Mouse Tissues Research Articles

Novel 99mTc-Labeled Mannose Derivative as a Highly Promising Single Photon Emission Computed Tomography Probe for Tumor Imaging.

18F-2-fluoro-2-deoxy-d-glucose ([18F]FDG) has been the most used positron emission tomography imaging agent for clinical applications. Single photon emission computed tomography (SPECT) imaging is cheaper and used more widely for diagnostic use, but there is no SPECT tumor imaging agent for clinical applications comparable to [18F]FDG. Mannose is a C2 epimer of glucose and can also be transported into tumor cells via glucose transporters (GLUTs). To develop a novel SPECT tumor imaging agent with satisfactory tumor uptake and tumor/nontarget ratios, here a mannose derivative (CN7DM) was synthesized and radiolabeled with technetium-99m to prepare [99mTc]Tc-CN7DM. The six-coordinated structure of [99mTc]Tc-CN7DM was confirmed by the corresponding rhenium compound (Re-CN7DM). [99mTc]Tc-CN7DM was transported into cancer cells via GLUTs and may be trapped in the cancer cells by electrostatic attraction. The probe exhibited high uptake in tumors and low uptake in nontarget tissues in mice bearing different tumors, indicating that [99mTc]Tc-CN7DM exhibited promising potential for SPECT tumor imaging and warranted further clinical investigation.

Regulation of targeted blocking cannabinoid receptor 1 on spleen immune function and inflammatory response in mice under chronic intermittent hypoxia

Objective: To observe the effects of targeting and blocking cannabinoid receptor 1 (CB1R) on mouse spleen immune function and inflammatory response under chronic intermittent hypoxia (CIH) conditions, and to explore its regulatory effort. Methods: Forty SPF male C57BL/6 mice aged 4 to 5 weeks,from May 2021 to August 2021 in Experimental Animal Center of the Second Hospital of Shanxi Medical University, were randomly divided into normal oxygen control group (NC), 6-week CIH group (6w CIH), 10-week CIH group (10w CIH), 6-week CIH+CB1R group (6w CIH+AM251) and 10-week CIH+CB1R group (10w CIH+AM251) according to the method of random number table. The advanced programmable intermittent low oxygen chamber was used to prepare the CIH mouse model. The morphological structure of spleen tissue of CIH mice was stained by hematoxylin-eosin (HE) staining. The expression levels of M1 and M2 macrophage surface markers CD86, CD206 were determined by immunofluorescence. The mRNA expression levels of CB1R, CD86, CD206 and the relative expression levels of RORγt and Foxp3,which are characteristic transcriptional regulators of T helper 17(Th17) and Treg cells were detected by quantitative reverse transcriptase PCR(qRT-PCR). The expression of inflammatory factors IL-6 and IL-10 was determined by ELISA. SPSS 26.0 and Graphpad prism 8.3 were used to analyze the data. Results: (1) Compared with NC group, spleen tissue structure was disordered, fibrous tissue hyperplasia, lymphocyte proliferation and disordered arrangement in periarteriole lymphatic sheath in CIH group. The expression of CB1R in CIH group was higher than that in NC group (P<0.05), and with the prolongation of CIH time, the expression of 10w CIH group was higher than that in 6w CIH group(P<0.05). The expression of CB1R in CIH+AM251 group was lower than that in the corresponding CIH group(all P<0.05). (2) Compared with NC group, the expression level of CD86 in macrophages in CIH group was higher than that in NC group(all P<0.05). The relative expression of RORγt in 6w and 10w CIH groups was 0.76±0.03 and 0.91±0.04, respectively, which was higher than that in NC group (0.65±0.06)(all P<0.05). The relative expression levels of inflammatory factor IL-6 were 10.80±1.73 and 14.86±0.01, respectively, which were higher than 6.69±0.23 in the NC group (all P<0.05). The expression level of CD206 in macrophages in the CIH+AM251 group was higher than that in the CIH group(all P<0.05). The relative expression levels of Foxp3 in 6w and 10w CIH+AM251 groups were 0.62±0.05 and 0.32±0.21, respectively, which were higher than those in 6w CIH group (0.28±0.02) and 10w CIH group (0.02±0.01)(P<0.05). The relative expression levels of anti-inflammatory factor IL-10 were 668.45±15.71 and 379.15±56.84, respectively, which were higher than those in CIH group (all P<0.05). Conclusion: Targeted sealing of CB1R may alleviate inflammatory response of mouse spleen under CIH conditions by regulating macrophage polarization and the expression of inflammatory factors, and may have some protective effect.

Development of a Lipid-encapsulated TGFβRI-siRNA Drug for Liver Fibrosis Induced by Schistosoma mansoni.

Schistosoma mansoni infection leads to chronic schistosomiasis and severe hepatic fibrosis. We designed a liver-targeted lipid nanoparticle (LNP) carrying siRNA against type I TGF-β receptor (TGFβRI) mRNA to treat schistosomiasis-induced liver fibrosis in BALB/c mice. Knockdown of TGFβRI by LNP-siTGFβRI reduced LX-2 cell activation in vitro and alleviated liver fibrosis in S. mansoni-infected mice. αSMA and Col1a1 fibrotic markers in the liver tissues of infected mice were significantly suppressed in the treatment groups. In the serum of the LNP-siTGFβRI-treated groups, cytokines IFNγ, IL-1α, IL-6, IL-12, RANTES (CCL5), and TNFα increased, while GM-CSF, IL-2, IL-4, IL-10, IL-13, and KC (CXCL1) decreased compared to the control. Cell proportions were significantly altered in S. mansoni-infected mice, with increased CD56d NK cells and decreased CD19+ B cells and CD4+ T cells compared to naïve mice. Following LNP-siTGFβRI treatment, CD56d NK cells were downregulated, while B and memory Th cell populations were upregulated. The density of fibrotic regions significantly decreased with LNP-siTGFβRI treatment in a dose-dependent manner, and no systemic toxicity was observed in the major organs. This targeted siRNA delivery strategy effectively reduced granulomatous lesions in schistosomiasis-induced liver fibrosis without detectable side effects.

Intermedin Alleviates Diabetic Cardiomyopathy by Up-Regulating CPT-1β through Activation of the Phosphatidyl Inositol 3 Kinase/Protein Kinase B Signaling Pathway.

Diabetic cardiomyopathy (DCM), one of the most serious long-term consequences of diabetes, is closely associated with myocardial fatty acid metabolism. Carnitine palmitoyltransferase-1β (CPT-1β) is the rate-limiting enzyme responsible for β-oxidation of long-chain fatty acids. Intermedin (IMD) is a pivotal bioactive small molecule peptide, participating in the protection of various cardiovascular diseases. However, the role and underlying mechanisms of IMD in DCM are still unclear. In this study, we investigated whether IMD alleviates DCM via regulating CPT-1β. A rat DCM model was established by having rats to drink fructose water for 12 weeks. A mouse DCM model was induced by feeding mice a high-fat diet for 16 weeks. We showed that IMD and its receptor complexes levels were significantly down-regulated in the cardiac tissues of DCM rats and mice. Reduced expression of IMD was also observed in neonatal rat cardiomyocytes treated with palmitic acid (PA, 300 μM) in vitro. Exogenous and endogenous IMD mitigated cardiac hypertrophy, fibrosis, dysfunction, and lipid accumulation in DCM rats and IMD-transgenic DCM mice, whereas knockout of IMD worsened these pathological processes in IMD-knockout DCM mice. In vitro, IMD alleviated PA-induced cardiomyocyte hypertrophy and cardiac fibroblast activation. We found that CPT-1β enzyme activity, mRNA and protein levels, and acetyl-CoA content were increased in T2DM patients, rats and mice. IMD up-regulated the CPT-1β levels and acetyl-CoA content in T2DM rats and mice. Knockdown of CPT-1β blocked the effects of IMD on increasing acetyl-CoA content and on inhibiting cardiomyocyte hypertrophy and cardiac fibroblast activation. IMD receptor antagonist IMD17-47 and the phosphatidyl inositol 3 kinase (PI3K)/protein kinase B (Akt) inhibitor LY294002 reversed the effects of IMD on up-regulating CPT-1β and acetyl-CoA expression and on inhibiting cardiomyocyte hypertrophy and cardiac fibroblast activation. We revealed that IMD alleviates DCM by up-regulating CPT-1β via calcitonin receptor-like receptor/receptor activity-modifying protein (CRLR/RAMP) receptor complexes and PI3K/Akt signaling. IMD may serve as a potent therapeutic target for the treatment of DCM.

METTL3 silencing inhibits ferroptosis to suppress ovarian fibrosis in PCOS by upregulating m6A modification of GPX4.

Methyltransferase-like 3 (METTL3) is extensively reported to be involved in organ fibrosis. Ovarian fibrosis is a main characteristic of polycystic ovary syndrome (PCOS). However, the reaction mechanism of METTL3 in PCOS is poorly investigated. This paper was intended to reveal the role and the mechanism of METTL3 in PCOS. Animal and cell models of PCOS were induced by dehydroepiandrosterone (DHEA). H&E staining was performed to detect the pathological alterations in ovary tissues. Masson staining, immunofluorescence, along with western blot measured fibrosis both in vitro and in vivo. To evaluate estrous cycle, vaginal smear was performed. Lipid peroxidation and ferroptosis were evaluated by MDA assay kits, GSH assay kits, immunohistochemistry, Prussian blue staining and western blot. qRT-PCRand western blot were adopted to estimate METTL3 and GPX4 expression. The m6A and hormone secretion levels were respectively assessed by m6A RNA Methylation Quantitative Kit and corresponding kits. The interaction between METTL3 and GPX4 was testified by immunoprecipitation. The fibrosis and ferroptosis were aggravated and m6A and METTL3 expression were increased in ovarian tissues of DHEA-induced PCOS mice. METTL3 silencing alleviated pathological changes, affected hormone secretion level, and repressed fibrosis, lipid peroxidation and ferroptosis in the ovarian tissues of PCOS mice. In vitro, DHEA stimulation increased m6A and METTL3 expression and induced ferroptosis and fibrosis. METTL3 knockdown promoted GPX4 expression in DHEA-induced granulosa cells by m6A modification and restrained DHEA-induced fibrosis, lipid peroxidation and ferroptosis in granulosa cells via elevating GPX4. METTL3 silence inhibited ovarian fibrosis in PCOS, which was mediated through suppressing ferroptosis by upregulating GPX4 in m6A-dependent manner.

Oral food-derived whey protein isolate-Tremella fuciformis polysaccharides pickering emulsions with adhesive ability to delivery magnolol for targeted treatment of ulcerative colitis

Magnolol (Mag) is a promising natural compound with therapeutic potential for ulcerative colitis (UC). Here we designed and fabricated an oral food-grade whey protein isolate-Tremella fuciformis polysaccharides (WPI-TFPS) stabilized pickering emulsions to encapsulate Mag (Mag-WPI-TFPS) for targeted treatment of UC. With the assistance of the WPI-TFPS, pickering emulsions were well encapsulated and formed stable microparticles with a particle size of approximately 9.49 ± 0.047 μm, a 93.63 ± 0.21 % encapsulation efficiency and a loading efficiency of 21.53 ± 0.01 %. In vitro, the formulation exhibited sustained-release properties in simulated colon fluid with a cumulative release rate of 60.78 % at 48 h. In vivo, the Mag-WPI-TFPS specifically accumulated in the colon tissue for 24 h with stronger fluorescence intensity, which demonstrated that TFPS and WPI had a good adherence ability to inflamed mucosa by electrostatic attraction and ligand-receptor interactions. As expected, compared with Free-Mag, the oral administration of Mag-WPI-TFPS remarkably alleviated the symptoms of UC and protected the colon tissue in DSS-induced UC mice. More importantly, WPI-TFPS enhanced gut microbiota balance by increasing the diversity and relative abundances of Lactobacillaceae and Firmicutes. Overall, this study presents a convenient, eco-friendly, food-derived oral formulation with potential as a dietary supplement for targeted UC treatment.

Hypothalamic SLC7A14 accounts for aging-reduced lipolysis in white adipose tissue of male mice

The central nervous system has been implicated in the age-induced reduction in adipose tissue lipolysis. However, the underlying mechanisms remain unclear. Here, we show the expression of SLC7A14 is reduced in proopiomelanocortin (POMC) neurons of aged mice. Overexpression of SLC7A14 in POMC neurons alleviates the aging-reduced lipolysis, whereas SLC7A14 deletion mimics the age-induced lipolysis impairment. Metabolomics analysis reveals that POMC SLC7A14 increased taurochenodeoxycholic acid (TCDCA) content, which mediates the SLC7A14 knockout- or age-induced WAT lipolysis impairment. Furthermore, SLC7A14-increased TCDCA content is dependent on intestinal apical sodium-dependent bile acid transporter (ASBT), which is regulated by intestinal sympathetic afferent nerves. Finally, SLC7A14 regulates the intestinal sympathetic afferent nerves by inhibiting mTORC1 signaling through inhibiting TSC1 phosphorylation. Collectively, our study suggests the function for central SLC7A14 and an upstream mechanism for the mTORC1 signaling pathway. Moreover, our data provides insights into the brain–gut–adipose tissue crosstalk in age-induced lipolysis impairment.

Total glucosides of paeony inhibit NLRP3/caspase-1/GSDMD-mediated inflammation and pyroptosis in C3H/HeJ alopecia areata mice.

One of the most prominent causes of alopecia areata (AA) is chronic inflammation of the hair follicles. Inhibiting cellular pyroptosis, a form of inflammatory programmed cell death, is crucial for reducing follicular inflammation in the skin. Total glucosides of paeony (TGP) possess anti-inflammatory properties across a broad range of illnesses. However, the role of TGP in AA and its relationship to pyroptosis remains unclear. A chronic unpredictable mild stress (CUMS) approach was used to create an AA mouse model. TGP suspension and MCC950 were administered to AA mice via gavage. HE staining, ELISA, immunohistochemistry, immunofluorescence, RT-qPCR, and Western blotting were performed to detect pathological changes in the skin and to investigate the levels of inflammatory factors and pyroptosis-related proteins, as well as the potential mechanisms of TGP's effects. TGP reduced hair loss, increased the number of hair follicles in skin tissues, and decreased inflammatory markers (IL-6, TNF-α, IL-18, and IL-1β) in AA mice. MCC950 significantly reduced the levels of NLRP3/caspase-1/GSDMD-mediated pyroptosis-related proteins (NLRP3, ASC, caspase-1 p10, and GSDMD-N), as well as inflammatory factors. TGP markedly inhibited NLRP3/caspase-1/GSDMD-mediated cellular pyroptosis in a concentration-dependent manner. TGP suppresses the NLRP3/caspase-1/GSDMD signaling cascade in the skin tissues of AA mice, thereby reducing cellular pyroptosis and inflammation. TGP may be a potential therapeutic agent for AA.

Improvement of androgenic alopecia by extracellular vesicles secreted from hyaluronic acid-stimulated induced mesenchymal stem cells

BackgroundAndrogenetic alopecia (AGA) is a common form of hair loss. Androgens, such as testosterone and dihydrotestosterone, are the main causes of AGA. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) can reduce AGA. However, preparing therapeutic doses of MSCs for clinical use is challenging. Induced pluripotent stem cell-derived MSCs (iMSCs) are homogenous and easily expandable, enabling scalable production of EVs. Hyaluronic acid (HA) can exert various functions including free radical scavenging, immune regulation, and cell migration. Herein, we examined whether hyaluronic acid (HA) stimulation of iMSCs could produce EVs with enhanced therapeutic outcomes for AGA.MethodsEVs were collected from iMSCs primed with HA (HA–iMSC–EVs) or without HA (iMSC–EVs). The characteristics of EVs were examined using dynamic light scattering, cryo-transmission electron microscopy, immunoblotting, flow cytometry, and proteomic analysis. In vitro, we compared the potential of EVs in stimulating the survival of hair follicle dermal papilla cells undergoing testosterone-mediated AGA. Additionally, the expression of androgen receptor (AR) and relevant growth factors as well as key proteins of Wnt/β-catenin signaling pathway (β-catenin and phosphorylated GSK3β) was analyzed. Subsequently, AGA was induced in male C57/BL6 mice by testosterone administration, followed by repeated injections of iMSC–EVs, HA–iMSC–EVs, finasteride, or vehicle. Several parameters including hair growth, anagen phase ratio, reactivation of Wnt/β-catenin pathway, and AR expression was examined using qPCR, immunoblotting, and immunofluorescence analysis.ResultsBoth types of EVs showed typical characteristics for EVs, such as size distribution, markers, and surface protein expression. In hair follicle dermal papilla cells, the mRNA levels of AR, TGF-β, and IL-6 increased by testosterone was blocked by HA–iMSC–EVs, which also contributed to the augmented expression of trophic genes related to hair regrowth. However, no notable changes were observed in the iMSC–EVs. Re-activation of Wnt/β-catenin was observed in HA–iMSC–EVs but not in iMSC–EVs, as shown by β-catenin stabilization and an increase in phosphorylated GSK3β. Restoration of hair growth was more significant in HA–iMSC–EVs than in iMSC–EVs, and was comparable to that in mice treated with finasteride. Consistently, the decreased anagen ratio induced by testosterone was reversed by HA–iMSC–EVs, but not by iMSC–EVs. An increased expression of hair follicular β-catenin protein, as well as the reduction of AR was observed in the skin tissue of AGA mice receiving HA–iMSC–EVs, but not in those treated with iMSC–EVs.ConclusionsOur results suggest that HA–iMSC–EVs have potential to improve AGA by regulating growth factors/cytokines and stimulating AR-related Wnt/β-catenin signaling.

The dynamics of the cytokine profile of the lungs and liver of BALB/C male mice infected with the H1N1 subtype avian influenza virus

The increasing number of reported cases of direct transmission of avian influenza viral strains to humans is obviously associated with the threat of a new pandemic and the need for a more detailed study of the pathogenesis of the viral infectious process. The aim of the research was to study the pathogenesis of influenza infection and in particular to establish the role of proinflammatory cytokines in the pathogenesis of the inectious process caused by influenza virus subtype A/WSN/1/33(H1N1). The experiment involved 21 male BALB/c mice aged 4-6 weeks weighing 16-18 g, which16were infected intranasally with influenza A/WSN/1/33(H1N1) virus under ether anesthesia by inoculation of 50 µl of allantoic fluid containing 10 LD50 of the virus. Histological studies were performed on samples of lung and liver tissues. It was evidenced that infection caused by the highly pathogenic for mice influenza virus A/WSN/1/33(H1N1) initiates the spreading of dystrophic and necrotic processes mainly in the lungs and liver. This can occur due the increase of proinflammatory cytokines leading to the violation of the circulatory system triggered by the active reproduction of the virus and toxic manifestations on behalf of cellular immunity. Structural changes in the lung and liver tissues of mice experimentally infected with the influenza A/WSN/1/33(H1N1) virus indicated the presence of a large amount of the virus at all stages of the experiment that requires further research.

Omega 3 Fatty Acids Attenuate the Acute Kidney Injury to CKD Transition and Renal Fibrosis: Identification of Antifibrotic Metabolites.

AKI is an established risk factor for developing CKD. Recently, the renoprotective effect of omega-3 polyunsaturated fatty acids (ω3PUFAs) has attracted attention. This study aimed to evaluate the effect of ω3PUFAs on the transition of AKI to CKD, and to identify fatty acid active metabolites in renal tissue. Two mice models of AKI to CKD (7-week, male) and unilateral ureteral obstruction (UUO)-induced renal fibrosis (11-week, male) were fed linseed oil, rich in ω3PUFAs (Lin group), or with soybean oil, low in ω3PUFAs (Soy group). Renal fatty acids and metabolites composition in mice were measured by liquid chromatography-mass spectrometry. Rat renal fibroblast cells (NRK-49F cells) were used for in vitro study. At day 14 after 35 min bilateral renal ischemia reperfusion (IR), significant increase in survival was observed in the Lin group compared to the Soy group. Using the 30 min bilateral renal IR model (AKI to CKD model), the Lin group showed attenuated renal tissue damage and fibrosis. In addition, the antifibrotic effect of Lin group was also observed in UUO renal fibrosis model. In the two mice models, levels of eicosapentaenoic acid (EPA) and its metabolites were significantly elevated in renal tissue of mice fed with Lin. Cultured NRK-49F incubated with EPA and its metabolites 18-hydroxyeicosapentaenoic acid (18-HEPE), 17,18-epoxyeicosatetraenoic acid (17,18-EpETE) and 17,18-dihydroxyeicosatetraenoic acid (17,18-diHETE) displayed suppressed TGF-β1-stimulated α-smooth muscle actin protein expression. These effects were suppressed in the presence of an inhibitor of a cytochrome P450 involved in EPA metabolism. This observation suggests that the EPA metabolites have antifibrotic effects. ω3PUFAs prevents AKI to CKD and renal fibrosis. Moreover, the EPA metabolites 18-HEPE, 17,18-EpETE and 17,18-diHETE were found to have antifibrotic effects.

Minocycline alleviates lipopolysaccharide-induced cardiotoxicity by suppressing the NLRP3/Caspase-1 signaling pathway.

Minocycline (Min), as an antibiotic, possesses various beneficial properties such as anti-inflammatory, antioxidant, and anti-apoptotic effects. Despite these known qualities, the precise cardioprotective effect and mechanism of Min in protecting against sepsis-induced cardiotoxicity (SIC) remain unspecified. To address this, our study sought to assess the protective effects of Min on the heart. Lipopolysaccharide (LPS) was utilized to establish a cardiotoxicity model both in vivo and in vitro. Min was pretreated in the models. In the in vivo setting, evaluation of heart tissue histopathological injury was performed using hematoxylin and eosin (H&E) staining and TUNEL. Immunohistochemistry (IHC) was employed to evaluate the expression levels of NLRP3 and Caspase-1 in the heart tissue of mice. During in vitro experiments, the viability of H9c2 cells was gauged utilizing the CCK8 assay kit. Intracellular ROS levels in H9c2 cells were quantified using a ROS assay kit. Both in vitro and in vivo settings were subjected to measurement of oxidative stress indexes, encompassing glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) levels. Additionglly, myocardial injury markers like lactate dehydrogenase (LDH) and creatine kinase MB (CK-MB) activity were quantified using appropriate assay kits. Western blotting (WB) analysis was conducted to detect the expression levels of NOD-like receptor protein-3 (NLRP3), caspase-1, IL-18, and IL-1β, alongside apoptosis-related proteins such as Bcl-2 and Bax, and antioxidant proteins including superoxide dismutase-1 (SOD-1) and antioxidant proteins including superoxide dismutase-1 (SOD-2), both in H9c2 cells and mouse heart tissues. In vivo, Min was effective in reducing LPS-induced inflammation in cardiac tissue, preventing cell damage and apoptosis in cardiomyocytes. The levels of LDH and CK-MB were significantly reduced with Min treatment. In vitro studies showed that Min improved the viability of H9C2 cells, reduced apoptosis, and decreased ROS levels in these cells. Further analysis indicated that Min decreased the protein levels of NLRP3, Caspase-1, IL-18, and IL-1β, while increasing the levels of SOD-1 and SOD-2 both in vivo and in vitro. Min alleviates LPS-induced SIC by suppressing the NLRP3/Caspase-1 signalling pathway in vivo and in vitro.

A Chemoselective Enrichment Strategy for In-Depth Coverage of the Methyllysine Proteome.

Proteomics is a powerful method to comprehensively understand cellular posttranslational modifications (PTMs). Owing to low abundance, tryptic peptides with PTMs are usually enriched for enhanced coverage by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Affinity chromatography for phosphoproteomes by metal-oxide and pan-specific antibodies for lysine acetylome allow identification of tens of thousands of modification sites. Lysine methylation is a significant PTM; however, only hundreds of methylation sites were identified by available approaches. Herein we report an aryl diazonium based chemoselective strategy that enables enrichment of monomethyllysine (Kme1) peptides through covalent bonds with extraordinary sensitivity. We identified more than 10000 Kme1 peptides from diverse cell lines and mouse tissues, which implied a wide lysine methylation impact on cellular processes. Furthermore, we found a significant amount of methyl marks that were not S-adenosyl methionine (SAM)-dependent by isotope labeling experiments.

A Chemoselective Enrichment Strategy for In‐Depth Coverage of the Methyllysine Proteome

AbstractProteomics is a powerful method to comprehensively understand cellular posttranslational modifications (PTMs). Owing to low abundance, tryptic peptides with PTMs are usually enriched for enhanced coverage by liquid chromatography‐mass spectrometry/mass spectrometry (LC–MS/MS). Affinity chromatography for phosphoproteomes by metal‐oxide and pan‐specific antibodies for lysine acetylome allow identification of tens of thousands of modification sites. Lysine methylation is a significant PTM; however, only hundreds of methylation sites were identified by available approaches. Herein we report an aryl diazonium based chemoselective strategy that enables enrichment of monomethyllysine (Kme1) peptides through covalent bonds with extraordinary sensitivity. We identified more than 10000 Kme1 peptides from diverse cell lines and mouse tissues, which implied a wide lysine methylation impact on cellular processes. Furthermore, we found a significant amount of methyl marks that were not S‐adenosyl methionine (SAM)‐dependent by isotope labeling experiments.

IL23R-Specific CAR Tregs for the Treatment of Crohn’s Disease

Abstract Background and Aims Regulatory T cells (Tregs) are key regulators in maintaining tissue homeostasis. Disrupted immune homeostasis is associated with Crohn’s disease (CD) pathogenesis. Thus, Treg therapy represents a promising long-acting treatment to restore immune balance in the diseased intestine. Chimeric antigen receptor (CAR) T-cell therapy has revolutionized cancer treatment. This innovative approach also provides the opportunity to improve therapy for CD. By targeting a disease-relevant protein, interleukin-23 receptor (IL23R), we engineered Tregs expressing IL23R-CAR for treating active CD. Methods Intestinal IL23R expression from active CD was verified by immunohistochemical analysis. Phenotypic and functional characteristics of IL23R-CAR Tregs were assessed using in vitro assays and their migration capacity was monitored in a xenograft tumor model. Transcriptomic and proteomic analyses were performed to associate molecular profiles with IL23R-CAR Treg activation against colon biopsy-derived cells from active CD patients. Results Our study showed that IL23R-CAR displayed negligible tonic signaling and a strong signal-to-noise ratio. IL23R-CAR Tregs maintained regulatory phenotype during in vitro expansion, even when chronically exposed to proinflammatory cytokines and target antigen. IL23R engagement on IL23R-CAR Tregs triggered CAR-specific activation and significantly enhanced their suppressive activity. Also, IL23R-CAR Tregs migrated to IL23R-expressing tissue in humanized mice. Finally, IL23R-CAR Tregs elicited a specific activation against colon biopsy-derived cells from active CD, suggesting an efficient CAR engagement in active CD. Molecular profiling of CD patient biopsies also revealed transcriptomic and proteomic patterns associated with IL23R-CAR activation. Conclusions Overall, our results demonstrate that IL23R-CAR Tregs represent a promising therapy for active CD.

Silencing TRIM8 alleviates allergic asthma and suppressing Th2 differentiation through inhibiting NF-κB/NLRP3 signaling pathway

Background and aimAllergic asthma is a primary type of asthma and characterized by T helper 2 (Th2) cells -mediated inflammation. Tripartite motif containing 8 (TRIM8) protein is involved in immunoreaction and inflammatory response in many diseases. However, its role in allergic asthma remains unclear. Medical databank showed that TRIM8 was increased in lung of ovalbumin (OVA)-challenged mice. This study aimed to elucidate the effects of TRIM8 on allergic asthma and Th2 development. MethodsAsthma were induced by OVA challenge in mice, and the adenovirus vector loaded with TRIM8 knockdown sequence was delivered into asthma mice by nasal inhalation. The percentage of Th2 cells in lung was assessed by flow cytometric analysis, and the contents of Th2 cytokines (interleukin (IL)-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) were assessed with ELISA. In vitro Th2 induction was performed in CD4+ cells from mouse spleen, the expression of Th2 molecules (IL-4, IL-5 and GATA binding protein 3 (GATA3)) were measured by real-time PCR. In addition, the nuclear factor-kappa B (NF-κB)/nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain containing 3 (NLRP3) signaling was determined. ResultsTRIM8 was highly expressed in the lung tissues of asthmatic mice and Th2-induced CD4+ cells. OVA challenge-induced Th2 development and Th2 cytokine secretion were restrained by silencing of TRIM8 in vivo. Similarly, the Th2 differentiation in vitro was also suppressed by TRIM8 knockdown. TRIM8 inhibited the NF-κB/NLRP3 activity by blocking transforming growth factor-beta-activated kinase 1 (TAK1), and the effects of TRIM8 were abrogated by overexpression of NLRP3. ConclusionsSilencing TRIM8 relieved the asthmatic injury in mice and excessive Th2 development via inhibiting the NF-κB/NLRP3 pathway. It is indicated that TRIM8 may contribute to the airway inflammation in allergic asthma via activating the NF-κB/NLRP3 signaling pathway. The current study provided a novel potential target for allergic asthma treatment.

Regulation of autophagy by ST3GAL2-mediated α2-3 sialylated glycosphingolipids in hepatic encephalopathy

In neurological diseases, the regulation of autophagy plays a crucial role in their pathology, particularly the relationship between autophagy and hepatic encephalopathy (HE) which merits detailed investigation. Glycosphingolipids are abundant and broadly functional in the nervous system and are closely associated with autophagy. However, the specific link and mechanisms between glycosphingolipids and autophagy in HE remain unclear. This study aims to explore the impact of glycosphingolipid changes on the autophagy in HE and its potential mechanisms. Utilizing lectin microarrays, we observed elevated expression levels of α2-3 sialylated glycosphingolipid in the brain tissue of HBV transgenic mice and ammonia-induced astrocyte models, suggesting that the increase in α2-3 sialylated glycosphingolipid is related to HE. Further research revealed that the increased expression of α2-3 sialylated glycosphingolipid, mediated by ST3GAL2, affects autophagy by regulating the autophagy initiation complex Vps34-Beclin-1. In summary, our research not only comprehensively reveals the changes in brain glycosphingolipid during HBV-related HE but also elucidates the interactions and regulatory mechanisms between α2-3 sialylated glycosphingolipid and autophagy. This study provides a new perspective on understanding the pathogenesis of HE and offers novel theories and targets for future research and treatment strategies.

The highly stabilized biologically derived peptide VIESPPEI alleviates DSS-induced colitis in mice by preventing colonic atrophy and modulating gut microbiota

Ulcerative colitis (UC) is a recurrent gastrointestinal infection within the spectrum of inflammatory bowel disease, posing risks associated with long-term medication. Consequently, this study aimed to investigate the effects of novel duck liver protein-derived bioactive peptides, characterized by a higher safety profile, on dextran sulfate sodium (DSS)-induced colitis in mice. The results indicated that the retention rate of VIESPPEI remained above 80% following simulated gastrointestinal digestion in vitro, demonstrating strong stability and practical application potential. The peptide VIESPPEI was found to alleviate weight loss in colitis-afflicted mice, inhibit the elevation of the disease activity index (DAI), and significantly improve symptoms such as atrophy and shortening of the colon. Histological examination further confirmed that VIESPPEI intake promoted the recovery of acute colitis in mice. Additionally, it significantly reduced myeloperoxidase activity and increased superoxide dismutase and catalase activities in the colon tissues of UC mice. Notably, a substantial increase in beneficial gut microbiota and the populations of three beneficial bacteria species (Anaplasma spp., Tannabacterium spp., and Bifidobacterium spp.) that produce short-chain fatty acids, along with a decrease in pathogenic groups such as Streptococcus and Turicibacter, may account for the improvement in colitis observed in UC mice treated with VIESPPEI. This study provides new evidence that VIESPPEI alleviates UC and provides a theoretical basis for the development of functional peptide beverages.

Establishment and biological characteristics of a human buccal mucosa squamous cell carcinoma cell line SCC117

Objective: To establish a human buccal mucosa squamous cell carcinoma (BMSCC) cell line SCC117 in China, analyze and identify its basic biological characteristics. Methods: A 59-year-old Chinese male patient with BMSCC in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology in January 2011 was included in this study, his surgical specimens were primary cultured in vitro by improved tissue block culture method. The BMSCC cell line SCC117 was established after continuous passage and stable growth. The morphological characteristics of the cells were observed by light and electron microscope, and their basic biological characteristics were analyzed by growth curve, chromosome karyotype and xenotransplantation tumorigenicity in nude mice experiment. The expressions of cytokeratin (CK14), tumor-related proteins retinoblastoma tumor suppressor protein (RB), P53, E-cadherin, P21, phosphatase and tensin homolog deleted on chromosome ten (PTEN) were detected by immunohistochemical and human papilloma virus (HPV) were tested by PCR. SCC117 was identified by short tandem repeat (STR) analysis of genomic DNA. Results: SCC117, a human BMSCC cell line, had been continuously subcultured in vitro for more than 150 generations. The cells grew in polygonal mosaic and lost contact inhibition, the typical desmosomes and tensional fibrils were observed by electron microscope, and CK14 was positive by immunohistochemistry. The doubling time was 40.16 h, the chromosome mode of the cell line was concentrated between 67 and 69, hypo-triploid. All 4 nude mice inoculated with SCC117 cells developed tumors, indicating that the SCC117 cell line had the ability of xenogeneic tumorigenesis. The histopathological type of the transplanted tumor in nude mice was consistent with that of the primary tumor tissue, both of which were squamous cell carcinoma. The immunohistochemical results showed that in both human primary tumor and the transplanted tumor tissue in nude mice, RB, P53, and E-cadherin were all positive, P21 was weakly positive, while PTEN was negative. SCC117 was tested negative for the presence of HPV. STR sequence analysis showed that SCC117 cell line originated from primary tumor tissue and was not cross-contaminated by other cell lines. Conclusions: The human BMSCC cell line SCC117 was successfully established in China, which could provide a new experimental model for the study of oral SCC without HPV infection, especially BMSCC.

New Utilization of Fraxinus mandshurica Leaves: As a Safe and Promising Natural Antioxidant.

In this paper, an in-depth study on Fraxinus mandshurica (FM) was conducted, focusing on the chemical constituents, in vitro and in vivo antioxidant activities of flavonoids, acute oral toxicity testing, network pharmacology, and molecular docking in the leaves of FM. The in vitro antioxidant results revealed that the total flavonoid extract (TFE), kaempferol, quercetin, and rutin exhibited similar antioxidant activities, with TFE demonstrating significantly better scavenging ability against hydroxyl radical compared to the other flavonoids. Moreover, in vivo antioxidant findings indicated that TFE led to a significant increase in glutathione peroxidase and superoxide dismutase activities along with a decrease in malondialdehyde levels in the liver tissues of mice in an ethanol-induced oxidative stress model, outperforming quercetin. The acute oral toxicity test established 5000 mg/kg of bw as the LD50 for TFE in rats. Through network pharmacological analysis, it was observed that all seven flavonoids in FM exhibited spontaneous binding to their respective key targets, reinforcing their potential antioxidant properties. Consequently, based on the experimental outcomes, TFE appears to be a safe and promising antioxidant source, indicating its potential as a new natural antioxidant resource.