Self-assembly of rigid amphiphilic graft cyclic-brush copolymers to nanochannels using dissipative particle dynamics simulation.

The synthesis of specific artificial nanochannels remains a formidable challenge in the field of nanomaterials and synthetic chemistry. In particular, the preparation of artificial nanochannels using amphiphilic graft cyclic-brush copolymers (AGCCs) as monomers has garnered substantial attention. Nevertheless, because of the constrained time and length scales inherent in traditional molecular dynamics simulations, a comprehensive theoretical understanding of the morphological regulation mechanism governing the self-assembly of AGCCs into nanochannels remains elusive. In this study, we employed the dissipative particle dynamics (DPD) method to explore the self-assembly mechanism considering factors such as the DPD interaction parameters, concentrations, and sizes of AGCCs. By calculating the phase diagrams, we predicted the emergence of four distinct nanochannel types: short independent, long independent, parallel, and disordered channels. Importantly, the formation of these nanochannels is highly contingent on specific environmental conditions. Furthermore, we extensively discussed self-assembly processes that lead to different types of nanochannels. The self-assembly of AGCCs is revealed as a multistep process primarily influenced by the interaction parameters. However, while the monomer size and concentration do not introduce novel self-assembly morphologies, they do influence the final aggregation state. The elucidation of the self-assembly mechanism presented in this study deepens our understanding of AGCC nanochannel formation. Consequently, this is a valuable guide for the preparation of copolymer materials with specific functionalities, offering insights into targeted copolymer material design.

A theoretical study of the mechanism of cationic polymerization of isobutylene catalysed by EtAlCl2/t-BuCl with bis(2-chloroethyl)ether in hexanes.

The mechanism of cationic polymerization of isobutylene catalyzed by t-BuCl/ethylaluminum dichloride (EADC) combined with bis(2-chloroethyl)ether (CEE) in n-hexane solvent has been investigated using ab initio molecular dynamics (AIMD) and metadynamics (MTD) simulations. The results indicated that the polyisobutylene (PIB) initiation stage involves a clear two-step mechanism. Calculation of the free energy landscapes of the other two ether reactions reveals that the energy barriers of diisopropyl ether (i-Pr2O) and 2-chloroethyl ethyl ether (CEEE) are much higher than those of CEE, which is consistent with the experimental results. During the chain propagation phase, the required free energy barrier gradually decreases and tends to reach equilibrium as the chain length increases. Finally, the oxonium mechanism during the chain initiation stage was investigated by calculating the 1H NMR spectra and MTD simulation. Our calculations can confirm that the existence of tert-butyloxonium ions during the reaction is possible. Their contribution to the whole reaction is further discussed.

Ligation-Based High-Performance Mimetic Enzyme Sensing Platform for Nucleic Acid Detection.

G-quadruplex (G4)/hemin DNAzyme is a promising candidate to substitute horseradish peroxidase in biosensing systems, especially for the detection of nucleic acids. However, the relatively suboptimal catalytic capacity limits its potential applications. This makes it imperative to develop an ideal signal for the construction of highly sensitive biosensing platforms. Herein, we integrated a novel chimeric peptide-DNAzyme (CPDzyme) with the ligase chain reaction (LCR) for the cost-efficient and highly sensitive detection of nucleic acids. By employing microRNA (miRNA) and single-nucleotide polymorphism detection as the model, we designed a G4-forming sequence on the LCR probe with a terminally labeled amino group. Subsequently, asymmetric hemin with carboxylic arms allowed assembly with the LCR products and peptide to form CPDzyme, followed by the magnetic separation of the extraneous components and chemiluminescence detection. Compared with the conventional G4/hemin signaling-based method, the LCR-CPDzyme system demonstrated 3 orders of magnitude improved sensitivity, with accurate quantification of as low as 25 aM miRNA and differentiation of 0.1% of mutant DNA from the pool containing a large amount of wild-type DNA. The proposed LCR-CPDzyme strategy is a potentially powerful method for in vitro diagnostics and serves as a reference for the development of other ligation- or hybridization-based nucleic acid amplification assays.

Myeloid Vamp3 deletion attenuates CFA-induced inflammation and pain in mice via ameliorating macrophage infiltration and inflammatory cytokine production.

Persistent inflammation and associated pain significantly impact individuals' quality of life, posing substantial healthcare challenges. Proinflammatory cytokines, released by activated macrophages, play crucial roles in the development of chronic inflammatory conditions such as rheumatoid arthritis. To identify and evaluate potential therapeutic interventions targeting this process for mitigating inflammation and pain, we created myeloid cell-specific knockout of Vamp3 (vesicle-associated membrane protein 3) mice (Vamp3 Δmyel) by crossing LysM-Cre mice with newly engineered Vamp3flox/flox mice. Bone marrow-derived macrophages and peritoneal resident macrophages from Vamp3 Δmyel mice exhibited a significant reduction in TNF-α and IL-6 release compared to control mice. Moreover, Vamp3 deficiency led to decreased paw edema and ankle joint swelling induced by intraplantar injection of complete Freund's adjuvant (CFA). Furthermore, Vamp3 depletion also mitigated CFA-induced mechanical allodynia and thermal hyperalgesia. Mechanistically, Vamp3 loss ameliorated the infiltration of macrophages in peripheral sites of the hind paw and resulted in reduced levels of TNF-α and IL-6 in the CFA-injected paw and serum. RT-qPCR analysis demonstrated downregulation of various inflammation-associated genes, including TNF-α, IL-6, IL-1ß, CXCL11, TIMP-1, COX-2, CD68, and CD54 in the injected paw at the test day 14 following CFA administration. These findings highlight the novel role of Vamp3 in regulating inflammatory responses and suggest it as a potential therapeutic target for the development of novel Vamp-inactivating therapeutics, with potential applications in the management of inflammatory diseases.

The PLAUR signaling promotes chronic pruritus.

Chronic itch is a complex sensation of the skin frequently associated with skin diseases, such as atopic dermatitis (AD) and psoriasis. Although Serpin E1 is implicated in chronic itch, its receptor and signaling pathways involved in itch are not known. In this study, the clinical relevance of a putative Serpin E1 receptor PLAUR to chronic itch, and the neuro-cutaneous Serpin E1-PLAUR signaling are explored. We found that PLAUR is overexpressed in skin specimens of human lesional AD and lesional psoriasis, and sensory neurons innervating MC903-induced AD-like murine skin. Murine PLAUR+ sensory neurons responded to Serpin E1, resulting in enrichment of numerous itch- and inflammation-related genes and their protein release. PLAUR resides in TLR2+ neurons and Serpin E1 stimulus led to transcriptional upregulation of TLR2 and its co-signaling proteins. Agonists of TLR2 propagated itch-related gene transcription including BNP, OSM, and PAR2. OSM induced acute itch in mice and promoted G-CSF and IL-8 release from human keratinocytes. Serpin E1 inhibitor reduced MC903-induced itch, epidermal hyperplasia, immunocyte infiltration, and resulted in lower transcription/expression levels of Serpin E1 and OSM. Taken together, the PLAUR-TLR2-OSM signaling promotes skin-nerve communication, cutaneous inflammation, and itch, all feeding into an aggravation of AD and exaggerated itch circuits.

IL-20 promotes cutaneous inflammation and peripheral itch sensation in atopic dermatitis.

Atopic dermatitis (AD) is a chronic skin disease, which is associated with intense itch, skin barrier dysfunction and eczematous lesions. Aberrant IL-20 expression has been implicated in numerous inflammatory diseases, including psoriasis. However, the role of IL-20 in AD remains unknown. Here, RNA-seq, Q-PCR, and immunocytochemistry were utilized to examine disease-driven changes of IL-20 and its cognate receptor subunits in skin from healthy human subjects, AD patients and murine AD-models. Calcium imaging, knockdown and cytokine array were used to investigate IL-20-evoked responses in keratinocytes and sensory neurons. The murine cheek model and behavioral scoring were employed to evaluate IL-20-elicited sensations in vivo. We found that transcripts and protein of IL-20 were upregulated in skin from human AD and murine AD-like models. Topical MC903 treatment in mice ear enhanced IL-20R1 expression in the trigeminal sensory ganglia, suggesting a lesion-associated and epidermal-driven mechanism for sensitization of sensory IL-20 signaling. IL-20 triggered calcium influx in both keratinocytes and sensory neurons, and promoted their AD-related molecule release and transcription of itch-related genes. In sensory neurons, IL-20 application increased TLR2 transcripts, implicating a link between innate immune response and IL-20. In a murine cheek model of acute itch, intradermal injection IL-20 and IL-13 elicited significant itch-like behavior, though only when co-injected. Our findings provide novel insights into IL-20 function in peripheral (skin-derived) itch and clinically relevant intercellular neuron-epidermal communication, highlighting a role of IL-20 signaling in the pathophysiology of AD, thus forming a new basis for the development of a novel antipruritic strategy via interrupting IL-20 epidermal pathways.

Integration of the Ligase Chain Reaction with the CRISPR-Cas12a System for Homogeneous, Ultrasensitive, and Visual Detection of microRNA.

The ligase chain reaction (LCR), as a classic nucleic acid amplification technique, is popular in the detection of DNA and RNA due to its simplicity, powerfulness, and high specificity. However, homogeneous and ultrasensitive LCR detection is still quite challenging. Herein, we integrate the LCR with a CRISPR-Cas12a system to greatly promote the application of the LCR in a homogeneous fashion. By employing microRNA as the model target, we design LCR probes with specific protospacer adjacent motif sequences and the guide RNA. Then, the LCR is initiated by target microRNA, and the LCR products specifically bind to the guide RNA to activate the Cas12a system, triggering secondary signal amplification to achieve ultrasensitive detection of microRNA without separation steps. Moreover, by virtue of a cationic conjugated polymer, microRNA can not only be visually detected by naked eyes but also be accurately quantified based on RGB ratio analysis of images with no need of sophisticated instruments. The method can quantify microRNA up to 4 orders of magnitude, and the determination limit is 0.4 aM, which is better than those of other reported studies using CRISPR-Cas12a and can be compared with that of the reverse-transcription polymerase chain reaction. This study demonstrates that the CRISPR-Cas12a system can greatly expand the application of the LCR for the homogeneous, ultrasensitive, and visual detection of microRNA, showing great potential in efficient nucleic acid detection and in vitro diagnosis.

Dynamic monitoring of urban built-up object expansion trajectories in Karachi, Pakistan with time series images and the LandTrendr algorithm.

In the complex process of urbanization, retrieving its dynamic expansion trajectories with an efficient method is challenging, especially for urban regions that are not clearly distinguished from the surroundings in arid regions. In this study, we propose a framework for extracting spatiotemporal change information on urban disturbances. First, the urban built-up object areas in 2000 and 2020 were obtained using object-oriented segmentation method. Second, we applied LandTrendr (LT) algorithm and multiple bands/indices to extract annual spatiotemporal information. This process was implemented effectively with the support of the cloud computing platform of Earth Observation big data. The overall accuracy of time information extraction, the kappa coefficient, and average detection error were 83.76%, 0.79, and 0.57 a, respectively. These results show that Karachi expanded continuously during 2000-2020, with an average annual growth rate of 4.7%. However, this expansion was not spatiotemporally balanced. The coastal area developed quickly within a shorter duration, whereas the main newly added urban regions locate in the northern and eastern inland areas. This study demonstrated an effective framework for extract the dynamic spatiotemporal change information of urban built-up objects and substantially eliminate the salt-and-pepper effect based on pixel detection. Methods used in our study are of general promotion significance in the monitoring of other disturbances caused by natural or human activities.

Polymyxin B-modified conjugated oligomer nanoparticle for targeted identification and enhanced photodynamic antimicrobial therapy.

We report a photosensitive polymyxin B-modified conjugated oligomer nanoparticle that integrates the targeted identification and synergistic photodynamic therapy in one treatment against resistant Gram-negative bacteria. The study expands the application of antibiotics and opens a new avenue for enhancing photodynamic antimicrobial therapy and fighting bacterial resistance.

Innate immune regulates cutaneous sensory IL-13 receptor alpha 2 to promote atopic dermatitis.

The clinical significance and regulators of IL-13Rα2 in itch and atopic dermatitis (AD) remain unclear. To identify disease-driven regulatory circuits of IL-13Rα2, transcriptomic/pathological analysis was performed in skin from patients with AD, psoriasis, healthy subjects, and murine AD model. Functionality was investigated in sensory neurons, keratinocytes and animal model, by using knockdown (KD), calcium imaging, RNA-seq, cytokine arrays, pharmacological assays, and behavioural investigations. In our study, an upregulated IL-13Rα2 expression was revealed in skin of AD patients, but not psoriasis, in a disease activity-dependent manner. In cultured human keratinocytes, IL-13 increased IL-13Rα2 transcription levels, and this were downregulated by IL-13Rα1KD. IL-13Rα2KD reduced transcription levels of EDNRA, CCL20, CCL26. In contrast, sensory neuron-derived IL-13Rα2 was upregulated by TLR2 heterodimer agonists, Pam3CSK4 and FSL-1. In a mouse cheek model, pre-administration of Pam3CSK4 and FSL-1 enhanced IL-13-elicited scratching behaviour. Consistently, in cultured sensory neurons Pam3CSK4 enhanced IL-13-elicted calcium transients, increased number of responders, and orchestrated chemerin, CCL17 and CCL22 release. These release was inhibited by IL-13Rα2KD. Collectively, IL-13 regulates keratinocyte-derived IL-13Rα2 and TLR2 to modulate neuronal IL-13Rα2, thereby promoting neurogenic inflammation and exacerbating AD and itch. Thus, the cutaneous IL-13-IL-13Rα2 and neuronal TLR2-IL-13Rα2 pathway represent important targets to treat AD and itch.

Dynamics of Leaf-Litter Biomass, Nutrient Resorption Efficiency and Decomposition in a Moso Bamboo Forest After Strip Clearcutting.

Strip clearcutting can significantly reduce the harvesting costs of moso bamboo forests. Although bamboo is characterized by rapid accumulation of biomass, it is still a concern that this management method may reduce long-term productivity. Nutrient cycling has long been considered essential for forests to maintain high primary productivity. However, nutrient cycling of bamboo forests after strip cutting has not been previously reported. We conducted a strip clearcutting experiment and surveyed the litter dynamics for 1 year. We assessed changes in litter nutrients in response to the cutting and calculated the nutrient resorption efficiency and litter decomposition rate to evaluate the effect on nutrient use efficiency and nutrient return. Our results showed that strip cutting had no significant effect on litter production and nutrient return in the moso bamboo forest (p > 0.05). However, annual litter biomass and nutrient return in reserved belts (RB) were significantly higher than those in the control (CK) (p < 0.05). P and K resorption efficiencies in RB were significantly higher than in CK during certain periods of bamboo growth (p < 0.05). We also observed that the annual decay constant of CK was significantly higher than that of plots that were strip clearcut (SC) (p < 0.05). Our results suggest that strip cutting does not affect nutrient use efficiency or storage in the short term.

Soil bacterial community structure of mixed bamboo and broad-leaved forest based on tree crown width ratio.

Moso bamboo (Phyllostachysheterocycla (Carr.) Mitford cv. Pubescens) is an economically valuable plant in bamboo production areas of southern China, for which the management mode is crucial for improving the comprehensive benefits of bamboo forest stands. In this respect, mixed forested areas of bamboo and broad-leaved tree species can provide sound ecological management of bamboo in forestry operations. To further this goal, an outstanding question is to better understand the spatial distribution of soil bacterial communities in relation to the proportion of mixed in bamboo and broad-leaved forest. We analyzed soil bacterial community diversity and composition along a proportional gradient of 0-40% mixed-ratio (as represented by the width and size of the broad-leaved tree crown over the plot area) of bamboo and broad-leaved forest in Tianbao Yan Nature Reserve using the highthroughputsequencing of the 16S rRNA gene.Specifically, the sampling plots for the mixed proportions were divided according to the percentage of summed projected area of live broadleaf tree crowns. The main broad-leaved species in the five mixed ratio plots are the same. Each plot was 20 m × 20 m in size, and a total of 15 plots were established, three per forest ratio class. From each plot, soil samples were taken at the surface (0-10 cm depth) in December 2017. Our analysis revealed that soil bacterial diversity community structure and dominant flora changed under different mixing ratios of bamboo and broad-leaved trees. In the stand with a mixed ratio of 10-20%, the bacterial diversity index is higher; however, the diversity was lowest in the 20-30% stands. Among the 20-30% forest soil, Acidobacteria (Solibacteria, Solibacteriales, Acidobacteriales) was more abundant than in soils from other mixed-ratio stands.Redundancy analysis showed that mixed forest stand structure, soil pH, organic carbon, total nitrogen, and soil moisture all contributed to shaping the bacterial community structure. Changes in microbial communities were associated with species diversity in tree layers, availability of soil nutrients (SOC and TN), and changes in soil physical properties (MS, pH). Together, these empirical results suggest that different mixing ratios in the bamboo-broad-leaved mixed forest could influence the soil bacterial community structure indirectly, specifically by affecting the soil physical and chemical properties of the forest.

Reelin regulates male mouse reproductive capacity via the sertoli cells.

Reelin plays important roles in brain development. Reeler mutant mice that lack the protein reelin (RELN) suffer from cell type- and region-dependent changes in their neocortical layers, and adult reeler mutant mice have dilated seminiferous tubules. Meanwhile, the mechanism by which Reelin regulates the spermatogenic cell development in mice and their reproductive abilities remains unclear. In the present study, we used reeler mutant mice to investigate the effects of Reelin on reproduction in mice. The results indicated variations in sex hormone expression among the reeler mice, indicating that they produce few offspring and their spermatogenic cells are irregularly developed. Moreover, glial cell line-derived neurotrophic factor (GDNF)/GDNF family receptor alpha 1, Ras/extracellular regulated protein kinases (ERK), and promyelocytic leukemia zinc finger (PLZF)/chemokine (C-X-C motif) receptor 4 (CXCR4) serve as potential regulatory pathways that respond to the changes in sertoli cells and the niche of male germ cells. Our findings provided valuable insights into the role of reeler in the reproductive abilities of male mice and development of their spermatogonia stem cells.

A lentiviral vector visualizing the germ cell specification in vitro under the control of Figla promoter.

Premature ovarian failure (POF) is affecting more and more women, which is the loss of function of the ovaries before age 40. To elucidate the underlying mechanisms of the oogenesis is of importance to understand the causes of impaired fertility and POF. However, mammalian oogenesis in vivo is a complex process. Thus, building an oogenesis visualizing system is beneficial for the study of oogenesis. In this study, we found that Figla is specifically expressed in female mice oocyte. Then, we constructed a lentiviral vector (pTRIP-Figla-EGFP-puro) under the control of Figla promoter, which drived enhanced green fluorescent protein (EGFP) as an indicator and used the lentiviral vector transduction the ovarian cells and induced germ cells derived from human umbilical cord mesenchymal stem cells (hUC-MSCs), and the results showed that the lentiviral vector we constructed was able to specifically express green fluorescent protein (GFP) in the ovarian oocyte and induced oocyte-like cells derived from hUC-MSCs, which was Figla-positive cells. These results suggest that pTRIP-Figla-EGFP vector provides a new system to study the role of Figla in oogenesis, and an approach to study the development and the differentiation of germ cells derived from stem cells.

Retinol (vitamin A) maintains self-renewal of pluripotent male germline stem cells (mGSCs) from adult mouse testis.

Studies have shown that male germline stem cells (mGSCs), which are responsible for maintaining spermatogenesis in the male, could be obtained from mouse and human testis. However, the traditional cultural methods were mostly dependent on serum and feeder, and the initial mGSCs were either obtained from neonatal mice or the detailed description of its potency and origin was not provided. Here we reported a novel (retinol (RE) serum-free and feeder-free) system for the successful culture of adult germline stem cells from adult Kunming mice (8-24 weeks) testis. The isolated mGSCs cultured in RE serum-free and feeder-free medium maintained the typical morphology of undifferentiated embryonic stem cells (ESCs), and they proliferated well in RE medium analyzed by proliferation assay, RT-PCR, microarray, and Western blotting. These cells also showed typical properties of ESCs (alkaline phosphatase (AP) positive, expressions of Oct4, Sox2, Nanog, and SSEA1, with the capacity to form teratomas and differentiate into various types of cells within three germ layers). Taken together, we conclude that RE promotes the self-renewal of mGSCs and maintains the pluripotency of mGSCs, the RE serum-free and feeder-free system may be useful for the culture of pluripotent stem cell lines from adult testis tissues, which provides a new resource for tissue engineering and therapy for infertility.