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Applied and Environmental Microbiology Jul 2024tarch tilization ystem (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the operon in microorganisms affiliated with the...
UNLABELLED
tarch tilization ystem (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics.
IMPORTANCE
SusD1 and SusD38489 can be considered for further applications regarding their putative adsorption toward fossil-fuel based polymers. This is the first time that SusD homologs from the polysaccharide utilization loci (PUL), largely described for the phylum Bacteroidota, are characterized as synthetic polymer-binding proteins.
PubMed: 38953372
DOI: 10.1128/aem.00933-24 -
Advanced Healthcare Materials Jun 2024Polyetheretherketone (PEEK), a bioinert polymer known for its mechanical properties similar to bone, is capable of averting stress shielding. Due to these attributes, it...
Polyetheretherketone (PEEK), a bioinert polymer known for its mechanical properties similar to bone, is capable of averting stress shielding. Due to these attributes, it finds applications in diverse fields like orthopedics, encompassing cervical disc replacement for the neck and spine, along with dentistry and plastic surgery. However, due to insufficient bonding with bone, various methods such as hydroxyapatite (HA) coating on the surface are attempted. Nonetheless, the interface between the polymer and ceramic, two different materials, tended to delaminate after transplantation, posing challenges in preventing implant escape or dislodgement. This research delves into the laser-driven hydroxyapatite penetration-synthesis technique. Differing from conventional coating methods that bond layers of dissimilar materials like HA and PEEK, this technology focuses on synthesizing and infiltrating ionized HA within the PEEK substrate resulting in an interface-free HA-PEEK surface. Conversely, HA-PEEK with this technology applied achieves complete, gap-free direct bone-implant integration. Our research involved the analysis of various aspects. By means of these, we quantitatively assesed the enhanced bone bonding characteristics of HA-PEEK surfaces treated with this approach and offered and explanation for the mechanism responsible for direct bone integration.
PubMed: 38953344
DOI: 10.1002/adhm.202401260 -
ELife Jul 2024The enhancement of associative synaptic plasticity often results in impaired rather than enhanced learning. Previously, we proposed that such learning impairments can...
The enhancement of associative synaptic plasticity often results in impaired rather than enhanced learning. Previously, we proposed that such learning impairments can result from saturation of the plasticity mechanism (Nguyen-Vu et al., 2017), or, more generally, from a history-dependent change in the threshold for plasticity. This hypothesis was based on experimental results from mice lacking two class I major histocompatibility molecules, MHCI H2-K and H2-D (MHCI KD), which have enhanced associative long-term depression at the parallel fiber-Purkinje cell synapses in the cerebellum (PF-Purkinje cell LTD). Here, we extend this work by testing predictions of the threshold metaplasticity hypothesis in a second mouse line with enhanced PF-Purkinje cell LTD, the knockout mouse model of Fragile X syndrome (FXS). Mice lacking gene expression in cerebellar Purkinje cells (L7- KO) were selectively impaired on two oculomotor learning tasks in which PF-Purkinje cell LTD has been implicated, with no impairment on LTD-independent oculomotor learning tasks. Consistent with the threshold metaplasticity hypothesis, behavioral pre-training designed to reverse LTD at the PF-Purkinje cell synapses eliminated the oculomotor learning deficit in the L7- KO mice, as previously reported in MHCI KDmice. In addition, diazepam treatment to suppress neural activity and thereby limit the induction of associative LTD during the pre-training period also eliminated the learning deficits in L7- KO mice. These results support the hypothesis that cerebellar LTD-dependent learning is governed by an experience-dependent sliding threshold for plasticity. An increased threshold for LTD in response to elevated neural activity would tend to oppose firing rate stability, but could serve to stabilize synaptic weights and recently acquired memories. The metaplasticity perspective could inform the development of new clinical approaches for addressing learning impairments in autism and other disorders of the nervous system.
Topics: Animals; Fragile X Syndrome; Mice; Disease Models, Animal; Fragile X Mental Retardation Protein; Mice, Knockout; Purkinje Cells; Neuronal Plasticity; Male; Learning
PubMed: 38953282
DOI: 10.7554/eLife.92543 -
Cell Biology International Jul 2024Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, is emerging as a promising target in cancer therapy. It is regulated by a network of...
Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, is emerging as a promising target in cancer therapy. It is regulated by a network of molecules and pathways that modulate lipid metabolism, iron homeostasis and redox balance, and related processes. However, there are still numerous regulatory molecules intricately involved in ferroptosis that remain to be identified. Here, we indicated that suppression of Golgi protein acyl-coenzyme A binding domain A containing 3 (ACBD3) increased the sensitivity of Henrieta Lacks and PANC1 cells to ferroptosis. ACBD3 knockdown increases labile iron levels by promoting ferritinophagy. This increase in free iron, coupled with reduced levels of glutathione peroxidase 4 due to ACBD3 knockdown, leads to the accumulation of reactive oxygen species and lipid peroxides. Moreover, ACBD3 knockdown also results in elevated levels of polyunsaturated fatty acid-containing glycerophospholipids through mechanisms that remain to be elucidated. Furthermore, inhibition of ferrtinophagy in ACBD3 downregulated cells by knocking down the nuclear receptor co-activator 4 or Bafilomycin A1 treatment impeded ferroptosis. Collectively, our findings highlight the pivotal role of ACBD3 in governing cellular resistance to ferroptosis and suggest that pharmacological manipulation of ACBD3 levels is a promising strategy for cancer therapy.
PubMed: 38953242
DOI: 10.1002/cbin.12213 -
Aesthetic Surgery Journal Jul 2024Perioperative hypothermia in plastic surgery has underestimated risks, including increased risk of infection, cardiac events, blood loss, prolonged recovery time,...
BACKGROUND
Perioperative hypothermia in plastic surgery has underestimated risks, including increased risk of infection, cardiac events, blood loss, prolonged recovery time, increased nausea, pain, and opioid usage. Inadequate preventive measures can result in up to 4 hours of normothermia restoration.
OBJECTIVES
Compare the impact of different strategies for normothermia during plastic surgery procedures and its relationship with clinical outcomes.
METHODS
A non-randomized clinical trial was conducted in a single center in Bogota, Colombia. We enrolled adult patients undergoing body contouring surgery and divided them into four intervention groups with different measures to control body temperature. Univariate and Bivariate analyses were performed comparing several clinical symptoms to evaluate outcomes.
RESULTS
A total of 197 patients were analyzed. Most of them were women (84,3%). Mean age was 38.6 years, and a median procedure duration of 260 minutes. Demographic and clinical characteristics did not exhibit significant differences between the groups. However, there were notable variations in temperature measurements at crucial moments during the surgical procedure among the groups, attributed to the implementation of distinct thermal protective strategies. Group comparisons showed a relationship between hypothermia with increased nausea, vomiting, shivering, pain, and additional analgesia requirements.
CONCLUSIONS
Incorporation of active thermal protective measures, such as Blanketrol or HotDog, during body contouring procedures, markedly diminishes the risk of hypothermia and enhances overall clinical outcomes. Implementing these active measures to maintain the patient in a state of normothermia not only improves operating room efficiency but also leads to a reduction in recovery room duration.
PubMed: 38953184
DOI: 10.1093/asj/sjae142 -
PeerJ 2024The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets.... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
Comparative bond failure rate of orthodontic brackets when bracket base is treated with micro-abrasive blasting . acid etching: eighteen month randomized control trial and scanning electron microscope study.
BACKGROUND
The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets' microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period.
METHODS
The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes.
RESULTS
A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 ( value = 0.804).
CONCLUSION
Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side.
Topics: Orthodontic Brackets; Humans; Acid Etching, Dental; Microscopy, Electron, Scanning; Female; Male; Dental Bonding; Adolescent; Surface Properties; Adult; Resin Cements; Young Adult; Stainless Steel; Dental Etching
PubMed: 38952970
DOI: 10.7717/peerj.17645 -
Frontiers in Plant Science 2024Phenotypic complexity in species complexes and recently radiated lineages has resulted in a diversity of forms that have historically been classified into separate taxa....
INTRODUCTION
Phenotypic complexity in species complexes and recently radiated lineages has resulted in a diversity of forms that have historically been classified into separate taxa. Increasingly, with the proliferation of high-throughput sequencing methods, additional layers of complexity have been recognized, such as frequent hybridization and reticulation, which may call into question the previous morphological groupings of closely related organisms.
METHODS
We investigated Northern European, Asian, and Beringian populations of agg. with phylogenomic analysis of 736 genes and 27,586 SNPs in order to deduce the interrelatedness and hybrid origin of this phenotypically and taxonomically complicated group from Europe characterized by a history of hybridization, polyploidy, apomixis, and recent radiation. The ploidy levels and the reproductive mode of the Northern European populations were assessed via flow cytometric seed screening. In addition, in order to examine the phenotypic plasticity of the dwarf forms previously described as species and summarized as the group, we conducted climate chamber experiments under cold (northern) and warm (temperate) conditions.
RESULTS
The Northern European populations are tetra- to hexaploid and propagate primarily through apomixis. The complex is characterized by highly reticulate relationships. Genetic differentiation of the main clusters has occurred between the above-mentioned geographical regions. We find evidence for the hybrid origin of the taxa in these areas with differing genomic contributions from the geographically nearest European sexual progenitor species. Furthermore, polyphyly in the taxa of the group is supported. Experiments show low lability in the traits associated with the group.
DISCUSSION
We conclude that multiple adaptations of hybrids to colder climates and shorter vegetation periods have shaped the phenotypes of the group, and we suggest a formal classification as nothotaxa within the group.
PubMed: 38952845
DOI: 10.3389/fpls.2024.1415059 -
Behavioral Ecology : Official Journal... 2024It is well known that maternal age at reproduction affects offspring lifespan and some other fitness-related traits, but it remains understudied whether maternal...
It is well known that maternal age at reproduction affects offspring lifespan and some other fitness-related traits, but it remains understudied whether maternal senescence affects how offspring respond to their environments. Early environment often plays a significant role in the development of an animal's behavioral phenotype. For example, complex environments can promote changes in cognitive ability and brain morphology in young animals. Here, we study whether and how maternal effect senescence influences offspring plasticity in cognition, group behavior, and brain morphology in response to environmental complexity. For this, juvenile 3-spined sticklebacks from young and old mothers (i.e. 1-yr and 2-yr-old) were exposed to different levels of environmental enrichment and complexity (i.e. none, simple, and complex), and their behavior, cognitive ability, and brain size were measured. Exposing fish to enriched conditions improved individual learning ability assessed by a repeated detour-reaching task, increased the size of the whole brain, and decreased aggressive interactions in the shoal. Maternal age did not influence the inhibitory control, learning ability, and group behavioral responses of offspring to the experimental environmental change. However, maternal age affected how some brain regions of offspring changed in response to environmental complexity. In offspring from old mothers, those exposed to the complex environment had larger telencephalons and cerebellums than those who experienced simpler environments. Our results suggest that maternal effect senescence may influence how offspring invest in brain functions related to cognition in response to environmental complexity.
PubMed: 38952837
DOI: 10.1093/beheco/arae049 -
BioRxiv : the Preprint Server For... May 2024Biological sex shapes the manifestation and progression of neurodevelopmental disorders (NDDs). These disorders often demonstrate male-specific vulnerabilities; however,...
UNLABELLED
Biological sex shapes the manifestation and progression of neurodevelopmental disorders (NDDs). These disorders often demonstrate male-specific vulnerabilities; however, the identification of underlying mechanisms remains a significant challenge in the field. Hemideletion of the 16p11.2 region (16p11.2 del/+) is associated with NDDs, and mice modeling 16p11.2 del/+ exhibit sex-specific striatum-related phenotypes relevant to NDDs. Striatal circuits, crucial for locomotor control, consist of two distinct pathways: the direct and indirect pathways originating from D1 dopamine receptor (D1R) and D2 dopamine receptor (D2R) expressing spiny projection neurons (SPNs), respectively. In this study, we define the impact of 16p11.2 del/+ on striatal circuits in male and female mice. Using snRNA-seq, we identify sex- and cell type-specific transcriptomic changes in the D1- and D2-SPNs of 16p11.2 del/+ mice, indicating distinct transcriptomic signatures in D1-SPNs and D2-SPNs in males and females, with a ∼5-fold greater impact in males. Further pathway analysis reveals differential gene expression changes in 16p11.2 del/+ male mice linked to synaptic plasticity in D1- and D2-SPNs and GABA signaling pathway changes in D1-SPNs. Consistent with our snRNA-seq study revealing changes in GABA signaling pathways, we observe distinct changes in miniature inhibitory postsynaptic currents (mIPSCs) in D1- and D2-SPNs from 16p11.2 del/+ male mice. Behaviorally, we utilize conditional genetic approaches to introduce the hemideletion selectively in either D1- or D2-SPNs and find that conditional hemideletion of genes in the 16p11.2 region in D2-SPNs causes hyperactivity in male mice, but hemideletion in D1-SPNs does not. Within the striatum, hemideletion of genes in D2-SPNs in the dorsal lateral striatum leads to hyperactivity in males, demonstrating the importance of this striatal region. Interestingly, conditional 16p11.2 del/+ within the cortex drives hyperactivity in both sexes. Our work reveals that a locus linked to NDDs acts in different striatal circuits, selectively impacting behavior in a sex- and cell type-specific manner, providing new insight into male vulnerability for NDDs.
HIGHLIGHTS
- 16p11.2 hemideletion (16p11.2 del/+) induces sex- and cell type-specific transcriptomic signatures in spiny projection neurons (SPNs). - Transcriptomic changes in GABA signaling in D1-SPNs align with changes in inhibitory synapse function. - 16p11.2 del/+ in D2-SPNs causes hyperactivity in males but not females. - 16p11.2 del/+ in D2-SPNs in the dorsal lateral striatum drives hyperactivity in males. - 16p11.2 del/+ in cortex drives hyperactivity in both sexes.
PubMed: 38952795
DOI: 10.1101/2024.05.17.594746 -
IScience Jun 2024Plasticity during the critical period is important for the functional maturation of cortical neurons. While characteristics of plasticity are diverse among cortical...
Plasticity during the critical period is important for the functional maturation of cortical neurons. While characteristics of plasticity are diverse among cortical layers, it is unknown whether critical period timing is controlled by a common or unique molecular mechanism among them. We here clarified layer-specific regulation of the critical period timing of ocular dominance plasticity in the primary visual cortex. Mice lacking the endocannabinoid synthesis enzyme diacylglycerol lipase-α exhibited precocious critical period timing, earlier maturation of inhibitory synaptic function in layers 2/3 and 4, and impaired development of the binocular matching of orientation selectivity exclusively in layer 2/3. Activation of cannabinoid receptor restored ocular dominance plasticity at the normal critical period in layer 2/3. Suppression of GABA receptor rescued precocious ocular dominance plasticity in layer 4. Therefore, endocannabinoids regulate critical period timing and maturation of visual function partly through the development of inhibitory synaptic functions in a layer-dependent manner.
PubMed: 38952682
DOI: 10.1016/j.isci.2024.110145