Essential roles of the nucleolus during early embryonic development: a regulatory hub for chromatin organization.

The nucleolus is the most prominent liquid droplet-like membrane-less organelle in mammalian cells. Unlike the nucleolus in terminally differentiated somatic cells, those in totipotent cells, such as murine zygotes or two-cell embryos, have a unique nucleolar structure known as nucleolus precursor bodies (NPBs). Previously, it was widely accepted that NPBs in zygotes are simply passive repositories of materials that will be gradually used to construct a fully functional nucleolus after zygotic genome activation (ZGA). However, recent research studies have challenged this simplistic view and demonstrated that functions of the NPBs go beyond ribosome biogenesis. In this review, we provide a snapshot of the functions of NPBs in zygotes and early two-cell embryos in mice. We propose that these membrane-less organelles function as a regulatory hub for chromatin organization. On the one hand, NPBs provide the structural platform for centric and pericentric chromatin remodelling. On the other hand, the dynamic changes in nucleolar structure control the release of the pioneer factors (i.e. double homeobox (Dux)). It appears that during transition from totipotency to pluripotency, decline of totipotency and initiation of fully functional nucleolus formation are not independent events but are interconnected. Consequently, it is reasonable to hypothesize that dissecting more unknown functions of NPBs may shed more light on the enigmas of early embryonic development and may ultimately provide novel approaches to improve reprogramming efficiency.

Aggregation-enhanced photothermal therapy of organic dyes.

Photothermal therapy (PTT) represents a groundbreaking approach to targeted disease treatment by harnessing the conversion of light into heat. The efficacy of PTT heavily relies on the capabilities of photothermal agents (PTAs). Among PTAs, those based on organic dyes exhibit notable characteristics such as adjustable light absorption wavelengths, high extinction coefficients, and high compatibility in biological systems. However, a challenge associated with organic dye-based PTAs lies in their efficiency in converting light into heat while maintaining stability. Manipulating dye aggregation is a key aspect in modulating non-radiative decay pathways, aiming to augment heat generation. This review delves into various strategies aimed at improving photothermal performance through constructing aggregation. These strategies including protecting dyes from photodegradation, inhibiting non-photothermal pathways, maintaining space within molecular aggregates, and introducing intermolecular photophysical processes. Overall, this review highlights the precision-driven assembly of organic dyes as a promising frontier in enhancing PTT-related applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

NRDE2 deficiency impairs homologous recombination repair and sensitizes hepatocellular carcinoma to PARP inhibitors.

To identify novel susceptibility genes for hepatocellular carcinoma (HCC), we performed a rare-variant association study in Chinese populations consisting of 2,750 cases and 4,153 controls. We identified four HCC-associated genes, including NRDE2, RANBP17, RTEL1, and STEAP3. Using NRDE2 (index rs199890497 [p.N377I], p = 1.19 × 10-9) as an exemplary candidate, we demonstrated that it promotes homologous recombination (HR) repair and suppresses HCC. Mechanistically, NRDE2 binds to the subunits of casein kinase 2 (CK2) and facilitates the assembly and activity of the CK2 holoenzyme. This NRDE2-mediated enhancement of CK2 activity increases the phosphorylation of MDC1 and then facilitates the HR repair. These functions are eliminated almost completely by the NRDE2-p.N377I variant, which sensitizes the HCC cells to poly(ADP-ribose) polymerase (PARP) inhibitors, especially when combined with chemotherapy. Collectively, our findings highlight the relevance of the rare variants to genetic susceptibility to HCC, which would be helpful for the precise treatment of this malignancy.

Small-molecule-induced epigenetic rejuvenation promotes SREBP condensation and overcomes barriers to CNS myelin regeneration.

Remyelination failure in diseases like multiple sclerosis (MS) was thought to involve suppressed maturation of oligodendrocyte precursors; however, oligodendrocytes are present in MS lesions yet lack myelin production. We found that oligodendrocytes in the lesions are epigenetically silenced. Developing a transgenic reporter labeling differentiated oligodendrocytes for phenotypic screening, we identified a small-molecule epigenetic-silencing-inhibitor (ESI1) that enhances myelin production and ensheathment. ESI1 promotes remyelination in animal models of demyelination and enables de novo myelinogenesis on regenerated CNS axons. ESI1 treatment lengthened myelin sheaths in human iPSC-derived organoids and augmented (re)myelination in aged mice while reversing age-related cognitive decline. Multi-omics revealed that ESI1 induces an active chromatin landscape that activates myelinogenic pathways and reprograms metabolism. Notably, ESI1 triggered nuclear condensate formation of master lipid-metabolic regulators SREBP1/2, concentrating transcriptional co-activators to drive lipid/cholesterol biosynthesis. Our study highlights the potential of targeting epigenetic silencing to enable CNS myelin regeneration in demyelinating diseases and aging.

Adipose tissue-selective ablation of ADAM10 results in divergent metabolic phenotypes following long-term dietary manipulation.

A Disintegrin And Metalloproteinase domain-containing protein 10 (ADAM10), is involved in several metabolic and inflammatory pathways. We speculated that ADAM10 plays a modulatory role in adipose tissue inflammation and metabolism. To this end, we studied adipose tissue-specific ADAM10 knock-out mice (aKO). While young, regular chow diet-fed aKO mice showed increased insulin sensitivity, following prolonged (33 weeks) high-fat diet (HFD) exposure, aKO mice developed obesity and insulin resistance. Compared to controls, aKO mice showed less inflammatory adipokine profile despite the significant increase in adiposity. In brown adipose tissue, aKO mice on HFD had changes in CD8+ T cell populations indicating a lesser inflammatory pattern. Following HFD, both aKO and control littermates demonstrated decreased adipose tissue pro-inflammatory macrophages, and increased anti-inflammatory accumulation, without differences between the genotypes. Collectively, our observations indicate that selective deletion of ADAM10 in adipocytes results in a mitigated inflammatory response, leading to increased insulin sensitivity in young mice fed with regular diet. This state of insulin sensitivity, following prolonged HFD, facilitates energy storage resulting in increased fat accumulation which ultimately leads to the development of a phenotype of obesity and insulin resistance. In conclusion, the data indicate that ADAM10 has a modulatory effect of inflammation and whole-body energy metabolism.

Netrin-1 Promotes M2 Type Activation and Inhibits Pyroptosis of Microglial Cells by Depressing RAC1/Nf-?B Pathway to Alleviate Inflammatory Pain.

Netrin-1 (NTN-1) plays a vital role in the progress of nervous system development and inflammatory diseases. However, the role and underlying mechanism of NTN-1 in inflammatory pain (IP) are unclear. BV2 microglia were treated with LPS to mimic the cell status under IP. Adeno-associated virus carrying the NTN-1 gene (AAV-NTN-1) was used to overexpress NTN-1. Complete Freund's Adjuvant (CFA)-induced mouse was recruited as an in vivo model. MTT and commercial kits were utilized to evaluate cell viability and cell death of BV2 cells. The mRNA expressions and secretions of cytokines were measured using the ELISA method. Also, the pyroptosis and activation of BV2 cells were investigated based on western blotting. To verify the role of Rac1/NF-kappaB signaling, isochamaejasmin (ISO) and AAV-Rac1 were presented. The results showed that NTN-1 expression was decreased in LPS-treated BV2 microglia and spinal cord tissues of CFA-injected mice. Overexpressing NTN-1 dramatically reversed cell viability and decreased cell death rate of BV2 microglia under lipopolysaccharide (LPS) stimulation, while the level of pyroptosis was inhibited. Besides, AAV-NTN-1 rescued the activation of microglia and inflammatory injury induced by LPS, decreasing IBA-1 expression, as well as iNOS, IL-1beta and IL-6 secretions. Meanwhile AAV-NTN-1 promoted the anti-inflammation response, including increases in Arg-1, IL-4 and IL-10 levels. In addition, the LPS-induced activation of Rac1/NF-kappaB signaling was depressed by NTN-1 overexpression. The same results were verified in a CFA-induced mouse model. In conclusion, NTN-1 alleviated IP by suppressing pyroptosis and promoting M2 type activation of microglia via inhibiting Rac1/NF-?B signaling, suggesting the protective role of NTN-1 in IP. Keywords: Netrin-1, Inflammatory pain, Pyroptosis, Microglia M2 activation, Rac1/NF-kappaB.

PINK1/Park2-Mediated Mitophagy Relieve Non-Alcoholic Fatty Liver Disease.

Up to now, there's a limited number of studies on the relationship between PINK1/Park2 pathway and mitophagy in NAFLD. To investigate the effect of Park2-mediated mitophagy on non-alcoholic fatty liver disease (NAFLD). Oleic acid was used for the establishment of NAFLD model. Oil red-dyed lipid drops and mitochondrial alternations were observed by transmission electron microscopy. Enzymatic kit was used to test lipid content. The levels of IL-8 and TNF-alpha were determined by ELISA. Lenti-Park2 and Park2-siRNA were designed to upregulate and downregulate Park2 expression, respectively. The changing expression of PINK and Park2 was detected by RT-qPCR and Western blot. Immunofluorescence staining was applied to measure the amount of LC3. Successful NAFLD modeling was featured by enhanced lipid accumulation, as well as the elevated total cholesterol (TC), triglyceride (TG), TNF-alpha and IL-8 levels. Mitochondria in NAFLD model were morphologically and functionally damaged. Park2 expression was upregulated by lenti-Park2 and downregulated through Park2-siRNA. The PINK1 expression showed the same trend as Park2 expression. Immunofluorescence staining demonstrated that the when Park2 was overexpressed, more LC3 protein on mitochondrial autophagosome membrane was detected, whereas Park2 knockdown impeded LC3' locating on the membrane. The transmission electron microscopy image exhibited that the extent of damage to the mitochondrial in NAFLD model was revered by enhanced Park2 expression but further exacerbated by reduced Park2 expression. Park2-mediated mitophagy could relive NAFLD and may be a novel therapeutic target for NAFLD treatment. Keywords: Non-alcoholic Fatty Liver Disease (NAFLD), Mitophagy, PINK1/Park2, Park2, PINK1.

Endurance Training Inhibits the JAK2/STAT3 Pathway to Alleviate Sarcopenia.

Aging leads to a decrease in muscle function, mass, and strength in skeletal muscle of animals and humans. The transcriptome identified activation of the JAK/STAT pathway, a pathway that is associated with skeletal muscle atrophy, and endurance training has a significant effect on improving sarcopenia; however, the exact mechanism still requires further study. We investigated the effect of endurance training on sarcopenia. Six-month-old male SAMR1 mice were used as a young control group (group C), and the same month-old male SAMP8 mice were divided into an exercise group (group E) and a model group (group M). A 3-month running exercise intervention was performed on group E, and the other two groups were kept normally. Aging caused significant signs of sarcopenia in the SAMP8 mice, and endurance training effectively improved muscle function, muscle mass, and muscle strength in the SAMP8 mice. The expression of JAK2/STAT3 pathway factor was decreased in group E compared with group M, and the expression of SOCS3, the target gene of STAT3, and NR1D1, an atrophy-related factor, was significantly increased. Endurance training significantly improved the phenotypes associated with sarcopenia, and the JAK2/STAT3 pathway is a possible mechanism for the improvement of sarcopenia by endurance training, while NR1D1 may be its potential target. Keywords: Sarcopenia, Endurance training, Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3), Nuclear receptor subfamily 1, group D member 1 (Nr1d1).

Establishment of Induced Pancreatic Stem Cells by Yes-Associated Protein 1.

Recently, we and others generated induced tissue-specific stem/progenitor (iTS/iTP) cells. The advantages of iTS/iTP cells compared with induced pluripotent stem (iPS) cells are (1) easier generation, (2) efficient differentiation, and (3) no teratomas formation. In this study, we generated mouse induced pancreatic stem cells (iTS-P cells) by the plasmid vector expressing Yes-associated protein 1 (YAP). The iTS-P YAP9 cells expressed Foxa2 (endoderm marker) and Pdx1 (pancreatic marker) while the expressions of Oct3/4 and Nanog (marker of embryonic stem [ES] cells) in iTS-P YAP9 cells was significantly lower compared with those in ES cells. The iTS-P YAP9 cells efficiently differentiated into insulin-expressing cells compared with ES cells. The ability to generate autologous iTS cells may be applied to diverse applications of regenerative medicine.

B cells in the pneumococcus-infected lung are heterogeneous and require CD4+ T cell help including CD40L to become resident memory B cells.

Recovery from respiratory pneumococcal infections generates lung-localized protection against heterotypic bacteria, mediated by resident memory lymphocytes. Optimal protection in mice requires re-exposure to pneumococcus within days of initial infection. Serial surface marker phenotyping of B cell populations in a model of pneumococcal heterotypic immunity revealed that bacterial re-exposure stimulates the immediate accumulation of dynamic and heterogeneous populations of B cells in the lung, and is essential for the establishment of lung resident memory B (BRM) cells. The B cells in the early wave were activated, proliferating locally, and associated with both CD4+ T cells and CXCL13. Antagonist- and antibody-mediated interventions were implemented during this early timeframe to demonstrate that lymphocyte recirculation, CD4+ cells, and CD40 ligand (CD40L) signaling were all needed for lung BRM cell establishment, whereas CXCL13 signaling was not. While most prominent as aggregates in the loose connective tissue of bronchovascular bundles, morphometry and live lung imaging analyses showed that lung BRM cells were equally numerous as single cells dispersed throughout the alveolar septae. We propose that CD40L signaling from antigen-stimulated CD4+ T cells in the infected lung is critical to establishment of local BRM cells, which subsequently protect the airways and parenchyma against future potential infections.

The IMPDH cytoophidium couples metabolism and fetal development in mice.

The cytoophidium is an evolutionarily conserved subcellular structure formed by filamentous polymers of metabolic enzymes. In vertebrates, inosine monophosphate dehydrogenase (IMPDH), which catalyses the rate-limiting step in guanosine triphosphate (GTP) biosynthesis, is one of the best-known cytoophidium-forming enzymes. Formation of the cytoophidium has been proposed to alleviate the inhibition of IMPDH, thereby facilitating GTP production to support the rapid proliferation of certain cell types such as lymphocytes, cancer cells and pluripotent stem cells (PSCs). However, past studies lacked appropriate models to elucidate the significance of IMPDH cytoophidium under normal physiological conditions. In this study, we demonstrate that the presence of IMPDH cytoophidium in mouse PSCs correlates with their metabolic status rather than pluripotency. By introducing IMPDH2 Y12C point mutation through genome editing, we established mouse embryonic stem cell (ESC) lines incapable of forming IMPDH polymers and the cytoophidium. Our data indicate an important role of IMPDH cytoophidium in sustaining a positive feedback loop that couples nucleotide biosynthesis with upstream metabolic pathways. Additionally, we find that IMPDH2 Y12C mutation leads to decreased cell proliferation and increased DNA damage in teratomas, as well as impaired embryo development following blastocoel injection. Further analysis shows that IMPDH cytoophidium assembly in mouse embryonic development begins after implantation and gradually increases throughout fetal development. These findings provide insights into the regulation of IMPDH polymerisation in embryogenesis and its significance in coordinating cell metabolism and development.

LAMP2A regulates cisplatin resistance in colorectal cancer through mediating autophagy.

BACKGROUND: Drug resistance is an important constraint on clinical outcomes in advanced cancers. LAMP2A is a limiting protein in molecular chaperone-mediated autophagy. This study was aimed to explore LAMP2A function in cisplatin (cis-diamminedichloroplatinum, DDP) resistance colorectal cancer (CRC) to seek new ideas for CRC clinical treatment. METHODS: In this study, LAMP2A expression was analyzed by molecular experimental techniques,such as qRT-PCR and western blot. Then, LAMP2A in cells was interfered by cell transfection experiments. Subsequently, the function of LAMP2A on proliferation, migration, invasion, DDP sensitivity, and autophagy of CRC/DDP cells were further investigated by a series of experiments, such as CCK-8, transwell, and western blot. RESULTS: We revealed that LAMP2A was clearly augmented in DDP-resistant CRC and was related to poor patient prognosis. Functionally, LAMP2A insertion remarkably CRC/DDP proliferation, migration, invasion ability and DDP resistance by strengthen autophagy. In contrast, LAMP2A knockdown limited the proliferation, migration, and invasion while heightened cellular sensitivity to DDP by restraining autophagy in CRC/DDP cells. Furthermore, LAMP2A silencing was able to curb tumor formation and enhance sensitivity to DDP in vivo. CONCLUSION: In summary, LAMP2A boosted malignant progression and DDP resistance in CRC/DDP cells through mediating autophagy. Clarifying LAMP2A function in DDP resistance is promising to seek cancer therapies biomarkers targeting LAMP2A activity.

Bacteroidota inhibit microglia clearance of amyloid-beta and promote plaque deposition in Alzheimer's disease mouse models.

The gut microbiota and microglia play critical roles in Alzheimer's disease (AD), and elevated Bacteroides is correlated with cerebrospinal fluid amyloid-ß (Aß) and tau levels in AD. We hypothesize that Bacteroides contributes to AD by modulating microglia. Here we show that administering Bacteroides fragilis to APP/PS1-21 mice increases Aß plaques in females, modulates cortical amyloid processing gene expression, and down regulates phagocytosis and protein degradation microglial gene expression. We further show that administering Bacteroides fragilis to aged wild-type male and female mice suppresses microglial uptake of Aß1-42 injected into the hippocampus. Depleting murine Bacteroidota with metronidazole decreases amyloid load in aged 5xFAD mice, and activates microglial pathways related to phagocytosis, cytokine signaling, and lysosomal degradation. Taken together, our study demonstrates that members of the Bacteroidota phylum contribute to AD pathogenesis by suppressing microglia phagocytic function, which leads to impaired Aß clearance and accumulation of amyloid plaques.

Targeting EMT using low-dose Teniposide by downregulating ZEB2-driven activation of RNA polymerase I in breast cancer.

Metastatic dissemination from the primary tumor is a complex process that requires crosstalk between tumor cells and the surrounding milieu and involves the interplay between numerous cellular-signaling programs. Epithelial-mesenchymal transition (EMT) remains at the forefront of orchestrating a shift in numerous cellular programs, such as stemness, drug resistance, and apoptosis that allow for successful metastasis. Till date, there is limited success in therapeutically targeting EMT. Utilizing a high throughput screen of FDA-approved compounds, we uncovered a novel role of the topoisomerase inhibitor, Teniposide, in reversing EMT. Here, we demonstrate Teniposide as a potent modulator of the EMT program, specifically through an IRF7-NMI mediated response. Furthermore, Teniposide significantly reduces the expression of the key EMT transcriptional regulator, Zinc Finger E-Box Binding Homeobox 2 (ZEB2). ZEB2 downregulation by Teniposide inhibited RNA polymerase I (Pol I) activity and rRNA biogenesis. Importantly, Teniposide treatment markedly reduced pulmonary colonization of breast cancer cells. We have uncovered a novel role of Teniposide, which when used at a very low concentration, mitigates mesenchymal-like invasive phenotype. Overall, its ability to target EMT and rRNA biogenesis makes Teniposide a viable candidate to be repurposed as a therapeutic option to restrict breast cancer metastases.

MeCP2 binds to methylated DNA independently of phase separation and heterochromatin organisation.

Correlative evidence has suggested that the methyl-CpG-binding protein MeCP2 contributes to the formation of heterochromatin condensates via liquid-liquid phase separation. This interpretation has been reinforced by the observation that heterochromatin, DNA methylation and MeCP2 co-localise within prominent foci in mouse cells. The findings presented here revise this view. MeCP2 localisation is independent of heterochromatin as MeCP2 foci persist even when heterochromatin organisation is disrupted. Additionally, MeCP2 foci fail to show hallmarks of phase separation in live cells. Importantly, we find that mouse cellular models are highly atypical as MeCP2 distribution is diffuse in most mammalian species, including humans. Notably, MeCP2 foci are absent in Mus spretus which is a mouse subspecies lacking methylated satellite DNA repeats. We conclude that MeCP2 has no intrinsic tendency to form condensates and its localisation is independent of heterochromatin. Instead, the distribution of MeCP2 in the nucleus is primarily determined by global DNA methylation patterns.

Spontaneous persistent activity and inactivity in vivo reveals differential cortico-entorhinal functional connectivity.

Understanding the functional connectivity between brain regions and its emergent dynamics is a central challenge. Here we present a theory-experiment hybrid approach involving iteration between a minimal computational model and in vivo electrophysiological measurements. Our model not only predicted spontaneous persistent activity (SPA) during Up-Down-State oscillations, but also inactivity (SPI), which has never been reported. These were confirmed in vivo in the membrane potential of neurons, especially from layer 3 of the medial and lateral entorhinal cortices. The data was then used to constrain two free parameters, yielding a unique, experimentally determined model for each neuron. Analytic and computational analysis of the model generated a dozen quantitative predictions about network dynamics, which were all confirmed in vivo to high accuracy. Our technique predicted functional connectivity; e. g. the recurrent excitation is stronger in the medial than lateral entorhinal cortex. This too was confirmed with connectomics data. This technique uncovers how differential cortico-entorhinal dialogue generates SPA and SPI, which could form an energetically efficient working-memory substrate and influence the consolidation of memories during sleep. More broadly, our procedure can reveal the functional connectivity of large networks and a theory of their emergent dynamics.

Phenformin activates ER stress to promote autophagic cell death via NIBAN1 and DDIT4 in oral squamous cell carcinoma independent of AMPK.

The efficient clinical treatment of oral squamous cell carcinoma (OSCC) is still a challenge that demands the development of effective new drugs. Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors, however, not much is known about the influence of phenformin on OSCC cells. We found that phenformin suppresses OSCC cell proliferation, and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro. RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4 (DNA damage inducible transcript 4) and NIBAN1 (niban apoptosis regulator 1). We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy. Further, the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4 (activation transcription factor 4), which was induced by phenformin treatment in OSCC cells. Mechanistically, these results revealed that phenformin triggers endoplasmic reticulum (ER) stress to activate PERK (protein kinase R-like ER kinase), which phosphorylates the transitional initial factor eIF2, and the increased phosphorylation of eIF2 leads to the increased translation of ATF4. In summary, we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth. Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.

Hyperthyroidism-driven bone loss depends on BMP receptor Bmpr1a expression in osteoblasts.

Hyperthyroidism is a well-known trigger of high bone turnover that can lead to the development of secondary osteoporosis. Previously, we have shown that blocking bone morphogenetic protein (BMP) signaling systemically with BMPR1A-Fc can prevent bone loss in hyperthyroid mice. To distinguish between bone cell type-specific effects, conditional knockout mice lacking Bmpr1a in either osteoclast precursors (LysM-Cre) or osteoprogenitors (Osx-Cre) were rendered hyperthyroid and their bone microarchitecture, strength and turnover were analyzed. While hyperthyroidism in osteoclast precursor-specific Bmpr1a knockout mice accelerated bone resorption leading to bone loss just as in wildtype mice, osteoprogenitor-specific Bmpr1a deletion prevented an increase of bone resorption and thus osteoporosis with hyperthyroidism. In vitro, wildtype but not Bmpr1a-deficient osteoblasts responded to thyroid hormone (TH) treatment with increased differentiation and activity. Furthermore, we found an elevated Rankl/Opg ratio with TH excess in osteoblasts and bone tissue from wildtype mice, but not in Bmpr1a knockouts. In line, expression of osteoclast marker genes increased when osteoclasts were treated with supernatants from TH-stimulated wildtype osteoblasts, in contrast to Bmpr1a-deficient cells. In conclusion, we identified the osteoblastic BMP receptor BMPR1A as a main driver of osteoporosis in hyperthyroid mice promoting TH-induced osteoblast activity and potentially its coupling to high osteoclastic resorption.

Identification of master regulator genes controlling pathogenic CD4+ T cell fate in inflammatory bowel disease through transcriptional network analysis.

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including dysregulation of the immune response. Effector CD4+ T cells and regulatory CD4+ T cells (Treg) are central players in maintaining the balance between tolerance and inflammation. Interestingly, genetic modifications in these cells have been implicated in regulating the commitment of specific phenotypes and immune functions. However, the transcriptional program controlling the pathogenic behavior of T helper cells in IBD progression is still unknown. In this study, we aimed to find master transcription regulators controlling the pathogenic behavior of effector CD4+ T cells upon gut inflammation. To achieve this goal, we used an animal model of IBD induced by the transfer of naïve CD4+ T cells into recombination-activating gene 1 (Rag1) deficient mice, which are devoid of lymphocytes. As a control, a group of Rag1-/- mice received the transfer of the whole CD4+ T cells population, which includes both effector T cells and Treg. When gut inflammation progressed, we isolated CD4+ T cells from the colonic lamina propria and spleen tissue, and performed bulk RNA-seq. We identified differentially up- and down-regulated genes by comparing samples from both experimental groups. We found 532 differentially expressed genes (DEGs) in the colon and 30 DEGs in the spleen, mostly related to Th1 response, leukocyte migration, and response to cytokines in lamina propria T-cells. We integrated these data into Gene Regulatory Networks to identify Master Regulators, identifying four up-regulated master gene regulators (Lef1, Dnmt1, Mybl2, and Jup) and only one down-regulated master regulator (Foxo3). The altered expression of master regulators observed in the transcriptomic analysis was confirmed by qRT-PCR analysis and found an up-regulation of Lef1 and Mybl2, but without differences on Dnmt1, Jup, and Foxo3. These two master regulators have been involved in T cells function and cell cycle progression, respectively. We identified two master regulator genes associated with the pathogenic behavior of effector CD4+ T cells in an animal model of IBD. These findings provide two new potential molecular targets for treating IBD.

Periodic heat waves-induced neuronal etiology in the elderly is mediated by gut-liver-brain axis: a transcriptome profiling approach.

Heat stress exposure in intermittent heat waves and subsequent exposure during war theaters pose a clinical challenge that can lead to multi-organ dysfunction and long-term complications in the elderly. Using an aged mouse model and high-throughput sequencing, this study investigated the molecular dynamics of the liver-brain connection during heat stress exposure. Distinctive gene expression patterns induced by periodic heat stress emerged in both brain and liver tissues. An altered transcriptome profile showed heat stress-induced altered acute phase response pathways, causing neural, hepatic, and systemic inflammation and impaired synaptic plasticity. Results also demonstrated that proinflammatory molecules such as S100B, IL-17, IL-33, and neurological disease signaling pathways were upregulated, while protective pathways like aryl hydrocarbon receptor signaling were downregulated. In parallel, Rantes, IRF7, NOD1/2, TREM1, and hepatic injury signaling pathways were upregulated. Furthermore, current research identified Orosomucoid 2 (ORM2) in the liver as one of the mediators of the liver-brain axis due to heat exposure. In conclusion, the transcriptome profiling in elderly heat-stressed mice revealed a coordinated network of liver-brain axis pathways with increased hepatic ORM2 secretion, possibly due to gut inflammation and dysbiosis. The above secretion of ORM2 may impact the brain through a leaky blood-brain barrier, thus emphasizing intricate multi-organ crosstalk.