IL-13 secreted by ILC2s promotes the self-renewal of intestinal stem cells through circular RNA circPan3.

Intestinal stem cells (ISCs) are maintained by stemness signaling for precise modulation of self-renewal and differentiation under homeostasis. However, the way in which intestinal immune cells regulate the self-renewal of ISCs remains elusive. Here we found that mouse and human Lgr5+ ISCs showed high expression of the immune cell-associated circular RNA circPan3 (originating from the Pan3 gene transcript). Deletion of circPan3 in Lgr5+ ISCs impaired their self-renewal capacity and the regeneration of gut epithelium in a manner dependent on immune cells. circPan3 bound mRNA encoding the cytokine IL-13 receptor subunit IL-13Rα1 (Il13ra1) in ISCs to increase its stability, which led to the expression of IL-13Rα1 in ISCs. IL-13 produced by group 2 innate lymphoid cells in the crypt niche engaged IL-13Rα1 on crypt ISCs and activated signaling mediated by IL-13‒IL-13R, which in turn initiated expression of the transcription factor Foxp1. Foxp1 is associated with ß-catenin in rendering its nuclear translocation, which caused activation of the ß-catenin pathway and the maintenance of Lgr5+ ISCs.

Single-cell brain organoid screening identifies developmental defects in autism.

The development of the human brain involves unique processes (not observed in many other species) that can contribute to neurodevelopmental disorders1-4. Cerebral organoids enable the study of neurodevelopmental disorders in a human context. We have developed the CRISPR-human organoids-single-cell RNA sequencing (CHOOSE) system, which uses verified pairs of guide RNAs, inducible CRISPR-Cas9-based genetic disruption and single-cell transcriptomics for pooled loss-of-function screening in mosaic organoids. Here we show that perturbation of 36 high-risk autism spectrum disorder genes related to transcriptional regulation uncovers their effects on cell fate determination. We find that dorsal intermediate progenitors, ventral progenitors and upper-layer excitatory neurons are among the most vulnerable cell types. We construct a developmental gene regulatory network of cerebral organoids from single-cell transcriptomes and chromatin modalities and identify autism spectrum disorder-associated and perturbation-enriched regulatory modules. Perturbing members of the BRG1/BRM-associated factor (BAF) chromatin remodelling complex leads to enrichment of ventral telencephalon progenitors. Specifically, mutating the BAF subunit ARID1B affects the fate transition of progenitors to oligodendrocyte and interneuron precursor cells, a phenotype that we confirmed in patient-specific induced pluripotent stem cell-derived organoids. Our study paves the way for high-throughput phenotypic characterization of disease susceptibility genes in organoid models with cell state, molecular pathway and gene regulatory network readouts.

Assembly of 43 human Y chromosomes reveals extensive complexity and variation.

The prevalence of highly repetitive sequences within the human Y chromosome has prevented its complete assembly to date1 and led to its systematic omission from genomic analyses. Here we present de novo assemblies of 43 Y chromosomes spanning 182,900 years of human evolution and report considerable diversity in size and structure. Half of the male-specific euchromatic region is subject to large inversions with a greater than twofold higher recurrence rate compared with all other chromosomes2. Ampliconic sequences associated with these inversions show differing mutation rates that are sequence context dependent, and some ampliconic genes exhibit evidence for concerted evolution with the acquisition and purging of lineage-specific pseudogenes. The largest heterochromatic region in the human genome, Yq12, is composed of alternating repeat arrays that show extensive variation in the number, size and distribution, but retain a 1:1 copy-number ratio. Finally, our data suggest that the boundary between the recombining pseudoautosomal region 1 and the non-recombining portions of the X and Y chromosomes lies 500 kb away from the currently established1 boundary. The availability of fully sequence-resolved Y chromosomes from multiple individuals provides a unique opportunity for identifying new associations of traits with specific Y-chromosomal variants and garnering insights into the evolution and function of complex regions of the human genome.

A polarized FGF8 source specifies frontotemporal signatures in spatially oriented cell populations of cortical assembloids.

Organoids generating major cortical cell types in distinct compartments are used to study cortical development, evolution and disorders. However, the lack of morphogen gradients imparting cortical positional information and topography in current systems hinders the investigation of complex phenotypes. Here, we engineer human cortical assembloids by fusing an organizer-like structure expressing fibroblast growth factor 8 (FGF8) with an elongated organoid to enable the controlled modulation of FGF8 signaling along the longitudinal organoid axis. These polarized cortical assembloids mount a position-dependent transcriptional program that in part matches the in vivo rostrocaudal gene expression patterns and that is lost upon mutation in the FGFR3 gene associated with temporal lobe malformations and intellectual disability. By producing spatially oriented cell populations with signatures related to frontal and temporal area identity within individual assembloids, this model recapitulates in part the early transcriptional divergence embedded in the protomap and enables the study of cortical area-relevant alterations underlying human disorders.

A Circular RNA Protects Dormant Hematopoietic Stem Cells from DNA Sensor cGAS-Mediated Exhaustion.

Disrupting the balance between self-renewal and differentiation of hematopoietic stem cells (HSCs) leads to bone marrow failure or hematologic malignancy. However, how HSCs sustain their quiescent state and avoid type I interferon (IFN)-mediated exhaustion remains elusive. Here we defined a circular RNA that we named cia-cGAS that was highly expressed in the nucleus of long-term (LT)-HSCs. Cia-cGAS deficiency in mice caused elevated expression of type I IFNs in bone marrow and led to decreased numbers of dormant LT-HSCs. Under homeostatic conditions, cia-cGAS bound DNA sensor cGAS in the nucleus to block its synthase activity, thereby protecting dormant LT-HSCs from cGAS-mediated exhaustion. Moreover, cia-cGAS harbored a stronger binding affinity to cGAS than self-DNA did and consequently suppressed cGAS-mediated production of type I IFNs in LT-HSCs. Our findings reveal a mechanism by which cia-cGAS inhibits nuclear cGAS by blocking its enzymatic activity and preventing cGAS from recognizing self-DNA to maintain host homeostasis.

Bone marrow-derived IGF-1 orchestrates maintenance and regeneration of the adult skeleton.

Insulin-like growth factor I (IGF-1) is a key regulator of tissue growth and development in response to growth hormone stimulation. In the skeletal system, IGF-1 derived from osteoblasts and chondrocytes are essential for normal bone development; however, whether bone marrow (BM)-resident cells provide distinct sources of IGF-1 in the adult skeleton remains elusive. Here, we show that BM stromal cells (BMSCs) and megakaryocytes/platelets (MKs/PLTs) express the highest levels of IGF-1 in adult long bones. Deletion of Igf1 from BMSCs by Lepr-Cre leads to decreased bone formation, impaired bone regeneration, and increased BM adipogenesis. Importantly, reduction of BMSC-derived IGF-1 contributes to fasting-induced marrow fat accumulation. In contrast, deletion of Igf1 from MKs/PLTs by Pf4-Cre leads to reduced bone formation and regeneration without affecting BM adipogenesis. To our surprise, MKs/PLTs are also an important source of systemic IGF-1. Platelet-rich plasma (PRP) from Pf4-Cre; Igf1f/fmice showed compromised osteogenic potential both in vivo and in vitro, suggesting that MK/PLT-derived IGF-1 underlies the therapeutic effects of PRP. Taken together, this study identifies BMSCs and MKs/PLTs as two important sources of IGF-1 that coordinate to maintain and regenerate the adult skeleton, highlighting reciprocal regulation between the hematopoietic and skeletal systems.

Engineering a conserved immune coreceptor into a primed state enhances fungal resistance in crops without growth penalty.

Plants must tactically balance immunity and growth when combating lethal pathogens like fungi. CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1), a conserved cell-surface co-receptor for the fungal elicitor chitin, enables plants to induce chitin-triggered immunity to counteract fungal invasion. Previously, we reported that bacterial infection can prime CERK1 through juxtamembrane (JM) phosphorylation to enhance fungal resistance, which only occurs in Arabidopsis (Arabidopsis thaliana) and its close relatives in Brassicaceae. Here, we aim to transfer the priming mechanism of Arabidopsis CERK1 (AtCERK1) to crop CERK1 via JM substitution. We revealed in protoplasts that the entire AtCERK1 JM variable region (AtJM) is essential for imparting the bacterial elicitor flg22-induced primed state to the Nicotiana benthamiana CERK1 (NbCERK1). The NbCERK1 chimera containing AtJM (NbCERK1AtJM) and similarly constructed rice (Oryza sativa) OsCERK1AtJM could undergo flg22-induced JM phosphorylation and confer enhanced antifungal immunity upon bacterial co-infection. Moreover, the NbCERK1AtJM+3D derivative with AtJM phosphomimetic mutations to mimic a constant primed state and similarly constructed OsCERK1AtJM+3D were sufficient to mediate strengthened chitin responses and fungal resistance in transgenic plants independent of bacterial infection. Importantly, no growth and reproduction defects were observed in these plants. Taken together, this study demonstrates that manipulating the primed state of a cell-surface immune receptor offers an effective approach to improve disease resistance in crops without compromising growth and yield and showcases how fundamental insights in plant biology can be translated into crop breeding applications.

Natural Killer-like B Cells Prime Innate Lymphocytes against Microbial Infection.

Natural killer (NK) cells and non-cytotoxic interferon-γ (IFN-γ)-producing group I innate lymphoid cells (ILC1s) produce large amounts of IFN-γ and cause activation of innate and adaptive immunity. However, how NKs and ILC1s are primed during infection remains elusive. Here we have shown that a lymphocyte subpopulation natural killer-like B (NKB) cells existed in spleen and mesenteric lymph nodes (MLNs). NKBs had unique features that differed from T and B cells, and produced interleukin-18 (IL-18) and IL-12 at an early phase of infection. NKB cells played a critical role in eradication of microbial infection via secretion of IL-18 and IL-12. Moreover, IL-18 deficiency abrogated the antibacterial effect of NKBs. Upon bacterial challenge, NKB precursors (NKBPs) rapidly differentiated to NKBs that activated NKs and ILC1s against microbial infection. Our findings suggest that NKBs might be exploited to develop effective therapies for treatment of infectious diseases.

Application of improved GalNAc conjugation in development of cost-effective siRNA therapies targeting cardiovascular diseases.

N-Acetylgalactosamine (GalNAc)-conjugated small interfering RNA (siRNA) therapies have received approval for treating both orphan and prevalent diseases. To improve in vivo efficacy and streamline the chemical synthesis process for efficient and cost-effective manufacturing, we conducted this study to identify better designs of GalNAc-siRNA conjugates for therapeutic development. Here, we present data on redesigned GalNAc-based ligands conjugated with siRNAs against angiopoietin-like 3 (ANGPTL3) and lipoprotein (a) (Lp(a)), two target molecules with the potential to address large unmet medical needs in atherosclerotic cardiovascular diseases. By attaching a novel pyran-derived scaffold to serial monovalent GalNAc units before solid-phase oligonucleotide synthesis, we achieved increased GalNAc-siRNA production efficiency with fewer synthesis steps compared to the standard triantennary GalNAc construct L96. The improved GalNAc-siRNA conjugates demonstrated equivalent or superior in vivo efficacy compared to triantennary GalNAc-conjugated siRNAs.

Recent advances in super-resolution optical imaging based on aggregation-induced emission.

Super-resolution imaging has rapidly emerged as an optical microscopy technique, offering advantages of high optical resolution over the past two decades; achieving improved imaging resolution requires significant efforts in developing super-resolution imaging agents characterized by high brightness, high contrast and high sensitivity to fluorescence switching. Apart from technical requirements in optical systems and algorithms, super-resolution imaging relies on fluorescent dyes with special photophysical or photochemical properties. The concept of aggregation-induced emission (AIE) was proposed in 2001, coinciding with unprecedented advancements and innovations in super-resolution imaging technology. AIE probes offer many advantages, including high brightness in the aggregated state, low background signal, a larger Stokes shift, ultra-high photostability, and excellent biocompatibility, making them highly promising for applications in super-resolution imaging. In this review, we summarize the progress in implementation methods and provide insights into the mechanism of AIE-based super-resolution imaging, including fluorescence switching resulting from photochemically-converted aggregation-induced emission, electrostatically controlled aggregation-induced emission and specific binding-regulated aggregation-induced emission. Particularly, the aggregation-induced emission principle has been proposed to achieve spontaneous fluorescence switching, expanding the selection and application scenarios of super-resolution imaging probes. By combining the aggregation-induced emission principle and specific molecular design, we offer some comprehensive insights to facilitate the applications of AIEgens (AIE-active molecules) in super-resolution imaging.

Unconventional Superconducting Diode Effects via Antisymmetry and Antisymmetry Breaking.

Symmetry breaking plays a pivotal role in unlocking intriguing properties and functionalities in material systems. For example, the breaking of spatial and temporal symmetries leads to a fascinating phenomenon: the superconducting diode effect. However, generating and precisely controlling the superconducting diode effect pose significant challenges. Here, we take a novel route with the deliberate manipulation of magnetic charge potentials to realize unconventional superconducting flux-quantum diode effects. We achieve this through suitably tailored nanoengineered arrays of nanobar magnets on top of a superconducting thin film. We demonstrate the vital roles of inversion antisymmetry and its breaking in evoking unconventional superconducting effects, namely a magnetically symmetric diode effect and an odd-parity magnetotransport effect. These effects are nonvolatilely controllable through in situ magnetization switching of the nanobar magnets. Our findings promote the use of antisymmetry (breaking) for initiating unconventional superconducting properties, paving the way for exciting prospects and innovative functionalities in superconducting electronics.

Study of the mechanism by which Xiaoyan decoction combined with E7449 regulates tumorigenesis in lung adenocarcinoma.

TNKS is a new target for the treatment of lung adenocarcinoma, the synergistic effects of the TCM compound Xiaoyan decoction and the TNKS inhibitor E7449 in the intervention on TNKS were investigated, and the possible underlying mechanisms involved were clarified. Immunohistochemistry was used to analyse TNKS expression in tumour tissues. The impact of targeting TNKS on cell growth, invasion, apoptosis, key genes and signalling pathways was investigated in tumour cells by Western blotting, rescue experiments, colony formation assays, flow cytometry and label-free experiments. Tumour xenografts with A549 cells were then transplanted for in vivo study. We found that TNKS high expression was closely related to the advanced tumour stage and tumour size in lung adenocarcinom. After TNKS was knocked down in vitro, the growth, proliferation, migration and invasion were markedly reduced in A549 and H1975 cells. We subsequently applied the Xiaoyan decoction and TNKS inhibitors to intervene in lung adenocarcinoma. Xiaoyan decoction and E7449 suppressed TNKS expression and inhibited adenocarcinoma cell proliferation, migration, invasion and apoptosis in vitro. Proteomic analysis revealed that E7449 treatment may be most closely associated with the classic Wnt/ß-catenin pathway, whereas Xiaoyan decoction treatment may be related to the WNT/PLAN pathway. Xenograft studies confirmed that E7449 or Xiaoyan decoction inhibited lung tumour growth in vivo and attenuated the Wnt signalling pathway in adenocarcinoma. These findings suggest that TNKS is a novel therapeutic target. TCM preparations and small molecule inhibitors are expected to constitute an effective combination strategy.

Chiral Liquid Crystalline Metal-Organic Framework Thin Films for Highly Circularly Polarized Luminescence.

Combining metal-organic frameworks (MOFs) with liquid crystals to construct liquid crystalline MOFs (LCMOF) offers the advantage of endowing and enhancing their functionality, yet it remains a challenging task. Herein, we report chiral liquid crystalline MOF (CLCMOF) thin films by cross-linking the chiral liquid crystals (CLC) with MOF thin films to realize highly circular polarization luminescence (CPL) performance with photo and thermal switching. By layer by layer cross-linking stilbene-containing CLC with stilbene-based MOF (CLC/MOF) thin film, the CLCMOF thin films were successfully obtained after UV irradiation due to the abundant [2 + 2] photocycloaddition. The resulted CLCMOF thin films have strong chirality, obvious photochromic fluorescent, and strong CPL performance (the asymmetry factor reaches to 0.4). Furthermore, due to the photochromic fluorescent MOF and thermotropic CLC, the CPL can be reversed and red-shifted after heating and UV irradiation treatment, showing photo- and thermal CPL switching. Such MOF-based CPL thin films with photo/thermal CPL switching were prepared to patterns and codes for the demonstration of potential application in advanced information anticounterfeit and encryption. This study not only opens a strategy for developing chiral thin films combining MOFs and liquid crystals but also offers a new route to achieve CPL switching in optical applications.

Enhancement of Magneto-Chiral Dichroism Intensity by Chemical Design: The Key Role of Magnetic-Dipole Allowed Transitions.

Here we report on the strong magneto-chiral dichroism (MChD) detected through visible and near-infrared light absorption up to 5.0 T on {Er5Ni6} metal clusters obtained by reaction of enantiopure chiral ligands and NiII and ErIII precursors. Single-crystal diffraction analysis reveals that these compounds are 3d-4f heterometallic clusters, showing helical chirality. MChD spectroscopy reveals a high gMChD dissymmetry factor of ca. 0.24 T-1 (T = 4.0 K, B = 1.0 T) for the 4I13/2 ← 4I15/2 magnetic-dipole allowed electronic transition of the ErIII centers. This record value is 1 or 2 orders of magnitude higher than that of the d-d electronic transitions of the NiII ions and the others f-f electric-dipole induced transitions of the ErIII centers. These findings clearly show the key role that magnetic-dipole allowed transitions have in the rational design of chiral lanthanide systems showing strong MChD.

Exosomal miR-4745-5p/3911 from N2-polarized tumor-associated neutrophils promotes gastric cancer metastasis by regulating SLIT2.

Tumor cells remodel the phenotype and function of tumor microenvironment (TME) cells to favor tumor progression. Previous studies have shown that neutrophils in TME are polarized to N2 tumor-associated neutrophils (TANs) by tumor derived factors, thus promoting tumor growth and metastasis, angiogenesis, therapy resistance, and immunosuppression. Exosomes act as critical intercellular messengers in human health and diseases including cancer. So far, the biological roles of exosomes from N2 TANs in gastric cancer have not been well characterized. Herein, we represented the first report that exosomes from N2 TANs promoted gastric cancer metastasis in vitro and in vivo. We found that exosomes from N2 TANs transferred miR-4745-5p/3911 to gastric cancer cells to downregulate SLIT2 (slit guidance ligand 2) gene expression. Adenovirus-mediated overexpression of SLIT2 reversed the promotion of gastric cancer metastasis by N2 TANs derived exosomes. We further revealed that gastric cancer cells induced glucose metabolic reprogramming in neutrophils through exosomal HMGB1 (high mobility group protein B1)/NF-κB pathway, which mediated neutrophil N2 polarization and miR-4745-5p/3911 upregulation. We further employed ddPCR (droplet digital PCR) to detect the expression of miR-4745-5p/3911 in N2 TANs exosomes from human serum samples and found their increased levels in gastric cancer patients compared to healthy controls and benign gastric disease patients. Conclusively, our results indicate that N2 TANs facilitate cancer metastasis via regulation of SLIT2 in gastric cancer cells by exosomal miR-4745-5p/3911, which provides a new insight into the roles of TME cells derived exosomes in gastric cancer metastasis and offers a potential biomarker for gastric cancer diagnosis.

O-GlycoIsoQuant: A Novel O-Glycome Quantitative Approach through Superbase Release and Isotopic Girard's P Labeling.

Quantitative glycosylation analysis serves as an effective tool for detecting changes in glycosylation patterns in cancer and various diseases. However, compared with N-glycans, O-glycans present challenges in both qualitative and quantitative mass spectrometry analysis due to their low abundance, ease of peeling, lack of a universal enzyme, and difficult accessibility. To address this challenge, we developed O-GlycoIsoQuant, a novel O-glycome quantitative approach utilizing superbase release and isotopic Girard's P labeling. This method facilitates rapid and efficient nonreducing ß-elimination to dissociate O-glycans from proteins using the organic superbase, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), combined with light and heavy isotopic Girard's reagent P (GP) labeling for relative quantification of O-glycans by mass spectrometry. Employing this method, labeled O-glycans exhibit a double peak with a mass difference of 5 Da, suitable for stable relative quantification. The O-GlycoIsoQuant method is characterized by its high labeling efficiency, excellent reproducibility (CV < 20%), and good linearity (R2 > 0.99), across a dynamic range spanning a 100-fold range. This method was applied to various complex sample types, including human serum, porcine spermatozoa, human saliva, and urinary extracellular vesicles, detecting 33, 39, 49, and 37 O-glycans, respectively, thereby demonstrating its broad applicability.

Inhibition of glycolysis enhances the efficacy of immunotherapy via PDK-mediated upregulation of PD-L1.

BACKGROUND: Immunotherapy for gastric cancer remains a challenge due to its limited efficacy. Metabolic reprogramming toward glycolysis has emerged as a promising avenue for enhancing the sensitivity of tumors to immunotherapy. Pyruvate dehydrogenase kinases (PDKs) play pivotal roles in regulating glycolysis. The importance of PDKs in the context of gastric cancer immunotherapy and their potential as therapeutic targets have not been fully explored. METHODS: PDK and PD-L1 expression was analyzed using data from the GSE66229 and The Cancer Genome Atlas (TCGA) cohorts. Additionally, the Immune Checkpoint Blockade Therapy Atlas (ICBatlas) database was utilized to assess PDK expression in an immune checkpoint blockade (ICB) therapy group. Subsequently, the upregulation of PD-L1 and the enhancement of anticancer effects achieved by targeting PDK were validated through in vivo and in vitro assays. The impact of PDK on histone acetylation was investigated using ChIP‒qPCR to detect changes in histone acetylation levels. RESULTS: Our analysis revealed a notable negative correlation between PD-L1 and PDK expression. Downregulation of PDK led to a significant increase in PD-L1 expression. PDK inhibition increased histone acetylation levels by promoting acetyl-CoA generation. The augmentation of acetyl-CoA production and concurrent inhibition of histone deacetylation were found to upregulate PD-L1 expression in gastric cancer cells. Additionally, we observed a significant increase in the anticancer effect of PD-L1 antibodies following treatment with a PDK inhibitor. CONCLUSIONS: Downregulation of PDK in gastric cancer cells leads to an increase in PD-L1 expression levels, thus potentially improving the efficacy of PD-L1 immune checkpoint blockade therapy.

LASS2 enhances chemosensitivity to cisplatin by inhibiting PP2A-mediated ß-catenin dephosphorylation in a subset of stem-like bladder cancer cells.

BACKGROUND: The benefits of first-line, cisplatin-based chemotherapy for muscle-invasive bladder cancer are limited due to intrinsic or acquired resistance to cisplatin. Increasing evidence has revealed the implication of cancer stem cells in the development of chemoresistance. However, the underlying molecular mechanisms remain to be elucidated. This study investigates the role of LASS2, a ceramide synthase, in regulating Wnt/ß-catenin signaling in a subset of stem-like bladder cancer cells and explores strategies to sensitize bladder cancer to cisplatin treatment. METHODS: Data from cohorts of our center and published datasets were used to evaluate the clinical characteristics of LASS2. Flow cytometry was used to sort and analyze bladder cancer stem cells (BCSCs). Tumor sphere formation, soft agar colony formation assay, EdU assay, apoptosis analysis, cell viability, and cisplatin sensitivity assay were used to investigate the functional roles of LASS2. Immunofluorescence, immunoblotting, coimmunoprecipitation, LC-MS, PCR array, luciferase reporter assays, pathway reporter array, chromatin immunoprecipitation, gain-of-function, and loss-of-function approaches were used to investigate the underlying mechanisms. Cell- and patient-derived xenograft models were used to investigate the effect of LASS2 overexpression and a combination of XAV939 on cisplatin sensitization and tumor growth. RESULTS: Patients with low expression of LASS2 have a poorer response to cisplatin-based chemotherapy. Loss of LASS2 confers a stem-like phenotype and contributes to cisplatin resistance. Overexpression of LASS2 results in inhibition of self-renewal ability of BCSCs and increased their sensitivity to cisplatin. Mechanistically, LASS2 inhibits PP2A activity and dissociates PP2A from ß-catenin, preventing the dephosphorylation of ß-catenin and leading to the accumulation of cytosolic phospho-ß-catenin, which decreases the transcription of the downstream genes ABCC2 and CD44 in BCSCs. Overexpression of LASS2 combined with a tankyrase inhibitor (XAV939) synergistically inhibits tumor growth and restores cisplatin sensitivity. CONCLUSIONS: Targeting the LASS2 and ß-catenin pathways may be an effective strategy to overcome cisplatin resistance and inhibit tumor growth in bladder cancer patients.

Recent Progress of Photoswitchable Fluorescent Diarylethenes for Bioimaging.

Photochromic diarylethene has attracted broad research interest in optical applications owing to its excellent fatigue resistance and unique bistability. Photoswitchable fluorescent diarylethene become a powerful molecular tool for fluorescence imaging recently. Herein, the recent progress on photoswitchable fluorescent diarylethenes in bioimaging is reviewed. We summarize summarized the structures and properties of diarylethene fluorescence probes, and emphatically introduces their applications in bioimaging as well as super-resolution imaging. Additionally, we highlight the current challenges in practical applications and provides the prospects of the future development directions of photoswitchable fluorescent diarylethene in the field of bioimaging.  This comprehensive review aims to stimulate further research into higher performance photoswitchable fluorescent molecules and advance their progress in biological application.

Classification and management strategy of spontaneous carotid artery dissection.

OBJECTIVE: Spontaneous carotid artery dissections (sCADs) are the common cause of stroke in middle-aged and young people. There is still a lack of clinical classification to guide the management of sCAD. We reviewed our experience with 179 patients with sCAD and proposed a new classification for sCAD with prognostic and therapeutic significance. METHODS: This is a retrospective review of prospectively collected data from June 2018 to June 2023 of patients with sCAD treated at a large tertiary academic institution in an urban city in China. Based on imaging results, we categorize sCAD into four types: type Ⅰ, intramural hematoma or dissection with <70% luminal narrowing; type Ⅱ, intramural hematoma or dissection with ≥70% luminal narrowing; type Ⅲ, dissecting aneurysm; type ⅣA, extracranial carotid artery occlusion; and type ⅣB, tandem occlusion. We compared the clinical data and prognostic outcomes among various types of sCADs. RESULTS: A total of 179 patients and 197 dissected arteries met the inclusion criteria. The mean age of the 179 patients with sCAD was 49.5 years, 78% were male, and 18 patients (10%) had bilateral sCAD. According to our classification, there were 56 type Ⅰ (28.4%), 50 type Ⅱ (25.4%), 60 type Ⅲ (30.5%), and 31 type Ⅳ (15.7%) dissections. During a mean hospitalization length of 11.4 ± 47.0 days, there were nine recurrent strokes (4.6%) after medical treatment, two type Ⅲ dissections (1.0%), seven type Ⅳ dissections (3.6%), all ipsilateral, and one death. Overall, there were seven (3.6%, 1 type Ⅰ dissection, 3 type Ⅱ dissections, 2 type Ⅲ dissections, and 1 type Ⅳ dissection) recurrent strokes and three (1.5%, all type Ⅲ dissections) recurrent transient ischemic attacks in patients treated with just medical therapy during the follow-up period, all ipsilateral, with a mean follow-up of 26 months (range, 3-59 months). These patients did not undergo further intervention due to the high difficulty associated with endovascular treatment (EVT) or the mild nature of recurrent cerebral ischemic symptoms. Twenty-nine type I dissections (51.8%) were completely recanalized after antithrombotic therapy. A total of 19 type II dissections (38%) and 44 type III dissections (73%) received EVT for persistent flow-limited dissections, enlargement of dissecting aneurysms, or aggravation of neurological symptoms despite antithrombotic therapy. Type Ⅳ dissections are more likely to lead to the occurrence of ischemic stroke and presented with more severe symptoms. Eight type IVB dissections (33%) received acute phase intervention due to distal thromboembolism or aggravation of neurological symptoms after medical treatment. In terms of cerebral ischemic events and mortality, there were no statistically significant differences among the four types of sCAD (all P > .05). Favorable outcome was achieved in 168 patients (93.9%). CONCLUSIONS: This study proposed a novel and more comprehensive classification method and the modern management strategy for sCAD. Antithrombotic therapy is beneficial to reduce the risk of recurrent stroke for stable sCAD. Non-emergent EVT can be an alternative therapeutic approach for patients who meet indications as in type II to IVA dissections. Urgent procedure with neurovascular intervention is necessary for some type IVB dissections. The short-term results of EVT for sCAD are encouraging, and long-term device-related and functional outcomes should undergo further research.