AcrIIC4 inhibits type II-C Cas9 by preventing R-loop formation.

Anti-CRISPR (Acr) proteins are encoded by phages and other mobile genetic elements and inhibit host CRISPR-Cas immunity using versatile strategies. AcrIIC4 is a broad-spectrum Acr that inhibits the type II-C CRISPR-Cas9 system in several species by an unknown mechanism. Here, we determined a series of structures of Haemophilus parainfluenzae Cas9 (HpaCas9)-sgRNA in complex with AcrIIC4 and/or target DNA, as well as the crystal structure of AcrIIC4 alone. We found that AcrIIC4 resides in the crevice between the REC1 and REC2 domains of HpaCas9, where its extensive interactions restrict the mobility of the REC2 domain and prevent the unwinding of target double-stranded (ds) DNA at the PAM-distal end. Therefore, the full-length guide RNA:target DNA heteroduplex fails to form in the presence of AcrIIC4, preventing Cas9 nuclease activation. Altogether, our structural and biochemical studies illuminate a unique Acr mechanism that allows DNA binding to the Cas9 effector complex but blocks its cleavage by preventing R-loop formation, a key step supporting DNA cleavage by Cas9.

Anti-CRISPR AcrIIC5 is a dsDNA mimic that inhibits type II-C Cas9 effectors by blocking PAM recognition.

Anti-CRISPR proteins are encoded by phages to inhibit the CRISPR-Cas systems of the hosts. AcrIIC5 inhibits several naturally high-fidelity type II-C Cas9 enzymes, including orthologs from Neisseria meningitidis (Nme1Cas9) and Simonsiella muelleri (SmuCas9). Here, we solve the structure of AcrIIC5 in complex with Nme1Cas9 and sgRNA. We show that AcrIIC5 adopts a novel fold to mimic the size and charge distribution of double-stranded DNA, and uses its negatively charged grooves to bind and occlude the protospacer adjacent motif (PAM) binding site in the target DNA cleft of Cas9. AcrIIC5 is positioned into the crevice between the WED and PI domains of Cas9, and one end of the anti-CRISPR interacts with the phosphate lock loop and a linker between the RuvC and BH domains. We employ biochemical and mutational analyses to build a model for AcrIIC5's mechanism of action, and identify residues on both the anti-CRISPR and Cas9 that are important for their interaction and inhibition. Together, the structure and mechanism of AcrIIC5 reveal convergent evolution among disparate anti-CRISPR proteins that use a DNA-mimic strategy to inhibit diverse CRISPR-Cas surveillance complexes, and provide new insights into a tool for potent inhibition of type II-C Cas9 orthologs.

Multiple cropping effectively increases soil bacterial diversity, community abundance and soil fertility of paddy fields.

BACKGROUND: Crop diversification is considered as an imperative approach for synchronizing the plant nutrient demands and soil nutrient availability. Taking two or more crops from the same field in one year is considered as multiple cropping. It improves the diversity and abundance of soil microbes, thereby improving the growth and yield of crops. Therefore, the present study was conducted to explore the effects of different multiple winter cropping on soil microbial communities in paddy fields. In this study, eight rice cropping patterns from two multiple cropping systems with three different winter crops, including Chinese milk vetch (CMV), rape, and wheat were selected. The effects of different multiple winter cropping on soil microbial abundance, community structure, and diversity in paddy fields were studied by 16 S rRNA high-throughput sequencing and real-time fluorescence quantitative polymerase chain reaction (PCR). RESULTS: The results showed that different multiple winter cropping increased the operational taxonomic units (OTUs), species richness, and community richness index of the bacterial community in 0 ~ 20 cm soil layer. Moreover, soil physical and chemical properties of different multiple cropping patterns also affected the diversity and abundance of microbial bacterial communities. The multiple cropping increased soil potassium and nitrogen content, which significantly affected the diversity and abundance of bacterial communities, and it also increased the overall paddy yield. Moreover, different winter cropping changed the population distribution of microorganisms, and Proteobacteria, Acidobacteria, Nitrospira, and Chloroflexi were identified as the most dominant groups. Multiple winter cropping, especially rape-early rice-late rice (TR) andChinese milk vetch- early rice-late rice (TC) enhanced the abundance of Proteobacteria, Acidobacteria, and Actinobacteria and decreased the relative abundance of Verrucomicrobia and Euryarchaeota. CONCLUSION: In conclusion, winter cropping of Chinese milk vetch and rape were beneficial to improve the soil fertility, bacteria diversity, abundance and rice yield.

Photoactive rhodamine-based photosensitizer eliminates Staphylococcus aureus via superoxide radical photosensitization.

Due to the antibiotics abuse, bacterial infection has become one of the leading causes of human death worldwide. Novel selective antimicrobial agents are urgently needed, with the hope of maintaining the balance of the microbial environment. Photo-activated chemotherapeutics have shown great potential to eliminate bacteria with appealing spatiotemporal selectivity. In this work, we reported the structural modification to enhance the triplet excited state property of Rhodamine B, synthesizing a rhodamine-based photosensitizer RBPy. Upon light activation, RBPy exhibited much stronger photosensitization ability than the parent compound Rhodamine B both in solution and in bacteria. Importantly, RBPy can selectively inactivate Staphylococcus aureus and inhibit biofilm formation with high biocompatibility. This work provides a new strategy to develop rhodamine-based photoactive chemotherapeutics for antimicrobial photodynamic therapy.

Expression profiles, biological functions and clinical significance of circRNAs in bladder cancer.

Circular RNAs (circRNAs), which are single-stranded closed-loop RNA molecules lacking terminal 5' caps and 3' poly(A) tails, are attracting increasing scientific attention for their crucial regulatory roles in the occurrence and development of various diseases. With the rapid development of high-throughput sequencing technologies, increasing numbers of differentially expressed circRNAs have been identified in bladder cancer (BCa) via exploration of the expression profiles of BCa and normal tissues and cell lines. CircRNAs are critically involved in BCa biological behaviours, including cell proliferation, tumour growth suppression, cell cycle arrest, apoptosis, invasion, migration, metastasis, angiogenesis, and cisplatin chemoresistance. Most of the studied circRNAs in BCa regulate cancer biological behaviours via miRNA sponging regulatory mechanisms. CircRNAs have been reported to be significantly associated with many clinicopathologic characteristics of BCa, including tumour size, grade, differentiation, and stage; lymph node metastasis; tumour numbers; distant metastasis; invasion; and recurrence. Moreover, circRNA expression levels can be used to predict BCa patients' survival parameters, such as overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS). The abundance, conservation, stability, specificity and detectability of circRNAs render them potential diagnostic and prognostic biomarkers for BCa. Additionally, circRNAs play crucial regulatory roles upstream of various signalling pathways related to BCa carcinogenesis and progression, reflecting their potential as therapeutic targets for BCa. Herein, we briefly summarize the expression profiles, biological functions and mechanisms of circRNAs and the potential clinical applications of these molecules for BCa diagnosis, prognosis, and targeted therapy.

Comparison of contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with nondilated collecting system: a randomized controlled trial.

OBJECTIVE: To compare the safety, effectiveness, and feasibility of contrast-enhanced ultrasound (CEUS) versus conventional ultrasound-guided percutaneous nephrolithotomy (PCNL) in patients with nondilated collecting system. METHODS: Between July 2018 and July 2020, 160 kidney stone patients with nondilated collecting system planned for PCNL were randomly assigned into two groups, CEUS with retrograde ureteral contrast injection and conventional ultrasound with retrograde ureteral normal saline injection. Patient's demographics, the success rate of puncture, success rate of a single-needle puncture, number of punctures, puncture time, perioperative outcomes, stone-free rate, and incidence of complications were compared. RESULTS: The success rate of a single-needle puncture for CEUS-guided PCNL was higher than that in the conventional ultrasound group (88.5% vs. 73.7%, p = 0.02). Patients performed with CEUS-guided PCNL required less needle passes (p = 0.02), shorter needle puncture time (p = 0.031), and shorter channel establishment time (p = 0.04) than those guided with conventional ultrasound. The postoperative hemoglobin decrease in the CEUS-guided PCNL group was less than that of the control group (p = 0.02). There was no significant difference in operating time, length of hospital stays, kidney function change, and complications between the two groups (p > 0.05). The 1-month stone-free rate was 94.9% in the CEUS group and 90.8% in the control group (p > 0.05). CONCLUSIONS: Compared with conventional ultrasound, CEUS-guided PCNL may facilitate ultrasound-guided PCNL for patients without hydronephrosis, and benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR1800016981 KEY POINTS: • Compared with conventional ultrasound, CEUS-guided PCNL is a safe and efficacious procedure for kidney stone patients with nondilated collecting system. • Compared with conventional ultrasound, CEUS-guided PCNL benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop. • CEUS-guided PCNL associated with the more accurate needle puncture and acceptable complications.

Genome-Wide Mapping of Cytosine Methylation Revealed Dynamic DNA Methylation Patterns Associated with Sporophyte Development of Saccharina japonica.

Cytosine methylation plays vital roles in regulating gene expression and plant development. However, the function of DNA methylation in the development of macroalgae remains unclear. Through the genome-wide bisulfite sequencing of cytosine methylation in holdfast, stipe and blade, we obtained the complete 5-mC methylation landscape of Saccharina japonica sporophyte. Our results revealed that the total DNA methylation level of sporophyte was less than 0.9%, and the content of CHH contexts was dominant. Moreover, the distribution of CHH methylation within the genes exhibited exon-enriched characteristics. Profiling of DNA methylation in three parts revealed the diverse methylation pattern of sporophyte development. These pivotal DMRs were involved in cell motility, cell cycle and cell wall/membrane biogenesis. In comparison with stipe and blade, hypermethylation of mannuronate C5-epimerase in holdfast decreased the transcript abundance, which affected the synthesis of alginate, the key component of cell walls. Additionally, 5-mC modification participated in the regulation of blade and holdfast development by the glutamate content respectively via glutamine synthetase and amidophosphoribosyl transferase, which may act as the epigenetic regulation signal. Overall, our study revealed the global methylation characteristics of the well-defined holdfast, stipe and blade, and provided evidence for epigenetic regulation of sporophyte development in brown macroalgae.

An Anti-FOD Method Based on CA-CM-CFAR for MMW Radar in Complex Clutter Background.

Traditional constant false alarm rate (CFAR) methods have shown their potential for foreign object debris (FOD) indication. However, the performance of these methods would deteriorate under the complex clutter background in airport scenes. This paper presents a threshold-improved approach based on the cell-averaging clutter-map (CA-CM-) CFAR and tests it on a millimeter-wave (MMW) radar system. Clutter cases are first classified with variability indexes (VIs). In homogeneous background, the threshold is calculated by the student-t-distributed test statistic; under the discontinuous clutter conditions, the threshold is modified according to current VI conditions, in order to address the performance decrease caused by extended clutter edges. Experimental results verify that the chosen targets can be indicated by the t-distributed threshold in homogeneous background. Moreover, effective detection of the obscured targets could also be achieved with significant detectability improvement at extended clutter edges.

Non-Coding RNAs Participate in the Regulation of CRY-DASH in the Growth and Early Development of Saccharina japonica (Laminariales, Phaeophyceae).

CRY-DASH, a new cryptochrome blue light receptor, can repair damaged DNA and regulate secondary metabolism and development of fungus. However, its role in regulation during the growth of Saccharina japonica is still unclear. After cloning the full-length of CRY-DASH from S. japonica (sjCRY-DASH), we deduced that its open reading frame was 1779 bp long and encoded 592 amino acids. sjCRY-DASH transcription was rapidly upregulated within 30 min in response to blue light and exhibited 24 h periodicity with different photoperiods. Moreover, sjCRY-DASH maintained the same periodicity in suitable growth temperature, suggesting a close relationship between this periodicity and circadian rhythm regulation. Novel-m3234-5p, which was targeted to sjCRY-DASH, decreased with increasing sjCRY-DASH transcription, acting as a negative modulator of sjCRY-DASH. Six long non-coding RNAs classified as long intergenic non-coding RNAs (lincRNAs) exhibited co-expression with sjCRY-DASH. A miRNA sjCRY DASH lincRNA network was consequently identified. By predicting the endogenous competing mRNAs of novel-m3234-5p, we found that sjCRY-DASH indirectly participated in the regulation of DNA damage repair, protein synthesis and processing, and actin transport. In conclusion, our results revealed that non-coding RNAs participate in the regulation of sjCRY-DASH, which played vital roles in the growth and early development of S. japonica.

Pioglitazone decreased renal calcium oxalate crystal formation by suppressing M1 macrophage polarization via the PPAR-γ-miR-23 axis.

Interaction of pioglitazone (PGZ) and macrophages (Mps) in renal crystal formation remains unclear. In the present study, we investigated the possible mechanisms involved with Mps of PGZ in suppressing renal crystal formation. Crystal formation in the mouse kidney was detected using polarized light optical microscopy and Pizzolato staining. Gene expression was detected by Western blot analysis, quantitative RT-PCR, immunohistochemistry, immunofluorescence, and ELISA. Mp phenotypes were identified by flow cytometric analysis. Cell apoptosis was detected with TUNEL assay, and tubular injury was detected with periodic acid-Schiff staining. Interaction of peroxisome proliferator-activated receptor (PPAR)-γ and promoter was determined by chromatin immunoprecipitation assay. Luciferase reporter assay was performed to authenticate target genes of miRNA-23 (miR-23). Recombinant adenovirus was used to elucidate the role of miR-23 in vivo. Renal crystal formation, inflammation, tubular injury, and cell apoptosis were significantly marked in glyoxylic acid-treated groups and significantly decreased in PGZ-treated groups. PGZ significantly reduced Mp infiltration and M1 Mp polarization in the kidney. In vitro, PGZ shifted crystal-stimulated M1-predominant Mps to M2-predominant Mps, which were anti-inflammatory. PPAR-γ could directly bind to one PPAR-γ regulatory element in the promoter of pre-miR-23 to promote expression of miR-23 in Mps. We identified two downstream target genes of miR-23, interferon regulatory factor 1 and Pknox1. Moreover, miR-23 decreased crystal deposition, M1 Mp polarization, and injury in the kidney. This study has proven that PGZ decreased renal calcium oxalate crystal formation and renal inflammatory injury by suppressing M1 Mp polarization through a PPAR-γ-miR-23-interferon regulatory factor 1/Pknox1 axis. PGZ is liable to be a potential therapeutic medicine for treating urolithiasis.

PI signal transduction and ubiquitination respond to dehydration stress in the red seaweed Gloiopeltis furcata under successive tidal cycles.

BACKGROUND: Intermittent dehydration caused by tidal changes is one of the most important abiotic factors that intertidal seaweeds must cope with in order to retain normal growth and reproduction. However, the underlying molecular mechanisms for the adaptation of red seaweeds to repeated dehydration-rehydration cycles remain poorly understood. RESULTS: We chose the red seaweed Gloiopeltis furcata as a model and simulated natural tidal changes with two consecutive dehydration-rehydration cycles occurring over 24 h in order to gain insight into key molecular pathways and regulation of genes which are associated with dehydration tolerance. Transcription sequencing assembled 32,681 uni-genes (GC content = 55.32%), of which 12,813 were annotated. Weighted gene co-expression network analysis (WGCNA) divided all transcripts into 20 modules, with Coral2 identified as the key module anchoring dehydration-induced genes. Pathways enriched analysis indicated that the ubiquitin-mediated proteolysis pathway (UPP) and phosphatidylinositol (PI) signaling system were crucial for a successful response in G. furcata. Network-establishing and quantitative reverse transcription PCR (qRT-PCR) suggested that genes encoding ubiquitin-protein ligase E3 (E3-1), SUMO-activating enzyme sub-unit 2 (SAE2), calmodulin (CaM) and inositol-1,3,4-trisphosphate 5/6-kinase (ITPK) were the hub genes which responded positively to two successive dehydration treatments. Network-based interactions with hub genes indicated that transcription factor (e.g. TFIID), RNA modification (e.g. DEAH) and osmotic adjustment (e.g. MIP, ABC1, Bam1) were related to these two pathways. CONCLUSIONS: RNA sequencing-based evidence from G. furcata enriched the informational database for intertidal red seaweeds which face periodic dehydration stress during the low tide period. This provided insights into an increased understanding of how ubiquitin-mediated proteolysis and the phosphatidylinositol signaling system help seaweeds responding to dehydration-rehydration cycles.

A Clutter-Analysis-Based STAP for Moving FOD Detection on Runways.

Security risks and economic losses of civil aviation caused by Foreign Object Debris (FOD) have increased rapidly. Synthetic Aperture Radars (SARs) with high resolutions potentially have the capability to detect FODs on the runways, but the target echo is hard to be distinguished from strong clutter. This paper proposes a clutter-analysis-based Space-time Adaptive Processing (STAP) method in order to obtain effective clutter suppression and moving FOD indication, under inhomogeneous clutter background. Specifically, we first divide the radar coverage into equal scattering cells in the rectangular coordinates system rather than the polar ones. We then measure normalized RCSs within the X-band and employ the acquired results to modify the parameters of traditional models. Finally, we describe the clutter expressions as responses of the scattering cells in space and time domain to obtain the theoretical clutter covariance. Experimental results at 10 GHz show that FODs with a reflection higher than -30 dBsm can be effectively detected by a Linear Constraint Minimum Variance (LCMV) filter in azimuth when the noise is -60 dBm. It is also validated to indicate a -40 dBsm target in Doppler. Our approach can obtain effective clutter suppression 60dB deeper than the training-sample-coupled STAP under the same conditions.

Autophagy as a Potential Target for Sarcopenia.

Sarcopenia is an aging-related disease with a significant reduction in mass and strength of skeletal muscle due to the imbalance between protein synthesis and protein degradation. The loss of skeletal muscle is an inevitable event during aging process, which can result in the significant impact on the quality of life, and also can increase the risk for other aging-associated diseases in the elderly. However, the underlying molecular mechanism of aging-related skeletal muscle loss is still poorly understood. Autophagy is a degradation pathway for the clearance of dysfunctional organelles and damaged macromolecules during aging process. Appropriate induction or accurate regulation of autophagic process and improved quality control of mitochondria through autophagy or other strategies are required for the maintenance of skeletal muscle mass. In this article, we have summarized the current understanding of autophagic pathways in sarcopenia, and discussed the functional status of autophagy and autophagy-associated quality control of mitochondria in the pathogenesis of sarcopenia. Moreover, this article will provide some theoretical references for the exploration of scientific and optimal intervention strategies such as exercise and caloric restriction for the prevention and treatment of sarcopenia through the regulation of autophagic pathways.

Down-regulation of miR-489 contributes into NSCLC cell invasion through targeting SUZ12.

microRNAs are small, non-coding RNAs that contribute into various biological processes during cancer progression. However, the potential role of miR-489 in the development of Non-Small Cell Lung Cancer (NSCLC) is not demonstrated. In present study, miR-489 was down-regulated both in tumor tissues and cells. Inhibition of miR-489 promoted cells invasion by using an invasion assay. Furthermore, miR-489 could regulate SUZ12 as shown by luciferase reporter and Western blot assays. Aberrant miR-489 expression could regulate the molecular changes (E-cadherin, N-cadherin, and Vimentin) of epithelial mesenchymal transition (EMT). In conclusion, our study revealed that miR-489 may play an essential role in the progression of NSCLC.

The effects of Massa Medicata Fermentata on the digestive function and intestinal flora of mice with functional dyspepsia.

Introduction: The purpose of this study was to identify the chemical components of Massa Medicata Fermentata (MMF) in different fermentation methods, analyze its regulatory effects on gastrointestinal propulsion and intestinal flora in mice with food accumulation, and further explore its mechanism of action in the treatment of dyspepsia. Methods: The chemical compositions of three kinds of MMF were identified using the UPLC-Q- Exactive Orbitrap mass spectrometer. A model of spleen deficiency and food accumulation in mice was established. The gastric emptying rate and intestinal propulsion rate were calculated, serum gastrin concentration and cholinesterase activity were measured, and 16S rRNA microbial detection was performed in different groups of mouse feces. Results: The results showed that a total of 95 chemical components were identified from the three MMF extracts, 62 of which were the same, but there were differences in flavonoids and their glycosides, organic acids, and esters. MMF, PFMMF, and commercial MMF could all significantly improve the gastric emptying rate, intestinal propulsion rate, and GAS concentration in the serum of model mice; PFMMF has a better effect, while there was no significant difference in cholinesterase activity among the groups (p > 0.05). The 16S rRNA sequencing results showed that the MMF and PFMMF could increase the content of beneficial bacteria Bacteroidetes and decrease the pathogenic bacteria Verrucomicrobia in the intestines of model mice, while the commercial MMF could not. Discussion: Studies suggest that MMF has a variety of possible mechanisms for improving food accumulation and treating gastrointestinal dyspepsia, which provides reference value for the quality evaluation and clinical application of MMF.

Physical literacy and health of Chinese medical students: the chain mediating role of physical activity and subjective well-being.

Background/objective: While Physical Literacy has been highlighted as a determinant in health in recent study, there is a dearth of studies examining its effect on physical health, and there is a little in the way of empirical data linking Physical Literacy to health outcomes. Accordingly, further empirical research is needed to clarify the mechanisms by which Physical Literacy affects physical health. The purpose of this study was to verify the role of medical students' Physical Literacy on Health-related quality of life as well as to explore the chain mediating role of Physical Activity and Subjective Well-being in it. Methods: This study utilized a cross-sectional study design. The Physical Literacy, Health-related Quality of Life, Physical Activity ratings, and Subjective Well-being of students at Shanxi Medical University were all measured using an online survey administered in September 2023. A total of 1968 valid questionnaires were returned. First, descriptive statistics and correlation analysis were performed using SPSS software. Second, PROCESS was used to test the mediating role. Finally, we used structural equation modeling (Amos) to test the model fit. Results: There is a significant correlation between all variables. After mediation effects analysis, we found that there were three indirect pathways of physical literacy on health-related quality of life: a single mediating effect of physical activity, a single mediating effect of subjective well-being, and a chained mediating effect of physical activity-subjective well-being. Conclusion: The mediating role of physical activity and subjective well-being on the relationship between physical literacy and health-related quality of life has been confirmed. Our research results support the integration of physical literacy into physical education teaching and the modification of curriculum content by physical education teachers as part of efforts to enhance students' physical activity levels, subjective well-being levels, and overall health. This study provides a new perspective for intervention in improving the health of medical students.

Peripheral nervous system lymphatic vessels: A simple delivery route to promote nerve regeneration.

The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.

Gasdermin D silencing alleviates airway inflammation and remodeling in an ovalbumin-induced asthmatic mouse model.

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. Gasdermin D (GSDMD) is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. Immunofluorescence staining was conducted on airway epithelial tissues obtained from both asthma patients and healthy controls (HCs) to evaluate the expression level of N-GSDMD. ELISA was used to measure concentrations of cytokines (IL-1ß, IL-18, IL-17A, and IL-10) in serum samples collected from asthma patients and healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1ß were significantly increased in samples with mild asthma compared with those from the controls. Then, wild type and Gsdmd-knockout (Gsdmd-/-) mice were used to establish asthma model. We performed histopathological staining, ELISA, and flow cytometry to explore the function of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the expression of N-GSDMD, IL-18, and IL-1ß was enhanced in OVA-induced asthma mouse model. Gsdmd knockout resulted in attenuated IL-18, and IL-1ß production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd-/- mice exhibit a significant reduction in airway inflammation and remodeling, which might be associated with reduced Th17 inflammatory response and M2 polarization of macrophages. Further, we found that GSDMD knockout may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion, migration, and macrophage M2 polarization by targeting Notch signaling pathway. These findings demonstrate that GSDMD deficiency profoundly alleviates allergic inflammation and tissue remodeling. Therefore, GSDMD may serve as a potential therapeutic target against asthma.

Netrin-1-engineered endothelial cell exosomes induce the formation of pre-regenerative niche to accelerate peripheral nerve repair.

The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.

Real time monitoring peripheral nerve function with ICG and BDA-ICG by NIR-II fluorescence imaging.

Neuroanatomical tract tracers are important for studying axoplasmic transport and the complex interconnections of the nervous system. Though traditional fluorescent tracers are widely used, they have several prominent drawbacks when imaging, including low resolutions and low tissue penetrations and inability to be supervised dynamically within a long peripheral nerve during the long term. Here, we explored the potential of ICG as a neural tracer for axoplasmic transport and for the first time demonstrated that ICG could be used to detect transport function within peripheral nerve by near-infrared region II (NIR-II) imaging. On basis of this finding, a novel bi-directional neural tracer biotinylated dextran amine-indocyanine green (BDA-ICG) was prepared and characterized with better long-term stability and higher nerve-to-background ratio than ICG in vivo, and successfully imaged the injured peripheral nerve from the healthy one within 24 h. Our results show that BDA-ICG are promising neural tracers and clinically available dyes with NIR-II emission tail characteristics as ICG.