Unveiling the Immunostimulatory Potential of Rhus Toxicodendron in Immunocompromised Balb/C Mice Induced with Cyclophosphamide.

This study investigated how Rhus toxicodendron (RT) (6C, 30C, and 200C) can boost the immune system of BALB/c mice that were given cyclophosphamide (CPM), which is an anticancer drug that weakens the immune system. RT, known for its historical use in traditional homeopathic remedies, has demonstrated immunomodulatory and anti-inflammatory effects in various experimental models. To test the immune-boosting effects of RT, CPM (80 mg/kg) was given intraperitoneally to mice on days 4, 8, and 12 of the study but not to the normal control group. CPM-induced immunosuppression led to significant decreases in red blood cell (RBC), white blood cell (WBC), and hemoglobin (Hb) levels, and reduced spleen and thymus indices. Phagocytic activity, cytokine concentrations, and spleen architecture were also adversely affected. RT treatment, particularly at 200C, significantly ameliorated these effects, improving RBC, WBC, and Hb levels. Furthermore, RT partially prevented CPM-induced atrophy of immune organs. Treatment positively influenced cytokine production at both the protein and mRNA levels, restoring immune balance. Histopathological results confirmed that RT stimulated the immune system. The cells were more stable, and the white pulp in the spleen was arranged in a regular pattern. These findings suggest that RT may serve as an adjunctive immunostimulant therapy for conditions characterized by immunosuppression. However, further investigations in other immunocompromised states must validate these results before considering human clinical trials.

The IRE1α/XBP1 signaling axis drives myoblast fusion in adult skeletal muscle.

Skeletal muscle regeneration involves a signaling network that regulates the proliferation, differentiation, and fusion of muscle precursor cells to injured myofibers. IRE1α, one of the arms of the unfolded protein response, regulates cellular proteostasis in response to ER stress. Here, we demonstrate that inducible deletion of IRE1α in satellite cells of mice impairs skeletal muscle regeneration through inhibiting myoblast fusion. Knockdown of IRE1α or its downstream target, X-box protein 1 (XBP1), also inhibits myoblast fusion during myogenesis. Transcriptome analysis revealed that knockdown of IRE1α or XBP1 dysregulates the gene expression of molecules involved in myoblast fusion. The IRE1α-XBP1 axis mediates the gene expression of multiple profusion molecules, including myomaker (Mymk). Spliced XBP1 (sXBP1) transcription factor binds to the promoter of Mymk gene during myogenesis. Overexpression of myomaker in IRE1α-knockdown cultures rescues fusion defects. Inducible deletion of IRE1α in satellite cells also inhibits myoblast fusion and myofiber hypertrophy in response to functional overload. Collectively, our study demonstrates that IRE1α promotes myoblast fusion through sXBP1-mediated up-regulation of the gene expression of multiple profusion molecules, including myomaker.

Expanding Possibilities for Foreign Gene Expression by Cucumber Green Mottle Mosaic Virus Genome-Based Bipartite Vector System.

Expanding possibilities for foreign gene expression in cucurbits, we present a novel approach utilising a bipartite vector system based on the cucumber green mottle mosaic virus (CGMMV) genome. Traditional full-length CGMMV vectors face limitations such as a restricted cargo capacity and unstable foreign gene expression. To address these challenges, we developed two 'deconstructed' CGMMV genomes, DG-1 and DG-2. DG-1 features a major internal deletion, resulting in the loss of crucial replicase enzyme domains, rendering it incapable of self-replication. However, a staggered infiltration of DG-1 in CGMMV-infected plants enabled successful replication and movement, facilitating gene-silencing experiments. Conversely, DG-2 was engineered to enhance replication rates and provide multiple cloning sites. Although it exhibited higher replication rates, DG-2 remained localised within infiltrated tissue, displaying trans-replication and restricted movement. Notably, DG-2 demonstrated utility in expressing GFP, with a peak expression observed between 6 and 10 days post-infiltration. Overall, our bipartite system represents a significant advancement in functional genomics, offering a robust tool for foreign gene expression in Nicotiana benthamiana.

A quantitative comparison of macro-plastic debris between undisturbed and populous coastal ecosystems of West Bengal, India.

Unmanaged plastic debris from both terrestrial and aquatic sources is causing havoc on Indian coastlines. Tajpur Beach and Haliday Island were selected as two distinct coastal ecosystems in West Bengal for inventorying sighted macro-plastics, aiming to assess their distribution and compare pollution levels. This study employs a comprehensive methodological approach, integrating field-based observations along with lab-based measurements, and information derived from geospatial analysis. Total 34 random points across two study sites were considered for the physical, chemical, and biological characterization of macro-plastics to assess their relative abundance. Areas with higher human footfalls exhibited greater accumulation of plastic debris, with polypropylene, either alone or in combination with polyurethane and polystyrene, identified as highly toxic. Fragmented plastic debris was prevalent at both test sites, yet undisturbed Haliday Island exhibited an abundance of less fragmented materials. Emphasis was also given on implementing appropriate management regimes to achieve plastic-free diverse coastal landscapes.

Identification of quantitative trait loci (QTLs) regulating leaf SPAD value and trichome density in mungbean (Vigna radiata L.) using genotyping-by-sequencing (GBS) approach.

Quantitative trait loci (QTL) mapping is used for the precise localization of genomic regions regulating various traits in plants. Two major QTLs regulating Soil Plant Analysis Development (SPAD) value (qSPAD-7-1) and trichome density (qTric-7-2) in mungbean were identified using recombinant inbred line (RIL) populations (PMR-1×Pusa Baisakhi) on chromosome 7. Functional analysis of QTL region identified 35 candidate genes for SPAD value (16 No) and trichome (19 No) traits. The candidate genes regulating trichome density on the dorsal leaf surface of the mungbean include VRADI07G24840, VRADI07G17780, and VRADI07G15650, which encodes for ZFP6, TFs bHLH DNA-binding superfamily protein, and MYB102, respectively. Also, candidate genes having vital roles in chlorophyll biosynthesis are VRADIO7G29860, VRADIO7G29450, and VRADIO7G28520, which encodes for s-adenosyl-L-methionine, FTSHI1 protein, and CRS2-associated factor, respectively. The findings unfolded the opportunity for the development of customized genotypes having high SPAD value and high trichome density having a possible role in yield and mungbean yellow vein mosaic India virus (MYMIV) resistance in mungbean.

Bottle gourd IC-0262269, a super-susceptible genotype to tomato leaf curl Palampur virus.

While conducting field trial of 82 genotypes of bottle gourd at Delhi during 2020-2021, a particular genotype, IC-0262269 was found to be affected by chlorotic curly stunt disease (CCSD). The affected plants were severely stunted and bearing very small chlorotic and crinkle leaves. The disease incidence in the said genotype was as high as 80% among different replicated trial blocks. The application of PCR using a generic primers specific to begomoviruses, as well as species-specific PCR diagnostics to six tomato-infecting begomoviruses: tomato leaf curl New Delhi virus (ToLCNDV), tomato leaf curl Palampur virus (ToLCPalV), tomato leaf curl Joydebpur virus (ToLCJoV), tomato leaf curl Gujrat virus (ToLCGuV), tomato leaf curl Bangalore virus (ToLCBV), and chilli leaf curl virus (ChiLCV) showed that, only ToLCPalV could be detected in the genotype IC-0262269. Following, rolling circle amplification, cloning and sequencing of full-length DNA-A and DNA-B genome of an isolate BoG1-ND from the genotype IC-0262269 revealed association of ToLCPalV with the disease. The successful agro-infection of the cloned genome of BoG1-ND (DNA-A and DNA-B) in the plants of Nicotiana benthamiana and bottle gourd demonstrated that ToLCPalV is the causal begomovirus of CCSD. The study provides the first evidence of the natural occurrence of ToLCPalV in bottle gourd crop and also showed that the bottle gourd genotype IC-0262269 is super-susceptible to ToLCPalV. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03838-y.

Accelerated Long-Fragment Circular PCR for Genetic Manipulation of Plant Viruses in Unveiling Functional Genomics.

Molecular cloning, a crucial prerequisite for engineering plasmid constructs intended for functional genomic studies, relies on successful restriction and ligation processes. However, the lack of unique restriction sites often hinders construct preparation, necessitating multiple modifications. Moreover, achieving the successful ligation of large plasmid constructs is frequently challenging. To address these limitations, we present a novel PCR strategy in this study, termed 'long-fragment circular-efficient PCR' (LC-PCR). This technique involves one or two rounds of PCR with an additional third-long primer that complements both ends of the newly synthesized strand of a plasmid construct. This results in self-circularization with a nick-gap in each newly formed strand. The LC-PCR technique was successfully employed to insert a partial sequence (210 nucleotides) of the phytoene desaturase gene from Nicotiana benthamiana and a full capsid protein gene (770 nucleotides) of a begomovirus (tomato leaf curl New Delhi virus) into a 16.4 kb infectious construct of a tobamovirus, cucumber green mottle mosaic virus (CGMMV), cloned in pCambia. This was done to develop the virus-induced gene silencing vector (VIGS) and an expression vector for a foreign protein in plants, respectively. Furthermore, the LC-PCR could be applied for the deletion of a large region (replicase enzyme) and the substitution of a single amino acid in the CGMMV genome. Various in planta assays of these constructs validate their biological functionality, highlighting the utility of the LC-PCR technique in deciphering plant-virus functional genomics. The LC-PCR is not only suitable for modifying plant viral genomes but also applicable to a wide range of plant, animal, and human gene engineering under in-vitro conditions. Additionally, the LC-PCR technique provides an alternative to expensive kits, enabling quick introduction of modifications in any part of the nucleotide within a couple of days. Thus, the LC-PCR proves to be a suitable 'all in one' technique for modifying large plasmid constructs through site-directed gene insertion, deletion, and mutation, eliminating the need for restriction and ligation.

Fn14 promotes myoblast fusion during regenerative myogenesis.

Skeletal muscle regeneration involves coordinated activation of an array of signaling pathways. Fibroblast growth factor-inducible 14 (Fn14) is a bona fide receptor for the TWEAK cytokine. Levels of Fn14 are increased in the skeletal muscle of mice after injury. However, the cell-autonomous role of Fn14 in muscle regeneration remains unknown. Here, we demonstrate that global deletion of the Fn14 receptor in mice attenuates muscle regeneration. Conditional ablation of Fn14 in myoblasts but not in differentiated myofibers of mice inhibits skeletal muscle regeneration. Fn14 promotes myoblast fusion without affecting the levels of myogenic regulatory factors in the regenerating muscle. Fn14 deletion in myoblasts hastens initial differentiation but impairs their fusion. The overexpression of Fn14 in myoblasts results in the formation of myotubes having an increased diameter after induction of differentiation. Ablation of Fn14 also reduces the levels of various components of canonical Wnt and calcium signaling both in vitro and in vivo. Forced activation of Wnt signaling rescues fusion defects in Fn14-deficient myoblast cultures. Collectively, our results demonstrate that Fn14-mediated signaling positively regulates myoblast fusion and skeletal muscle regeneration.

Size variations of mesoporous silica nanoparticle control uptake efficiency and delivery of AC2-derived dsRNA for protection against tomato leaf curl New Delhi virus.

KEY MESSAGE: We report the size dependent uptake of dsRNA loaded MSNPs into the leaves and roots of Nicotiana benthamiana plants and accessed for their relative reduction in Tomato leaf curl New Delhi viral load. A non-GMO method of RNA interference (RNAi) has been recently in practice through direct delivery of double stranded RNA into the plant cells. Tomato leaf curl New Delhi virus (ToLCNDV), a bipartitie begomovirus, is a significant viral pathogen of many crops in the Indian subcontinent. Conventional RNAi cargo delivery strategies for instance uses viral vectors and Agrobacterium-facilitated delivery, exhibiting specific host responses from the plant system. In the present study, we synthesized three different sizes of amine-functionalized mesoporous silica nanoparticles (amino-MSNPs) to mediate the delivery of dsRNA derived from the AC2 (dsAC2) gene of ToLCNDV and showed that these dsRNA loaded nanoparticles enabled effective reduction in viral load. Furthermore, we demonstrate that amino-MSNPs protected the dsRNA molecules from nuclease degradation, while the complex was efficiently taken up by the leaves and roots of Nicotiana benthamiana. The real time gene expression evaluation showed that plants treated with nanoparticles of different sizes ~ 10 nm (MSNPDEA), ~ 32 nm (MSNPTEA) and ~ 66 nm (MSNPNH3) showed five-, eleven- and threefold reduction of ToLCNDV in N. benthamiana, respectively compared to the plants treated with naked dsRNA. This work clearly demonstrates the size dependent internalization of amino-MSNPs and relative efficacy in transporting dsRNA into the plant system, which will be useful in convenient topical treatment to protect plants against their pathogens including viruses. Mesoporous silica nanoparticles loaded with FITC, checked for its uptake into Nicotiana benthamiana.

Delivery of progeny virus from the infectious clone of cucumber green mottle mosaic virus and quantification of the viral load in different host plants.

Cucumber green mottle mosaic virus (CGMMV, genus Tobamovirus) is a widely occurring tobamovirus in cucurbits. The genome of CGMMV has been used previously for the expression of foreign genes in the plant. High throughput delivery and high viral titer are important requirements of foreign protein expression in plant through virus genome-based vector, in this study, Agrobacterium containing infectious construct of CGMMV was infiltrated through syringe, vacuum and high-speed spray to N. benthamiana, cucumber and bottle gourd leaves. The success rate of systemic infection of CGMMV agro-construct through all three methods was higher (80-100%) in N. benthamiana compared to the cucurbits (40-73.3%). To determine the high-throughput delivery of CGMMV in the plant system, four delivery methods viz. rubbing, syringe infiltration, vacuum infiltration and high-speed spray using the progeny virus derived through CGMMV agro-construct were compared in the three different plant species. Based on the rate of systemic infection and time required to perform delivery by different methods, vacuum infiltration was found most efficient for the high-throughput delivery of CGMMV. The quantification of CGMMV through qPCR revealed that CGMMV load varied considerably in leaf and fruit tissues depending with the time of infection. Immediately after expression of symptoms, a high load of CGMMV (~ 1 µg/100 mg of tissues) was noticed in young leaves of N. benthamiana and cucumber. In bottle gourd leaves, the CGMMV load was far low compared to N. benthamiana and cucumber plants. In the fruit tissues of cucumber and bottle gourd higher virus load was observed in mature fruit but not in immature fruit. The findings of the present study will serve as an important base line information to produce foreign protein through CGMMV genome-vector. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03630-y.

Novel insights into the recognition of acetylated histone H4 tail by the TRIM24 PHD-Bromo module.

TRIM24 is a multi-functional chromatin reader, and it binds to the estrogen receptor to activate estrogen-dependent target genes associated with tumor development. TRIM24 is known to ubiquitinate p53 via an N-terminal RING domain and binds a specific combinatorial histone signature of H3K4me0/H3K23ac via its C-terminal plant homeodomain (PHD) and bromodomain (Bromo). Aberrant expression of TRIM24 positively correlates with H3K23ac levels, and high levels of both TRIM24 and H3K23ac predict poor survival of breast cancer patients. Little has been explored about the acetylated histone H4 (H4ac) signatures of TRIM24 and their biological functions. Herein, we report novel H4ac binding partners of TRIM24 and their localization in the genome. Isothermal titration calorimetry binding assay on the histone peptides revealed that the TRIM24 PHD-Bromo preferably binds to H4K5ac, H4K8ac, and H4K5acK8ac compared with other acetylated histone H4 ligands. Co-immunoprecipitation on the endogenous histones suggests that the recognition of H4ac by Bromo does not interfere with the recognition of H3K4me0 mark by the PHD domain of TRIM24. Consistent with this, TRIM24 PHD-Bromo exhibits minimal discrimination among H4ac binding partners at endogenous histone and nucleosome levels. Moreover, ChIP-seq analysis revealed that the H4K5ac and H4K8ac histone signatures strongly co-localize near the transcription start sites of different hub genes or TRIM24-targeted genes in breast cancer. In addition, the KEGG pathway analysis demonstrates that the TRIM24 and its H4ac targets are associated with several important biological pathways. Our findings describe that the H4ac recognition by TRIM24 PHD-Bromo enables access to the chromatin for specific transcriptional regulation.

Innately expressed estrogen-related receptors in the skeletal muscle are indispensable for exercise fitness.

Transcriptional determinants in the skeletal muscle that govern exercise capacity, while poorly defined, could provide molecular insights into how exercise improves fitness. Here, we have elucidated the role of nuclear receptors, estrogen-related receptor alpha and gamma (ERRα/γ) in regulating myofibrillar composition, contractility, and exercise capacity in skeletal muscle. We used muscle-specific single or double (DKO) ERRα/γ knockout mice to investigate the effect of ERRα/γ deletion on muscle and exercise parameters. Individual knockout of ERRα/γ did not have a significant impact on the skeletal muscle. On the other hand, DKO mice exhibit pale muscles compared to wild-type (WT) littermates. RNA-seq analysis revealed a predominant decrease in expression of genes linked to mitochondrial and oxidative metabolism in DKO versus WT muscles. DKO muscles exhibit marked repression of oxidative enzymatic capacity, as well as mitochondrial number and size compared to WT muscles. Mitochondrial function is also impaired in single myofibers isolated from DKO versus WT muscles. In addition, mutant muscles exhibit reduced angiogenic gene expression and decreased capillarity. Consequently, DKO mice have a significantly reduced exercise capacity, further reflected in poor fatigue resistance of DKO mice in in vivo contraction assays. These results show that ERRα and ERRγ together are a critical link between muscle aerobic capacity and exercise tolerance. The ERRα/γ mutant mice could be valuable for understanding the long-term impact of impaired mitochondria and vascular supply on the pathogenesis of muscle-linked disorders.

Targeted ablation of Fn14 receptor improves exercise capacity and inhibits neurogenic muscle atrophy.

Skeletal muscle atrophy is a prevalent complication in multiple chronic diseases and disuse conditions. Fibroblast growth factor-inducible 14 (Fn14) is a member of the TNF receptor superfamily and a bona fide receptor of the TWEAK cytokine. Accumulating evidence suggests that Fn14 levels are increased in catabolic conditions as well as during exercise. However, the role of Fn14 in the regulation of skeletal muscle mass and function remains poorly understood. In this study, through the generation of novel skeletal muscle-specific Fn14-knockout mice, we have investigated the muscle role of Fn14 in the regulation of exercise capacity and denervation-induced muscle atrophy. Our results demonstrate that there was no difference in skeletal muscle mass between control and muscle-specific Fn14-knockout mice. Nevertheless, the deletion of Fn14 in skeletal muscle significantly improved exercise capacity and resistance to fatigue. This effect of Fn14 deletion is associated with an increased proportion of oxidative myofibers and higher capillaries number per myofiber in skeletal muscle. Furthermore, our results demonstrate that targeted deletion of Fn14 inhibits denervation-induced muscle atrophy in adult mice. Deletion of Fn14 reduced the expression of components of the ubiquitin-proteasome system and non-canonical NF-kappa B signaling in denervated skeletal muscle, as well as increased the phosphorylation of Akt kinase and FoxO3a transcription factor. Collectively, our results demonstrate that targeted inhibition of Fn14 improves exercise tolerance and inhibits denervation-induced muscle atrophy in adult mice.

The intertwining of Zn-finger motifs and abiotic stress tolerance in plants: Current status and future prospects.

Environmental stresses such as drought, high salinity, and low temperature can adversely modulate the field crop's ability by altering the morphological, physiological, and biochemical processes of the plants. It is estimated that about 50% + of the productivity of several crops is limited due to various types of abiotic stresses either presence alone or in combination (s). However, there are two ways plants can survive against these abiotic stresses; a) through management practices and b) through adaptive mechanisms to tolerate plants. These adaptive mechanisms of tolerant plants are mostly linked to their signalling transduction pathway, triggering the action of plant transcription factors and controlling the expression of various stress-regulated genes. In recent times, several studies found that Zn-finger motifs have a significant function during abiotic stress response in plants. In the first report, a wide range of Zn-binding motifs has been recognized and termed Zn-fingers. Since the zinc finger motifs regulate the function of stress-responsive genes. The Zn-finger was first reported as a repeated Zn-binding motif, comprising conserved cysteine (Cys) and histidine (His) ligands, in Xenopus laevis oocytes as a transcription factor (TF) IIIA (or TFIIIA). In the proteins where Zn2+ is mainly attached to amino acid residues and thus espousing a tetrahedral coordination geometry. The physical nature of Zn-proteins, defining the attraction of Zn-proteins for Zn2+, is crucial for having an in-depth knowledge of how a Zn2+ facilitates their characteristic function and how proteins control its mobility (intra and intercellular) as well as cellular availability. The current review summarized the concept, importance and mechanisms of Zn-finger motifs during abiotic stress response in plants.

Direct Foliar Application of dsRNA Derived From the Full-Length Gene of NSs of Groundnut Bud Necrosis Virus Limits Virus Accumulation and Symptom Expression.

Groundnut bud necrosis virus (GBNV) is the most significant member of the genus Orthotospovirus occurring in the Indian subcontinent. There is hardly any effective measure to prevent GBNV in crop plants. In order to develop GBNV infection prevention procedure, we examined the effect of the direct foliar application of double-stranded RNA (dsRNA) derived from the full-length NSs gene (1,320 nucleotides) of GBNV. The bacterially expressed dsRNA to the non-structural (dsNSs) gene of GBNV was purified and delivered to plants as an aqueous suspension containing 0.01% Celite for evaluating its efficacy in preventing GBNV infection in systemic host, Nicotiana benthamiana as well as in local lesion and systemic host, cowpea cv. Pusa Komal (Vigna unguiculata). The dsNSs application and challenge-inoculation were conducted in three different combinations, where plants were challenge-inoculated with GBNV a day after, immediately, and a day before the application of dsNSs. N. benthamiana plants, which were not treated with dsRNA showed severe systemic wilting and death by 9-16 days post-inoculation (dpi). The non-treated cowpea plants exhibited many chlorotic and necrotic lesions on the cotyledonary leaves followed by systemic necrosis and death of the plants by 14-16 dpi. The dsNSs treated plants in all the combinations showed significant reduction of disease severity index in both N. benthamiana and cowpea. The treatment combination where the GBNV inoculation was conducted immediately after the dsNSs treatment was found to be the most effective treatment in preventing symptom expression. The viral RNA analysis by real time PCR also showed 20 and 12.5 fold reduction of GBNV in cowpea and N. benthamiana, respectively. Our results suggest that the foliar application of dsRNA derived from the full-length NSs gene of GBNV through Celite is successful in delivering long dsRNA leading to effective prevention of GBNV infection.

Sub-cellular localization of suppressor proteins of tomato leaf curl New Delhi virus.

Tomato leaf curl New Delhi virus (ToLCNDV), a bipartite begomovirus, is the most important among the 14 species of begomoviruses infecting tomato in Indian subcontinent. Begomovirus is known to  evade RNA silencing of host plants through suppressor proteins. However, in case of ToLCNDV, the suppressor proteins have not been studied well. The objective of the study is to know the sub-cellular localization of three suppressor proteins encoded by AV2, AC2 and AC4 ORFs of ToLCNDV in Nicotiana benthamiana. AV2, AC2 and AC4 ORFs of ToLCNDV were  cloned and sequenced (accession numbers MW423574, MW423576, MW423575, respectively) from a ToLCNDV isolate characterized earlier (accession number MW429271) and GFP tagged constructs were prepared in a plant expressing binary vector pEarleygate103. Bioinformatics analysis using Peptide 2.0 server predicted that all these proteins have more basic amino acid residues then acidic amino acid and AV2 protein has more hydrophobic amino acid residues. ScanProsite server predicted presence of different fuctional motifs in these proteins amongst which presence of kinase motif was observed in all of them. Virus mPLoc server predicted their subcellular localization. The suppressor gene constructs were agroinfiltrated on to leaves of one month old N. benthamiana plants and their subcellular localization has been studied through confocal microscopy. Results have shown that AV2 localizes in the host cell membrane and nucleus, AC2 in the nucleus and AC4 in the host cell membrane. Earlier reports with other begomoviruses also showed similar localization behaviour of these suppressor protein except AV2, where it was shown to be present in cytoplasm. Such localization study will help understand the mechanism of their suppression activity.

Identification and Functional Analysis of Four RNA Silencing Suppressors in Begomovirus Croton Yellow Vein Mosaic Virus.

Croton yellow vein mosaic virus (CYVMV), a species in the genus Begomovirus, is a prolific monopartite begomovirus in the Indian sub-continent. CYVMV infects multiple crop plants to cause leaf curl disease. Plants have developed host RNA silencing mechanisms to defend the threat of viruses, including CYVMV. We characterized four RNA silencing suppressors, namely, V2, C2, and C4 encoded by CYVMV and betasatellite-encoded C1 protein (ßC1) encoded by the cognate betasatellite, croton yellow vein betasatellite (CroYVMB). Their silencing suppressor functions were verified by the ability of restoring the ß-glucuronidase (GUS) activity suppressed by RNA silencing. We showed here for the first time that V2 was capable of self-interacting, as well as interacting with the V1 protein, and could be translocalized to the plasmodesmata in the presence of CYVMV. The knockout of either V2 or V1 impaired the intercellular mobility of CYVMV, indicating their novel coordinated roles in the cell-to-cell movement of the virus. As pathogenicity determinants, each of V2, C2, and C4 could induce typical leaf curl symptoms in Nicotiana benthamiana plants even under transient expression. Interestingly, the transcripts and proteins of all four suppressors could be detected in the systemically infected leaves with no correlation to symptom induction. Overall, our work identifies four silencing suppressors encoded by CYVMV and its cognate betasatellite and reveals their subcellular localizations, interaction behavior, and roles in symptom induction and intercellular virus movement.

TAK1 preserves skeletal muscle mass and mitochondrial function through redox homeostasis.

Skeletal muscle atrophy is debilitating consequence of a large number of chronic disease states, aging, and disuse conditions. Skeletal muscle mass is regulated through coordinated activation of a number of signaling cascades. Transforming growth factor-ß activated kinase 1 (TAK1) is a central kinase that mediates the activation of multiple signaling pathways in response to various growth factors, cytokines, and microbial products. Accumulating evidence suggests that TAK1 promotes skeletal muscle growth and essential for the maintenance of muscle mass in adults. Targeted inactivation of TAK1 leads to severe muscle wasting and kyphosis in mice. However, the mechanisms by which TAK1 prevents loss of muscle mass remain poorly understood. Through generation of inducible skeletal muscle-specific Tak1-knockout mice, we demonstrate that targeted ablation of TAK1 disrupts redox signaling leading to the accumulation of reactive oxygen species and loss of skeletal muscle mass and contractile function. Suppression of oxidative stress using Trolox improves muscle contractile function and inhibits the activation of catabolic signaling pathways in Tak1-deficient muscle. Moreover, Trolox inhibits the activation of ubiquitin-proteasome system and autophagy markers in skeletal muscle of Tak1-deficient mice. Furthermore, inhibition of oxidative stress using Trolox prevents the slow-to-fast type fiber transition and improves mitochondrial respiration in skeletal muscle of Tak1-deficient mice. Overall, our results demonstrate that TAK1 maintains skeletal muscle mass and health through redox homeostasis.

ER Stress and Unfolded Protein Response in Cancer Cachexia.

Cancer cachexia is a devastating syndrome characterized by unintentional weight loss attributed to extensive skeletal muscle wasting. The pathogenesis of cachexia is multifactorial because of complex interactions of tumor and host factors. The irreversible wasting syndrome has been ascribed to systemic inflammation, insulin resistance, dysfunctional mitochondria, oxidative stress, and heightened activation of ubiquitin-proteasome system and macroautophagy. Accumulating evidence suggests that deviant regulation of an array of signaling pathways engenders cancer cachexia where the human body is sustained in an incessant self-consuming catabolic state. Recent studies have further suggested that several components of endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) are activated in skeletal muscle of animal models and muscle biopsies of cachectic cancer patients. However, the exact role of ER stress and the individual arms of the UPR in the regulation of skeletal muscle mass in various catabolic states including cancer has just begun to be elucidated. This review provides a succinct overview of emerging roles of ER stress and the UPR in cancer-induced skeletal muscle wasting.

Protective Role of Black Tea Flavonoids Against Ethanol-Induced Gastropathy via Matrix Metalloproteinase Pathway.

ABSTRACT: Tea polyphenols are known to prevent various ailments like cancer, atherosclerosis, hypertension and diabetes. Our study aimed at to decipher the gastroprotective effect of aqueous black tea extract (BTE) against ethanol-induced gastric damage and the role of BTE in modulating MMP-9 activity and expression, both in vivo and in vitro. The protective role of BTE was assessed in Sprague-Dawley rats after inducing damage with 70% ethanol. Human gastric adenocarcinoma cells (AGS) were treated with ethanol in ex vivo experiment. MMP-9 activity and expression were investigated through gelatin zymography and western blotting. Reactive oxygen species (ROS) generation was also studied by fluorescence spectroscopy and confocal microscopy, with or without treatment of BTE both in vivo and in vitro experiments. In addition, the effect of citric acid treated BTE (cBTE), which mimics lemon tea, was examined on ethanol-induced gastropathy. BTE exhibited antiulcer activity through reduction of glutathione depletion, lipid peroxidation, protein oxidation, ROS production and inflammatory cell infiltration in rat gastric tissues. In addition, BTE significantly inhibited synthesis and secretion of proMMP-9 both in vivo and in vitro. The mitochondrial enzymes succinate dehydrogenase and NADH oxidase in rat gastric tissues were downregulated by BTE while protecting gastric ulcer. Citric acid addition to BTE was observer to enrich the lead compound, catechin. Interestingly, cBTE showed higher anti-ulcer activity than the untreated one. BTE shows protective role against ethanol-induced gastric ulcer in rats through scavenging ROS and downregulating proMMP-9 activity. While cBTE shows better protection due to enrichment of catechin and removal of tannins in tea extract leading to enhanced inhibitory role on proMMP-9 activity and ROS production.