Modulation Of Signaling Research Articles

Branching out: nitrogen-dependent modulation of strigolactone signalling.

Branching out: nitrogen-dependent modulation of strigolactone signalling.

Abstract 4132120: Down syndrome-trisomy-mediated gene, Dscr-1, protects against lifestyle-related vascular diseases

Epidemiological studies indicate that individuals with Down syndrome (DS) have an increased risk of leukemia and neuronal diseases but a significantly reduced incidence of most solid tumors and advanced vascular dysfunction. This suggests that one or a combination of trisomy genes on human chromosome 21 (HSA21) or murine chromosome 16 ( Mmu16 ) may be responsible for protecting against vasculopathy. Our previous research has shown that the Down syndrome critical region (Dscr)-1 gene, located on HSA21 or Mmu16 , encodes a feedback modulator of calcineurin-NFAT signaling in endothelial cells (ECs). Null mutation or overexpression of Dscr-1 has been found to increase or prevent septic mortality, angiogenesis, liver steatosis, and susceptibility of tumor metastasizing to the lung, respectively, demonstrating its significant role in these processes. In a unique approach, we crossed DS model mice with ApoE -null mice and fed them a high-fat diet (HFD) for 12 weeks to survey the effects of DS-related genes on atherosclerosis. The results were striking, with HFD-mediated increased LDL and triglyceride levels in ApoE -null mice significantly reduced in the combined DS plus ApoE -null mice. This innovative method allowed us to observe a remarkable (~35%) reduction in ApoE-null mediated atheroma formation in the DS model. This finding was also replicated in EC-specific DSCR-1 transgenic (DSCR-1 ECTg ) mice. Furthermore, to test the effect of HSA21, we have collected DS patient-derived trisomy and disomy iPS cells and executed them for the chromatin conformation capture analysis and the in vitro ECs differentiation experiments. DS-derived trisomy iPS cells already changed the whole chromatin structure, typically within the X chromosome. Moreover, the trisomy iPS-derived ECs revealed less proliferation compared to the disomy. RNA-seqs indicated trisomy iPS derived ECs dramatically (21-fold) increased DSCR-1 , but some HSA21 genes, Alzheimer’s related App and Bace2 , e.g., were inversely reduced the expression. Our comprehensive studies not only shed new light on the mechanisms of atherosclerosis in vascular pathology but also offer potential therapeutic strategies. The discovery of the Dscr-1 gene on the DS chromosome, which could be a powerful tool in combating lifestyle-related vascular diseases, underscores the significance of our research.

Structures of complete extracellular assemblies of type I and type II Oncostatin M receptor complexes.

Oncostatin M (OSM) is a unique Interleukin 6 (IL-6) family cytokine that plays pivotal roles in numerous biological events by signaling via two types of receptor complexes. While type I OSM receptor complex is formed by glycoprotein 130 (gp130) heterodimerization with Leukemia Inhibitory Factor receptor (LIFR), type II OSM receptor complex is composed of gp130 and OSM receptor (OSMR). OSM is an important contributor to multiple inflammatory diseases and cancers while OSM inhibition has been shown to be effective at reducing symptoms, making OSM an attractive therapeutic target. Using cryogenic electron microscopy (cryo-EM), we characterize full extracellular assemblies of human type I OSM receptor complex and mouse type II OSM receptor complex. The juxtamembrane domains of both complexes are situated in close proximity due to acute bends of the receptors. The rigid N-terminal extension of OSM contributes to gp130 binding and OSM signaling. Neither glycosylation nor pro-domain cleavage of OSM affects its activity. Mutagenesis identifies multiple OSM and OSMR residues crucial for complex formation and signaling. Our data reveal the structural basis for the assemblies of both type I and type II OSM receptor complexes and provide insights for modulation of OSM signaling in therapeutics.

Abstract 4138606: Toll-like Receptor 4 Signaling Establishes Trained Innate Immunity Through Interferon-Mediated Epigenetic Modifications Leading to Cardioprotection in a Stress-induced Cardiomyopathy Model

Introduction: The mechanisms responsible for establishing preconditioning-induced cardioprotection remain unknown. We have shown that a high dose of isoproterenol (ISO) induces cardioprotection against a second ISO dose in mice. The durability of protection and the lack of an innate immune response suggests trained immunity as a novel cardioprotective mechanism. Hypothesis: We hypothesize that cardioprotection is conferred through trained immunity, by interferon signaling downstream of necrotic cardiac material-mediated Toll-like receptor 4 (TLR4) activation. Methods: Wild-type C57BL/6J mice were intraperitoneally injected with TLR agonists or diluent, and challenged with 300 mg/kg ISO 7 days later. Mice were assessed by 2-D echocardiography, serum cardiac troponin levels, flow cytometry immune cell counts, and Multiome (single nuclei RNA+ATAC) sequencing. Results: The TLR4 agonist lipopolysaccharide (LPS) induced cardioprotection against ISO injury, with mice having enhanced survival (P=0.049) and no changes in cardiac troponin levels (P>0.99), cardiac neutrophil influx (P>0.99) or left ventricular motion (P=0.057) relative to baseline values before injury. Treating LPS-injected mice with β-glucan reversed the effects of LPS on immune cells and abolished cardioprotection. Multiome analysis of genes linked to chromatin peaks with increased accessibility in LPS+vehicle (protected) compared to LPS+β-glucan and diluent control (non-protected) hearts revealed the interferon pathway to be up-regulated across all major cell types. Modulation of interferon signaling with monoclonal antibodies against type 1+2 interferon receptors abolished cardioprotection in LPS-treated mice, whereas pre-treatment with recombinant type 1+2 interferons induced cardioprotection. Importantly, interferon-treated hearts shared similar chromatin accessibility features and enriched transcription factor motifs, including interferon-specific motifs, with LPS-protected hearts across cell types, particularly among non-cardiomyocytes. Conclusions: TLR4-induced interferon signaling is sufficient and in part necessary for cardioprotection against ISO injury. Moreover, our findings show that epigenetic modifications downstream of interferon signaling lead to cardioprotection consistent with trained innate immunity.

Oriented triplex DNA as a synthetic receptor for transmembrane signal transduction.

Signal transduction across biological membranes enables cells to detect and respond to diverse chemical or physical signals, and replicating these complex biological processes through synthetic methods is of significant interest in synthetic biology. Here we present an artificial signal transduction system using oriented cholesterol-tagged triplex DNA (TD) as synthetic receptors to transmit and amplify signals across lipid bilayer membranes through H+-mediated TD conformational transitions from duplex to triplex. An auxiliary sequence, complementary to the third strand of the TD, ensures a controlled and preferred outward orientation of cholesterol-tagged TD on membranes. Upon external H+ stimuli, the conformational change triggers the translocation of the third strand from the outer to the inner membrane leaflet, resulting in effective transmembrane signal transduction. This mechanism enables fluorescence resonance energy transfer (FRET), selective photocleavage, catalytic signal amplification, and logic gate modulation within vesicles. Our findings demonstrate that these TD-based receptors mimic the functional dynamics of natural G protein-coupled receptors (GPCRs), providing a foundation for advanced applications in biosensing, cell signaling modulation, and targeted drug delivery systems.

DDDR-27. BMP SIGNALING MODULATES APOPTOTIC AND NON-APOPTOTIC CELL DEATH IN GLIOBLASTOMA

Abstract Recurrence occurs in approximately 90% of glioblastoma (GBM) patients, in part due to the tumors becoming resistant to cell death in response to existing therapies. These therapies often trigger apoptosis; however, apoptosis is only one of several different forms of cell death. We hypothesize that activating non-canonical death mechanisms could provide a back door to killing treatment-resistant GBM cells. To test this hypothesis, we first developed a new imaging-based high-throughput method to directly quantify cell death in 3D models. Using this method, we find patient-derived GBM spheroids to be resistant to the induction of cell death in response to various standard-of-care and experimental therapeutic compounds. To further investigate mechanisms underlying this resistance, we screened a panel of extracellular protein ligands for the modulation of cell death response. We find that bone morphogenic protein (BMP) signaling increases resistance to several apoptosis-inducing compounds, including temozolomide and tyrosine kinase inhibitors. Intriguingly, BMP signaling simultaneously enhanced sensitivity to a novel non-apoptotic cell death pathway triggered by the small molecule CIL56. Efforts are ongoing to further understand how BMP signaling governs apoptotic and non-apoptotic cell death mechanisms. Nevertheless, our results suggest a novel approach to treating GBM, centered upon the modulation of BMP signaling combined with the use of agents that induce non-apoptotic cell death.

Biochanin A Induces Apoptosis in MCF-7 Breast Cancer Cells through Mitochondrial Pathway and Pi3K/AKT Inhibition.

The study aimed to investigate the molecular mechanisms by which Biochanin A inhibits proliferation and induces apoptosis in breast cancer cells. Cultured MCF-7 cells were divided into four groups: Group 1-control, while Groups 2, 3, and 4 were treated with Biochanin A at different concentrations. After treatment, the cells were monitored, and morphological changes were examined after 24 h of incubation. The results showed that Biochanin A inhibited cell proliferation, increased reactive oxygen species formation, and induced apoptosis. Furthermore, western blot analysis revealed that Biochanin A-treated cells exhibited lower expression of the Bcl-2, p-PI3K and p-AKT and higher expression of proapoptotic genes, including Bax, Caspase-3, Caspase-9, and cytochrome c. Additionally, PCR array analysis indicated that the gene expression levels of cyclin D3, cyclin B1, CDK1, CDK2, and CDK4 were downregulated, while the expression levels of p21, p27, and p53 were significantly upregulated. These results suggest that Biochanin A can suppress the viability of breast cancer cells and induce apoptosis via the mitochondrial pathway, along with inhibition of the Pi3K/Akt signaling pathway and modulation of cell cycle markers.

Mitochondrial calcium uptake orchestrates vertebrate pigmentation via transcriptional regulation of keratin filaments.

Mitochondria regulate several physiological functions through mitochondrial Ca2+ dynamics. However, role of mitochondrial Ca2+ signaling in melanosome biology remains unknown. Here, we show that pigmentation requires mitochondrial Ca2+ uptake. In vitro gain and loss of function studies demonstrate that mitochondrial Ca2+ uniporter (MCU) is crucial for melanogenesis while MCU rheostat, MCUb negatively control melanogenesis. Zebrafish, MCU+/- and MCUb-/- mice models show that MCU complex drives pigmentation in vivo. Mechanistically, MCU silencing activates transcription factor NFAT2 to induce expression of keratin (5, 7, and 8) filaments. Interestingly, keratin5 in turn augments mitochondrial Ca2+ uptake and potentiates melanogenesis by regulating melanosome biogenesis and maturation. Hence this signaling module acts as a negative feedback loop that fine-tunes both mitochondrial Ca2+ signaling and pigmentation. Notably, mitoxantrone, an FDA approved drug that inhibits MCU, reduces pigmentation thereby highlighting therapeutic potential of targeting mitochondrial Ca2+ uptake for clinical management of pigmentary disorders. Taken together, we reveal an MCU-NFAT2-Keratin5 driven signaling axis that acts as a critical determinant of mitochondrial Ca2+ uptake and pigmentation. Given the vital role of mitochondrial Ca2+ signaling and keratin filaments in cellular physiology, this feedback loop could be operational in a variety of other patho-physiological processes.

Photo-physical characterizations and evaluation of in-vitro antioxidant, anti-inflammatory and antidiabetic potentials of green synthesized ackee (Blighia sapida) selenium nano-particles

BackgroundGreen synthesized nanoparticles have recently gained significant medicinal applications and oftentimes outperform their green sources. Selenium is of fundamental importance to human health, stemming from its distinctive physicochemical properties, such as antioxidant activity, inhibition of Lipid peroxidation, stabilization of membrane proteins, maintenance of membrane fluidity and modulation of cell signaling. Though reports have shown some therapeutic potential of Ackee plant parts such as antioxidant, anti-inflammatory, antimicrobial, neuroprotective, very few scientific proofs still exist in support of these effects.MethodsThis study synthesized selenium nanoparticles (Se-NPs) from crude methanolic extracts of Ackee leaves (AKL) and Ackee arils (AKA), examined the photo-physical characteristics of the Se-NPs and determined the in-vitro antioxidant, antidiabetic, and anti-inflammatory potentials of AKL, AKA, and their Se-NPs using established protocols.ResultsIn both leaves and arils Se-NPs: UV spectroscopy revealed a qualitative absorbance at 310 nm; FTIR indicated multiple vibrations around 4000 cm−1- 400 cm−1; SEM images of 5 µm principally showed consistent size distribution of amorphous and granular shape at a magnification of 10,000X; while EDS spectra strongly confirm the presence of atomic Se compound at 30 kV. Various antioxidant activities assays carried out showed a range of approximately 4 to 60 times higher activities of the AKL, AKA, and Se-NPs than Ascorbic acid—the standard drug used. Furthermore, appreciable activities of more than 50% were obtained for alpha-amylase and alpha-glucosidase inhibitory activities, along with highly significant activities of haemoglobin glycosylation, glucose uptake, membrane stabilization, anti-arthritic, anti-haemolysis activities, when AKL, AKA, and Se-NPs were compared with standard drugs.ConclusionEncouraging the development and utilization of AKL, AKA, and Se-NPs will provide tremendous therapeutic efficacy and bioavailability approaches towards the management of diabetes, inflammation, and other oxidative stress-related diseases.

β2-Chimaerin, a GTPase-Activating Protein for Rac1, Is a Novel Regulator of Hepatic Insulin Signaling and Glucose Metabolism

Glucose homeostasis is a complex process regulated by multiple organs and hormones, with insulin playing a central role. Recent evidence underscores the role of small GTP-binding proteins, particularly Rac1, in regulating insulin secretion and glucose uptake. However, the role of Rac1-regulatory proteins in these processes remains largely unexplored. In this study, we investigated the role of β2-chimaerin, a Rac1-specific GTPase-activating protein (GAP), in glucose homeostasis using whole-body β2-chimaerin knockout mice. Our data revealed that β2-chimaerin deficiency results in improved glucose tolerance and enhanced insulin sensitivity in mice. These metabolic effects were associated with increased insulin-induced AKT phosphorylation in the liver and activation of downstream pathways that regulate gluconeogenesis and glycogen synthesis. We show that insulin activates Rac1 in the liver. However, β2-chimaerin deletion did not significantly alter Rac1 activation in this organ, suggesting that β2-chimaerin regulates insulin signaling via a Rac1-independent mechanism. These findings expand our understanding of Rac1 regulation in glucose metabolism, and identify β2-chimaerin as a novel modulator of hepatic insulin signaling, with potential implications for the development of insulin resistance and diabetes.

From Regulation to Application: The Role of Abscisic Acid in Seed and Fruit Development and Agronomic Production Strategies

Abscisic acid (ABA) is a crucial plant hormone that plays a decisive role in regulating seed and fruit development and is becoming increasingly important in agricultural applications. This article delves into ABA’s regulatory functions in plant growth, particularly during the stages of seed and fruit development. In the seed phase, elevated ABA levels help maintain seed dormancy, aiding seed survival under unfavorable conditions. During fruit development, ABA regulates pigment synthesis and sugar accumulation, influencing the nutritional value and market quality of the fruit. This article highlights three main strategies for applying ABA in agricultural production: the use of ABA analogs, the development of ABA signal modulators, and breeding techniques based on ABA signaling. ABA analogs can mimic the natural functions of ABA, while ABA signal modulators, including enhancers and inhibitors, are used to finely tune plant responses to ABA, optimizing crop performance under specific growth conditions. Furthermore, breeding strategies based on ABA signaling aim to select crop varieties that effectively utilize ABA pathways through genetic engineering and other technologies. ABA is not only a key regulator of plant growth and development but also holds great potential for modern agricultural practices.

TRIM Proteins: Key Regulators of Immunity to Herpesvirus Infection

Herpesviruses are ubiquitous DNA viruses that can establish latency and cause a range of mild to life-threatening diseases in humans. Upon infection, herpesviruses trigger the activation of several host antiviral defense programs that play critical roles in curbing virus replication and dissemination. Recent work from many groups has integrated our understanding of TRIM (tripartite motif) proteins, a specific group of E3 ligase enzymes, as pivotal orchestrators of mammalian antiviral immunity. In this review, we summarize recent advances in the modulation of innate immune signaling by TRIM proteins during herpesvirus infection, with a focus on the detection of herpes simplex virus type 1 (HSV-1, a prototype herpesvirus) by cGAS-STING, RIG-I-like receptors, and Toll-like receptors. We also review the latest progress in understanding the intricate relationship between herpesvirus replication and TRIM protein-regulated autophagy and apoptosis. Finally, we discuss the maneuvers used by HSV-1 and other herpesviruses to overcome TRIM protein-mediated virus restriction.

SGSM2 in Uveal Melanoma: Implications for Survival, Immune Infiltration, and Drug Sensitivity.

The abnormal expression of small G protein signaling modulator 2 (SGSM2) is related to the occurrence of thyroid cancer and breast cancer. However, the role of SGSM2 in uveal melanoma (UVM) is unclear. To elucidate this ambiguity, our study utilized bioinformatics analysis and experimental validation. The expression of SGSM2 was detected in UVM cell lines through quantitative real-- time PCR (qRT-PCR). We utilized the Cancer Genome Atlas (TCGA) database to assess the relationship between SGSM2 expression and clinical characteristics, as well as its prognostic significance in UVM. Furthermore, the study examined potential regulatory networks involving SGSM2 in relation to immune infiltration, immune checkpoint genes, microsatellite instability (MSI), and drug sensitivity in UVM. The study also examined SGSM2 expression in UVM single-cell sequencing data. SGSM2 was highly expressed in UVM cell lines. Moreover, elevated levels of SGSM2 in UVM patients were significantly linked to poorer overall survival (OS) (p < 0.001), progress- free survival (PFS) (p < 0.001), and disease-specific survival (DSS) (p < 0.001). Additionally, SGSM2 expression was identified as an independent prognostic factor in UVM patients (p < 0.001). SGSM2 was associated with several pathways, including the calcium signaling pathway, natural killer cell-mediated cytotoxicity, cell adhesion molecules (CAMs), and others. The study revealed that SGSM2 expression in UVM is linked to immune infiltration, immune checkpoint genes, and MSI. Additionally, a significant inverse correlation was observed between SGSM2 expression and the compounds GSK690693, TL-2-105, PHA-793887, Tubastatin A, and SB52334 in UVM patients. SGSM2 may not only serve as an important indicator for prognostic assessment. Still, it may also be a key target for the development of new therapeutic approaches, providing new perspectives on the treatment of UVM patients.

Wheat TaPYL9-involved signalling pathway impacts plant drought response through regulating distinct osmotic stress-associated physiological indices.

The abscisic acid (ABA) signalling pathway plays a crucial role in plants' response to drought stress. In this study, we aimed to characterize the impact of an ABA signalling module, which consisted of TaPYL9 and its downstream partners in Triticum aestivum, on plant drought adaptation. Our results showed that TaPYL9 protein contains conserved motifs and targets plasma membrane and nucleus after being sorted by the endoplasmic reticulum. In addition, TaPYL9 transcripts in both roots and leaves were significantly upregulated in response to drought stress. We conducted glucuronidase (GUS) histochemical staining analysis for transgenic plants carrying a truncated TaPYL9 promoter, which suggested that cis-elements associate with ABA and drought response, such as ABRE, DRE and recognition sites MYB and MYC, regulating the gene transcription under drought conditions. Using protein interaction assays (i.e., yeast two-hybrid, bimolecular fluorescence complementation (BiFC), co-immunoprecipitation (Co-IP) and in vitro pull-down), we demonstrated interactions between the intermediate segment of TaPYL9, the intermediate segment of TaPP2C6, the N-terminus of TaSnRK2.8 and the C-terminus of the transcription factor TabZIP1 in wheat, indicating the involvement of TaPYL9 in the constitution of an ABA signalling module, namely TaPYL9/TaPP2C6/TaSnRK2.8/TabZIP1. Transgene analysis revealed that TaPYL9, TaSnRK2.8 and TabZIP1 positively regulated drought response, while TaPP2C6 negatively regulated it, and that these genes were closely associated with the regulation of stomata movement, osmolyte accumulation and ROS homeostasis. Electrophoretic mobility shift (EMSA) and transcriptioal activation assays indicated that TabZIP1 interacted promoters of TaP5CS2, TaSLAC1-1 and TaCAT2 and activated transcription of these genes, which regulated proline biosynthesis, stomata movement and ROS scavenging upon drought signalling, respectively. Furthermore, we found that the transcripts of TaPYL9 and stress-responsive genes were positively correlated with yields in wheat cultivars under field drought conditions. Altogether, our findings suggest that the TaPYL9-involved signalling pathway significantly regulates drought response by modulating osmotic stress-associated physiological processes in T. aestivum.

Replacement of fish meal with full fat Hermetia illucens modulates hepatic FXR signaling in juvenile rainbow trout (Oncorhynchus mykiss): exploring a potential role of ecdysteroids

The present study was conducted to investigate the effects of fish meal (FM) replacement with full fat Hermetia illucens (HI) on the molecular mechanisms regulating lipid and bile salt (BA) homeostasis in rainbow trout (Oncorhynchus mykiss) juveniles. We thus explore the presence of 20-hydroxyecdysone (20E) in an insect meal-based diet and evaluate its potential involvement in regulating the molecular mechanisms/basis of FXR:RXR axis signaling. Ecdysteroids are a category of steroid hormones which bind a nuclear–receptor complex composed of ecdysone receptor (EcR) and ultraspiracle protein (USP) and regulate insect molting and metamorphosis. In all vertebrates, including fish, EcR-USP homologs are the Farnesoid X receptors (FXR) and the Retinoid X receptors (RXR), which are known to regulate crucial physiological and metabolic aspects, including BA synthesis and cholesterol homeostasis. In silico prediction indicates that 20E binds the heterodimeric complex with a binding affinity constant Kd equals to 610±60 nM and affects positively the dimerization process. Results also demonstrated the coordinated increased expression of FXR and RXR, as well as their downstream target genes (i.e. short heterodimer partner 1 and 2) in rainbow trout fed diets containing HI meal. This latter finding was paralleled by a significant down-regulation of CYP7a1 and CYP8b1 gene expression together with a decrease in hepatic total cholesterol, triglyceride, and BA levels. Overall, our study suggested that FXR is a potential target for 20E content in insect meal and provided preliminary data on the potential role of ecdysteroids in regulating the metabolic status of teleost fish through modulation of FXR signaling in the enterohepatic system.

4-Octyl itaconate inhibits vascular calcification partially via modulation of HMOX-1 signaling

Vascular calcification frequently occurs in patients with chronic conditions such as chronic kidney disease (CKD), diabetes, and hypertension and represents a significant cause of cardiovascular events. Thus, identifying effective therapeutic targets to inhibit the progression of vascular calcification is essential. 4-Octyl itaconate (4-OI), a derivative of itaconate, exhibits anti-inflammatory and antioxidant activity, both of which play an essential role in the progression of vascular calcification. However, the role and molecular mechanisms of 4-OI in vascular calcification have not yet been elucidated. In this study, we investigated the effects of exogenous 4-OI on vascular calcification using vascular smooth muscle cells (VSMCs), arterial rings, and mice. Alizarin red staining and western blot revealed that 4-OI inhibited calcification and osteogenic differentiation of human VSMCs. Similarly, 4-OI inhibited calcification of rat arterial rings and VitD3-overloaded mouse aortas. Mechanistically, RNA sequencing analysis revealed that 4-OI treatment is most likely to affect heme oxygenase 1 (HMOX-1) mRNA expression. The study demonstrated that 4-OI treatment increased HMOX-1 mRNA and protein levels, but suppressed inflammation and oxidative stress in VSMCs under osteogenic conditions. Moreover, 4-OI treatment. HMOX-1 knockdown by siRNA or treatment with the HMOX-1 inhibitor ZnPP9 significantly reversed the suppression effect on calcification of VSMCs and aortas of VitD3-overloaded mice by 4-OI. Furthermore, HMOX-1 knockdown by siRNA markedly abrogated the inhibitory effect of 4-OI on inflammation in VSMCs. These findings suggest that 4-OI alleviates vascular calcification and inhibits oxidative stress and inflammation through modulation of HMOX-1, indicating its potential as a therapeutic target for vascular calcification.

Modulation of tyrosine receptor imposed by Estrogen in Memory and Cognition in Female Rats.

The present study aimed to investigate the potential role of estrogen in modulating the pathogenesis of dementia-type-AD phenotype, possibly by tyrosine kinase. Female Wistar rats were ovariectomized (OVX) and were treated with Diethylstilbesterol (DES), an estrogen analogue (20μg/kg/day, i.m.), and Imatinib, a tyrosine kinase inhibitor (30mg/kg/day, orally), for two months. Animals underwent surgical ovariectomy exhibited significant memory deficits in spatial memory assessment as mean dwell time, short-term memory as spontaneous alteration, and novel object recognition after a chronic period of 4 weeks. OVX animals administered with DES produced significant restoration of memory dysfunction in comparison to OVX, as exhibited by Morris water maze (p=0.0003), Y maze (p<0.0001), and NORT. Imatinib prior to DES treatment in OVX animals showed significant decline in memory functions, which confirms the potential involvement of tyrosine receptor kinase activity in improved memory functions offered by estrogen. Levels of estradiol were significantly (p<0.0001) lower in the OVX group compared to normal which was significantly (p<0.0001) restored in the OVX+E group. Biochemical estimations of TBARS, glutathione, and acetylcholinesterase levels in the brain showed a significant increase in oxidative stress among the OVX group. However, a significant restoration of oxidative changes with TBARS (p=0.0496), glutathione (p<0.0001), and acetylcholinesterase activity (p=0.0201) of OVX animals receiving DES was observed in comparison to animals receiving imatinib followed by DES. These implications in the brain signify that estrogen and tyrosine kinase play an important role in the pathogenesis of dementia. In conclusion, estrogen offers neurochemical mediation for cognition and memory possibly via modulation of tyrosine kinase signaling in female subjects.

Female sex hormones inversely regulate acute kidney disease susceptibility throughout life.

While epidemiological and experimental studies have demonstrated kidney-protective effects of estrogen and female sex in adulthood, some epidemiological data showed deterioration of kidney function during puberty when estrogen production increases. However, molecular mechanisms explaining these conflicting phenomena remain unknown. Here, we showed that the pubertal sex hormone surge in female mice increases susceptibility to kidney ischemia reperfusion injury partly via downregulation of insulin-like growth factor 1 receptor (IGF-1R) expression in proximal tubules. Adult mice ovariectomized pre-pubertally (at postnatal day 21) showed strong tolerance to kidney ischemia, which was partly reversed by the administration of 17β-estradiol, while adult mice ovariectomized post-pubertally (at 8 weeks of age) were vulnerable to kidney ischemia. Kidney tubular IGF-1R protein expression decreased during postnatal growth but was highly expressed in adult mice ovariectomized pre-pubertally and in infant mice, which might be partly explained by different expression of an E3 ligase (MDM2) of IGF-1R. Mice deficient of Igf-1r in proximal tubules (iIGF-1RKO mice) during postnatal kidney growth showed increased susceptibility to ischemic injury. RNA-seq and western blotting analysis using proximal tubular cells from pre-pubertally ovariectomized iIGF-1RKO and control mice revealed altered expression of cell cycle-associated molecules such as cyclin D1. These results suggest that Igf-1r deletion during postnatal growth renders proximal tubular cells susceptible to ischemia possibly via altered cell cycle regulation. Thus, our findings provide evidence that exposure to pubertal sex hormones leads to increased susceptibility to kidney ischemia, which is partly mediated by modulation of IGF-1R signaling.

Berberine In Combination With Evodiamine Ameliorates Gastroesophageal Reflux Disease Through TAS2R38/TRPV1-Mediated Regulation of MAPK/NF-κB Signaling Pathways and Macrophage Polarization

BackgroundGastroesophageal reflux disease (GERD) is a chronic condition of the digestive tract with limited therapeutic options. Bitter taste receptors (TAS2Rs) and transient receptor potential vanilloid-1 (TRPV1) are implicated in modulating inflammatory responses. Berberine (BBR) and evodiamine (EVO) are known to activate TAS2Rs and TRPV1, respectively. However, whether BBR and EVO can ameliorate GERD by targeting TAS2Rs and TRPV1 remains uncertain. PurposeThis study aims to determine whether BBR and EVO mitigate esophageal injury by targeting TAS2R38 and TRPV1 and to elucidate their underlying molecular mechanisms. MethodsA GERD rat model was developed using esophagogastric anastomosis, while GERD in human esophageal epithelial cells (HEECs) was induced via bile acid (BA) exposure. Esophageal pathology was analyzed through hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM). mRNA and protein levels were measured via qRT-PCR, immunofluorescence, immunohistochemistry and Western blot analysis. Small interfering RNA was used to silence TAS2R38 and TRPV1 in HEECs. The activation of TAS2R38 and TRPV1 by BBR and EVO was assessed through Ca2+ mobilization assays. Finally, in vivo validation was conducted using U73122 to inhibit TAS2Rs and resiniferatoxin (RTX) to ablate TRPV1. ResultsBBR and EVO treatments significantly improved esophageal pathology in GERD rats and reduced BA-induced inflammation in HEECs. Additionally, BBR and EVO suppressed proinflammatory factors expression, upregulated barrier proteins such as E-cadherin and claudin-1, and inhibited the phosphorylation of p65, JNK, and ERK in the MAPK/NF-κB signaling pathways in both in vivo and in vitro models. Furthermore, BBR and EVO, whether individually or in combination, reduced dilated intercellular spaces (DIS), increased desmosome numbers, and modulated macrophage polarization in GERD rats. Knockdown of TAS2R38 and TRPV1 in HEECs notably diminished the stimulatory effects of BBR and EVO. Moreover, the regulation of barrier function and MAPK/NF-κB pathway proteins by BBR and EVO in BA-induced HEECs was abrogated upon TAS2R38 and TRPV1 knockdown. Similarly, U73122 and RTX reversed the effects of BBR and EVO on macrophage polarization and MAPK/NF-κB signaling pathways in vivo. ConclusionWe firstly demonstrate that BBR and EVO alleviate GERD, with enhanced synergistic efficacy observed when used in combination. Mechanistically, BBR and EVO activate the TAS2R38 and TRPV1, respectively, leading to downregulation of phosphorylation in MAPK/NF-κB signaling pathways and modulation of macrophage polarization. These findings offer a novel foundation for the clinical application of BBR and EVO in GERD treatment.

Flavonoids from Rhododendron nivale Hook. f ameliorate alcohol-associated liver disease via activating the PPARα signaling pathway

Background: Flavonoids are increasingly recognized for their potent antioxidant properties and potential therapeutic roles in the management of alcohol-associated liver disease (ALD). Extracts derived from Rhododendron nivale Hook. f. (FRN) have been shown to influence glutathione metabolism in aging animal models, exhibiting notable antioxidant effects. However, the specific impact of FRN on ALD remains insufficiently explored. Hypothesis/PurposeThis study seeks to elucidate the efficacy of FRN in alleviating the pathology associated with ALD, delving into the underlying molecular mechanisms that facilitate its protective effects. Study Design: We employed network pharmacology to predict the functional roles and pathway enrichments associated with FRN targets. Both a murine model of ALD and in vitro cellular models were utilized to clarify the mechanistic basis by which FRN mitigates ALD. Methods: FRN was extracted and characterized according to well-established methodologies outlined in our previous studies. Potential functions and pathways implicated by FRN were predicted through network pharmacology analyses. A combination of liver transcriptomics, targeted lipidomics, molecular biology techniques, and antagonists of relevant targets were employed to investigate the mechanisms through which FRN exerts its protective effects in ALD. Results: Network pharmacology identified multiple target genes modulated by FRN, particularly those within critical ALD-related signaling pathways, such as PPARα signaling and fatty acids (FAs) degradation. Notably, treatment with FRN in the ALD murine model led to a significant attenuation of hepatic lipid accumulation and a restoration of serum AST and ALT to baseline ranges. Subsequent validation through liver transcriptomics and molecular biology techniques revealed an upregulation of PPARα expression concomitant with a downregulation of ACSL1 in FRN-treated ALD mice. Targeted lipidomic and bioinformatic analyses from cellular assays demonstrated that FRN substantially reduced the accumulation of long-chain fatty acids in hepatocytes. Importantly, the reversal of FRN's protective effects on lipid accumulation through the PPARα antagonist GW6471 provides compelling evidence for the critical role of PPARα signaling modulation in mediating the beneficial impact of FRN on ALD. Conclusion: Our research highlights FRN's capacity to alleviate ALD through PPARα pathway activation, paving the way for innovative treatment strategies. This underscores the significance of natural compounds in pharmacotherapy, suggesting that FRN may provide an effective alternative for managing ALD.