Biology subjects

Anwar, S.

Publications and source records attributed to Anwar, S..

At least 19 recordsLinked to original sources

bioRxiv2026

Neural Crest-Derived Endocardial Cells Required for Heart Valve Development

Abnormalities in cardiac valves, which maintain unidirectional blood flow through the heart, affect 2-3% of people worldwide and are the most common form of structural heart disease (1).Yet the cell types that make up the valve, and how they communicate to direct development and homeostasis, remain poorly understood. Here, we identify a rare, essential population of highly secretory valve endocardial cells in mouse and human that derive from migrating neural crest cells. Ablation of these cells in mice caused perinatal lethality with thickened leaflets, stenosis, and regurgitation, mirroring human valve disease. This subset of endocardial cells uniquely expresses the secreted signaling protein parathyroid hormone-like hormone (Pthlh). Global disruption of Pthlh caused valve stenosis and lethality and neural crest-specific deletion produced similar valve disease, with impaired maturation of valvular interstitial cells and disrupted bone morphogenetic protein signaling. These findings identify a previously unrecognized cell type and signaling pathway essential for valve morphogenesis, with implications for the pathogenesis and treatment of human valve defects.

developmental biology↗

bioRxiv2026

Autologous biopsy-derived co-culture platform for interrogation of intestinal epithelial-T cell crosstalk

Interactions between intraepithelial lymphocytes (IELs) and the intestinal epithelium are central to mucosal homeostasis and disease. However, mechanistic in vitro studies describing their crosstalk in humans are limited by scarceness of primary material and insufficient knowledge about co-culture requirements. Here, we establish an autologous human duodenal IEL-organoid co-culture system encompassing expandable and bankable IEL and organoid protocols, with co-culture conditions that allow viability of both cell types. This system enables successive interrogation of lympho-epithelial interactions starting from minimal biopsy material. Under baseline conditions, CD45CD8CD103TCR{beta} IELs retain tissue-residency and effector features and induce an epithelial interferon response and chemokine production, without overt epithelial apoptosis. IL-15 and IL-21, essential cytokines involved in IEL-activation in intestinal enteropathies like celiac disease, increases granzyme B expression and interferon-{gamma} secretion but do not trigger epithelial cell death. However, enforcing IEL-epithelial contact using an anti-CD3-anti-Ep-CAM bispecific antibody induces epithelial apoptosis accompanied by increased tumor necrosis factor (TNF) and FAS-ligand (FASLG) secretion. These findings validate the platforms ability to resolve non-destructive and cytotoxic lympho-epithelial interaction and provide a tractable system for studying intestinal inflammation and immune-mediated epithelial cell death.

immunology↗

bioRxiv2026

Identification of Human Gut Microbiome Derived Peptides Targeting Biofilm Specific Lectin Proteins of Pseudomonas aeruginosa

The carbohydrate-binding proteins (LecA and LecB) present within the extracellular polymeric substance (EPS) matrix of Pseudomonas aeruginosa play an essential role in maintaining the structural integrity of the biofilms through interactions with the EPS polysaccharides. Therefore, targeting the above lectins can turn out to be one of the promising strategies for disrupting P. aeruginosa biofilms. In the current study, we investigated the potency of antimicrobial peptides (AMPs) produced by the human gut microbiome in targeting LecA and LecB proteins of P. aeruginosa. Initially, a comprehensive in-silico pipeline was developed to identify and characterize putative antibacterial and antibiofilm AMPs produced by the human gut microbiome. These AMPs were then subsequently studied for their interaction with the lectin proteins through molecular docking, MM-GBSA, residue analysis, and molecular dynamics (MD) simulation. Among the studied peptides, amp21 and amp24 exhibited the strongest interactions with the lectin protein, occupying binding sites overlapping with key active-site residues previously reported for raffinose binding. amp6, amp21, and amp24 were selected for in vitro validation based on the MD simulation results of both LecA and LecB proteins. The above selected peptides exhibited minimal hemolytic activity across the tested concentration range. amp21 and amp6 were non-toxic to mammalian cells while amp24 demonstrated cytotoxicity only at higher doses. amp21 was found to be the most potent AMP and inhibited the growth of P. aeruginosa by [~]60% at 50 {micro}g mL{square}{superscript 1}. amp6 and amp21 resulted in a significant disruption of P. aeruginosa biofilms. Membrane permeabilization assays and scanning electron microscopy revealed that amp6, amp21, and amp24 damaged the bacterial cell membranes apart from compromising the integrity of the biofilm EPS matrix. Lastly, through in-silico studies, we designed ultrashort peptides (USPs) from the lead AMPs. The USPs (amp21.4 and amp24.2) exhibit superior antibiofilm efficacy compared to their parent AMPs. These findings establish human-gut microbiome-derived AMPs as promising candidates to target P. aeruginosa biofilms via inhibition of lectin proteins.

microbiology↗

bioRxiv2026

Interleukin-6 restricts pre-thymic T cell lineage commitment of progenitors driving loss of SIV control

Effective T cell reconstitution in people living with HIV is central to durable immune control and cure strategies. Sustained thymic output underpins T cell recovery and requires continuous seeding by T cell-committed progenitors originating in the bone marrow (BM). Using the SIV/rhesus macaque model, we identified a thymus-seeding progenitor (TSP; CD4-CD8-CD34CD38-CD7) in BM declining rapidly following SIV infection. This loss closely associated with reduction in T cell lineage committed differentiation of BM-derived hematopoietic stem and progenitor cells (HSPCs). Importantly, both the decline in TSPs and the impairment of pre-thymic T cell potential were strongly associated with early loss of viral control, independent of peripheral T cell dynamics. Plasma interleukin-6 (IL-6) levels robustly predicted the magnitude of TSP loss and the restriction of T cell-biased HSPC differentiation. Integrated transcriptomic and proteomic analyses revealed inflammatory imprinting of HSPCs characterized by activation of the IL-6-JAK-STAT axis, inflammasome engagement, and coordinated suppression of key T cell specification factors, including RUNX1, FYN, and ZAP70. In a nonanimal model of thymopoiesis, IL-6 exposure of rhesus macaque and human HSPCs inhibited their transition from DN1 (CD38-) to DN2 (CD38) TSP states, indicating an early block in T cell lineage commitment. Conversely, ex vivo IL-6 receptor blockade restored thymocyte differentiation to levels comparable to untreated controls. Collectively, these findings demonstrate that pathogenic inflammation restricts pre-thymic T cell development early after infection, directly contributing to loss of viral control. These findings have important implications for understanding the mediators of anti-viral T cell immunity and HIV cure.

immunology↗

bioRxiv2026

Genome-Wide in silico analysis reveals activation of a silent resistome driving imipenem resistance in Pseudomonas aeruginosa

Resistance to imipenem in Pseudomonas aeruginosa relies on multiple factors that remain poorly understood. In our work, we performed a systemic analysis of genome-wide changes involved in resistance in a set of 95 clinically unrelated strains, including 41 resistant (MIC [≥] 64 mg/L) and 54 susceptible (MIC [≤] 2 mg/L) isolates. Our approach is based on the pan-genomics analysis, combining the use of core-genome phylogenetic analysis, MLST (Multilocus Sequence Typing), GWAS (Genome-Wide Association Studies) and variant level profiling of the blaOXA genes. Higher-order structure within the set was studied using methods of the co-occurrence networks and WGCNA (weighted gene co-expression network analysis) specifically adjusted to handle presence/absence data. Despite having a broader and more diverse resistome, no clonal grouping of the resistant isolates was observed indicating independent evolutionary origins. The LASSO model using a lineage-aware approach showed robust predictive capability (AUC = 0.836) that validates the polygenic characteristic of resistance. Twelve accessory genes were found to be significant determinants of resistance; however, only four genes (group_10880, group_10887, group_4947, and phzB) were identified using both GWAS and gene network analysis, showing involvement in protein folding, metal stress response, genome plasticity, and metabolic adaptation. Interestingly, some carbapenemase-active variants of blaOXA were also found in imipenem-susceptible strains, showing that gene presence alone does not ensure resistance. We therefore propose the Silent Resistome Activation Model, where resistance genes become functional only with support from identified accessory genes and coordinated interactions at both the genomic and network levels.

bioinformatics↗

bioRxiv2025

Phylogenetic Analysis of Beta-Lactamases Reveals Distinct Evolutionary Patterns of Chromosomal and Plasmid-Encoded BLs and the Mosaic Role of VIM Linking NDM and IMP

Beta-lactamases (BLs) are a major driver of antibiotic resistance in pathogens like Acinetobacter baumannii, Enterobacteriaceae and Pseudomonas aeruginosa. This study explores the structural stability and functional divergence of metallo-beta-lactamases (MBLs) and AmpC through study of protein-protein interaction (PPI) network analysis, phylogenetics and identification of conserved domains and motifs. The study also involves analysis of co-evolutionary dynamics of BLs with related genes. PPI analysis identified NagZ as central interacting partner for BLs in P. aeruginosa and Enterobacteriaceae, suggesting its pivotal role in BL expression, and highlighting its probable role as a potential drug target. In contrast, A. baumannii exhibited such a high diversity in protein interactions, that considering a single protein as topmost interacting partner was difficult. Phylogenetic analysis revealed strong co-evolutionary trends between functionally-related proteins. A. baumannii and Enterobacteriaceae were found to be closely related in case of not just the chromosomally-encoded MBL-fold containing proteins, but also the true MBLs which are plasmid-encoded. On the other hand, similar evolutionary patterns for chromosomally-encoded BLs like AmpC and related genes was found in A. baumannii and P. aeruginosa. Analysis of PFAM domains showed that catalytic and substrate binding domains are more conserved than accessory ones. Several motifs, such as, ASNGLI were found to be conserved across all MBLs and thus carry the potential to be significant drug targets. Finally, inter-BL analysis revealed that VIM acts as an evolutionary link by acting like a mosaic between IMP and NDM as supported by intermediate GC content, positioning in phylogenetic trees and shared sequence features.

evolutionary biology↗

bioRxiv2025

Dissipation of lysosome pH impairs formation and collapses existing LPS-induced lysosome tubules in macrophages

While lysosomes are typically globular in morphology, lipopolysaccharide-activated macrophages reorganize lysosomes into an expanded tubular network. Here, we sought to determine if the V-ATPase and the lysosomal pH contribute to LPS-mediated lysosome tubulation in macrophages. We found that inhibition of the V-ATPase prevented lysosome tubulation and collapsed preformed tubules. However, the V-ATPase also controls mTORC1 activity, which itself is needed for tubulation. To distinguish between lysosomal pH and mTORC1, we turned to NH4Cl, which alkalinized lysosomal pH but did not interfere with mTORC1; yet NH4Cl blocked tubulation showing that an acidic lysosomal pH is needed for lysosome remodelling. Moreover, clamping the pH to either acidic or alkaline pH caused tubules to collapse, indicating that the pH gradient promotes tubulation, rather than a specific pH. These effects were not due to altered microtubule organization or impaired lysosome motility, suggesting that motors remained associated with lysosomes. On the other hand, while LPS did not alter the average pH of spherical or tubular lysosomes, growing tubules displayed a more acidic peripheral end relative to the pericentral end. Based on this observation, we propose that a localized pH gradient along the tubule may enable tubulation by modulating factors that catalyse tubule growth.

cell biology↗

bioRxiv2025

A thymus-independent artificial organoid system supports complete thymopoiesis from Rhesus macaque-derived hematopoietic stem and progenitor cells

Thymic output has been extensively studied. While advanced ex-vivo T cell generative approaches exist for mouse and human models, such advancements for nonhuman primate model are lacking. We report the establishment of a rhesus macaque-specific artificial thymic organoid (Rh-ATO) system enabling robust ex vivo T cell generation from CD34 hematopoietic stem and progenitor cells (HSPCs). A continuum of distinct thymopoietic stages were recorded - robust T cell specification of HSPCs resembling thymus seeding progenitors, emergence of CD4+CD3-immature single positive, CD4+CD8+ double positive thymocytes, and finally, generation of CD4 and CD8 single-positive T cell subsets expressing CD38, consistent with recent thymic emigrant phenotype. These events closely mirrored Bonafide thymopoietic stages observed in the thymus. T cells expressed TCRs and exhibited polyfunctional cytokine expression. Thus, we report first demonstration of an off the shelf NHP-specific 3D system recapitulating thymopoiesis, providing a translational platform for modeling T cell development, therapeutic strategies, and immunopathogenesis.

immunology↗

bioRxiv2025

How F repeats help in peptide binding with VIM-2 metallo-beta-lactamase and destabilizing the enzyme

The global surge in antimicrobial resistance is a major public health concern, largely driven by the dissemination of beta-lactamases. Among them, VIM-2 metallo-beta-lactamase (MBL) poses a significant therapeutic challenge. In this study, we explore the role of phenylalanine and lysine residues, especially their repeat patterns, in modulating peptide binding affinity and structural interactions with VIM-2. Docking, molecular dynamics simulations, free energy decomposition analysis and residue analysis were conducted on gut metagenome-derived AMPs, PolyF and a control peptide (PolyR). Binding affinity with VIM-2 decreased with declining F content, yet PolyF alone showed unexpectedly low binding. However, PolyF exhibited most negative polar solvation energy in free energy decomposition analysis. This indicates that F repeats play a role in stabilizing a VIM-2-peptide complex in presence of a solvent. PolyF peptide lacks favorable electrostatic or dynamic interactions, likely due to the absence of K residues. Interestingly, loop1 and loop2 analysis of VIM-2 revealed that F repeats interfere with the loops that play a role in functioning of substrate binding at the active site. Additionally, F repeats were found to bind to residues lying adjacent to or nearby active site residues, which points towards the fact that F helps other residues like K to bind more stably with active site residues of VIM-2. Finally, analog designing and analysis reveals that a balance of aromatic (F) and positively charged (K) residues could enhance peptide binding with MBLs like VIM-2 when having hydrophobic on N-terminal and positively charged on C-terminal.

bioinformatics↗

bioRxiv2025

Plant silicon defence disrupts cryptic colouration in an insect herbivore by restricting carotenoid sequestration into the haemolymph

O_LICryptic colouration is a primary anti-predation strategy in herbivorous insects. Achieving crypsis often requires acquiring dietary carotenoids--tetraterpene pigments vital for plant colouration and photoprotection. Silicon (Si) accumulation in plants makes tissues tougher and less digestible for insects, but its effect on plant pigment levels remains unclear. It is also unknown whether feeding on silicified plants impairs insects ability to sequester carotenoids and achieve crypsis. C_LIO_LIUsing the model grass Brachypodium distachyon, we demonstrate that the cotton bollworm (Helicoverpa armigera) larvae exhibited stunted growth and reduced carotenoid sequestration, particularly lutein, into their hemolymph when feeding on Si- supplemented (+Si) plants. This reduction led to distinct body-colour morphs: larvae feeding on +Si plants developed brown colouration, contrasting sharply with the green leaves, whereas larvae feeding on Si-free (-Si) plants exhibited green cryptic colouration that blended seamlessly with the foliage. C_LIO_LIPlant leaves contained various carotenoids (neoxanthin, violaxanthin, {beta}-carotene and lutein) and chlorophylls (a and b), but larvae only sequestered {beta}-carotene and lutein into their haemolymph while excreting substantial amounts of pigments, regardless of plant Si status. Under insect-free conditions, +Si plants had lower carotenoid and chlorophyll contents than -Si plants. However, following insect herbivory, pigment levels in -Si and +Si plants equalised. Insect herbivory also increased Si accumulation in +Si plants. C_LIO_LIOur findings provide novel evidence that plant Si defences can disrupt cryptic colouration in insect herbivores by restricting carotenoid sequestration from host plant tissues. This disruption could increase insect visibility to predators, potentially elevating their risk of predation. C_LI

ecology↗

bioRxiv2025

High-frequency Wus2-integrated transformation toolkit enhances Cas9 editing efficiency and expands capability with SpRY in sorghum

Sorghum bicolor L. (Moench), the fifth most important cereal crop internationally, is used as food, feed, forage, and fuels. Importantly, sorghums natural tolerance to environmental stresses leads to tolerance to climate variation. To optimize sorghum germplasm for crop improvement requires highly efficient genetic transformation and genome editing; however, sorghum has historically been recalcitrant to these genetic approaches. In this study, we report a high-efficiency engineering toolkit, optimized for genome editing via Agrobacterium-mediated transformation. Using CRISPR/Cas9-based editing machinery, the genetic tools led to editing efficiencies up to 95.7% when monocistronic guide RNAs targeted the phytoene desaturase (SbPDS) gene. We also tested a PAM (protospacer adjacent motif)-broadened Cas9 variant, intronized SpRY (ZmSpRYi), achievling comparable editing efficiencies. Using this toolkit permits exploitation of advanced editing tools, like prime editors, base editors, and targeted knock-in methods. These genetic advances offer new methods for sustainable crop improvement in sorghum and potentially other cereals. Technology readinessThis study demonstrates the development of an integrated genome engineering platform that combines morphogenic gene-assisted transformation with CRISPR/Cas9- and SpRY-mediated mutagenesis for multiplex genome editing, establishing a Technology Readiness Level (TRL) of 4/5. This workflow enables the generation of allelic variants through editing of both functional and regulatory elements in the plant genome. Advancing toward TRL 5 will require additional validation in relevant sorghum genotypes, including elite varieties. Moreover, the PAM-flexible editor SpRY is still under optimization, particularly at non-canonical PAM sites, which may limit its application for the modification of certain cis-regulatory elements. Further improvements in precision genome editing, such as the integration of prime editing or targeted knock-in technologies, will also be necessary to enable desired and predictable modifications. With continued optimization and incorporation of these advanced tools, this robust genome engineering platform has the potential to accelerate plant breeding and enable basic research supporting plant-based solutions to address climate change.

plant biology↗

bioRxiv2025

Activation of cGAS-STING signaling pathway during HCV infection

Hepatitis C virus (HCV) is a major global health issue, infecting over 170 million people worldwide and leading to severe liver diseases, including cirrhosis and hepatocellular carcinoma. The ability of HCV to persist and cause chronic infection is partly due to its evasion of the hosts innate immune responses, particularly those mediated by the RIG-I-MAVS pathway, which is critical for antiviral defense. Studies have shown the crucial role genome sensing of DNA viruses by cyclic GMP-AMP synthase (cGAS) followed cGAMP production and activation of downstream effector STING (stimulator of interferon genes) to induce IFN-{beta}, however it is not understood in RNA viruses specially in HCV infection. In this study, we explored first time the mechanism of the cGAS-STING pathway in the context of HCV infection, specifically using the JFH-1 strain of HCV (genotype 2a). We observed that cGAS expression is significantly upregulated during the early HCV infection, leading to the production of the second messenger cyclic GMP-AMP (cGAMP), which in turn activates STING. This activation results in the significant induction of type I interferon responses, particularly interferon-{beta} (IFN-{beta}), which is essential for mounting an effective antiviral response. Moreover, our results demonstrated the translocation of cGAS and STING with cellular organelles such as the endoplasmic reticulum (ER) and mitochondria. This suggests that the cGAS-STING pathway is intricately linked with other cellular signaling networks in detecting and responding to HCV infection. Furthermore, knockdown experiments targeting cGAS, STING and RIG-I revealed that these proteins play a crucial role in suppressing HCV replication, underscoring their potential as therapeutic targets. These findings provide valuable insights into the molecular mechanisms of the cGAS-STING pathway in mediating the innate immune response against HCV. Understanding this pathways role in the immune defense against HCV opens up new possibilities for therapeutic strategies aimed at enhancing the hosts antiviral immunity and potentially developing new treatments for chronic HCV infection.

microbiology↗

bioRxiv2025

Star-Shaped Glatiramer Acetate Mitigates Pulmonary Dysfunction and Brain Neurodegeneration in a Murine Model of Cryptococcus-Associated IRIS

Cryptococcal-associated immune reconstitution inflammatory syndrome (C-IRIS) is a clinical worsening or new presentation of cryptococcal disease following the initiation of antiretroviral therapy. C-IRIS is primarily driven by an influx of pathological CD4+ T cells, which triggers a hyperinflammatory response. The murine model of C-IRIS is a way to study the disease in mice and understand how the immune system triggers life-threatening outcomes in patients. We previously developed a murine C-IRIS model and demonstrated that C-IRIS is triggered by pathological CD4+ T cells, particularly Th1 cells, in the brain, which triggers neurodegeneration and pulmonary dysfunction. Using this unique mouse model, we tested the therapeutic effect of a star-shaped glatiramer acetate (sGA), which is a more effective isomeric form than linear GA. Here, we observed that sGA suppresses Th1 differentiation in the lung tissues, reducing CD4+ T cell and Th1 cell count. It also reduced microglia populations in the brain. Together, these changes improved respiratory dysfunction caused by C-IRIS, lowered mortality rate, and reduced brain neurodegeneration. These findings suggest that sGA could be an effective therapeutic strategy for managing C-IRIS.

immunology↗

bioRxiv2022

An energy-saving glasshouse film reduces seasonal, and cultivar dependent Capsicum yield due to light limited photosynthesis

Glasshouse films can be used to reduce energy costs by limiting non-productive heat-generating radiation, but the impact on yield of greenhouse horticultural crops remains unknown. The effects of energy-saving film ULR-80 (referred to as Smart Glass; SG) designed to block long wavelength light that generates heat also reduced photosynthetically active radiation (PAR) consequently affecting crop morphology, photosynthesis, leaf pigments, and yield of two hydroponically grown capsicum (Capsicum annuum L.) cultivars (Red and Orange). The crops were grown in four high-tech glasshouse bays over two seasons of similar daily light integrals (DLI) during ascending (Autumn) and descending (Summer) photoperiods. The Red cultivar exhibited higher photosynthetic rates (light saturated - Asat and maximal - Amax) and yield than the Orange cultivar in control but displayed stronger reductions in modelled photosynthetic rates at growth light and yield in SG without changes in photosynthetic capacity. Foliar pigment ratios of chlorophyll a/b and carotenoid: chlorophyll remained unaffected by the SG during both seasons indicating that chloroplast homeostasis was similar between SG and control. The seasonal differences in photosynthetic pigments and xanthophyll de-epoxidation state (DPS) revealed that cultivars were able to sense the SG-altered light environment during the ascending, but not descending photoperiod. The descending photoperiod correlated with a lower daily light level and a substantial yield reduction of 29 % and 13 % in Red and Orange cultivars, respectively. Thus, SG-induced higher reductions in yield during the descending photoperiod indicate that SG may be more beneficial for capsicum crops planted during Autumn with an ascending photoperiod. HighlightsO_LIA potential energy saving SG film limited net photosynthesis of capsicum C_LIO_LIThe SG film reduced yield of two capsicum cultivars that can be mitigated by planting during the low light growth season with a shorter photoperiod C_LIO_LISG reduced genotype-dependent capsicum yield was associated with alterations in the level of foliar pigments required for photoprotection under adverse light conditions C_LI

plant biology↗

bioRxiv2022

Biochemical analysis, photosynthetic gene (psbA) down-regulation, and in silico receptor prediction in weeds in response to exogenous application of phenolic acids and their analogs

Chemical herbicides are the primary weed management tool, although several incidences of herbicide resistance have been emerged, causing serious threat to agricultural sustainability. Plant derived phenolic acids with herbicidal potential may provide organic and eco-friendly substitute to such harmful chemicals. In present study, efficacy of two phenolic compounds, ferulic acid (FA) and gallic acid (GA), were evaluated in vitro and in vivo against three prevalent herbicide-resistant weed species (Sinapis arvensis, Lolium multiflorum and Parthenium hysterophorus). FA and GA not only suppressed the weed germination (80 to 60 % respectively), but also inhibited biochemical and photosynthetic pathway of weeds. In addition to significantly lowering the total protein and chlorophyll contents of the targeted weed species, the application of FA and GA treatments increased the levels of antioxidant enzymes and lipid peroxidation. Photosynthetic gene (psbA) expression was downregulated (10 to 30 folds) post 48 h of phenolic application. In silico analysis for receptor identification of FA and GA in psbA protein (D1) showed histidine (his-198) and threonine (thr-286) as novel receptors of FA and GA. These two receptors differ from the D1 amino acid receptors which have previously been identified (serine-264 and histidine-215) in response to PSII inhibitor herbicides. Based on its toxicity responses, structural analogs of FA were also designed. Four out of twelve analogs (0.25 mM) significantly inhibited weed germination (30 to 40%) while enhancing their oxidative stress. These results are unique which provide fundamental evidence of phytotoxicity of FA and GA and their analogs to develop cutting-edge plant based formulation to suppress weed growth in future.

biochemistry↗

bioRxiv2021

GOLDEN TANGERINE TOMATO ROOTS SHOW INCREASED ACCUMULATION OF ACYCLIC CAROTENOIDS, LESS ABSCISIC ACID, DROUGHT SENSITIVITY, AND IMPAIRED ENDOMYCORRHIZAL COLONIZATION

Heirloom golden tomato fruit varieties are highly nutritious as they accumulate tetra-cis-lycopene, which has a higher bioavailability and recognised health benefits in treating anti-inflammatory diseases compared to all-trans-lycopene isomers found in red tomatoes. We investigated if photoisomerization of tetra-cis-lycopene occurs in roots of the golden tangerine Micro-Tom variety (tangmic), and how this affects root to shoot biomass, mycorrhizal colonization, abscisic acid accumulation, and responses to drought. tangmic plants grown in soil under glasshouse conditions displayed a reduction in height, number of flowers, fruit yield, and root length compared to wild type (WT). Soil inoculation with Rhizophagus irregularis revealed fewer arbuscules and other fungal structures in the endodermal cells of roots in tangmic relative to WT. The roots of tangmic hyperaccumulated acyclic cis-carotenes, while only trace levels of xanthophylls and abscisic acid were detected. In response to a water deficit, leaves from the tangmic plants displayed a rapid decline in maximum quantum yield of photosystem II compared to WT, indicating a defective root to shoot signalling response to drought. The lack of xanthophylls biosynthesis in tangmic roots reduced abscisic acid levels, thereby likely impairing endomycorrhiza colonisation and drought-induced root to shoot signalling. Research HighlightsO_LIPhotoisomerization of prolycopene to lycopene is limited in root plastids. C_LIO_LIRoots of tangerine reveal an important tissue sink to store micronutrients such as prolycopene. C_LIO_LIRoots of tangerine lack ABA and show impaired mycorrhizal colonization. C_LIO_LIThe tangerine plant is drought sensitive and has a smaller biomass as well as reduced yield. C_LI

plant biology↗

bioRxiv2021

Anti-allergic and anti-inflammatory activities of black cumin extracts in in vitro and in vivo model systems

Black cumin (Nigella sativa) is a widely used ingredient of traditional medicine for its broad-spectrum pharmacological actions, including anti-allergic, bronchial asthma, and anti-inflammatory properties. We sought to evaluate BC extracts efficacy for their anti-allergic and anti-inflammatory properties using a comprehensive in vitro, in vivo, and silico experimental setup. To investigate whether BC extract has anti-inflammatory, anti-allergic, and analgesic therapeutic potentials in vitro and in vivo. The activity of BC was assessed through anti-allergic activity on rat basophilic leukemia-2H3 cell line, anti-inflammatory activity on J774.1A cell line, anti-inflammatory activity by carrageenan-induced rat paw edema, analgesic activity by acetic acid-induced writhing test, and ingenuity analysis of the BC extracts in inflammation control. BC exerted potent anti-allergic activity by inhibiting antigen-induced degranulation. An anti-inflammatory effect is shown by inhibiting TNF- production. The acetic acid-induced writhing test shown a dose-dependent reduction of writhing number following BC administration. Rat paw edema test shown the dose-dependent reduction of paw edema volume following BC administration. Ingenuity Pathway Analysis (IPA) suggested BC extracts containing ferulic acid, p-coumaric acid, kaempferol, and quercetin can inhibit inflammation. This study suggests that bioactive compounds in BC extract act as an anti-allergic and anti-inflammatory agent by regulating several downstream and upstream inflammation pathways.

plant biology↗

bioRxiv2021

Neuroprotective derivatives of tacrine that target NMDA receptor and acetyl cholinesterase - Design, synthesis and biological evaluation

The complex and multifactorial nature of neuropsychiatric diseases demands multi-target drugs that can intervene with various sub-pathologies underlying disease progression. Targeting the impairments in cholinergic and glutamatergic neurotransmissions with small molecules has been suggested as one of the potential disease-modifying approaches for Alzheimers disease (AD). Tacrine, apotent inhibitor of acetylcholinesterase (AChE) is the first FDA approved drug for the treatment of AD. Tacrine is also a low affinity antagonist of N-methyl-D-aspartate receptor (NMDAR). However, tacrine was withdrawn from its clinical use later due to its hepato-toxicity. With an aim to develop novel high affinity multi-target directed ligands (MTDLs) against AChE and NMDAR, with reduced hepatotoxicity, we performed in silico structure-based modifications on tacrine, chemical synthesis of the derivatives and in vitro validation of their activities. Nineteen such derivatives showed inhibition with IC50 values in the range of 18.53{+/-}2.09 to 184.09{+/-}19.23 nM against AChE and 0.27{+/-}0.05 to 38.84{+/-}9.64 M against NMDAR. Some of the selected compounds also protected rat primary cortical neurons from glutamate induced excitotoxicity. Two of the tacrine derived MTDLs, 201 and 208 exhibited in vivo efficacy in rats by protecting against behavioral impairment induced by administration of the excitotoxic agent, monosodium glutamate. Additionally, several of these synthesized compounds also exhibited promising inhibitory activities against butyrylcholinesterase and {beta}-secretase. Given the therapeutic potential of MTDLs in disease-modifying therapy, our studies revealed several promising MTDLs of which 201 appears to be a potential candidate for immediate preclinical and clinical evaluations.

neuroscience↗