilepsy and together with the emergence of small molecule inhibitors of ΔFosB activity makes it an interesting therapeutic target. However, whether ΔFosB contributes to pathophysiology or provides protection in drug-resistant epilepsy is still unclear. In this study, ΔFosB was specifically downregulated by delivering AAV-shRNA into the hippocampus of chronically epileptic mice using the drug-resistant pilocarpine model of mesial temporal epilepsy (mTLE). Immunohistochemistry analyses showed that prolonged downregulation of ΔFosB led to exacerbation of neuroinflammatory markers of astrogliosis and microgliosis, loss of mossy fibers, and hippocampal granule cell dispersion. Furthermore, prolonged inhibition of ΔFosB using a ΔJunD construct to block ΔFosB signaling in a mouse model of Alzheimer's disease, that exhibits spontaneous recurrent seizures, led to similar findings, with increased neuroinflammation and decreased NPY expression in mossy fibers. Together, these data suggest that seizure-induced ΔFosB, regardless of seizure-etiology, is part of a homeostatic mechanism that protects the epileptic brain from further deterioration.

Activation of neutrophils excels the therapeutic potential of Mycobacterium indicus pranii and heat-induced promastigotes against antimony-resistant Leishmania donovani infection.

Repurposing drugs and adjuvants is an attractive choice of present therapy that reduces the substantial costs, chances of failure, and systemic toxicity. Mycobacterium indicus pranii was originally developed as a leprosy vaccine but later has been found effective against Leishmania donovani infection. To extend our earlier study, here we reported the immunotherapeutic modulation of the splenic and circulatory neutrophils in favour of hosts as neutrophils actually serve as the pro-parasitic portable shelter to extend the Leishmania infection specifically during the early entry into the hosts' circulation. We targeted to disrupt this early pro-parasitic incidence by the therapeutic combination of M. indicus pranii and heat-induced promastigotes against antimony-resistant L. donovani infection. The combination therapy induced the functional expansion of CD11b+Ly6CintLy6Ghi neutrophils both in the post-infected spleen, and also in the circulation of post-treated animals followed by the immediate Leishmania infection. More importantly, the enhanced expression of MHC-II, phagocytic uptake of the parasites by the circulatory neutrophils as well as the oxidative burst were induced that limited the chances of the very early establishment of the infection. The enhanced expression of pro-inflammatory cytokines, like IL-1α and TNF-α indicated resistance to the parasite-mediated takeover of the neutrophils, as these cytokines are critical for the activation of T cell-mediated immunity and host-protective responses. Additionally, the induction of essential transcription factors and cytokines for early granulocytic lineage commitment suggests that the strategy not only contributed to the peripheral activation of the neutrophils but also promoted granulopoiesis in the bone marrow.

Resistin Pathway as Novel Mechanism of Post-lung Transplantation Bronchial Stenosis.

Bronchial stenosis remains a significant source of morbidity among lung transplant recipients. Though infection and anastomotic ischemia have been proposed etiologies of the development of bronchial stenosis, the pathophysiologic mechanism has not been well elucidated. In this single-centered prospective study, from January 2013 through September 2015, we prospectively collected bronchoalveolar lavage (BAL) and endobronchial epithelial brushings from the direct anastomotic site of bronchial stenosis of bilateral lung transplant recipients who developed unilateral post-transplant bronchial stenosis. Endobronchial epithelial brushings from the contralateral anastomotic site without bronchial stenosis and BAL from bilateral lung transplant recipients who did not develop post-transplant bronchial stenosis were used as controls. Total RNA was isolated from the endobronchial brushings and real-time polymerase chain reaction reactions were performed. Electrochemiluminescence biomarker assay was used to measure 10 cytokines from the BAL. Out of 60 bilateral lung transplant recipients, 9 were found to have developed bronchial stenosis with 17 samples adequate for analysis. We observed a 1.56 to 70.8 mean-fold increase in human resistin gene expression in the anastomotic bronchial stenosis epithelial cells compared with nonstenotic airways. Furthermore, IL-1β (21.76±10.96pg/mL; control 0.86±0.44pg/mL; P <0.01) and IL-8 levels (990.56±326.60pg/mL; control 20.33±1.17pg/mL; P <0.01) were significantly elevated in the BAL of the lung transplant patients who developed anastomotic bronchial stenosis. Our data suggest that the development of postlung transplantation bronchial stenosis may be in part mediated through the human resistin pathway by IL-1β induced transcription factor nuclear factor-κβ activation and downstream upregulation of IL-8 in alveolar macrophages. Further study is needed in the larger patient cohorts and to determine its potential therapeutic role in the management of post-transplant bronchial stenosis.