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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 317: 124415, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38733918

ABSTRACT

SO2 derivatives play an important role in many metabolic processes, excessive ingestion of them can lead to serious complications of various diseases. In this work, a novel dual ratiometric NIR fluorescent probe XT-CHO based on ICT effect was synthesized for detecting SO2 derivative. In the design of the probe, the α, ß-unsaturated bond formed between benzopyran and coumarin was used as the reaction site for SO2, meanwhile, the extended π-conjugate system promoted maximum emission wavelength of the probe up to 708 nm. Notably, the probe exhibited high selectivity and sensitivity for detecting SO2, the limit of detection reached 2.13 nM and 58.5 nM in fluorescence spectra and UV-Vis absorption spectra, respectively. The reaction mechanism of SO2 and XT-CHO had been verified by 1H NMR, ESI-MS spectra and DFT calculation. Moreover, the probe was successfully applied in detecting endogenous and exogenous SO2 in living cells and proved possessed the mitochondrial targeted ability.

2.
Exp Biol Med (Maywood) ; 249: 10112, 2024.
Article in English | MEDLINE | ID: mdl-38715976

ABSTRACT

Chronic inflammation is a key element in the progression of essential hypertension (EH). Calcium plays a key role in inflammation, so its receptor, the calcium-sensing receptor (CaSR), is an essential mediator of the inflammatory process. Compelling evidence suggests that CaSR mediates inflammation in tissues and immune cells, where it mediates their activity and chemotaxis. Macrophages (Mφs) play a major role in the inflammatory response process. This study provided convincing evidence that R568, a positive regulator of CaSR, was effective in lowering blood pressure in spontaneously hypertensive rats (SHRs), improving cardiac function by alleviating cardiac hypertrophy and fibrosis. R568 can increase the content of CaSR and M2 macrophages (M2Mφs, exert an anti-inflammatory effect) in myocardial tissue, reduce M1 macrophages (M1Mφs), which have a pro-inflammatory effect in this process. In contrast, NPS2143, a negative state regulator of CaSR, exerted the opposite effect in all of the above experiments. Following this study, R568 increased CaSR content in SHR myocardial tissue, lowered blood pressure, promoted macrophages to M2Mφs and improved myocardial fibrosis, but interestingly, both M1Mφs and M2Mφs were increased in the peritoneal cavity of SHRs, the number of M2Mφs remained lower than M1Mφs. In vitro, R568 increased CaSR content in RAW264.7 cells (a macrophage cell line), regulating intracellular Ca2+ ([Ca2+]i) inhibited NOD-like receptor family protein 3 (NLRP3) inflammasome activation and ultimately prevented its conversion to M1Mφs. The results showed that a decrease in CaSR in hypertensive rats causes further development of hypertension and cardiac damage. EH myocardial remodeling can be improved by CaSR overexpression by suppressing NLRP3 inflammasome activation and macrophage polarization toward M1Mφs and increasing M2Mφs.


Subject(s)
Macrophages , Rats, Inbred SHR , Receptors, Calcium-Sensing , Animals , Receptors, Calcium-Sensing/metabolism , Macrophages/metabolism , Rats , Male , Ventricular Remodeling/physiology , Myocardium/pathology , Myocardium/metabolism , Fibrosis/metabolism , Blood Pressure , Mice , Hypertension/metabolism , Hypertension/pathology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism
3.
J Proteome Res ; 2024 May 09.
Article in English | MEDLINE | ID: mdl-38723043

ABSTRACT

Acupuncture is widely used to treat dry eye disease (DED), but its effect has not been reported in treating video display terminal (VDT)-related dry eye, and the mechanism of acupuncture on VDT-related dry eye is also unknown. In our study, the tear proteome was compared with identifying possible mechanisms and biomarkers for predicting acupuncture effectiveness in VDT-related dry eye. The results showed that the ocular surface disease index scores were significantly different between the acupuncture group (AC group) and artificial tears group (AT group) at the end of the study, whereas tear film breakup time (TFBUT) and Schirmer I test (SIT) were not significantly different between the groups. Proteome changes pre- and post-treatment in the AC group were associated with B cell-related immune processes, inflammation, glycolysis, and actin cytoskeleton. Furthermore, the proteins hexosaminidase A and mannose-binding lectin 1 could prospectively predict whether acupuncture treatment was effective. Therefore, we believe that acupuncture can provide greater improvement in the clinical symptoms of VDT-related dry eye than artificial tears. The mechanism of acupuncture in VDT-related dry eye treatment may be associated with glycolysis- and actin cytoskeleton remodeling-mediated inflammatory and immune processes. Additionally, hexosaminidase A and mannose-binding lectin 1 are biomarkers for predicting the efficacy of acupuncture for VDT-related dry eye.

4.
Iran J Public Health ; 53(1): 1-11, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38694869

ABSTRACT

Background: Influenza is the first infectious disease that implements global monitoring and is one of the major public health issues in the world. Air pollutants have become an important global public health issue, in recent years, and much epidemiological and clinical evidence has shown that air pollutants are associated with respiratory diseases. Methods: We comprehensively searched articles published up to 15 November 2022 in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Database of Chinese sci-tech periodicals, and Wanfang Database. The search strategies were based on keyword combinations related to influenza and air pollutants. The air pollutants included particulate matter (PM2.5, PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3). Meta-analysis was performed using the R programming language (R4.2.1). Results: A total of 2926 records were identified and 1220 duplicates were excluded. Finally, 19 studies were included in the meta-analysis according to inclusion and exclusion criteria. We observed a significant association between partial air pollutants (PM2.5, NO2, PM10 and SO2) and the incidence risk of influenza. The RRs were 1.0221 (95% CI: 1.0093~1.0352), 1.0395 (95% CI: 1.0131~1.0666), 1.007 (95% CI: 1.0009~1.0132), and 1.0352 (95% CI. 1.0076~1.0635), respectively. However, there was no significant relationship between CO and O3 exposure and influenza, and the RRs were 1.2272 (95% CI: 0.9253~1.6275) and 1.0045 (95% CI: 0.9930~1.0160), respectively. Conclusion: Exposure to PM2.5, NO2, PM10, and SO2 was significantly associated with influenza, which may be risk factors for influenza. The association of CO and O3 with influenza needs further investigation.

5.
Medicine (Baltimore) ; 103(16): e37877, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38640263

ABSTRACT

RATIONALE: Inflammatory fibroid polyp (IFP), also known as Vanek tumor, is a rare, benign gastrointestinal lesion characterized by its inflammatory and fibroid histological features. IFP is often discovered incidentally during endoscopic examinations. It is exceedingly rare for an IFP to prolapse into the duodenum and results in incomplete obstruction of the pylorus. PATIENT CONCERNS: A 64-year-old male patient was admitted to the hospital with recurrent episodes of melena over a 6-month period, along with complaints of dizziness and fatigue in the past 10 days. DIAGNOSES: Gastroscopy showed a giant polypoid mass on the posterior wall of the gastric antrum, prolapsing into the duodenum. Abdominal computer tomography (CT) confirmed the tumor protruding into the duodenum. Pathologic examination of the resected specimen confirmed the IFP diagnosis. INTERVENTIONS: The giant tumor was completely and successfully excised using endoscopic submucosal dissection (ESD). After the surgery, the patient underwent acid suppression and fluid replenishment therapy. OUTCOMES: The patient responded well to ESD and was discharged in stable condition. As of the submission of the case report, there has been no recurrence of the tumor after a 5-month follow-up, and the patient is still under follow-up. LESSONS: While IFPs have traditionally been managed surgically, ESD demonstrates promising treatment outcomes, avoiding the need for surgical distal gastrectomy, and emerges as a safe and effective treatment option.


Subject(s)
Endoscopic Mucosal Resection , Gastrointestinal Neoplasms , Leiomyoma , Polyps , Stomach Neoplasms , Male , Humans , Middle Aged , Pyloric Antrum/surgery , Pyloric Antrum/pathology , Stomach Neoplasms/complications , Stomach Neoplasms/surgery , Stomach Neoplasms/diagnosis , Polyps/complications , Polyps/surgery , Gastroscopy , Gastrointestinal Neoplasms/pathology , Duodenum/pathology , Leiomyoma/complications , Leiomyoma/surgery , Leiomyoma/pathology
7.
J Cell Mol Med ; 28(9): e18377, 2024 May.
Article in English | MEDLINE | ID: mdl-38686488

ABSTRACT

There are few effective therapeutic strategies for temporomandibular joint osteoarthritis (TMJOA) due to the unclear pathology and mechanisms. We aimed to confirm the roles of GPX4 and ferroptosis in TMJOA progression. ELISA assay was hired to evaluate concentrations of ferroptosis-related markers. The qRT-PCR assay was hired to assess gene mRNA level. Western blot assay and immunohistochemistry were hired to verify the protein level. CCK-8 assay was hired to detect cell viability. Human fibroblast-like synoviocytes (FLSs) were cultured to confirm the effects of GPX4 and indicated inhibitors, and further verified the effects of GPX4 and ferroptosis inhibitors in TMJOA model rats. Markers of ferroptosis including 8-hidroxy-2-deoxyguanosine (8-OHdG) and iron were notably increased in TMJOA tissues and primary OA-FLSs. However, the activity of the antioxidant system including the glutathione peroxidase activity, glutathione (GSH) contents, and glutathione/oxidized glutathione (GSH/GSSG) ratio was notably inhibited in TMJOA tissues, and the primary OA-FLSs. Furthermore, the glutathione peroxidase 4 (GPX4) expression was down-regulated in TMJOA tissues and primary OA-FLSs. Animal and cell experiments have shown that ferroptosis inhibitors notably inhibited ferroptosis and promoted HLS survival as well as up-regulated GPX4 expression. Also, GPX4 knockdown promoted ferroptosis and GPX4 overexpression inhibited ferroptosis. GPX4 also positively regulated cell survival which was the opposite with ferroptosis. In conclusion, GPX4 and ferroptosis regulated the progression of TMJOA. Targeting ferroptosis might be an effective therapeutic strategy for TMJOA patients in the clinic.


Subject(s)
Ferroptosis , Osteoarthritis , Phospholipid Hydroperoxide Glutathione Peroxidase , Temporomandibular Joint , Animals , Female , Humans , Male , Middle Aged , Rats , Cell Survival/drug effects , Disease Models, Animal , Disease Progression , Ferroptosis/genetics , Ferroptosis/drug effects , Fibroblasts/metabolism , Osteoarthritis/metabolism , Osteoarthritis/pathology , Osteoarthritis/genetics , Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism , Phospholipid Hydroperoxide Glutathione Peroxidase/genetics , Rats, Sprague-Dawley , Synoviocytes/metabolism , Synoviocytes/pathology , Temporomandibular Joint/pathology , Temporomandibular Joint/metabolism
8.
Sci Rep ; 14(1): 6053, 2024 03 13.
Article in English | MEDLINE | ID: mdl-38480774

ABSTRACT

The bioactivity of interferon-γ (IFN-γ) in cancer cells in the tumor microenvironment (TME) is not well understood in the current immunotherapy era. We found that IFN-γ has an immunosuppressive effect on colorectal cancer (CRC) cells. The tumor volume in immunocompetent mice was significantly increased after subcutaneous implantation of murine CRC cells followed by IFN-γ stimulation, and RNA sequencing showed high expression of B7 homologous protein 4 (B7H4) in these tumors. B7H4 promotes CRC cell growth by inhibiting the release of granzyme B (GzmB) from CD8+ T cells and accelerating apoptosis in CD8+ T cells. Furthermore, interferon regulatory factor 1 (IRF1), which binds to the B7H4 promoter, is positively associated with IFN-γ stimulation-induced expression of B7H4. The clinical outcome of patients with CRC was negatively related to the high expression of B7H4 in cancer cells or low expression of CD8 in the microenvironment. Therefore, B7H4 is a biomarker of poor prognosis in CRC patients, and interference with the IFN-γ/IRF1/B7H4 axis might be a novel immunotherapeutic method to restore the cytotoxic killing of CRC cells.


Subject(s)
Colorectal Neoplasms , T-Lymphocytes, Cytotoxic , Humans , Animals , Mice , Interferon-gamma/pharmacology , CD8-Positive T-Lymphocytes , Tumor Microenvironment , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology
9.
Cancer Lett ; 589: 216836, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38556105

ABSTRACT

Despite the approval of immune checkpoint blockade (ICB) therapy for various tumor types, its effectiveness is limited to only approximately 15% of patients with microsatellite instability-high (MSI-H) or mismatch repair deficiency (dMMR) colorectal cancer (CRC). Approximately 80%-85% of CRC patients have a microsatellite stability (MSS) phenotype, which features a rare T-cell infiltration. Thus, elucidating the mechanisms underlying resistance to ICB in patients with MSS CRC is imperative. In this study, we demonstrate that ubiquitin-specific peptidase 4 (USP4) is upregulated in MSS CRC tumors and negatively regulates the immune response against tumors in CRC. Additionally, USP4 represses the cellular interferon (IFN) response and antigen presentation and impairs PRR signaling-mediated cell death. Mechanistically, USP4 impedes the nuclear localization of interferon regulator Factor 3 (IRF3) by deubiquitinating the K63-polyubiquitin chain of TRAF6 and IRF3. Knockdown of USP4 enhances the infiltration of T cells in CRC tumors and overcomes ICB resistance in an MC38 syngeneic mouse model. Moreover, published datasets revealed that patients showing higher USP4 expression exhibited decreased responsiveness to anti-PD-L1 therapy. These findings highlight an essential role of USP4 in the suppression of antitumor immunity in CRC.


Subject(s)
Brain Neoplasms , Colorectal Neoplasms , Interferons , Neoplastic Syndromes, Hereditary , Animals , Mice , Humans , Interferons/metabolism , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Microsatellite Instability , Deubiquitinating Enzymes/genetics , Interferon Regulatory Factor-3/genetics , Ubiquitin-Specific Proteases/genetics , Ubiquitin-Specific Proteases/metabolism
10.
Reprod Sci ; 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38441776

ABSTRACT

BACKGROUND: Polycystic ovary syndrome (PCOS) is a gynecological endocrine disorder characterized by ovulatory disorders, hyperandrogenemia, and polycystic changes in the ovaries. FDX1 is a ferredoxin-reducing protein on human mitochondria that plays an important role in steroid anabolism. Liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), has recently emerged as a potential therapeutic agent for PCOS. Recent studies have suggested that FDX1 may be associated with the development of PCOS. This study aims to explore the pivotal role of FDX1 in the amelioration of PCOS through liraglutide intervention. MATERIALS AND METHODS: A PCOS rat model was induced via subcutaneous DHEA injections. Following successful model establishment, the rats were treated with liraglutide combined with metformin, or with each drug individually, over a six-week period. After 6 weeks of treatment, we assessed changes in body weight, fasting blood glucose, sex hormone levels, estrous cycle regularity, ovarian morphology, FDX1 expression in ovarian tissue, and ovarian ROS levels. RESULTS: PCOS rats exhibited significant increases in body weight and fasting blood glucose levels, disrupted estrous cycles, and polycystic ovarian morphology. FDX1 expression was notably reduced in the ovarian tissues of PCOS rats. Treatment with liraglutide, both alone and in combination with metformin, led to improvements in body weight, fasting blood glucose, sex hormone balance, estrous cycle regularity, ovarian morphology, and ovarian ROS levels. Notably, FDX1 expression was significantly restored in all treatment groups, with the most substantial increase observed in the liraglutide-treated group. CONCLUSION: This study suggests that FDX1 could serve as a potential biomarker for elucidating the underlying mechanisms of liraglutide's therapeutic effects in PCOS management.

11.
J Hazard Mater ; 469: 134032, 2024 May 05.
Article in English | MEDLINE | ID: mdl-38492389

ABSTRACT

Plant invasions and microplastics (MPs) have significantly altered the structure and function of aquatic habitats worldwide, resulting in severe damage to aquatic ecosystem health. However, the effects of MPs on plant invasion and the underlying mechanisms remain largely unknown. In this study, we conducted mesocosm experiments over a 90-day period to assess the effects of polystyrene microplastics on the invasion of exotic submerged macrophytes, sediment physicochemical properties, and sediment bacterial communities. Our results showed that PS-MPs significantly promoted the performance of functional traits and the invasive ability of exotic submerged macrophytes, while native plants remained unaffected. Moreover, PS-MPs addition significantly decreased sediment pH while increasing sediment carbon and nitrogen content. Additionally, MPs increased the diversity of sediment bacterial community but inhibited its structural stability, thereby impacting sediment bacterial multifunctionality to varying degrees. Importantly, we identified sediment properties, bacterial composition, and bacterial multifunctionality as key mediators that greatly enhance the invasion of exotic submerged macrophytes. These findings provide compelling evidence that the increase in MPs may exacerbate the invasion risk of exotic submerged macrophytes through multiple pathways. Overall, this study enhances our understanding of the ecological impacts of MPs on aquatic plant invasion and the health of aquatic ecosystems.


Subject(s)
Microbiota , Microplastics , Microplastics/toxicity , Ecosystem , Plastics , Polystyrenes , Bacteria
12.
Front Immunol ; 15: 1335473, 2024.
Article in English | MEDLINE | ID: mdl-38533496

ABSTRACT

Differentiated embryo-chondrocyte expressed gene 2 (DEC2) is a member of the basic helix-loop-helix (bHLH) subfamily of transcription factors. DEC2 is implicated in tumor immunotherapy, immune system function regulation, and autoimmune diseases. DEC2 enhances Th2 cell differentiation by regulating the IL-2 and IL-4 signaling pathways and mediates the growth of B-1a cells, thereby promoting the occurrence and development of inflammatory responses. In this study, we review the reported roles of DEC2, including the regulation of immune cell differentiation and cytokine production in various cells in humans, and discuss its potential in treating autoimmune diseases and tumors.


Subject(s)
Autoimmune Diseases , Basic Helix-Loop-Helix Transcription Factors , Humans , Basic Helix-Loop-Helix Transcription Factors/metabolism , Chondrocytes/metabolism , Transcription Factors/metabolism , Gene Expression
13.
Otol Neurotol ; 45(3): 227-237, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38320571

ABSTRACT

OBJECTIVE: Age-related hearing loss (ARHL), also known as presbycusis, is a debilitating sensory impairment that affects the elderly population. There is currently no ideal treatment for ARHL. Long-term caffeine intake was reported to have anti-aging effects in many diseases. This study is to identify whether caffeine could ameliorate ARHL in mice and analyze its mechanism. METHODS: Caffeine was administered in drinking water to C57BL/6J mice from the age of 3 months to 12 months. The body weight, food intake and water intake of the mice were monitored during the experiment. The metabolic indicators of serum were detected by ELISA. The function of the hearing system was evaluated by ABR and hematoxylin and eosin staining of the cochlea. Genes' expression were detected by Q-PCR, immunofluorescencee and Western blot. RESULTS: The results showed that the ARHL mice exhibited impaired hearing and cochlear tissue compared with the young mice. However, the caffeine-treated ARHL mice showed improved hearing and cochlear tissue morphology. The expression of inflammation-related genes, such as TLR4, Myd88, NF-κB, and IL-1ß, was significantly increased in the cochleae of ARHL mice compared with young mice but was down-regulated in the caffeine-treated cochleae. CONCLUSIONS: Inflammation is involved in ARHL of mice, and long-term caffeine supplementation could ameliorate ARHL through the down-regulation of the TLR4/NF-κB inflammation pathway. Our findings provide a new idea for preventing ARHL and suggest new drug targets for ARHL treatment.


Subject(s)
Presbycusis , Aged , Humans , Animals , Mice , Infant , Presbycusis/drug therapy , Presbycusis/genetics , Caffeine/pharmacology , Caffeine/therapeutic use , NF-kappa B , Toll-Like Receptor 4 , Mice, Inbred C57BL , Inflammation/drug therapy
14.
Nat Commun ; 15(1): 955, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38302463

ABSTRACT

Ageing exhibits common and distinct features in various tissues, making it critical to decipher the tissue-specific ageing mechanisms. MiRNAs are essential regulators in ageing and are recently highlighted as a class of intercellular messengers. However, little is known about the tissue-specific transcriptomic changes of miRNAs during ageing. C. elegans is a well-established model organism in ageing research. Here, we profile the age-dependent miRNAomic changes in five isolated worm tissues. Besides the diverse ageing-regulated miRNA expression across tissues, we discover numerous miRNAs in the tissues without their transcription. We further profile miRNAs in the extracellular vesicles and find that worm miRNAs undergo inter-tissue trafficking via these vesicles in an age-dependent manner. Using these datasets, we uncover the interaction between body wall muscle-derived mir-1 and DAF-16/FOXO in the intestine, suggesting mir-1 as a messenger in inter-tissue signalling. Taken together, we systematically investigate worm miRNAs in the somatic tissues and extracellular vesicles during ageing, providing a valuable resource to study tissue-autonomous and nonautonomous functions of miRNAs in ageing.


Subject(s)
Caenorhabditis elegans Proteins , MicroRNAs , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Aging/genetics , Intestines , MicroRNAs/metabolism , Longevity/genetics
15.
Ren Fail ; 46(1): 2294148, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38186351

ABSTRACT

This study aimed to investigate ultrasound features of arteriovenous fistula stenosis and their relationship with primary patency after percutaneous transluminal angioplasty (post-intervention primary patency) and compare this classification with that using lesion location. Hemodialysis patients who underwent ultrasound-guided percutaneous transluminal angioplasty for arteriovenous fistula stenosis from July 2020 to December 2021 were retrospectively evaluated. Lesions (excluding inflow arteries) were categorized into five groups based on ultrasound features, and the clinical characteristics and risk factors affecting the post-intervention primary patency of the arteriovenous fistula were analyzed. Among 185 patients, 100 (54.05%), 36 (19.46%), 22 (11.89%), 11 (5.95%), and 16 (8.65%) were classified into the intima-dominant, non-intima-dominant, valve obstruction, vascular calcification, and mixed groups, respectively. The dialysis duration and arteriovenous fistula use time were the highest in the vascular calcification group at 86 (interquartile range: 49-140) and 77 (interquartile range: 49-110) months, respectively. Diabetes mellitus was most common in the intima-dominant group (42.0%). In Kaplan-Meier and univariate Cox analysis, type III lesion location (stenosis in the venous confluence site) was associated with the lower post-intervention primary patency. In the multivariate Cox analysis, percutaneous transluminal angioplasty times (the number of times patients were treated with percutaneous transluminal angioplasty for arteriovenous fistula stenosis dysfunction), vascular calcification, calcification at the lesion site requiring percutaneous transluminal angioplasty, and serum parathyroid hormone levels were independent risk factors for post-intervention primary patency. Ultrasound features showed that calcification of the arteriovenous fistula was detrimental to the post-intervention primary patency of arteriovenous fistula.


Subject(s)
Arteriovenous Fistula , Vascular Calcification , Humans , Constriction, Pathologic , Retrospective Studies , Ultrasonography , Vascular Calcification/diagnostic imaging , Vascular Calcification/therapy , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/therapy
16.
ACS Synth Biol ; 13(1): 269-281, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38061052

ABSTRACT

CRISPR-Cas9 systems have been widely harnessed for diverse genome editing applications because of their ease of use and high efficiency. However, the large molecular sizes and strict PAM requirements of commonly used CRISPR-Cas9 systems restrict their broad applications in therapeutics. Here, we report the molecular basis and genome editing applications of a novel compact type II-A Eubacterium ventriosum CRISPR-Cas9 system (EvCas9) with 1107 residues and distinct 5'-NNGDGN-3' (where D represents A, T, or G) PAM specificity. We determine the cryo-EM structure of EvCas9 in a complex with an sgRNA and a target DNA, revealing the detailed PAM recognition and sgRNA and target DNA association mechanisms. Additionally, we demonstrate the robust genome editing capacity of EvCas9 in bacteria and human cells with superior fidelity compared to SaCas9 and SpCas9, and we engineer it to be efficient base editors by fusing a cytidine or adenosine deaminase. Collectively, our results facilitate further understanding of CRISPR-Cas9 working mechanisms and expand the compact CRISPR-Cas9 toolbox.


Subject(s)
CRISPR-Cas Systems , Eubacterium , Gene Editing , Humans , Gene Editing/methods , CRISPR-Cas Systems/genetics , RNA, Guide, CRISPR-Cas Systems , DNA/genetics
17.
Nat Chem Biol ; 20(2): 180-189, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37697004

ABSTRACT

CRISPR-Cas12f nucleases are currently one of the smallest genome editors, exhibiting advantages for efficient delivery via cargo-size-limited adeno-associated virus delivery vehicles. Most characterized Cas12f nucleases recognize similar T-rich protospacer adjacent motifs (PAMs) for DNA targeting, substantially restricting their targeting scope. Here we report the cryogenic electron microscopy structure and engineering of a miniature Clostridium novyi Cas12f1 nuclease (CnCas12f1, 497 amino acids) with rare C-rich PAM specificity. Structural characterizations revealed detailed PAM recognition, asymmetric homodimer formation and single guide RNA (sgRNA) association mechanisms. sgRNA engineering transformed CRISPR-CnCas12f1, which initially was incapable of genome targeting in bacteria, into an effective genome editor in human cells. Our results facilitate further understanding of CRISPR-Cas12f1 working mechanism and expand the mini-CRISPR toolbox.


Subject(s)
CRISPR-Cas Systems , RNA, Guide, CRISPR-Cas Systems , Humans , CRISPR-Cas Systems/genetics , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , DNA/chemistry , Genome , Endonucleases/genetics , Endonucleases/metabolism , Gene Editing
18.
Plant Sci ; 340: 111963, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38103698

ABSTRACT

Cell deformation often occurs during sample preparation and imaging with scanning electron microscope (SEM), especially with delicate samples, which influences the accuracy of the results. Here we investigate the influence of several preparation methods on cell deformation, using water content and tissue hardness as indicators to classify "delicate" samples of plant species. The degree of deformation in samples resulting from five preparation methods was measured at the tissue and single-cell levels, revealing that a cryo- and methanol-fixation produced lower degrees of tissue dimension deformation and better preservation of cell shape for delicate samples, while for harder tissues, other preparation methods for a dehydrated specimen are also suitable. Stability and image quality of delicate samples could be improved with the application of a cryo-protectant combined with a lower cryo-stage temperature, e.g. - 30 °C. We show that the sample stability under the beam was improved by combining larger sample size and cryo-stage application. Furthermore, the influence of adaxial and abaxial tissue surfaces, the accelerating voltage, and sputter coating time on sample stability and image quality was evaluated. Our study is valuable for artifact reduction and easy application of SEM.


Subject(s)
Plants , Water , Microscopy, Electron, Scanning , Temperature
19.
Membranes (Basel) ; 13(9)2023 Aug 31.
Article in English | MEDLINE | ID: mdl-37755195

ABSTRACT

In order to enhance the separation performance and reduce the heat loss of transmembrane for membrane distillation, the thermal efficiency and hydrophobicity of the membrane distillation need to be simultaneously enhanced. In this work, a polyvinylidene difluoride/polyethylene glycol terephthalate (PVDF/PET) hydrophobic/hydrophilic membrane has been prepared by non-solvent phase induction method. Nanosized silica aerogel (SiAG) with high porosity has been added to the composite membranes. The modifying effects and operating conditions on permeate flux and thermal efficiency in direct contact membrane distillation (DCMD) are investigated. Furthermore, the latent heat of vaporization and the heat transfer across the membranes have been compared for SiAG addition, which indicates that the composite PVDF@SiAG/PET membranes demonstrate a great potential for distillation-separation application due to their high heat efficiency.

20.
Biomater Sci ; 11(21): 7158-7168, 2023 Oct 24.
Article in English | MEDLINE | ID: mdl-37718624

ABSTRACT

MR-guided focused ultrasound surgery (MRgFUS) is driving a new direction in non-invasive thermal ablation therapy with spatial specificity and real-time temperature monitoring. Although widely used in clinical practice, it remains challenging to completely ablate the tumor margin due to fear of damaging the surrounding tissues, thus leading to low efficacy and a series of complications. Herein, we have developed novel pH-responsive drug-loading magnetosomes (STPSD nanoplatform) for increasing the T2-contrast and improved the ablation efficiency with a clinical MRgFUS system. Specifically, this STPSD nanoplatform is functionalized by pH-responsive peptides (STP-TPE), encapsulating superparamagnetic iron oxide (SPIO) and doxorubicin (DOX), which can cause drug release and SPIO deposition at the tumor site triggered by acidity and MRgFUS. Under MRgFUS treatment, the increased vascular permeability caused by hyperthermia can improve the uptake of SPIO and DOX by tumor cells, so as to enhance ultrasound energy absorption and further enhance the efficacy of chemotherapy to completely ablate tumor margins. Moreover, we demonstrated that a series of MR sequences including T2-weighted imaging (T2WI), contrast-enhanced T1WI imaging (T1WI C+), maximum intensity projection (MIP), volume rendering (VR) and ADC mapping can be further utilized to monitor the MRgFUS ablation effect in rat models. Overall, this smart nanoplatform has the capacity to be a powerful tool to promote the therapeutic MRgFUS effect and minimize the side effects to surrounding tissues.

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