Signaling Genes Research Articles

ABA and Melatonin: Players on the Same Field?

In plants, abscisic acid (ABA) and melatonin (MT) are conventionally treated as molecules mitigating stress responses. To understand the mechanisms of ABA–MT interplay, we examined the effects of ABA and MT treatment in ABA and MT loss-of-function mutants of Arabidopsis thaliana exposed to high light (HL) stress. ABA constantly suppressed ASMT encoding N-acetylserotonin methyltransferase in the context of differential responses of other MT biosynthesis genes in both the wild type (WT) and mutants. However, this response was absent in the mutant with the disrupted ABI4. Given that the ASMT promoter region contains several potential ABI4-binding elements, these data suggest that ASMT can be a potential target gene for ABI4. A role for ABI4 in the interactions between ABA and MT is supported by the finding that ABI4 is constitutively derepressed in the MT signaling mutants cand2 and gpa1, which exhibited elevated steady state levels of ABI4 transcripts and were not regulated by either stress or melatonin. In addition, the abi4 mutant showed increased modulations in the expression of the MT catabolic genes M2H and M3H in response to ABA treatment, inferring that this transcription factor is a negative regulator of ABA-dependent changes in MT content. Furthermore, all tested mutants with impaired ABA synthesis or signaling displayed elevated steady state MT levels compared to WT, while MT treatment contributed to the downregulation of key ABA synthesis and signaling genes. Collectively, our results suggest that ABA and melatonin act antagonistically, modulating the expression of ABA and MT signaling and metabolism genes. To understand the mechanisms of ABA–MT interactions, we studied the effects of ABA and MT treatment in ABA and MT loss-of-function mutants of Arabidopsis thaliana exposed to severe light stress (SLS).

Saussurea involucrata SiLEA5 Enhances Tolerance to Drought Stress in Solanum lycopersicum

Drought adversely affects plant growth, which leads to reduced crop yields and exacerbates food insecurity. Late embryogenesis abundant (LEA) proteins are crucial for plants’ responses to abiotic stresses. This research further investigates the role of SiLEA5 by utilizing transgenic tomatoes under drought stress. The expression of SiLEA5 was upregulated under drought and abscisic acid (ABA) treatment, resulting in decreased electrolyte leakage and malondialdehyde content, alongside increased levels of osmotic regulators and antioxidant enzyme activity. These biochemical alterations reduce oxidative damage and enhance drought resistance. qRT-PCR analysis revealed the upregulation of ABA signaling genes and key enzymes involved in proline biosynthesis (P5CS) and dehydrin (DHN) synthesis under drought stress. Additionally, overexpression of SiLEA5 increased the net photosynthetic rate (Pn) and fruit yield of tomatoes by regulating stomatal density and aperture. These findings suggest that SiLEA5 may be a potential target for improving drought tolerance in tomatoes and other crops.

Nitrogen at the crossroads of light: Integration of light signalling and plant nitrogen metabolism.

Plants have developed complex mechanisms to perceive, transduce, and respond to environmental signals, such as light, which are essential for acquiring and allocating resources, including nitrogen (N). This review delves into the complex interaction between light signals and N metabolism, emphasising light-mediated regulation of N uptake and assimilation. Firstly, we discuss the details of light-mediated regulation of N uptake and assimilation, focusing on the light-responsive activity of nitrate reductase (NR) and nitrate transporters. Secondly, we discuss the influence of light on N-dependent developmental plasticity, elucidating how N availability regulates crucial developmental transitions such as flowering time, shoot branching, and root growth, as well as how light modulates these processes. Additionally, we discuss the molecular interaction between light and N signalling, focusing on photoreceptors and transcription factors such as HY5, which are necessary for N uptake and assimilation under varying light conditions. A recent understanding of the nitrate signalling and perception of low N is also highlighted. The insilico transcriptome analysis suggests a reprogramming of N signalling genes by shade and identifies NLP7, bZIP1, CPK30, CBL1, LBD37, LBD38 and HRS1 as crucial molecular regulators integrating light-regulated N metabolism.

Spatiotemporal control of subcellular O-GlcNAc signaling using Opto-OGT.

The post-translational modification of intracellular proteins through O-linked β-N-acetylglucosamine (O-GlcNAc) is a conserved regulatory mechanism in multicellular organisms. Catalyzed by O-GlcNAc transferase (OGT), this dynamic modification has an essential role in signal transduction, gene expression, organelle function and systemic physiology. Here, we present Opto-OGT, an optogenetic probe that allows for precise spatiotemporal control of OGT activity through light stimulation. By fusing a photosensitive cryptochrome protein to OGT, Opto-OGT can be robustly and reversibly activated with high temporal resolution by blue light and exhibits minimal background activity without illumination. Transient activation of Opto-OGT results in mTORC activation and AMPK suppression, which recapitulate nutrient-sensing signaling. Furthermore, Opto-OGT can be customized to localize to specific subcellular sites. By targeting OGT to the plasma membrane, we demonstrate the downregulation of site-specific AKT phosphorylation and signaling outputs in response to insulin stimulation. Thus, Opto-OGT is a powerful tool for defining the role of O-GlcNAcylation in cell signaling and physiology.

PLNC8 αβ Potently Inhibits the Flavivirus Kunjin and Modulates Inflammatory and Intracellular Signaling Responses of Alveolar Epithelial Cells

PLNC8 αβ is a cationic antimicrobial peptide that previously has been reported to express both antibacterial and antiviral properties. This study aimed to further elucidate the antiviral effects of PLNC8 αβ and its impact on virus-induced cytotoxicity and inflammatory signaling in human alveolar epithelial cells (A549) infected with the flavivirus Kunjin. Complementary in silico analyses using molecular dynamics (MD) simulation were conducted to investigate the mechanism of action of PLNC8 αβ by studying the interaction of PLNC8 α and β with models of a flavivirus membrane and a eukaryotic plasma membrane, respectively. Our findings demonstrated that PLNC8 αβ significantly reduces both extracellular and intracellular viral loads, as confirmed by plaque reduction assays and RT-PCR. The peptide also mitigated virus-induced cytotoxicity and inflammation. Notably, PLNC8 αβ modulated the virus-induced dysregulation of key signaling and inflammatory genes, such as TLR9, TLR3, NOD2, FOS, JUN, IL6, and CXCL8. MD simulation revealed that PLNC8 αβ exhibits higher binding affinity for a flavivirus membrane model compared to a model of the plasma membrane, likely due to stronger electrostatic interactions with anionic phospholipids. This selective interaction possibly accounts for a potent antiviral activity of PLNC8 αβ combined with a minimal cytotoxicity toward human cells. Overall, PLNC8 αβ shows significant promise as an antiviral agent against flavivirus infections and warrants further exploration for peptide-based antiviral therapies.

Autophagy in Acute Lung Injury.

Acute lung injury (ALI) is a critical condition marked by rapid-onset respiratory failure due to extensive inflammation and increased pulmonary vascular permeability, often progressing to acute respiratory distress syndrome (ARDS) with high mortality. Autophagy, a cellular degradation process essential for removing damaged organelles and proteins, plays a crucial role in regulating lung injury and repair. This review examines the protective role of autophagy in maintaining cellular function and reducing inflammation and oxidative stress in ALI. It underscores the necessity of precise regulation to fully harness the therapeutic potential of autophagy in this context. We summarize the mechanisms by which autophagy influences lung injury and repair, discuss the interplay between autophagy and apoptosis, and examine potential therapeutic strategies, including autophagy inducers, targeted autophagy signaling pathways, antioxidants, anti-inflammatory drugs, gene editing, and stem cell therapy. Understanding the role of autophagy in ALI could lead to novel interventions for improving patient outcomes and reducing mortality rates associated with this severe condition.

CNSC-69. GLIOBLASTOMA-NETWORK CONNECTIVITY IS REGULATED THROUGH ALTERATIONS IN CHLORIDE HOMEOSTASIS AND GABAERGIC SIGNALING

Abstract The specific pathophysiological mechanisms underlying glioma-related epilepsy, which presents an unfavorable clinical course, are still not well explored. To identify the candidate pathways involved in glioblastoma-induced neuronal hyperexcitability, we used high-density electrode arrays in vivo in humans to record local field potentials from cortically projecting gliomas and identified hyperexcitable intratumoral regions with elevated functional connectivity to the brain. Single-cell RNA sequencing (13,730 cells analyzed) of the functionally connected intratumoral regions identified several circuit assembly and GABAergic signaling genes elevated in glioma-intrinsic neurons, including the sodium-potassium-chloride co-transporter 1 (NKCC1), which accumulates chloride in the cells. We hypothesized that the hyperexcitable behavior of glioma-intrinsic neurons in glioblastoma is mediated by elevated NKCC1 and chloride dysregulation and that inhibiting NKCC1 would reinforce the inhibitory action of GABA and rescue the neuronal hyperresponsive phenotype. Single-nucleus (sNuc-seq) sequencing was performed on neuron-glioblastoma co-cultures (54,000 cells analyzed) to determine NKCC1-facilitated GABAergic signaling in glioblastoma-mediated neuronal responses. Mechanistic and functional studies using perforated whole-cell patch-clamp recordings, multielectrode array, calcium, and chloride imaging for validating therapeutic vulnerabilities to NKCC1 silencing by shRNA knockdown and by the FDA-approved drug bumetanide were performed using in vitro and organotypic mouse slice culture models. sNuc-seq revealed an upregulation of neuronal NKCC1 and GABAA receptors when co-cultured with NKCC1-high-expressing glioblastoma cells, indicating the strong association between neuronal NKCC1 and GABAergic signaling. Electrophysiological analysis of glioblastoma-neuron co-cultures demonstrated increased network burst synchrony and a positive shift in the GABA reversal potential (EGABA). This increase was eliminated in the presence of NKCC1 inhibition using bumetanide and shRNA knockdown, which correlated with a significant decrease in intracellular neuronal chloride. Mechanistically, glioma NKCC1 downregulation significantly decreased GAP43-mediated tumor microtube (TMT) formation. Whether this reduced TMT formation also results in decreased chloride release by glioma cells, thereby altering neuronal chloride equilibrium, is currently under investigation. Collectively, these findings aim to identify a new mechanism of glioma-associated epilepsy, which may provide a novel approach to treatment.

CSIG-24. BRAIN MICROENVIRONMENT-DEPENDENT NEURODEVELOPMENTAL LINEAGE PLASTICITY PROMOTES ADAPTATION TO ONCOGENE INHIBITION IN MALIGNANT GLIOMAS

Abstract Phenotypic plasticity drives non-genetic tumor adaptation in response to various microenvironmental and therapeutic pressures, consequently promoting tumor heterogeneity and progression. In malignant gliomas, the intrinsic and extrinsic mechanisms underlying phenotypic lineage plasticity and its contribution to drug resistance remain unclear. The epidermal growth factor receptor (EGFR) is frequently altered in glioma and serves as a critical regulator of normal radial glia (RG) cells – multipotent progenitors that give rise to cortical neurons and glia in the developing brain. Here, through interrogation of a large panel of diverse glioblastoma (GBM) patient-derived gliomaspheres and orthotopic xenografts, we find that enrichment of RG-like cells is significantly correlated with responses to pharmacological ablation of EGFR, highlighting EGFR as a crucial lineage survival factor for a population of malignant RG-like cells in GBM. Single-cell RNA sequencing and quantitative proteomics reveal that adaptation to EGFR inhibition is linked to a temporal contraction in RG-like cells and concomitant increase in lineage-restricted neuronal and oligodendrocyte progenitor (NPC/OPC)-like states exclusively in the orthotopic brain environment. This lineage transition is coupled to heightened RAS signaling gene expression programs and sustained activation of MAPK signaling, despite robust and durable inhibition of EGFR activation. Furthermore, constitutively active MEK – but not AKT – is sufficient to rescue tumor proliferation under EGFRi, suggesting that the brain microenvironment modulates RAS-MAPK oncogenic signaling to drive lineage transitions following EGFR blockade. Collectively, these results highlight a critical link between oncogenic signaling and neurodevelopmental lineage plasticity in malignant gliomas, presenting a compelling therapeutic opportunity to block tumor cell state transitions for more durable tumor responses in the native glioma tumor microenvironment.

CNSC-39. INTEGRATED CLINICAL GENETIC ANALYSIS REVEALS NEUROTRANSMITTER RECEPTOR DYSREGULATION IN MENINGIOMAS CAUSING SEIZURE

Abstract Molecular correlates of seizures in meningioma remain unexplored. Previously, we identified MenG molecular grouping, wherein MenG C meningiomas recur more than MenG A or B. We therefore sought to identify molecular and clinical drivers of seizures in meningioma. We identified 144 primary supratentorial meningiomas, excluding those with pre-existing epilepsy. Whole exome sequencing assessed somatic mutation burden. Bulk RNA-sequencing identified differentially expressed genes and gene ontologies (GO). Immunohistochemistry confirmed protein levels. No differences in canonical gene mutation burden (NF2, TRAF7, AKT1, KLF4, SMO, SMARC) was found between seizure and non-seizure groups. MenG C tumors had higher seizure incidence compared to MenG A or B (p=0.03). Seizure causing meningiomas, though extra-axial, exhibited dysregulated neuronal signaling genes. GABAA receptor subunit genes GABRA3 and GABRG1 were downregulated in tumors causing seizure (Log2FC=-1.67, padj=0.014; Log2FC=-2.24, padj=0.009). Immunohistochemistry confirmed expression of GABRB2 subunit, the first documentation of GABA receptor expression in meningiomas. Neuropeptide Y Receptor Y1 (NPY1R) is downregulated in seizure causing meningiomas (Log2FC=-1.64, padj=0.002). NPY1R loss correlates is observed in mesial temporal lobe epilepsy and post-electroconvulsive shock mouse brains. In GO analysis, the terms “GABA signaling pathway,” “neuropeptide signaling,” “excitatory postsynaptic membrane potential,” and “ionotropic glutamate pathway,” were downregulated in meningiomas with seizure (padj<0.05). We assessed which alterations within MenG C tumors caused seizures by identifying genes associated with both seizure presentation and MenG C classification. Glutamate ionotropic receptor AMPA type subunit 1 (GRIA1) is downregulated in MenG C tumors (Log2FC=-2.29, padj=6.02E-07) and seizure causing tumors (Log2FC=-1.75, padj=0.03). Clinically, patients experiencing pre-operative seizures more frequently had cerebral edema, non-homogenous enhancement, intratumoral calcification, higher MIB-1, atypical grade 1, reduced GCS, and ER presentation; they were less likely to have incidental or headache presentation (p<0.05 for all). MenG classification predicts seizure presentation whereas somatic mutation status does not. Meningiomas causing seizures show pathologic neurotransmitter receptor dysregulation.

Strigolactones Regulate Secondary Metabolism and Nitrogen/Phosphate Signaling in Tea Plants via Transcriptional Reprogramming and Hormonal Interactions.

Strigolactones (SLs) are known to regulate plant architecture formation, nitrogen (N) and phosphorus (P) responses, and secondary metabolism, but their effects in tea plants remain unclear. We demonstrated that the application of a bioactive SL analogue GR24 either to tea roots or leaves initially stimulated but later inhibited catechins, theanine, and caffeine biosynthesis. GR24 treatment also promoted the accumulation of flavonols and insoluble proanthocyanidins in a time- and dose-dependent manner. GR24 influenced flavonoid and theanine biosynthesis genes, such as up-regulating CsTT2c, CsMYB12, and CsbZIP1, modulating N-responsive and assimilation genes (CsNRT1,1, CsGSI/TS1, CsHRS1, CsPHR1, CsNLA1, and CsLBD37/38/39), and repressing N/P transport and signaling genes (CsPHO2, CsPHT1s, CsNRT2,2, CsHHO1, and CsWRKY38). GR24-induced changes in secondary metabolites were also observed in the leaves of tea plants. GR24-regulated CsLBD37a interacted with CsTT8a and CsTT2c, repressing catechins biosynthesis by interrupting MBW complex formation. GR24 regulated caffeine biosynthesis and regulator genes CsS40 and CsNAC7 and may thereby suppress caffeine production. GR24 altered the transcriptomic profiles of multiple hormone biosynthesis and signaling genes that potentially regulate tea characteristic metabolism and N/P signaling. This study provides new insights into SL-induced transcriptional reprogramming that leads to changes in N/P nutrition, secondary metabolism, and hormone signaling in tea plants.

Sugar beet root susceptibility to storage rots and downregulation of plant defense genes increases with time in storage

Storage rots are a significant cause of postharvest losses for the sugar beet crop, however, intrinsic physiological and genetic factors that determine the susceptibility of roots to pathogen infection and disease development are unknown. Research, therefore, was carried out to evaluate the disease development in sugar beet roots caused by two common storage pathogens as a function of storage duration and storage temperature, and to identify changes in the expression of defense genes that may be influencing the root susceptibility to disease. To evaluate root susceptibility to disease, freshly harvested roots were inoculated with Botrytis cinerea or Penicillium vulpinum on the day of harvest or after 12, 40, or 120 d storage at 5 or 12 °C and the weight of rotted tissue present in the roots after incubation for 35 d after inoculation were determined. Disease susceptibility and progression to B. cinerea and P. vulpinum increased with storage duration with elevations in susceptibility occurring more rapidly to B. cinerea than P. vulpinum. Also, B. cinerea was more aggressive than P. vulpinum and caused greater rotting and tissue damage in postharvest sugar beet roots. Storage temperature had minimal effect on root susceptibility to these rot-causing pathogens. Changes in defense gene expression were determined by sequencing mRNA isolated from uninoculated roots that were similarly stored for 12, 40 or 120 d at 5 or 12 °C. As susceptibility to rot increased during storage, concurrent changes in defense-related gene expression were identified, including the differential expression of 425 pathogen receptor and 275 phytohormone signal transduction pathway-related genes. Furthermore, plant resistance and hormonal signaling genes that were significantly altered in expression coincident with the change in root susceptibility to storage rots were identified. Further investigation into the function of these genes may ultimately elucidate methods by which storage rot resistance in sugar beet roots may be improved in the future.

Acupuncture-induced gene co-expression networks in postmenopausal women with osteoarthritis and osteoporosis: In-silico analysis.

Objective: Bone is a tissue that is constantly remodeled to adjust the microarchitecture and maintain the mechanical needs of bone through the balance of bone resorption and formation processes. Alterations in these processes can lead to the development of different diseases, such as osteoarthritis and osteoporosis. In recent years, it has been shown that acupuncture is an effective treatment for pain, physical dysfunctions, and the immune system, so the stimulation of acupuncture points could affect genes associated with inflammatory processes and, therefore, osteoarthritis and osteoporosis. To analyze changes in gene expression post-acupuncture in data from a group of individuals with osteoarthritis that also manifests in osteoporosis. Method: Through using microarray technology and bioinformatics analysis, potential genes associated with osteoarthritis after acupuncture treatment are identified and compared with genes implicated in osteoporosis. The genes identified in each disease were evaluated through a KEGG signaling pathway analysis, where the results allowed the generation of an in-silico model that shows interaction networks between signaling pathways and genes involved in both diseases. Results: In this interaction, 37 differentially expressed genes were identified in patients with osteoarthritis before and after acupuncture treatment, and 665 differentially expressed genes was involved in osteoporosis. In the osteoarthritis group, 15 signaling pathways involved in this disease were obtained, and for osteoporosis, 13 signaling pathways associated with immunological processes that participate in bone metabolism were obtained osteoarthritis and osteoporosis are two age-associated diseases that are characterized by alterations in the bone remodeling mechanism induced by changes in gene expression profiles. Conclusions: Treatment with acupuncture can modify various cytokines involved in diseases related to the immune system so that it can have beneficial effects on osteoarthritis and osteoporosis. In addition, bioinformatics analysis allows us to know those signaling pathways through which they could have acupuncture effects. Graphical abstract: http://links.lww.com/AHM/A137.

Insulin Resistance Is a Modifying Factor for Parkinson's Disease.

Parkinson's disease (PD) is the second most common, and the fastest-growing neurodegenerative disorder with unclear etiology in most cases. Therefore, the identification of non-genetic risk factors for PD pathology is crucial to develop effective preventative or therapeutic strategies. An increasing number of evidence suggests that central insulin resistance might have an essential role in PD pathology. Nevertheless, it is not clear whether insulin resistance arises from external factors/lifestyle, comorbidities such as type 2 diabetes or it can occur in a PD patient's brain independently from peripheral insulin resistance. We aimed to investigate insulin resistance and its role in GBA1mutation-associated PD pathogenesis and phenotype severity. Midbrain organoids, generated from induced pluripotent stem cells (iPSCs) of PD patients carrying the GBA1-N370S heterozygous mutation (GBA-PD) and healthy donors, were exposed to different insulin concentrations to modify insulin signaling function. Transcriptomics analysis was performed to explore insulin signaling gene expression patterns in GBA-PD and to find a potential target for GBA-PD-associated phenotype rescue. The insulin signaling pathway genes show dysregulation in GBA-PD. Particularly, we highlight that a knockdown of FOXO1 mitigates the loss of dopaminergic neurons and cellular death in GBA-PD. Additionally, our findings suggest a promising therapeutic potential of the anti-diabetic drug Pioglitazone in decreasing dopaminergic neuron loss associated with GBA-PD. Local insulin signaling dysfunction plays a substantial role in GBA-PD pathogenesis, exacerbating dopaminergic neuron death. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Interplay between Two Paralogous Human Silencing Hub (HuSH) Complexes in Regulating LINE-1 Element Silencing

The Human Silencing Hub (HuSH) complex silences retrotransposable elements in vertebrates. Here, we identify a second HuSH complex, designated HuSH2, which is centered around TASOR2, a paralog of the core TASOR protein in HuSH. Our findings reveal that HuSH and HuSH2 localize to distinct and non-overlapping genomic loci. Specifically, HuSH localizes to and represses LINE-1 retrotransposons, whereas HuSH2 targets and represses KRAB-ZNFs and interferon signaling and response genes. We use in silico protein structure predictions to simulate MPP8 interactions with TASOR paralogs, guiding amino acid substitutions that disrupted binding to HuSH complexes. These MPP8 transgenes and other constructs reveal the importance of HuSH complex quantities in regulating LINE-1 activity. Furthermore, our results suggest that dynamic changes in TASOR and TASOR2 expression enable cells to finely tune HuSH-mediated silencing. This study offers insights into the interplay of HuSH complexes, highlighting their vital role in retrotransposon regulation.

A MESOCORTICOLIMBIC INSULIN RECEPTOR GENE CO-EXPRESSION NETWORK MODERATES THE ASSOCIATION BETWEEN EARLY LIFE ADVERSITY AND FOOD APPROACH EATING BEHAVIOUR STYLE IN CHILDHOOD

Insulin receptors, located in brain regions associated with reward sensitivity and decision-making, facilitate insulin action in the brain, modulating intracellular signaling cascades, gene expression, and neural activity. Here, we tested if variations in the expression of the insulin receptor gene network in the prefrontal cortex (PFC) and striatum (STR) moderates the association between early life adversity and eating behaviour in childhood and if this moderation is sex-specific. Participants from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) and Basal Influences on the Baby´s Development (BIBO) were included as two independent cohorts. A biologically-informed polygenic score reflecting functional variation of the mesocorticolimbic insulin receptor gene network was created by using insulin receptor co-expression data from the PFC and STR in mice, and validated in humans through filtering by homologous expression in PFC using well-known databases. Early life adversity exposure was measured as a composite score. Eating behaviour was characterized using the Child Eating Behaviour Questionnaire administered to mothers of children aged 4 and 6 years in MAVAN, and 6 years in BIBO. We found that only in those with high expression of the mesocorticolimbic insulin receptor gene network a higher early adversity score associated with a higher desire to drink in 4-year boys and 6-year girls, as well as a higher food approach score and food approach/food avoidance ratio in 4-year girls. Also, a higher early life adversity was associated with higher food responsiveness, food approach score and food approach/food avoidance ratio at 6 years in the MAVAN full sample. The moderation observed on desire to drink was partially found in BIBO children aged 6 years. Identifying individual differences in response to early adversity may help to prioritize individuals at high risk for long-term disease and to design suitable interventions.

Drought-mediated oxidative stress and its scavenging differ between citrus hybrids with medium and late fruit maturation

Drought stress is a major environmental factor limiting citrus productivity. Still, differences in drought sensitivity between citrus hybrids of different maturation periods have so far not been reported. Here, we selected a medium-maturing (Fertile orange: FO (Citrus reticulata cv. Fertile orange) and a late-maturing citrus hybrid (Newhall Navel orange: NO (Citrus sinensis Osbeck cv. Newhall) and determined the physiological and biochemical traits of leaves, roots, wood and bark. Our results showed that drought significantly decreased net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of citrus leaves. Oxidative stress upon drought was indicated by enhanced foliar malondialdehyde (MDA) and hydrogen peroxide contents, as well as a stimulation of the anti-oxidative system. This stimulation included the contents of dehydroascorbic acid (DHA), glutathione (GSH) and oxidized glutathione (GSSG) in leaves, roots, wood and bark, as well as activities of antioxidative enzymes of glutathione reductase (GR), dehydroascorbate reductase (DHAR), superoxide dismutase (SOD) and peroxidase (POD). The late maturing NO hybrid not only showed better general physiological performance as indicated by increased Pn in leaves, but also higher biochemical ROS scavenging and osmotic capacity as indicated by increased ascorbic acids (ASA), DHA, and proline contents, as well as activities of enzymes of SOD, POD, ASA/DHA and GSH/GSSG ratios in the investigated tissues compared to the FO hybrid under drought and control conditions. Analysis of molecular mechanisms of signaling, regulatory and functional genes expression are suggested for future studies to elucidate the complex interplay of molecular, biochemical and physiological responses of citrus hybrids to drought.

The discovery and simulation analysis of a novel mutation c.40 G < T (V14F) in the NRAS gene in patients with colorectal cancer in Saudi Arabia

BackgroundColorectal cancer (CRC) is the most diagnosed cancer in men and the second most common cancer in women and remains associated with high morbidity and mortality in Saudi Arabia. The current understanding of genetic heterogeneity of colorectal cancer biology encourages the identification of the genetic causes of CRC in the Saudi population. MethodsIn this study, we ascertained 89 CRC patients’ tumor samples from Saudi Arabia and investigated the molecular alterations of the NRAS proto-oncogene, GTPase (NRAS) gene by sequencing the collected CRC tumor tissue samples to identify gene mutations. The impact of mutations was analyzed using different bioinformatics tools including Missense3D algorithm of Swiss Model platform, molecular dynamics simulations using YASARA DYNAMICS and Protein Variation Effect Analyzer (PROVEAN) tool. ResultsWe identified a novel mutation c.40 G > T, in one patient in whom valine was replaced by phenylalanine (V14F). Notably, we also identified another mutation in the same codon c.40 G > A where valine is replaced by isoleucine (V14I). Our in-silico analysis revealed that this novel mutation alters the binding affinity of the NRAS gene substantially, and as a result, could have lethal consequences on the downstream signaling genes and pathways including MAPK and PI3K involved in regulating CRC growth and progression. ConclusionsThese findings provide insights into the molecular etiology of CRC in general and particularly in the Saudi population. Thus, these findings in NRAS mutation testing may also guide further treatment modalities, and more personalized therapy may be optimized.

Single-cell RNA transcriptomics in mice reveals embryonic origin of fibrosis due to maternal obesity

Over 40% of pregnant women in the USA are obese which negatively affects fetal development and offspring health. Maternal obesity (MO) leads to fibrotic infiltration in multiple tissues and organs of offspring during their adulthood although the origin and mechanisms are unclear. C57BL/6J female mice were fed a control and high-fat diet to mimic MO condition. Embryonic somatic tissues were obtained at E9.5, E11.5, and E13.5 (equivalent to 6 weeks of human pregnancy) from control (CON) and MO mice for single-cell RNA-sequencing (scRNA-seq). To explore the role of AMP-activated protein kinase (AMPK), AMPK was activated by metformin and A769662, and knocked out in embryonic mesenchymal cells (EMC) using AMPKα1 floxed mice. Using unsupervised clustering, we identified three major cell populations with fibrogenic capacity. Compared to CON, the population of fibrogenic cells increased dramatically (by ∼125%) due to MO, supporting an embryonic origin of fibrosis in the offspring. MO induced inflammatory response and elevated expression of transforming growth factor β (TGFβ) signalling and fibrogenic genes in embryos. MO inhibited AMPK and its activation by metformin and A769662 inhibited TGFβ signalling and fibrogenesis. MO profoundly enhances embryonic fibrogenesis, explaining the origin of fibrosis in the offspring of mothers living with obesity. Our data underscore the importance of early intervention, before 5-6 weeks of pregnancy, in improving embryonic development, and AMPK is an amiable target for suppressing excessive fibrogenesis in MO embryos to assist increasing populations of obese mothers having healthy children. This work was funded by National Institutes of Health Grant R01HD067449.

Differential cellular communication in tumor immune microenvironment during early and advanced stages of lung adenocarcinoma.

Heterogeneous behavior of each cell type and their cross-talks in tumor immune microenvironment (TIME) refers to tumor immunological heterogeneity that emerges during tumor progression and represents formidable challenges for effective anti-tumor immune response and promotes drug resistance. To comprehensively elucidate the heterogeneous behavior of individual cell types and their interactions across different stages of tumor development at system level, a computational framework was devised that integrates cell specific data from single-cell RNASeq into networks illustrating interactions among signaling and metabolic response genes within and between cells in TIME. This study identified stage specific novel markers which remodel the cross-talks, thereby facilitating immune stimulation. Particularly, multicellular knockout of metabolic gene APOE (Apolipoprotein E in mast cell, myeloid cell and fibroblast) combined with signaling gene CAV1 (Caveolin1 in endothelial and epithelial cells) resulted in the activation of T-cell mediated signaling pathways. Additionally, this knockout also initiated intervention of cytotoxic gene regulations during tumor immune cell interactions at the early stage of Lung Adenocarcinoma (LUAD). Furthermore, a unique interaction motif from multiple cells emerged significant in regulating the overall immune response at the advanced stage of LUAD. Most significantly, FCER1G (Fc Fragment of IgE Receptor Ig) was identified as the common regulator in activating the anti-tumor immune response at both stages. Predicted markers exhibited significant association with patient overall survival in patient specific dataset. This study uncovers the significance of signaling and metabolic interplay within TIME and discovers important targets to enhance anti-tumor immune response at each stage of tumor development.

A Study on the Rationality of Baicalein in the Treatment of Osteoporosis: A Narrative Review.

Baicalein (BN) is an active ingredient naturally present in Chinese herbs, such as Scutellaria baicalein, Coptis chinensis, and Dendrobium officinale. It has a variety of pharmacological activities, including antioxidant, anti-inflammatory and antibacterial effects. Therefore, Baicalein (BN) is widely used in the field of medicine and is considered a potential natural medicine. Osteoporosis (OP) is a bone metabolic disease characterized by decreased bone mineral density and bone structure destruction, which is mainly caused by decreased bone formation and increased bone resorption. With the continuous development of molecular biology, the signaling pathways and gene targets of bone metabolism are also expanding. Recent studies have shown that baicalein may affect the function of osteoblasts, osteoclasts, and bone marrow mesenchymal stem cells through MAPK/ERK and MAPKs/NF-κB signaling pathways, so as to have a therapeutic effect on OP. However, the specific mechanism of baicalein in the treatment of OP is still unclear. This article reviews the literature, analyzes and summarizes the mechanism of action of baicalein, and discusses its potential in the prevention and treatment of OP, so as to provide a basis for the clinical application of baicalein.