Folic Acid Functionalized AQ4N/Gd@PDA Nanoplatform with Real-Time Monitoring of Hypoxia Relief and Enhanced Synergistic Chemo/Photothermal Therapy in Glioma.

Purpose: Hypoxia is often associated with glioma chemoresistance, and alleviating hypoxia is also crucial for improving treatment efficacy. However, although there are already some methods that can improve efficacy by alleviating hypoxia, real-time monitoring that can truly achieve hypoxia relief and efficacy feedback still needs to be explored. Methods: AQ4N/Gd@PDA-FA nanoparticles (AGPF NPs) were synthesized using a one-pot method and were characterized. The effects of AGPF NPs on cell viability, cellular uptake, and apoptosis were investigated using the U87 cell line. Moreover, the effectiveness of AGPF NPs in alleviating hypoxia was explored in tumor-bearing mice through photoacoustic imaging. In addition, the diagnosis and treatment effect of AGPF NPs were evaluated by magnetic resonance imaging (MRI) and bioluminescent imaging (BLI) on orthotopic glioma mice respectively. Results: In vitro experiments showed that AGPF NPs had good dispersion, stability, and controlled release. AGPF NPs were internalized by cells through endocytosis, and could significantly reduce the survival rate of U87 cells and increase apoptosis under irradiation. In addition, we monitored blood oxygen saturation at the tumor site in real-time through photoacoustic imaging (PAI), and the results showed that synergistic mild-photothermal therapy/chemotherapy effectively alleviated tumor hypoxia. Finally, in vivo anti-tumor experiments have shown that synergistic therapy can effectively alleviate hypoxia and inhibit the growth of orthotopic gliomas. Conclusion: This work not only provides an effective means for real-time monitoring of the dynamic feedback between tumor hypoxia relief and therapeutic efficacy, but also offers a potential approach for the clinical treatment of gliomas.

A Systematic Investigation of the Kinetic Models Applied to the Transport Behaviors of Aromatic Solvents in Unfilled Hydrogenated Nitrile Rubber/Ethylene Propylene Diene Monomer Composites.

Kinetic models of solvent transport behaviors are widely used in rubber-solvent systems, and some key points are still worthy of attention. In this work, the Korsmeyer-Peppas and Peppas-Sahlin models were chosen to fit the transport behaviors of three aromatic solvents, benzene, toluene and p-xylene, in the hydrogenated nitrile rubber (HNBR)/ethylene propylene diene monomer (EPDM)-based vulcanizates. The different effects of the various selected transport times (ti) used for fitting on the results of the mathematical models were compared. Moreover, a method to obtain the n parameter for the Korsmeyer-Peppas model and the m parameter for the Peppas-Sahlin model at ti = 0 was discussed. It was found that the differences in values of ti greatly influenced the impact on the fitting results of all the parameters for the two models. In addition, the n parameter for the Korsmeyer-Peppas model along with the m parameter for the Peppas-Sahlin model, which can characterize the transport mechanism, showed differing applicability. But the n and m parameters at ti = 0 obtained by linear fitting showed similar rules with some differences in values. These discussions give important guidance for the application of kinetic transport models in rubber-solvent systems.

Efficacy of remimazolam tosilate versus propofol for total intravenous anaesthesia in urological surgery: A randomised clinical trial.

BACKGROUND: Remimazolam is a novel ultra-short-acting benzodiazepine sedative that acts on the gamma-aminobutyric acid type A receptor (GABAAR). OBJECTIVE: To compare the efficacies of remimazolam (RMZ), and propofol (PROP) combined with remifentanil and cisatracurium for total intravenous anaesthesia (TIVA) in patients undergoing urological surgery. DESIGN: A prospective, single-blind, randomised, noninferiority clinical trial. SETTING: Single centre from 1 January 2022 to 30 March 2022. PATIENTS: A total of 146 adult patients undergoing elective urological surgery. INTERVENTION: Patients were randomly allocated in a 1 : 1 ratio to the PROP or RMZ groups. In the PROP group, anaesthesia was induced with propofol at 100 mg min -1 to reach a bispectral index score (BIS) of 40 to 60. After loss of consciousness (LOC), intravenous fentanyl 3 µg kg -1 was administered, followed by cisatracurium 0.3 mg kg -1 . Patients were intubated 3 min after cisatracurium administration. Anaesthesia was maintained with the combination of propofol (plasma concentration: 2.5 to 4 µg ml -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ). In the RMZ group, anaesthesia was induced with remimazolam tosilate starting at 10 mg kg -1  h -1 to reach a BIS of 40 to 60 and maintained between 0.2 and 2 mg kg -1  h -1 . After LOC, fentanyl and cisatracurium were administered and intubation was performed as in the PROP group. Anaesthesia was maintained with a combination of remimazolam (0.2 to 2 mg kg -1  h -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ). MAIN OUTCOME MEASURES: The primary outcome was the TIVA success rate. The predefined noninferiority margin considered an absolute difference of 6% in the primary outcome between the groups. The secondary outcomes were vital signs, anaesthesia and surgery characteristics, and adverse events. RESULTS: All patients completed the trial. The success rates of TIVA with remimazolam and propofol were 100 and 98.6%, respectively. The incidence of hypotension during anaesthesia was lower in the RMZ group (26%) than in the PROP group (46.6%) ( P  = 0.016). The median [IQR] total consumption of ephedrine during anaesthesia was higher in the PROP group 10 [0 to 12.5] mg than in the RMZ group 0 [0 to 10] mg ( P  = 0.0002). The incidence of injection pain was significantly higher in the PROP group (76.7%) than in the RMZ group (0; P  < 0.001). No significant differences in the controllability of the anaesthesia depth, anaesthesia and surgery characteristics, or vital signs were observed between the groups. CONCLUSION: Remimazolam demonstrated noninferior efficacy to propofol combined with remifentanil and cisatracurium for TIVA in patients undergoing urological surgery. TRIAL REGISTRATION: Chictr.org.cn, identifier: ChiCTR2100050923. CLINICAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100050923, Principal investigator: Xuehai Guan, Date of registration: 8 November 2021, https://www.chictr.org.cn/showproj.html?proj=133466 ).

Systematic Investigation of the Degradation Properties of Nitrile-Butadiene Rubber/Polyamide Elastomer/Single-Walled Carbon Nanotube Composites in Thermo-Oxidative and Hot Oil Environments.

The physical blending method was used in order to prepare nitrile-butadiene rubber/polyamide elastomer/single-walled carbon nanotube (NBR/PAE/SWCNT) composites with better thermal-oxidative aging resistance. The interactions between SWCNTs and NBR/PAE were characterized using the Moving Die Rheometer 2000 (MDR 2000), rheological behavior tests, the equilibrium swelling method, and mechanical property tests. The 100% constant tensile stress and hardness of NBR/PAE/SWCNT composites increased from 2.59 MPa to 4.14 MPa and from 62 Shore A to 69 Shore A, respectively, and the elongation decreased from 421% to 355% with increasing SWCNT content. NBR/PAE/SWCNT composites had improved thermal-oxidative aging resistance due to better interactions between SWCNTs and NBR/PAE. During the aging process, the tensile strength and elongation at break decreased with the increase in aging time compared to the unaged samples, and the constant tensile stress gradually increased. There was a more significant difference in the degradation of mechanical properties when aged in a variety of oils. The 100% constant tensile stress of NBR/PAE/SWCNT composites aged in IRM 903 gradually increased with aging time while it gradually decreased in biodiesel. The swelling index gradually increased with increasing SWCNT content. Interestingly, the swelling index of the composites in cyclohexanone decreased with the increase in SWCNT content. The reasons leading to different swelling behaviors when immersed in different kinds of liquids were investigated using the Hansen solubility parameter (HSP) method, which provides an excellent guide for the application of some oil-resistant products.

Effect of alkali pretreatment time on kitchen waste anaerobic digestion performance enhanced by alkali pretreatment combined with bentonite: performance enhancement, microbial community structure, and functional gene analysis.

Kitchen waste was mainly composed of carbohydrates, lipids, and proteins. Anaerobic digestion (AD) of kitchen waste usually occurred acidification and further deteriorated. In our previous study, alkali pretreatment combined with bentonite (AP/Be) treatment was proved to enhance high solid AD of kitchen waste. However, effects of AP time on AP/Be were not yet studied. This study investigated the effects of AP time on AP/Be treatment on enhancing high solid AD. The results showed that compared with the control group, the cumulative methane production rate could be increased by 3.30 times (149.7 mL CH4/g VS) and the volatile solids (VS) reduction rate increased by 63.36%. Microbial community analysis showed that the relative abundance of Methanosarcina and Methanosaeta were increased from 6.49 and 7.83% to 47.14 and 16.39% respectively. Predictive functional analysis showed that AP/Be treatment increased the abundance of energy production and conversion, coenzyme transport, and metabolism. This study revealed the potential mechanism of AP/Be enhanced kitchen waste AD performance and AP/Be was a potential strategy to strengthen AD.

CPSF6 regulates alternative polyadenylation and proliferation of cancer cells through phase separation.

Cancer cells usually exhibit shortened 3' untranslated regions (UTRs) due to alternative polyadenylation (APA) to promote cell proliferation and migration. Upregulated CPSF6 leads to a systematic prolongation of 3' UTRs, but CPSF6 expression in tumors is typically higher than that in healthy tissues. This contradictory observation suggests that it is necessary to investigate the underlying mechanism by which CPSF6 regulates APA switching in cancer. Here, we find that CPSF6 can undergo liquid-liquid phase separation (LLPS), and elevated LLPS is associated with the preferential usage of the distal poly(A) sites. CLK2, a kinase upregulated in cancer cells, destructs CPSF6 LLPS by phosphorylating its arginine/serine-like domain. The reduction of CPSF6 LLPS can lead to a shortened 3' UTR of cell-cycle-related genes and accelerate cell proliferation. These results suggest that CPSF6 LLPS, rather than its expression level, may be responsible for APA regulation in cancer cells.

Detection of human serum albumin using a rare-earth nanosheet fluorescent probe based on intensity and lifetime signals.

Human serum albumin (HSA) is an important biomarker for early disease diagnosis. Therefore, the detection of HSA in biological samples is important. In this study, for the sensitive detection of HSA, a fluorescent probe based on Eu(III)-doped yttrium hydroxide nanosheets was designed and sensitized by α-thiophenformyl acetone trifluoride as an antenna. The morphology and structure of the as-prepared nanosheet fluorescent probe were studied by transmission electron microscopy and atomic force microscopy. A detailed investigation of the fluorescence properties of the as-obtained nanosheet probe revealed that the Eu(III) emission intensity was linearly and selectively enhanced by the consecutive addition of HSA. Furthermore, the lifetime signal of this probe was enhanced with increasing concentration. The sensitivity of the nanosheet probe to HSA is discussed based on the results of ultraviolet-visible, fluorescence, and infrared spectral analyses, the findings demonstrate that the nanosheet fluorescent probe we prepared is a highly sensitive and selective tool for detecting HSA concentration with a high intensity and a large lifetime change.

The effect of charges on the corneal penetration of solid lipid nanoparticles loaded Econazole after topical administration in rabbits.

Fungal keratitis is an infectious disease caused by pathogenic fungi with a high blindness rate. Econazole (ECZ) is an imidazole antifungal drug with insoluble ability. Econazole-loaded solid lipid nanoparticles (E-SLNs) were prepared by microemulsion method, then modified with positive and negative charge. The mean diameter of cationic E-SLNs, nearly neutral E-SLNs and anionic E-SLNs were 18.73±0.14, 19.05±0.28, 18.54±0.10 nm respectively. The Zeta potential of these different charged SLNs formulations were 19.13±0.89, -2.20±0.10, -27.40±0.67 mV respectively. The Polydispersity Index (PDI) of these three kinds of nanoparticles were all about 0.2. The Transmission Electron Microscopy (TEM) and Differential Scanning Calorimetry (DSC) analysis showed that the nanoparticles were a homogeneous system. Compared with Econazole suspension (E-Susp), SLNs exhibited sustained release capability, stronger corneal penetration and enhanced inhibition of pathogenic fungi without irritation. The antifungal ability was further improved after cationic charge modification compared with E-SLNs. Studies on pharmacokinetics showed that the order of the AUC and t1/2 of different preparations was cationic E-SLNs > nearly neutral E-SLNs > anionic E-SLNs > E-Susp in cornea and aqueous humor. It was shown that SLNs could increase corneal penetrability and ocular bioavailability while these capabilities were further enhanced with positive charge modification compared with negative charge ones.

Microbial response behavior to powdered activated carbon in high-solids anaerobic digestion of kitchen waste: Metabolism and functional prediction analysis.

Anaerobic digestion (AD) can not only treat organic waste, but also recycle energy. However, high-solids AD of kitchen waste usually failed due to excessive acidification. In this study, the effect of activated carbon (AC) on kitchen waste AD performance was investigated under high-solids conditions (total solids contents = 15%). The results showed that efficiencies of acidogenesis and methanogenesis were promoted in presence of moderate concentration (50 g/L > AC >5 g/L), but high concentration (AC >70 g/L) weakened AD performance. Moreover, AC addition enhanced the methane production rate from 66.0 mL/g VS to 231.50 mL/g VS, i.e., up to 250.7%. High-throughput sequencing results demonstrated that the abundance of electroactive DMER64 increased from less than 1%-29.7% (20 g/L AC). As AC gradually increased，aceticlastic methanogenesis changed to hydrogenotrophic pathway. Predicted functional analysis indicated that AC can enhance abundances of energy and inorganic ion metabolism, resulting in high methane production.

The diurnal salivary glands transcriptome of Dermacentor nuttalli from the first four days of blood feeding.

The ixodid tick Dermacentor nuttalli is distributed from southern Siberia to North China and is a vector of many pathogens. This species can have severe impacts on animal husbandry and human health. To date, the control of D. nuttalli is limited to the use of acaricides such as organophosphorus, synthetic pyrethroids and amidine pesticides. There are no environmentally friendly or reliable prevention and control measures, and little is known regarding key antigens involved in blood feeding. Salivary glands are major tissues involved in the blood feeding and pathogen transmission of ticks. Therefore, this study focused on salivary glands tissue to identify the dominant antigens of D. nuttalli involved in tick feeding. For this, high-throughput RNA sequencing (RNA-seq) was used for analysis. The transcriptome of female D. nuttalli ticks was assembled and characterized, and differentially expressed genes (DEGs) were identified in the salivary glands of ticks that had not fed (0 h) and of ticks after 24, 48, 72 and 96 h of feeding. There were 22,802,784, 22,275,013, 26,629,453, 24,982,389, and 22,596,230 high-quality clean reads obtained from salivary glands tissues at the five different blood feeding time points. The total number of annotated unigenes was 100,347. The differences in gene expression between different time points were compared, and functional enrichment was performed. Quantitative reverse transcription PCR (RT‒qPCR) was used to validate the RNA-seq results, the results of which showed that the differences in expressed transcripts presented similar trends. Among the identified DEGs, the most numerous were those with catalytic and binding activities and those involved in diverse metabolic pathways and cellular processes. The expression patterns of homologous and family-member proteins throughout the blood feeding period exhibited significant differences, strongly suggesting that the transcriptome composition is highly dynamic and likely subjected to important variation throughout the life cycle. Studies of gene sequences in D. nuttalli will greatly increase the information on tick protective antigens, which could potentially function as effective vaccine candidates or drug targets for the development of environmentally friendly acaricides.

Research on Hepatocyte Regulation of PCSK9-LDLR and Its Related Drug Targets.

The prevalence of hyperlipidemia has increased significantly due to genetic, dietary, nutritional and pharmacological factors, and has become one of the most common pathological conditions in humans. Hyperlipidemia can lead to a range of diseases such as atherosclerosis, stroke, coronary heart disease, myocardial infarction, diabetes, and kidney failure, etc. High circulating low-density lipoprotein cholesterol (LDL-C) is one of the causes of hyperlipidemia. LDL-C in the blood binds to LDL receptor (LDLR) and regulates cholesterol homeostasis through endocytosis. In contrast, proprotein convertase subtilisin/kexin type 9 (PCSK9) mediates LDLR degradation via the intracellular and extracellular pathways, leading to hyperlipidemia. Targeting PCSK9-synthesizing transcription factors and downstream molecules are important for development of new lipid-lowering drugs. Clinical trials regarding PCSK9 inhibitors have demonstrated a reduction in atherosclerotic cardiovascular disease events. The purpose of this review was to explore the target and mechanism of intracellular and extracellular pathways in degradation of LDLR and related drugs by PCSK9 in order to open up a new pathway for the development of new lipid-lowering drugs.

Novel hKDR mouse model depicts the antiangiogenesis and apoptosis-promoting effects of neutralizing antibodies targeting vascular endothelial growth factor receptor 2.

Vascular endothelial growth factor receptor 2 (VEGFR2)/KDR plays a critical role in tumor growth, diffusion, and invasion. The amino acid sequence homology of KDR between mouse and human in the VEGF ligand-binding domain was low, thus the WT mice could not be used to evaluate Abs against human KDR, and the lack of a suitable mouse model hindered both basic research and drug developments. Using the CRISPR/Cas9 technique, we successfully inserted different fragments of the human KDR coding sequence into the chromosomal mouse Kdr exon 4 locus to obtain an hKDR humanized mouse that can be used to evaluate the marketed Ab ramucirumab. In addition, the humanized mAb VEGFR-HK19 was developed, and a series of comparative assays with ramucirumab as the benchmark revealed that VEGFR-HK19 has higher affinity and superior antiproliferation activity. Moreover, VEGFR-HK19 selectively inhibited tumor growth in the hKDR mouse model but not in WT mice. The most important binding epitopes of VEGFR2-HK19 are D257, L313, and T315, located in the VEGF binding region. Therefore, the VEGFR2-HK19 Ab inhibits tumor growth by blocking VEGF-induced angiogenesis, inflammation, and promoting apoptosis. To our best knowledge, this novel humanized KDR mouse fills the gaps both in an animal model and the suitable in vivo evaluation method for developing antiangiogenesis therapies in the future, and the newly established humanized Ab is expected to be a drug candidate possibly benefitting tumor patients.

Alleviating acid inhibition via bentonite supplementation during acidulated swine manure anaerobic digestion: Performance enhancement and microbial mechanism analysis.

Swine manure is usually transmitted by the "collection-storage-transport" mode of the biogas project. However, this particular application pattern results in high volatile fatty acids (VFAs) concentration due to the long transition time in the "collection-storage-transport" process. In this work, acidulated swine manure anaerobic digestion (AD) with bentonite supplementation was firstly investigated with an expectation of acid alleviation, performance enhancement and microbial mechanism. Results indicated that the methane production rate in the 20 g/L bentonite-added digester was 2.87 fold higher than that of the control digester. Chemical oxygen demand (COD) removal rate was elevated by 140.1% via bentonite supplementation. Besides, the rapid decrease of VFAs and ammonia indicated that bentonite supplementation could offer buffering capacity and alleviate acid inhibition. Microbial community analysis revealed that acetoclastic methanogenesis (Methanosaeta and Methanosarcina) was the predominant methanogenesis pathway in this AD system. Syntrophic acetate oxidation (SAO) bacteria were discovered in the bentonite-added digester, and they converted acetate into H2/CO2 to support hydrogenotrophic methanogenesis. This study could offer guidance for acidulated swine manure AD in the practical biogas project.

Enhanced anaerobic digestion of kitchen waste at different solids content by alkali pretreatment and bentonite addition: Methane production enhancement and microbial mechanism.

High solid anaerobic digestion (AD) has been considered as a promising and sustainable technology for treating kitchen waste. To enhance AD of kitchen waste, alkali pretreatment and bentonite addition treatment (AP/Be) was performed on kitchen waste, and microbial community was investigated at different total solids (TS) content (10%, 13%, 19%, 22% and 25%). The results indicated that after AP/Be treatment, methane yield was as high as 198 mL CH4/g volatile solid (VS), which increased by 236% as the control. Moreover, microbial community analysis revealed that AP/Be treatment enriched bacterial microbial diversity. At TS of 10%, AP/Be treatment enhanced the hydrogenotrophic methanogens (Methanobacterium) significantly. In addition, the dominant methanogenic pathways changed at different TS content. These results demonstrated AP/Be treatment had a positive effect on methanogenesis during kitchen waste anaerobic digestion process. This study threw new insights towards enhancing kitchen waste anaerobic digestion, as well as the microbial mechanism.

Frontiers and hotspots of adipose tissue and NAFLD: a bibliometric analysis from 2002 to 2022.

Background: The annual incidence of non-alcoholic fatty liver disease (NAFLD) continues to rise steadily. In recent years, adipose tissue (AT) has gained recognition as a pivotal contributor to the pathogenesis of NAFLD. Employing bibliometric analysis, we examined literature concerning AT and NAFLD. Methods: Relevant literature on AT in NAFLD from 1980 to 2022 was extracted from the Web of Science Core Collection. These records were visualized using CiteSpace and VOSviewer regarding publications, countries/regions, institutions, authors, journals, references, and keywords. Results: Since 2002, a total of 3,330 papers have been included, exhibiting an annual surge in publications. Notably, the quality of publications is superior in the USA and Europe. Kenneth Cusi stands out as the author with the highest number of publications and H-index. Hepatology is the journal boasting the highest citation and H-index. The University of California System holds the highest centrality among institutions. References specifically delve into physiological processes associated with AT in NAFLD. Currently, lipid metabolism and inflammation constitute the principal research mechanisms in the AT-based regulation of NAFLD, with pertinent keywords including microRNA, T cell, hypoxia, sarcopenia, hepatokine, gut microbiota, and autophagy. The Mediterranean diet is among the most widely recommended dietary approaches for potential NAFLD treatment. Conclusion: This paper represents the inaugural bibliometric study on the effects of AT on NAFLD, offering valuable insights and directions for future research.

Cyclin D1 mediates pain behaviour in a rat model of breast cancer-induced bone pain by a mechanism involving regulation of the proliferation of spinal microglia.

AIMS: The involvement of cyclin D1 in the proliferation of microglia, and the generation and maintenance of bone cancer pain (BCP), have not yet been clarified. We investigated the expression of microglia and cyclin D1, and the influences of cyclin D1 on pain threshold. METHODS: Female Sprague Dawley (SD) rats were used to establish a rat model of BCP, and the messenger RNA (mRNA) and protein expression of ionized calcium binding adaptor molecule 1 (IBA1) and cyclin D1 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot, respectively. The proliferation of spinal microglia was detected by immunohistochemistry. The pain behaviour test was assessed by quantification of spontaneous flinches, limb use, and guarding during forced ambulation, mechanical paw withdrawal threshold, and thermal paw withdrawal latency. RESULTS: IBA1 and cyclin D1 in the ipsilateral spinal horn increased in a time-dependent fashion. Spinal microglia proliferated in BCP rats. The microglia inhibitor minocycline attenuated the pain behaviour in BCP rats. The cyclin-dependent kinase inhibitor flavopiridol inhibited the proliferation of spinal microglia, and was associated with an improvement in pain behaviour in BCP rats. CONCLUSION: Our results revealed that the inhibition of spinal microglial proliferation was associated with a decrease in pain behaviour in a rat model of BCP. Cyclin D1 acts as a key regulator of the proliferation of spinal microglia in a rat model of BCP. Disruption of cyclin D1, the restriction-point control of cell cycle, inhibited the proliferation of microglia and attenuated the pain behaviours in BCP rats. Cyclin D1 and the proliferation of spinal microglia may be potential targets for the clinical treatment of BCP.Cite this article: Bone Joint Res 2022;11(11):803-813.

[Celastrol inhibits neurotoxicity induced by Cd2].

Cadmium (Cd) is a common heavy metal in the environment. Cd2+ may penetrate the blood-brain barrier and produce neurotoxicity, thus inducing various neurodegenerative diseases. Celastrol is an effective component of Tripterygium wilfordii Hook. F., which has many pharmacological effects such as anti-cancer and anti-inflammatory. Here we explored the effect of celastrol on the corresponding neurotoxicity induced by Cd2+. Cell proliferation test, cell membrane integrity test, and cell morphology were observed to analyze the effect of Cd2+ on the viability of HMC3. The neurotoxicity of Cd2+ and the effect of celastrol on the corresponding neurotoxicity induced by Cd2+ were analyzed by nitric oxide (NO) test, lipid peroxidation (MDA) test, and Western blotting. When the concentration of Cd2+ reached 40 µmol/L, the inhibition rate of HMC3 cell proliferation was (57.17±8.23)% (P < 0.01, n=5), compared with the control group. The cell activity continued to reduce when the Cd2+ concentration further increased. When the concentration of Cd2+ was higher than 40 µmol/L, the cell membrane of HMC3 was significantly damaged, and the damage was dose-dependent. Upon increasing the Cd2+ concentration, the cell morphology began to change and the adhesion also became worse. Cd2+ significantly increased the amount of NO released by HMC3 cells, while celastrol effectively inhibited the NO release of HMC3 cells induced by Cd2+. Cd2+ greatly increased the release of MDA in HMC3 cells, and the level of MDA decreased rapidly upon the addition of 10-7 mol/L celastrol. Cd2+ increased the expression of p-PI3K protein, and the levels of p-PI3K protein and p-AKT protein were inhibited by the addition of celastrol (10‒7 mol/L, 10‒6 mol/L), thus preventing cell apoptosis. In conclusion, celastrol inhibits Cd2+ induced microglial cytotoxicity and plays a neuroprotective role.

Assembly of Celastrol to Zeolitic Imidazolate Framework-8 by Coordination as a Novel Drug Delivery Strategy for Cancer Therapy.

Celastrol (Cel), a compound derived from traditional Chinese medicine Tripterygium wilfordii Hook. F, has attracted considerable attention as an anticancer drug. However, its clinical application is limited due to its low bioavailability and potential toxicity. With the advancement of nanoscale metal organic frameworks (MOF), the nano-delivery of drugs can effectively improve those disadvantages. Nevertheless, hydrophobic drugs apparently cannot be encapsulated by the hydrophilic channels of MOF-based drug delivery systems. To address these issues, a new assembly strategy for hydrophobic Cel was developed by coordinating the deprotonated Cel to zeolitic imidazolate framework-8 (ZIF-8) with the assistance of triethylamine (Cel-ZIF-8). This strategy greatly elevates the assembly efficiency of Cel from less than 1% to ca. 80%. The resulted Cel-ZIF-8 remains stable in the physiological condition while dissociating and releasing Cel after a 45-minute incubation in an acidic tumor microenvironment (pH 5.5). Furthermore, Cel-ZIF-8 is proved to be easily taken up by cancer cells and exhibits a better therapeutic effect on tumor cells than free Cel. Overall, the Cel-ZIF-8 provides a novel assembly strategy for hydrophobic drugs, and the findings are envisaged to facilitate the application of Cel in cancer therapies.

U1 snRNP proteins promote proximal alternative polyadenylation sites by directly interacting with 3' end processing core factors.

In eukaryotic cells, both alternative splicing and alternative polyadenylation (APA) play essential roles in the gene regulation network. U1 small ribonucleoprotein particle (U1 snRNP) is a major component of spliceosome, and U1 snRNP complex can suppress proximal APA sites through crosstalking with 3' end processing factors. However, here we show that both knockdown and overexpression of SNRPA, SNRPC, SNRNP70, and SNRPD2, the U1 snRNP proteins, promote the usage of proximal APA sites at the transcriptome level. SNRNP70 can drive the phase transition of PABPN1 from droplet to aggregate, which may reduce the repressive effects of PABPN1 on the proximal APA sites. Additionally, SNRNP70 can also promote the proximal APA sites by recruiting CPSF6, suggesting that the function of CPSF6 on APA is related with other RNA-binding proteins and cell context-dependent. Consequently, these results reveal that, on the contrary to U1 snRNP complex, the free proteins of U1 snRNP complex can promote proximal APA sites through the interaction with 3' end processing machinery.

Nuclear m6 A reader YTHDC1 suppresses proximal alternative polyadenylation sites by interfering with the 3' processing machinery.

N6-methyladenosine (m6 A) and alternative polyadenylation (APA) are important regulators of gene expression in eukaryotes. Recently, it was found that m6 A is closely related to APA. However, the molecular mechanism of this new APA regulation remains elusive. Here, we show that YTHDC1, a nuclear m6 A reader, can suppress proximal APA sites and produce longer 3' UTR transcripts by binding to their upstream m6 A sites. YTHDC1 can directly interact with the 3' end processing factor FIP1L1 and interfere with its ability to recruit CPSF4. Binding to the m6 A sites can promote liquid-liquid phase separation of YTHDC1 and FIP1L1, which may play an important role in their interaction and APA regulation. Collectively, YTHDC1 as an m6 A "reader" links m6 A modification with pre-mRNA 3' end processing, providing a new mechanism for APA regulation.