Exosomal AFAP1-AS1 Promotes the Growth, Metastasis, and Glycolysis of Pituitary Adenoma by Inhibiting HuR Degradation.

Exosomal long noncoding RNAs (lncRNAs), which are highly expressed in tumor-derived exosomes, regulate various cellular behaviors such as cell proliferation, metastasis, and glycolysis by facilitating intercellular communication. Here, we explored the role and regulatory mechanism of tumor-derived exosomal lncRNAs in pituitary adenomas (PA). We isolated exosomes from PA cells, and performed in vitro and in vivo assays to examine their effect on the proliferation, metastasis, and glycolysis of PA cells. In addition, we conducted RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, and ubiquitination assays to investigate the downstream mechanism of exosomal AFAP1-AS1. Exosomes from PA cells augmented the proliferation, mobility, and glycolysis of PA cells. Moreover, AFAP1-AS1 was significantly enriched in these exosomes and stimulated the growth, migration, invasion, and glycolysis of PA cells in vitro, as well as tumor metastasis in vivo. It also enhanced the binding affinity between Hu antigen R (HuR) and SMAD-specific E3 ubiquitin protein ligase 1 (SMURF1), resulting in HuR ubiquitination and degradation accompanied by enhanced expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). Moreover, HuR overexpression alleviated the exosomal AFAP1-AS1-mediated promotion of growth, metastasis, and glycolysis effects. These findings indicate that tumor-derived exosomal AFAP1-AS1 modulated SMURF1-mediated HuR ubiquitination and degradation to upregulate HK2 and PKM2 expression, thereby enhancing PA cell growth, metastasis, and glucose metabolism. This suggests targeting exosomal AFAP1-AS1 may be a potential strategy for the treatment of PA.

Regulating the Porosity and Bipolarity of Polyimide-Based Covalent Organic Framework for Advanced Aqueous Dual-Ion Symmetric Batteries.

The all-organic aqueous dual-ion batteries (ADIBs) have attracted increasing attention due to the low cost and high safety. However, the solubility and unstable activity of organic electrodes restrict the synergistic storage of anions and cations in the symmetric ADIBs. Herein, a novel polyimide-based covalent organic framework (labeled as NTPI-COF) is constructed, featured with the boosted structure stability and electronic conductivity. Through regulating the porosity and bipolarity integrally, the NTPI-COF possesses hierarchical porous structure (mesopore and micropore) and abundant bipolar active centers (C═O and C─N), which exhibits rapid dual-ion transport and storage effects. As a result, the NTPI-COF as the electrodes for ADIBs deliver a high reversible capacity of 109.7 mA h g-1 for Na+ storage and that of 74.8 mA h g-1 for Cl- storage at 1 A g-1, respectively, and with a capacity retention of 93.2% over 10 000 cycles at 10 A g-1. Additionally, the all-organic ADIBs with symmetric NTPI-COF electrodes achieve an impressive energy density of up to 148 W h kg-1 and a high power density of 2600 W kg-1. Coupling the bipolarity and porosity of the all-organic electrodes applied in ADIBs will further advance the development of low-cost and large-scale energy storage.

A Multimodal Point Cloud-Based Method for Tumor Localization in Robotic Ultrasound-Guided Radiotherapy.

Objectives: Part of the tumor localization methods in radiotherapy have poor real-time performance and may generate additional radiation. We propose a multimodal point cloud-based method for tumor localization in robotic ultrasound-guided radiotherapy, which only irradiates computed tomography (CT) during radiotherapy planning to avoid additional radiation. Methods: The tumor position was determined using the CT point cloud, and the red green blue depth (RGBD) point cloud was used to determine body surface scanning location corresponding to the tumor location. The relationship between the CT point cloud and RGBD point cloud was established through multi-modal point cloud registration. The point cloud was then used for robot tumor localization through coordinate transformation between camera and robot. Results: The maximum mean absolute error of the tumor location in the X, Y, and Z directions of the robot coordinate system were 0.781, 1.334, and 1.490 mm, respectively. The average point-to-point translation mean absolute error between the actual and predicted positions of the localization points was 1.847 mm. The maximum error in the random positioning experiment was 1.77 mm. Conclusion: The proposed method is radiation free and has real-time performance, with tumor localization accuracy that meets the requirements of radiotherapy. The proposed method, which potentially reduces the risks associated with radiation exposure while ensuring efficient and accurate tumor localization, represents a promising advancement in the field of radiotherapy.

NLRP3 inflammasome inhibition decreases Schistosomiasis japonica-induced granulomatous inflammation and fibrosis in BALB/c mice.

To research the role of the NLRP3 inflammasome in Schistosoma japonicum-induced granuloma formation and liver fibrosis. In in vivo tests, BALB/c mice were used. shNLRP3 plasmid based on adeno-associated virus serotype 8 (AAV8-shNLRP3) was injected to block NLRP3 inflammasome via tail vein. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were detected to assess liver injury. H&E staining was used for routine histopathological assessment; Masson's trichrome staining was used to detect fibrous tissues and collagen fibers. Hepatic expression of NLRP3, procaspase-1, bioactive caspase-1, collagen-1, tissue inhibitor of metalloproteinases-1 (TIMP-1), and α-smooth muscle actin (α-SMA) were detected by western blot. Serum levels of IL-1ß were detected by enzyme-linked immunosorbent assay (ELISA). The inflammatory cell infiltration and hepatic expression of IL-1ß around the granuloma were detected by immunohistochemistry staining. Treatment of S. japonicum infected mice with AAV8-shNLRP3 significantly reduced the hepatic levels of bioactive caspase-1 and IL-1ß, as well as circulating IL-1ß concentrations, while reducing the amounts of myeloperoxidase (MPO) and F4/80 positive cells around the granuloma. Moreover, collagen deposition, TIMP-1, and α-SMA, which are markers of hepatic stellate cell (HSC) activation, were reduced around the liver granuloma. These findings highlight a therapeutic potential of AAV8-shNLRP3 in schistosomiasis cirrhosis.

Scalable, Waterproof, Breathable, and Flexible Polyolefin-Elastomer/Polyethylene Glycol@Zinc Oxide Microfibrous Fabrics for Daytime Radiative Cooling Clothing.

In the face of escalating global temperatures, the demand for innovative passive cooling technologies that are both low-cost and environmentally sustainable is more critical than ever. However, traditional cooling fabrics face challenges in achieving wearing comfort while maintaining breathability and durability. Herein, a novel fluffy microfibrous fabric utilizing polyolefin-elastomer and polypropylene with embedded zinc oxide nanoparticles is fabricated through melt-blown technology. The results reveal that the prepared samples demonstrate exceptional daytime radiative cooling properties that present a 12.5 °C cooling capacity under 1083 W/m2 solar radiation, highlighted by their ability to reflect up to 90.8% of solar radiation and their significantly enhanced thermal emissivity. Moreover, key findings include that the samples have robust mechanical strength, high elastic performance, and excellent antifouling capabilities, alongside superior cooling performance, which will provide an opportunity to explore the development of cooling garments for outdoor environments and contribute substantially to sustainable cooling solutions.

Identifying polyamine related biomarkers in diagnosis and treatment of ulcerative colitis by integrating bulk and single-cell sequencing data.

Ulcerative colitis (UC) is a chronic inflammatory disorder of the colon, and its pathogenesis remains unclear. Polyamine metabolic enzymes play a crucial role in UC. In this study, we aimed to identify pivotal polyamine-related genes (PRGs) and explore the underlying mechanism between PRGs and the disease status and therapeutic response of UC. We analyzed mRNA-sequencing data and clinical information of UC patients from the GEO database and identified NNMT, PTGS2, TRIM22, TGM2, and PPARG as key PRGs associated with active UC using differential expression analysis and weighted gene co-expression network analysis (WCGNA). Receiver operator characteristic curve (ROC) analysis confirmed the accuracy of these key genes in UC and colitis-associated colon cancer (CAC) diagnosis, and we validated their relationship with therapeutic response in external verification sets. Additionally, single-cell analysis revealed that the key PRGs were specific to certain immune cell types, emphasizing the vital role of intestinal tissue stem cells in active UC. The results were validated in vitro and in vivo experiments, including the colitis mice model and CAC mice model. In conclusion, these key PRGs effectively predict the progression of UC patients and could serve as new pharmacological biomarkers for the therapeutic response of UC.

Dissociation of HBr in Water Clusters Based on a Hybrid Density Functional Approach.

The dissociation of acidic molecules within a microscopic water environment is crucial for understanding intermolecular interactions such as hydrogen bonding. This study explores the optimal configurations of HBr(H2O)n=1-7 using hybrid density functional theory. According to the different mixed cluster structures, the corresponding HBr bond lengths, single-point energies, and introduced proton-transfer parameters are computed and analyzed. The findings indicate that a minimum of three water molecules is necessary for the dissociation of HBr. Subsequently, this conclusion is reinforced through the decomposition of energy components between the acid molecule and water clusters, calculation of hydrogen bonding energies, and analysis of vibrational infrared spectroscopy.

Endogenous RBM4 prevents Ang II-induced cardiomyocyte hypertrophy via downregulating the expression of PTBP1.

Aberrant gene expression in cardiomyocyte has been revealed to be the fundamental essence of pathological cardiac hypertrophy. However, the detailed mechanisms are not fully understood. The underlying regulators of gene expression involved in cardiac hypertrophy remain to be further identified. Here, we report that the RNA-binding protein RNA-binding motif protein 4 (RBM4) functions as an endogenic protector that is able to fight against cardiomyocyte hypertrophy in vitro. Under pro-hypertrophic stimulation of angiotensin II (Ang II), the protein level of RBM4 in cardiomyocyte and myocardium is elevated. Knockdown of RBM4 can further aggravate cardiomyocyte hypertrophy, while over-expression of RBM4 represses cardiomyocyte hypertrophy. Mechanistically, RBM4 is localized in the nucleus and down-regulates the expression of polypyrimidine tract-binding protein 1 (PTBP1), which has been shown to aggravate cardiomyocyte hypertrophy. In addition, we suggest that the up-regulation of RBM4 in cardiomyocyte hypertrophy is caused by N6-methyladenosine (m6A). Ang II induces m6A methylation of RBM4 mRNA, which further enhances the YTH domain-containing family protein 1 (YTHDF1)-mediated translation of RBM4. Thus, our results reveal a novel pathway consisting of m6A, RBM4 and PTBP1, which is involved in cardiomyocyte hypertrophy.

Oleanonic acid ameliorates mutant Aß precursor protein-induced oxidative stress, autophagy deficits, ferroptosis, mitochondrial damage, and ER stress in vitro.

Accumulation in the brain of amyloid-ß (Aß), derived from cleavage of Aß precursor protein (APP), is a hallmark of Alzheimer's disease (AD). Oleanonic acid (OA), a phytochemical from several plants, has proven anti-inflammatory effects, but its role in AD remains unknown. Here we found that OA reduced APP expression and inhibited oxidative stress via Nrf2/HO-1 signaling in SH-SY5Y neuroblastoma cells stably overexpressing APP. OA suppressed phosphorylated mTOR but increased autophagy markers ATG5 and LC3-II. Moreover, OA rescued ferroptosis-related factors GPX4, NCOA, and COX2 and ER stress markers GRP78, CHOP, and three main induction pathways of ER stress including IRE1/XBP1s, PERK/EIF2α, and ATF6. OA alleviated mitochondrial damage through MFN1, MFN2, OPA1, FIS1, and DRP1. Furthermore, OA upregulated GDF11 expression and downregulated phosphorylation of ErbB4 and TrkB without affecting BDNF levels. Thus, OA might protect neurons from APP-induced neurotoxicity by inhibiting oxidative stress, autophagy deficits, ferroptosis, mitochondrial damage, and ER stress in AD, providing a new promising therapeutic strategy in patients with AD.

Spatiotemporal variations and priority ranking of emerging contaminants in nanwan reservoir: A case study from the agricultural region in huaihe river basin in China.

The presence of emerging contaminants (ECs) in drinking water sources is an increasing concern, yet limited data exists on their occurrence and risk in the upper Huaihe River Basin, an important agricultural region in Central China. This study investigated 70 ECs, including pesticide and antibiotics in surface water from drinking water source areas in Nanwan Reservoir along the upper reaches of the Huaihe River Basin to prioritize the ECs based on ecological risk and health risk assessment. A total of 66 ECs were detected in the surface water at least once at the selected 38 sampling sites, with concentrations ranging from 0.04 to 2508 ng/L. Ecological risk assessment using the risk quotient (RQ) method revealed high risks (RQ > 1) from 7 ECs in the dry season and 15 ECs in the wet season, with triazine pesticides as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoid and carbamate pesticides and macrolide antibiotics were concerning for teenagers. Ciprofloxacin exhibited a high level of resistance risk during the wet season. A multi-indicator prioritization approach integrating occurrence, risk, and chemical property data ranked 6 pesticides and 3 antibiotics as priority pollutants. The results highlight EC contamination of drinking water sources in this agriculturally-intensive region and the need for targeted monitoring and management to protect water quality.

Hydroxyl radical mediated extracellular degradation of tetracycline under aerobic and anaerobic conditions stimulated by bio-FeS nanoparticles.

The extracellular degradation of antibiotics facilitated by bio-nanoparticles is significant in the field of waste valorization. Among different bio-nanoparticles, bio-FeS nanoparticles stand out for their convenient and cost-effective synthesis. Nevertheless, there is a lack of understanding regarding the extracellular degradation of pollutants driven by bio-FeS nanoparticles. Hence, this study aimed to investigate the role of bio-FeS nanoparticles in the extracellular degradation of tetracycline under aerobic and anaerobic conditions. The findings demonstrated that bio-FeS nanoparticles generated hydroxyl radical (·OH), which significantly contributes to the degradation of tetracycline in both aerobic and anaerobic environments. The production of ·OH in anaerobic conditions was primarily attributed to the limited formation of FeS2 during the biosynthesis of nanoparticles, which was very different from aerobic conditions. The bio-FeS nanoparticles facilitated extracellular electron transport by promoting electron shuttles and Fe(II)/Fe(III) cycling, resulting in the continuous production of ·OH. The degradation pathways showed differences under aerobic and anaerobic conditions, with intermediates exhibiting higher toxicity and greater cellular damage under aerobic conditions. However, in anaerobic conditions, bio-FeS nanoparticles enabled the successful integration of intracellular and extracellular degradation of tetracycline. This research proposed a new avenue for biocatalysis and environmental remediation.

Bridging thrombolysis before endovascular therapy is associated with better outcomes in patients with large infarction core.

BACKGROUND: This study investigates the efficacy and safety of bridging intravenous thrombolysis (IVT) before endovascular therapy (EVT) compared with EVT alone in patients with large infarction core. METHODS: We conducted a comprehensive search of PubMed, EMBASE, and the Cochrane Library from January 2015 to June 2024. Included studies involved patients with acute ischemic stroke with an Alberta Stroke Program Early CT Score of ≤5 or an ischemic core volume of ≥50 mL. Studies were required to provide either 90-day modified Rankin Scale (mRS) score, reperfusion, symptomatic intracranial hemorrhage (sICH), or 90-day mortality. RESULTS: Nine observational studies with 2641 patients were analyzed. The IVT+EVT group had a higher rate of 90-day functional independence (mRS 0-2; OR 1.56, 95% CI 1.31 to 1.87; adjusted OR (aOR) 1.43, 95% CI 1.21 to 1.68) and 90-day functional outcome (mRS 0-3; OR 1.34, 95% CI 1.11 to 1.62; aOR 1.18, 95% CI 1.02 to 1.37) compared with EVT alone. There was no significant difference in successful reperfusion (OR 1.01, 95% CI 0.62 to 1.64; aOR 1.07, 95% CI 0.74 to 1.54) and 90-day mortality (OR 0.86, 95% CI 0.73 to 1.02; aOR 0.89, 95% CI 0.77 to 1.04) between the two groups. Moreover, patients who received IVT+EVT had a higher rate of sICH (OR 1.30, 95% CI 1.03 to 1.64; aOR 2.21, 95% CI 1.22 to 4.01). CONCLUSIONS: In patients with large infarction core, bridging IVT before EVT is associated with favorable functional outcomes compared with EVT, even though bridging therapy entails a higher risk of sICH. Further trials are needed to confirm these findings.

Contribution of chemical permeation enhancers to the process of transdermal drug delivery: Adsorption, microscopic interactions, and mechanism.

Transdermal drug delivery (TDD) has attracted widespread attention because of the advantage of its non-invasive nature, easy self-administration, and low side effects. The key to this pathway of drug delivery is how to overcome the barrier of the lipid matrix in the stratum corneum (SC). In this work, molecular dynamics (MD) were employed to investigate the adsorption of thyrotropin-releasing hormone (TRH) on the SC, and the effects of three different chemical permeation enhancers (ethanol (ETOH), carveol (CAV), and borneol (BOR)) on the SC were analyzed. The results showed that ETOH hardly altered the order of lipids in the SC, while CAV and BOR disrupted the morphology of the SC. The primary target of CAV was the CHOL in SC, which not only disrupted the ordered arrangement of CHOL, but also "extracted" CHOL from SC. The thickness distribution of SC became more inhomogeneous in the presence of CAV and BOR, which facilitated the penetration of drug molecules. Compared to no chemical permeation enhancers, the free energy of permeation in the presence of chemical permeation enhancers was less than 4-10 kcal mol-1, which suggested that chemical permeation enhancers were more favorable for the permeation of drugs from viewpoints of thermodynamics. All the results provided theoretical insights into the effect of chemical permeation enhancers on the transdermal permeation of drugs.

Clinical impact of metagenomic next-generation sequencing of bronchoalveolar lavage fluids for the diagnosis of pulmonary infections in respiratory intensive care unit.

Background: The real-world clinical impact of mNGS on BALF in the respiratory intensive care unit (RICU) is not yet fully understood. Methods: We investigated the clinical impact of mNGS on BALF samples obtained from 92 patients admitted to the RICU over a 2-year period. We utilized both mNGS and culture methods to evaluate the effectiveness of mNGS in diagnosing pulmonary infections. The clinical impact of mNGS were evaluated by the clinician committees. Results: Among the 92 diagnosed patients, 78 cases (84.7 %) were determined to have infectious diseases caused by pathogenic microorganisms, and the bacterial infections constituted the most prevalent diagnostic category. For mixed infection, the most common type was the Pneumocystis jironecii and cytomegalovirus co-infection. The mNGS results had a positive impact on the clinical management of 43 cases (46.7 %). Moreover, 19 cases (44.2 %) of positive clinical impacts were solely based on new diagnoses made possible by mNGS results. These new diagnoses were particularly helpful for identifying rare pathogens, which could not be detected by conventional diagnostic methods. Conclusions: The BALF mNGS has a positive real-world impact in RICU. Clinician committee play a critical role in ensuring the appropriate use of mNGS.

Renal clear cell carcinoma undergoing cystic change: A cases report and review of the literature.

INTRODUCTION: We presented a case diagnosed the renal clear cell carcinoma undergoing cystic change (RCCCC) with detailed clinical data. Along with literature review, we aimed to investigate clinical diagnosis and treatment of RCCCC and explore the differential diagnosis of RCCCC and multilocular cystic renal cell carcinoma (MCRCC). CASE PRESENTATION: The patient was diagnosed with a right renal cyst after physical examination, which was misdiagnosed as a renal cyst by imaging examination. Intraoperative surgical treatment was performed to remove the roof and decompress the renal cyst. Rapid pathology revealed MCRCC with low malignant potential during laparoscopic right renal cyst decompression. Radical nephrectomy was performed with the family's signature. The postoperative pathological diagnosis was clear cell carcinoma cystic lesion of kidney (RCCCC). No recurrence or metastasis during 1 year follow-up. CLINICAL DISCUSSION: RCCCC cases were similar to classical clear cell renal carcinoma. Radical nephrectomy should be avoided in patients with MCRCC, and radical nephrectomy should be chosen in patients with RCCCC, with postoperative and close follow-up. Unroofing decompression of renal cyst was performed during the operation, and the risk of tumor implantation and metastasis was worried after the operation. The patient agreed to receive eight cycles of immune checkpoint inhibitor therapy after surgery. Adrenal insufficiency occurred after 8 cycles of immune checkpoint inhibitor therapy(ICIs), then the immunotherapy was discontinued. CONCLUSION: RCCCC is a rare and special type of renal clear cell carcinoma, and its prognosis is the same as that of renal clear cell carcinoma. The preoperative diagnosis of RCCCC mainly depends on imaging examination (CT or B-ultrasound). The early differential diagnosis from multilocular cystic renal cell carcinoma is difficult, and the diagnosis usually depends on postoperative pathological diagnosis.

Enhanced Fenton catalytic degradation of methylene blue by the synergistic effect of Fe and Ce in chitosan-supported mixed-metal MOFs (Fe/Ce-BDC@CS).

Methylene blue (MB) is a refractory organic pollutant that poses a potential threat to the aquatic environment. Fenton reaction is considered a primrose strategy to treat MB. However, the traditional Fenton process is plagued by narrow pH application range, poor stability, and secondary pollution. To solve these problems, many Fenton-like catalysts including metal-organic frameworks (MOFs) have been prepared. Herein, a novel bimetallic MOF (Fe/Ce-BDC@CS) was prepared through simple adsorption for the effective removal of MB, where chitosan (CS) was used as the carrier. The degradation performance of Fe/Ce-BDC@CS (100 % within 20 min) was better than that of most reported monometallic MOFs. Moreover, Fe/Ce-BDC@CS exhibited good repeatability and its anti-interference performance of some inorganic ions was also remarkable. Column loading experiments showed that the removal efficiency of MB was still about 50 % over 155 h with a flowing speed of 0.30 L/h. Comparative analysis indicated that such excellent performances could be attributed to the synergistic effect between Fe and Ce. Furthermore, the results of quenching tests indicate that OH, O2-, and 1O2 contributed to MB degradation. In brief, Fe/Ce-BDC@CS has promising prospects in MB treatment, which can provide scientific references for the design and application of bimetallic MOFs.

Metal implant segmentation in CT images based on diffusion model.

BACKGROUND: Computed tomography (CT) is widely in clinics and is affected by metal implants. Metal segmentation is crucial for metal artifact correction, and the common threshold method often fails to accurately segment metals. PURPOSE: This study aims to segment metal implants in CT images using a diffusion model and further validate it with clinical artifact images and phantom images of known size. METHODS: A retrospective study was conducted on 100 patients who received radiation therapy without metal artifacts, and simulated artifact data were generated using publicly available mask data. The study utilized 11,280 slices for training and verification, and 2,820 slices for testing. Metal mask segmentation was performed using DiffSeg, a diffusion model incorporating conditional dynamic coding and a global frequency parser (GFParser). Conditional dynamic coding fuses the current segmentation mask and prior images at multiple scales, while GFParser helps eliminate high-frequency noise in the mask. Clinical artifact images and phantom images are also used for model validation. RESULTS: Compared with the ground truth, the accuracy of DiffSeg for metal segmentation of simulated data was 97.89% and that of DSC was 95.45%. The mask shape obtained by threshold segmentation covered the ground truth and DSCs were 82.92% and 84.19% for threshold segmentation based on 2500 HU and 3000 HU. Evaluation metrics and visualization results show that DiffSeg performs better than other classical deep learning networks, especially for clinical CT, artifact data, and phantom data. CONCLUSION: DiffSeg efficiently and robustly segments metal masks in artifact data with conditional dynamic coding and GFParser. Future work will involve embedding the metal segmentation model in metal artifact reduction to improve the reduction effect.

Structural basis for the activity of the type VII CRISPR-Cas system.

The newly identified type VII CRISPR-Cas candidate system uses a CRISPR RNA-guided ribonucleoprotein complex formed by Cas5 and Cas7 proteins to target RNA1. However, the RNA cleavage is executed by a dedicated Cas14 nuclease, which is distinct from the effector nucleases of the other CRISPR-Cas systems. Here we report seven cryo-electron microscopy structures of the Cas14-bound interference complex at different functional states. Cas14, a tetrameric protein in solution, is recruited to the Cas5-Cas7 complex in a target RNA-dependent manner. The N-terminal catalytic domain of Cas14 binds a stretch of the substrate RNA for cleavage, whereas the C-terminal domain is primarily responsible for tethering Cas14 to the Cas5-Cas7 complex. The biochemical cleavage assays corroborate the captured functional conformations, revealing that Cas14 binds to different sites on the Cas5-Cas7 complex to execute individual cleavage events. Notably, a plugged-in arginine of Cas7 sandwiched by a C-shaped clamp of C-terminal domain precisely modulates Cas14 binding. More interestingly, target RNA cleavage is altered by a complementary protospacer flanking sequence at the 5' end, but not at the 3' end. Altogether, our study elucidates critical molecular details underlying the assembly of the interference complex and substrate cleavage in the type VII CRISPR-Cas system, which may help rational engineering of the type VII CRISPR-Cas system for biotechnological applications.

Oral administration of Robinia pseudoacacia L. flower exosome-like nanoparticles attenuates gastric and small intestinal mucosal ferroptosis caused by hypoxia through inhibiting HIF-1α- and HIF-2α-mediated lipid peroxidation.

The prevention and treatment of gastrointestinal mucosal injury caused by a plateau hypoxic environment is a clinical conundrum due to the unclear mechanism of this syndrome; however, oxidative stress and microbiota dysbiosis may be involved. The Robinia pseudoacacia L. flower, homologous to a functional food, exhibits various pharmacological effects, such as antioxidant, antibacterial, and hemostatic activities. An increasing number of studies have revealed that plant exosome-like nanoparticles (PELNs) can improve the intestinal microbiota and exert antioxidant effects. In this study, the oral administration of Robinia pseudoacacia L. flower exosome-like nanoparticles (RFELNs) significantly ameliorated hypoxia-induced gastric and small intestinal mucosal injury in mice by downregulating hypoxia-inducible factor-1α (HIF-1α) and HIF-2α expression and inhibiting hypoxia-mediated ferroptosis. In addition, oral RFELNs partially improved hypoxia-induced microbial and metabolic disorders of the stomach and small intestine. Notably, RFELNs displayed specific targeting to the gastrointestinal tract. In vitro experiments using gastric and small intestinal epithelial cell lines showed that cell death caused by elevated HIF-1α and HIF-2α under 1% O2 mainly occurred via ferroptosis. RFELNs obviously inhibited HIF-1α and HIF-2α expression and downregulated the expression of NOX4 and ALOX5, which drive reactive oxygen species production and lipid peroxidation, respectively, suppressing ferroptosis under hypoxia. In conclusion, our findings underscore the potential of oral RFELNs as novel, naturally derived agents targeting the gastrointestinal tract, providing a promising therapeutic approach for hypoxia-induced gastric and small intestinal mucosal ferroptosis.