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Current Biology : CB May 2024Xyloglucan is believed to play a significant role in cell wall mechanics of dicot plants. Surprisingly, Arabidopsis plants defective in xyloglucan biosynthesis exhibit...
Xyloglucan is believed to play a significant role in cell wall mechanics of dicot plants. Surprisingly, Arabidopsis plants defective in xyloglucan biosynthesis exhibit nearly normal growth and development. We investigated a mutant line, cslc-Δ5, lacking activity in all five Arabidopsis cellulose synthase like-C (CSLC) genes responsible for xyloglucan backbone biosynthesis. We observed that this xyloglucan-deficient line exhibited reduced cellulose crystallinity and increased pectin levels, suggesting the existence of feedback mechanisms that regulate wall composition to compensate for the absence of xyloglucan. These alterations in cell wall composition in the xyloglucan-absent plants were further linked to a decrease in cell wall elastic modulus and rupture stress, as observed through atomic force microscopy (AFM) and extensometer-based techniques. This raised questions about how plants with such modified cell wall properties can maintain normal growth. Our investigation revealed two key factors contributing to this phenomenon. First, measurements of turgor pressure, a primary driver of plant growth, revealed that cslc-Δ5 plants have reduced turgor, preventing the compromised walls from bursting while still allowing growth to occur. Second, we discovered the conservation of elastic asymmetry (ratio of axial to transverse wall elasticity) in the mutant, suggesting an additional mechanism contributing to the maintenance of normal growth. This novel feedback mechanism between cell wall composition and mechanical properties, coupled with turgor pressure regulation, plays a central role in the control of plant growth and is critical for seedling establishment in a mechanically challenging environment by affecting shoot emergence and root penetration.
Topics: Cell Wall; Glucans; Xylans; Arabidopsis; Seedlings; Arabidopsis Proteins; Glucosyltransferases; Cellulose
PubMed: 38677280
DOI: 10.1016/j.cub.2024.04.016 -
International Journal of Biological... May 2024Enzymatic degradation of plant biomass requires the coordinated action of various enzymes. In this study, the production of reducing sugars from pectic substrates and...
Enzymatic degradation of plant biomass requires the coordinated action of various enzymes. In this study, the production of reducing sugars from pectic substrates and sugar beet pulp (SBP) was investigated and compared using commercial enzyme preparations, including M2, pectinase (E1), Viscozyme L (V-L) and L-40. V-L, a cellulolytic enzyme mix produced by Aspergillus sp. was further evaluated as the most robust enzyme cocktail with the strongest SBP degradation ability in terms of the release of monosaccharides, methanol, and acetate from SBP. Mass-spectrometry-based proteomics analysis of V-L revealed 156 individual proteins. Of these, 101 proteins were annotated as containing a carbohydrate-active enzyme module. Notably, of the 50 most abundant proteins, ca. 44 % were predicted to be involved in pectin degradation. To reveal the role of individual putative key enzymes in pectic substrate decomposition, two abundant galacturonases (PglA and PglB), were heterologously expressed in Pichia pastoris and further characterized. PglA and PglB demonstrated maximum activity at 57 °C and 68 °C, respectively, and exhibited endo-type cleavage patterns towards polygalacturonic acid. Further studies along this line may lead to a better understanding of efficient SBP degradation and may help to design improved artificial enzyme mixtures with lower complexity for future application in biotechnology.
Topics: Pectins; Proteomics; Substrate Specificity; Polygalacturonase; Beta vulgaris; Aspergillus
PubMed: 38580019
DOI: 10.1016/j.ijbiomac.2024.131309 -
Gastrointestinal Endoscopy Mar 2024Traction has become the reference strategy for colorectal endoscopic submucosal dissection (ESD). One of its major limitations is that the force of traction decreases as...
BACKGROUND AND AIMS
Traction has become the reference strategy for colorectal endoscopic submucosal dissection (ESD). One of its major limitations is that the force of traction decreases as dissection progresses. The ATRACT traction device uses a pulley system to increase traction during the procedure, making it easier and faster. A retrospective study of 54 cases showed interesting results in terms of efficacy and safety throughout the digestive tract. We sought to confirm these initial results with a prospective study of resections of colorectal lesions.
METHODS
In this prospective multicenter study, 5 experienced operators from 3 different centers each performed 10 procedures using the ATRACT device consecutively for all conventional colorectal ESDs measuring between 4 and 10 cm in conventional locations (no recurrent lesions, appendicular, of the ileo-cecal valve, in contact with the pectinate line or measuring more than 2/3 of the circumference).
RESULTS
Between November 2022 and April 2023, 50 ESDs were performed in 49 patients. On average, the main diameter of the lesions was 66.6 mm, with a surface area of 3066 mm2. The mean operating time was 55.2 minutes, resulting in a mean resection speed of 61.4 mm2/min. En Bloc and R0 resection rates were 100% and 98% respectively. Resections were curative in 94% of cases. 4 perforations (8%) occurred, all of which were closed endoscopically without the need for surgery. 1 case of delayed hemorrhage (2%) was noted. To date, this is the series with the highest resection speeds in the literature for colorectal ESD. For comparison, Yamamoto et al. reported a speed of 23.5 mm2/min using the "pocket" strategy and Bordillon et al. reported a speed of 39.1 mm2/min using the double-clip traction technique. These results need to be confirmed in larger studies, and in non-expert centers.
CONCLUSIONS
This prospective evaluation confirms the efficacy and safety of the adaptive traction strategy with the ATRACT device for colorectal ESD with high resection speed.
PubMed: 38458261
DOI: 10.1016/j.gie.2024.02.032 -
International Journal of Biological... Apr 2024Orally targeted delivery systems have attracted ample interest in colorectal cancer management. In this investigation, we developed Inositol hexaphosphate (IHP) loaded...
Orally targeted delivery systems have attracted ample interest in colorectal cancer management. In this investigation, we developed Inositol hexaphosphate (IHP) loaded Tripolyphosphate (Tr) crosslinked Pectin (Pe) Chitosan (Ch) nanoparticles (IHP@Tr*Pe-Ch-NPs) and modified them with l-Carnitine (CE) (CE-IHP@Tr*Pe-Ch-NPs) to improve uptake in colon cells. The formulated CE-IHP@Tr*Pe-Ch-NPs displayed a monodisperse distribution with 219.3 ± 5.5 nm diameter and 30.17 mV surface charge. Cell-line studies revealed that CE-IHP@Tr*Pe-Ch-NPs exhibited excellent biocompatibility in J774.2 and decreased cell viability in DLD-1, HT-29, and MCF7 cell lines. More cell internalization was seen in HT-29 and MCF7 due to overexpression of the OCTN2 and ATB transporter (CE transporters) compared to DLD-1. The cell cycle profile, reactive oxygen species, apoptosis, and mitochondrial membrane potential assays were performed to explore the chemo-preventive mechanism of CE-IHP@Tr*Pe-Ch-NPs. Moreover, the in-silico docking studies revealed enhanced interactive behavior of CE-IHP@Tr*Pe-Ch-NPs, thereby proving their targeting ability. All the findings suggested that CE-IHP@Tr*Pe-Ch-NPs could be a promising drug delivery approach for colon cancer targeting.
Topics: Humans; Phytic Acid; Chitosan; Pectins; Carnitine; MCF-7 Cells; Nanoparticles; Colon; Drug Carriers
PubMed: 38423444
DOI: 10.1016/j.ijbiomac.2024.130517 -
Cells Feb 2024In this study, we investigated the beneficial effects of grapefruit IntegroPectin, derived from industrial waste grapefruit peels via hydrodynamic cavitation, on...
In this study, we investigated the beneficial effects of grapefruit IntegroPectin, derived from industrial waste grapefruit peels via hydrodynamic cavitation, on microglia cells exposed to oxidative stress conditions. Grapefruit IntegroPectin fully counteracted cell death and the apoptotic process induced by cell exposure to tert-butyl hydroperoxide (TBH), a powerful hydroperoxide. The protective effects of the grapefruit IntegroPectin were accompanied with a decrease in the amount of ROS, and were strictly dependent on the activation of the phosphoinositide 3-kinase (PI3K)/Akt cascade. Finally, IntegroPectin treatment inhibited the neuroinflammatory response and the basal microglia activation by down-regulating the PI3K- nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB)- inducible nitric oxide synthase (iNOS) cascade. These data strongly support further investigations aimed at exploring IntegroPectin's therapeutic role in in vivo models of neurodegenerative disorders, characterized by a combination of chronic neurodegeneration, oxidative stress and neuroinflammation.
Topics: Humans; Microglia; Citrus paradisi; Phosphatidylinositol 3-Kinases; Anti-Inflammatory Agents; Cell Line
PubMed: 38391968
DOI: 10.3390/cells13040355 -
International Journal of Biological... Mar 2024The current research work focuses on preparing the polycaprolactone (PCL) based nanocomposite films embedded with surface modified Halloysite Nanotube (HNT). The avenue...
The current research work focuses on preparing the polycaprolactone (PCL) based nanocomposite films embedded with surface modified Halloysite Nanotube (HNT). The avenue of the study is to unravel the applicability of polymer nanocomposites for wound healing. The flexible property of HNT was taken as the major force to accomplish the addition of biopolymer pectin onto its surface. Functionalization of HNT with pectin has certainly enhanced its binding nature with the polymer. The PCL nanocomposite films were characterized by several promising techniques such as FTIR, XRD, DSC-TGA, FESEM, TEM, AFM, and mechanical properties were too examined along. When compared to the plane PCL film, the nanocomposite films manifested favorable results in terms of mechanical and chemical properties. Additionally, biometric studies such as in-vitro swelling, enzymatic degradation, and hemolysis performed on the films gave extremely good results. The haemolytic percentage recorded for the films exhibited a steady decrease with increasing amount of nanofillers. The MTT assay showed cell proliferation and its increase as the embedded HNT is more in the matrix. Wound closure study performed on NIH3T3 cell line with 1, 3 and 5wt% of films has given a strong proof for the involvement of polymer and HNT in the healing procedure.
Topics: Mice; Animals; Clay; Pectins; NIH 3T3 Cells; Wound Healing; Polymers; Nanotubes; Nanocomposites; Polyesters
PubMed: 38365152
DOI: 10.1016/j.ijbiomac.2024.130140 -
International Journal of Biological... Mar 2024Porous morphology and mechanical properties determine the applications of cryogels. To understand the influence of the ionic network on the microstructure and mechanical...
Porous morphology and mechanical properties determine the applications of cryogels. To understand the influence of the ionic network on the microstructure and mechanical properties of pectin cryogels, we prepared low-methoxyl pectin (LMP) cryogels with different Ca concentrations (measured as R-value, ranging from 0 to 2) through freeze-drying (FD). Results showed that the R-values appeared to be crucial parameters that impact the pore morphology and mechanical characteristics of cryogels. It is achieved by altering the network stability and water state properties of the cryogel precursor. Cryogel precursors with a saturated R-value (R = 1) produced a low pore diameter (0.12 mm) microstructure, obtaining the highest crispness (15.00 ± 1.85) and hardness (maximum positive force and area measuring 2.36 ± 0.31 N and 12.30 ± 1.57 N·s respectively). Hardness showed a negative correlation with Ca concentration when R ≤ 1 (-0.89), and a similar correlation with the porosity of the gel network when R ≥ 1 (-0.80). Given the impacts of crosslinking on the pore structure, it is confirmed that the pore diameter can be designed between 56.24 and 153.58 μm by controlling R-value in the range of 0-2.
Topics: Cryogels; Pectins; Mechanical Phenomena; Porosity; Hardness
PubMed: 38340927
DOI: 10.1016/j.ijbiomac.2024.130028 -
Plant, Cell & Environment May 2024The plant cell wall is a plastic structure of variable composition that constitutes the first line of defence against environmental challenges. Lodging and drought are...
The plant cell wall is a plastic structure of variable composition that constitutes the first line of defence against environmental challenges. Lodging and drought are two stressful conditions that severely impact maize yield. In a previous work, we characterised the cell walls of two maize inbreds, EA2024 (susceptible) and B73 (resistant) to stalk lodging. Here, we show that drought induces distinct phenotypical, physiological, cell wall, and transcriptional changes in the two inbreds, with B73 exhibiting lower tolerance to this stress than EA2024. In control conditions, EA2024 stalks had higher levels of cellulose, uronic acids and p-coumarate than B73. However, upon drought EA2024 displayed increased levels of arabinose-enriched polymers, such as pectin-arabinans and arabinogalactan proteins, and a decreased lignin content. By contrast, B73 displayed a deeper rearrangement of cell walls upon drought, including modifications in lignin composition (increased S subunits and S/G ratio; decreased H subunits) and an increase of uronic acids. Drought induced more substantial changes in gene expression in B73 compared to EA2024, particularly in cell wall-related genes, that were modulated in an inbred-specific manner. Transcription factor enrichment assays unveiled inbred-specific regulatory networks coordinating cell wall genes expression. Altogether, these findings reveal that B73 and EA2024 inbreds, with opposite stalk-lodging phenotypes, undertake different cell wall modification strategies in response to drought. We propose that the specific cell wall composition conferring lodging resistance to B73, compromises its cell wall plasticity, and renders this inbred more susceptible to drought.
Topics: Lignin; Zea mays; Droughts; Cell Wall; Uronic Acids
PubMed: 38317308
DOI: 10.1111/pce.14822 -
Gene May 2024Seed hardness is a critical quality trait impacting both the suitability of soybeans for consumption and their processing. The primary objective of this study was to...
Seed hardness is a critical quality trait impacting both the suitability of soybeans for consumption and their processing. The primary objective of this study was to explore the genetic foundations underlying seed hardness in soybeans. A 234 recombinant inbred line (RIL) population was evaluated for seed hardness across three years (2015 in Gansu, 2016, and 2017 in Hainan). Notably, the parent varieties, Zhonghuang35 and Jindou21, displayed significant differences in seed hardness. Also, the RIL population exhibited a wide range of genetic variation in seed hardness, with coefficients of variation between 70.53 % and 94.94 %. The frequency distribution of this trait conformed to a relatively normal distribution, making it suitable for QTL analysis. Six QTLs associated with seed hardness were identified with three located on chromosome 2 and three on chromosome 16. The major QTL, qHS-2-1, consistently exhibited the highest percentage of PVE and LOD in Gansu 2015, Hainan 2016, and Hainan 2017, suggesting its central role in determining seed hardness. Further investigation revealed four genes within the qHS-2-1 interval potentially related to seed hardness. GO enrichment analysis provided insights into their functions, including factors such as Glyma.02G307000, a pectin lyase-like superfamily protein, which could influence seed hardness through its role in pectin lyase enzyme activity. Expression analysis of these candidate genes demonstrated significant differences between the two parent varieties, further highlighting their potential role in seed coat hardness. This study offers valuable insights into the genetic mechanisms governing soybean seed coat hardness, providing a foundation for future research and crop improvement efforts.
Topics: Glycine max; Hardness; Chromosome Mapping; Phenotype; Seeds
PubMed: 38316262
DOI: 10.1016/j.gene.2024.148238 -
Toxicology Research Feb 2024The safety of a rhamnogalacturonan-I-enriched pectin extract (G3P-01) from pumpkin ( var. Dickinson) was evaluated for use as an ingredient in food and dietary...
The safety of a rhamnogalacturonan-I-enriched pectin extract (G3P-01) from pumpkin ( var. Dickinson) was evaluated for use as an ingredient in food and dietary supplements. G3P-01 was tested in a battery of genetic toxicity studies including reverse mutagenicity and micronucleus assay. In addition, Sprague-Dawley rats were randomized and orally dosed with G3P-01 incorporated in animal diet at concentrations of 0, 9000, 18,000, and 36,000 ppm daily for 13-weeks (n=10/sex/group) in line with OECD guidelines (TG 408). The results of the bacterial reverse mutation assay and micronucleus assay in TK6 cells demonstrated a lack of genotoxicity. The 13-week oral toxicity study in Sprague-Dawley rats demonstrated that the test article, G3P-01 was well tolerated; there were no mortalities and no adverse effects on clinical, gross pathology, hematology, blood chemistry, and histological evaluation of the essential organs of the animals. The present study demonstrates that G3P-01 is non-genotoxic and is safe when ingested in diet at concentrations up to 36, 000 ppm. The subchronic no-observed-adverse-effect level (NOAEL) for G3P-01 was concluded to be 36,000 ppm, equivalent to 1,899 and 2,361 mg/kg/day for male and female rats respectively.
PubMed: 38274036
DOI: 10.1093/toxres/tfae004