Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is the main pathogen that causes COVID-19,which is fast-mutating and highly transmissible.The infection has led to a global epidemic.As the main preventive and control measure,vaccination plays a critical role in fighting a-gainst COVID-19.Although a large number of epitope-based and mucosal vaccines have been stud-ied,few peptide epitope vaccines targeting the mucosa and their functional evaluation have been re-ported.In this study,we used SARS-CoV-2 structural protein M peptide epitope predicted by the IEDB database as an antigenic target to design the MS-3S gene containing 3 050 and 1 229 signal peptides and DCpep optimized for insertion into MS2 phage coat proteins.The expression plasmid pSIP:MS-3S was constructed by cloning the PCR fragments seamlessly and was transformed into Lactiplantibacillus plantarum 18 to obtain the recombinant bacterium LP18:MS-3S.Expression conditions such as induction time,inducer concentration,rotational speed and initial pH were opti-mized.The intranasal immunization experiments were performed to examine the vaccine efficacy.The results showed that the 916 bp-long target gene MS-3S modified and optimized was amplified and used to successfully construct the recombinant bacterial strain LP18:MS-3S.The optimal con-ditions for recombinant protein expression were obtained and verified by Western blot,flow cy-tometry,immunofluorescence and other detection methods.The optimal expression conditions were determined as follows:induction time was 4 h with 100 pg/L of SppIP as the optimal induction concentration.Antibody-specific for the epitope was verified by ELISA experiments in serum,alve-olar lavage fluid and fecal dilutions of mice.In summary,a recombinant bacterial strain expressing the epitope antigen of the SARS-CoV-2 M protein peptide was constructed.The obtained protein can induce the body to produce humoral and mucosal immunity,which lays the foundation for the development of a vaccine candidate for the mucosal immunity of COVID-19.

Renal fibrosis, especially tubulointerstitial fibrosis, is the most common pathway of all chronic kidney diseases progressing to end-stage renal diseases. Several adaptive reactions occur in renal tubular epithelial cells after chronic injury, such as changes in glycolipid metabolism, unfolded protein response, autophagy and senescence, epithelial-to-mesenchymal transition and G2/M cell cycle arrest. Maladaptive repair mechanisms can induce tubulointerstitial fibrosis. This article will discuss the molecular mechanism of these adaptive responses of renal tubular epithelial cells driving renal tubulointerstitial fibrosis, and provide a basis for exploring new drug targets for renal tubulointerstitial fibrosis.

ObjectiveTo investigate whether menaquinone-4 （MK-4） can exert a protective effect against carbon tetrachloride （CCl₄）-induced acute liver injury （ALI） in mice by alleviating ferroptosis. MethodsAfter adaptive feeding， adult male ICR mice， aged 8 weeks， were divided into Control group， MK-4 group， CCl₄ model group （6-hour， 12-hour， and 24-hour）， and MK-4+CCl₄ group （6-hour， 12-hour， and 24-hour）， with 6 mice in each group. The mice in the Control group were given intraperitoneal injection of an equal dose of corn oil； the mice in the MK-4 group were given intraperitoneal injection of 40 mg/kg MK-4 solution， followed by an equal dose of corn oil after 1 hour； the mice in the MK-4+CCl₄ group （6-hour， 12-hour， and 24-hour） were given intraperitoneal injection of 40 mg/kg MK-4 solution， and after 1 hour， the mice in this group and the CCl₄ model group （6-hour， 12-hour， and 24-hour） were given intraperitoneal injection of 0.3 mL/kg CCl₄ solution， with samples collected at 6， 12， and 24 hours. HE staining was used to observe the pathological changes of mouse liver； Prussian blue staining was used to observe iron accumulation in liver tissue； a biochemical analyzer was used to measure the serum levels of aspartate aminotransferase （AST） and alanine aminotransferase （ALT）； related kits were used to measure the levels of tissue iron content and the oxidative stress indices malondialdehyde （MDA） and glutathione （GSH） in liver homogenate； RT-PCR was used to measure the expression levels of ferroptosis marker genes （acyl-CoA synthetase long-chain family member 4 ［ACSL4］， prostaglandin-endoperoxide synthase 2 ［PTGS2］， and glutathione peroxidase 4 ［GPX4］） and iron metabolism-related genes （hemojuvelin ［HJV］， transferrin receptor 1 ［TFR1］， and ferroportin ［FPN］）， and Western blot was used to measure the protein expression level of GPX4. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsIn the aging study， compared with the Control group， the CCl₄ model group （6-hour， 12-hour， and 24-hour） had significant increases in liver weight coefficient and the serum levels of ALT and AST （all P<0.05）， and HE staining also showed that liver injury gradually aggravated over time. Meanwhile， compared with the CCl₄ model group （6-hour， 12-hour， and 24-hour）， the MK-4+CCl₄ （12-hour） group had significant reductions in liver weight coefficient and the serum levels of ALT and AST （all P<0.05）， with a reduction in the necrotic area of liver tissue， and therefore， 12-hour mouse tissue samples were used for detection in the following study. Compared with the Control group， the CCl₄ group had a significant increase in MDA and a significant reduction in GSH （both P<0.05）， and compared with the CCl₄ group， the MK-4+CCl₄ group had a significant reduction in MDA and a significant increase in GSH （both P<0.05）. Compared with the Control group， the CCl₄ group had significant increases in the key ferroptosis indices ASCL4 and PTGS2 and a significant reduction in GPX4 （all P<0.05）； compared with the CCl₄ group， the MK-4+CCl₄ group had significant reductions in the mRNA expression levels of ASCL4 and PTGS2 and a significant increase in the mRNA expression level of GPX4 （all P<0.05）. Western blotting showed that compared with the Control group， the CCl₄ group had a significant reduction in the protein expression level of GPX4 （P<0.05）， and compared with the CCl₄ group， the MK-4+CCl₄ group had a significant increase in the protein expression level of GPX4 （P<0.05）. Prussian blue staining showed that compared with the Control group， the CCl₄ group had a significant increase in iron accumulation； after MK-4 intervention， compared with the CCl₄ group， the MK-4+CCl₄ group had a significant reduction in iron accumulation. As for the measurement of iron metabolism genes in mouse liver， compared with the Control group， the CCl₄ group had a significant increase in iron content， significant reductions in the mRNA expression levels of FPN and HJV， and a significant increase in the mRNA expression level of TFR1 （all P<0.05）； after protection with MK-4， there was a significant reduction in iron content， significant increases in the mRNA expression levels of FPN and HJV， and a significant reduction in the mRNA expression level of TFR1 （all P<0.05）. ConclusionMK-4 intervention in advance can alleviate CCl₄-induced ALI in mice， possibly by inhibiting ferroptosis and improving the expression of iron metabolism-related genes in mouse liver.

Objective To investigate the mechanism of bis(2-ethylhexyl)phthalate(DEHP)in inducing cholestasis and liver injury in mice.Methods In the in vivo experiment,adult female ICR mice were randomly divided into control group(corn oil)and DEHP group(200 mg/kg/d),and a model of cholestasis was established by intragastric administration for 4 weeks.After blood and liver tissue samples were collected from all mice,a biochemical analyzer was used to measure the level of total bile acid(TBA)in serum and the liver,and a microplate reader was used to measure alkaline phosphatase(ALP)and gamma-glutamyl transpeptidase(GGT);HE staining was used to observe the pathological changes of the liver;RT-PCR was used to measure the mRNA expression levels of the inflammatory factors interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-α(TNF-α)in the liver;liquid chromatography/triple quadrupole mass spectrometry was used to measure the bile acid profile in the liver of mice.In the in vitro experiment,AML-12 mouse hepatocytes were cultured and treated with DEHP(250 μmol/L),DCA(125 μmol/L),and CDCA(125 μmol/L)for 24 hours,and RT-PCR was used to measure the mRNA expression levels of the inflammatory cytokines IL-1β,IL-6,and TNF-α.The independent-samples t test was used for comparison of continuous data between two groups;a one-way analysis of variance was used for comparison between multiple groups,and the LSD-t test was used for further comparison between two groups.Results The in vivo experiment showed that compared with the control group,the DEHP group had significant increases in the serum levels of TBA,ALP,and GGT and the level of TBA in the liver(the t values are respectively-4.396,-5.109,-8.504,-3.792 and-7.974,all P<0.05,).Compared with the control group,the DEHP group had significant increases in cholic acid,chenodeoxycholic acid,taurocholic acid,deoxycholic acid,and ursodeoxycholic acid(the t values are respectively-2.802,-3.177,-2.633,-2.874 and-2.311,all P<0.05).HE staining of the liver showed that the mice in the DEHP group had enlargement of the portal area,bile duct deformation,inflammatory cell infiltration around the bile duct,and significant increases in the mRNA expression levels of the inflammatory factors IL-1β,IL-6,and TNF-α in the liver(the t values are respectively-2.539,-2.823 and-4.636,all P<0.05).The in vitro experiment showed that the actual difference in hepatocyte viability after 0-1 000 μmol/L DEHP treatment does not exceed 15%,but there were significant increases in the mRNA expression levels of the inflammatory cytokines IL-1β,IL-6,and TNF-α after treatment with DEHP at different concentrations of 125 μmol/L,250 μmol/L,and 500 μmol/L(all P<0.05).Compared with DEHP stimulation alone,the combined stimulation of CDCA and DEHP upregulates the cytokine in hepatocyte IL-1β mRNA levels(P<0.01);the combined stimulation of DCA and DEHP can significantly increase the cytokine in hepatocyte IL-1β and IL-6 mRNA levels(all P<0.01).Conclusion DEHP exposure can cause cholestasis and induce liver inflammation in mice,possibly by promoting the production of toxic bile acids and the secretion of inflammatory factors.

Objective:To investigate the influence of prenatal stressful life event (SLE) exposure on child emotional and behavioral problem at age 2-6 years and identify the most risk exposure period.Methods:A total of 2 524 mother-child pairs were selected from Shanghai Maternal-Child Pairs Cohort based on pregnant women form 2016 to 2018 in Shanghai. Prenatal SLE exposure was assessed by Life Events Scale for Pregnant Women Questionnaire during the first and third trimester of pregnancy. Child emotional and behavioral problem was evaluated by Strengths and Difficulties Questionnaire at age 2-6 years. Multivariate binary logistic regression model and generalized estimating equation were conducted to quantify the association between prenatal SLE exposure and child emotional and behavioral problem at age 2-6 years, and identify the pregnancy period with strongest adverse effect.Results:The 2 524 mother-child pairs were divided into 4 groups: group with consistent low exposure to SLE (61.8%), group with high exposure to SLE in the first trimester (13.2%), group with high exposure to SLE in the third trimester (13.2%) and group with consistent high exposure to SLE (11.8%). The detection rates of emotional problem, hyperactivity, peer interaction problem and total difficulty score in children aged 3-6 years were highest in the group with consistent high exposure to SLE. Generalized estimating equation analysis showed that after controlling the confounding factors, compared with the consistent low exposure group, the children in the group with high exposure to SLE in the first trimester had significant increased risk for conduct problem at age 2-6 years (a OR=1.41, 95% CI:1.07-1.87). The children in the group with consistent high exposure to SLE were at increased risk for emotional problem, peer interaction problem, and high total difficulty score with the a OR of 1.41 (95% CI: 1.09-1.83), 1.46 (95% CI: 1.15-1.86) and 1.51(95% CI: 1.17-1.93). Conclusion:These findings indicated that prenatal exposure to SLE have adverse effect on child emotional and behavioral problem at age 2-6 years, especially the exposure in the first trimester.

Precise orchestration of cell fate determination underlies the success of scaffold-based skeletal regeneration.Despite extensive studies on mineralized parenchymal tissue rebuilding,regenerating and maintaining undifferentiated mesenchyme within calvarial bone remain very challenging with limited advances yet.Current knowledge has evidenced the indispensability of rebuilding suture mesenchymal stem cell niches to avoid severe brain or even systematic damage.But to date,the absence of promising therapeutic biomaterials/scaffolds remains.The reason lies in the shortage of fundamental knowledge and methodological evidence to understand the cellular fate regulations of scaffolds.To address these issues,in this study,we systematically investigated the cellular fate determinations and transcriptomic mechanisms by distinct types of commonly used calvarial scaffolds.Our data elucidated the natural processes without scaffold transplantation and demonstrated how different scaffolds altered in vivo cellular responses.A feasible scaffold,polylactic acid electrospinning membrane(PLA),was next identified to precisely control mesenchymal ingrowth and self-renewal to rebuild non-osteogenic suture-like tissue at the defect center,meanwhile supporting proper osteointegration with defect bony edges.Especially,transcriptome analysis and cellular mechanisms underlying the well-orchestrated cell fate determination of PLA were deciphered.This study for the first time cellularly decoded the fate regulations of scaffolds in suture-bony composite defect healing,offering clinicians potential choices for regenerating such complicated injuries.

Phytoremediation plays an important role in the treatment of heavy metal pollution in soil. In order to elucidate the mechanism of salicylic acid (SA) on copper absorption, seedlings from Xuzhou (with strong Cu-tolerance) and Weifang Helianthus tuberosus cultivars (with weak Cu-tolerance) were selected for pot culture experiments. 1 mmol/L SA was sprayed upon 300 mg/kg soil copper stress, and the photosynthesis, leaf antioxidant system, several essential mineral nutrients and the changes of root upon copper stress were analyzed to explore the mechanism of copper resistance. The results showed that Pn, Tr, Gs and Ci upon copper stress decreased significantly compared to the control group. Meanwhile, chlorophyll a, chlorophyll b and carotenoid decreased with significant increase in initial fluorescence (F₀), maximum photochemical quantum yield of PSⅡ (Fv/Fm), electron transfer rate (ETR) and photochemical quenching coefficient (qP) content all decreased. The ascorbic acid (AsA) content was decreased, the glutathione (GSH) value was increased, the superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity in the leaves were decreased, and the peroxidase (POD) activity was significantly increased. SA increased the Cu content in the ground and root system, and weakened the nutrient uptake capacity of K, Ca, Mg, and Zn in the root stem and leaves. Spray of exogenous SA can maintain the opening of leaf stomata, improve the adverse effect of copper on photosynthetic pigment and PSⅡ reaction center. Mediating the SOD and APX activity started the AsA-GSH cycle process, effectively regulated the antioxidant enzyme system in chrysanthemum taro, significantly reduced the copper content of all parts of the plant, and improved the ion exchange capacity in the body. External SA increased the content of the negative electric group on the root by changing the proportion of components in the root, promoted the absorption of mineral nutrient elements and the accumulation of osmoregulatory substances, strengthened the fixation effect of the root on metal copper, and avoided its massive accumulation in the H. tuberosus body, so as to alleviate the inhibitory effect of copper on plant growth. The study revealed the physiological regulation of SA upon copper stress, and provided a theoretical basis for planting H. tuberosus to repair soil copper pollution.
Antioxidants ; Copper ; Helianthus/metabolism* ; Salicylic Acid/pharmacology* ; Chlorophyll A/pharmacology* ; Spectroscopy, Fourier Transform Infrared ; Chlorophyll/pharmacology* ; Ascorbic Acid ; Superoxide Dismutase/metabolism* ; Photosynthesis ; Glutathione ; Plant Leaves ; Stress, Physiological ; Seedlings

Objective : High performance liquid chromatography⁃mass spectrometry (LC⁃MS/MS) system was used to accurately determine 22 bile acids in serum , liver, amniotic fluid and placenta of pregnant mice , and a LC⁃MS/ MS method was established for efficient detection and analysis of bile acids in serum , liver, amniotic fluid and placenta of mice. Methods : Pregnant mice serum , liver, amniotic fluid and placenta samples were processed , with 0. 1% glacial acetic acid in 4 mmol/L ammonium acetate aqueous solution as mobile phase A and pure methanol as mobile phase B , the flow rate was 0. 4 ml/min , a gradient elution program was used to elute with Phenomenex Gemini 3 μm NX⁃C18 110A ( 100 mm × 2. 0 mm) chromatographic column elution , and mass spectrometry detection system used an electrospray ion source for negative ion multiple reaction monitoring. Results : The linear relationship of 22 bile acids in the quantitative range was good. The RSD of inter⁃day and intra⁃day precision at low , medium and high concentrations was 0. 5% - 7. 4% , the matrix effect was 88% - 110% , and the extraction recovery was 84% - 108% . Conclusion In this experiment , LC⁃MS/MS was established to detect 22 bile acids in serum , liver, amniotic fluid and placenta of pregnant mice. The method not only has high sensitivity and selectivity , but also can stably detect a large number of samples.

Objective:To analyze the clinicopathological features of de novo early colorectal cancer and to evaluate the efficacy of endoscopic treatment.Methods:Patients with de novo early colorectal cancer who underwent endoscopic resection in Beijing Friendship Hospital, Capital Medical University from June 2020 to May 2022 were enrolled. The baseline data, endoscopic manifestations, treatment methods, postoperative pathological results and prognosis of the patients were collected retrospectively.Results:A total of 33 patients with de novo early colorectal cancer were enrolled with the age of 62.67 ± 8.62 years, and the male to female ratio was 7.25∶1. The long diameter of lesions was 0.96 ± 0.36 cm. The lesion morphology was mainly superficial phenotype (type 0-Ⅱ), accounting for 72.7% (24/33). Endoscopic submucosal dissection (ESD) was performed in 29 cases and endoscopic mucosal resection (EMR) was performed in 4 cases. Postoperative pathology showed that 11 cases (33.3%) were well differentiated tubular adenocarcinoma, of which the superficial submucosal layer was invaded in 2 cases. Twenty cases (60.6%) were moderately differentiated tubular adenocarcinoma, of which the superficial submucosa layer was invaded in 5 cases and the deep submucosa layer in 15 cases. Two cases (6.1%) were moderately-poorly differentiated tubular adenocarcinoma, where the deep submucosa layer was invaded in both. There was significant correlation between the depth of invasion and the degree of differentiation ( P<0.001), and moderately and moderately-poorly differentiated lesions were more likely to invade the deep submucosa layer. The en bloc resection rate was 100.0% (33/33), the complete resection rate was 97.0% (32/33), and the curative resection rate was 42.4% (14/33). Among the 19 patients who did not achieve curative resection, 13 patients received supplementary surgical treatment. No tumor residue or lymph node metastasis was found in the postoperative pathology. All patients were followed up for 3-25 months, and no signs of local recurrence or metastasis were found. Conclusion:Most de novo early colorectal cancers are superficial phenotype under endoscopy. The pathology is mainly moderately differentiated tubular adenocarcinoma. Endoscopic resection of de novo early colorectal cancer shows encouraging short-term efficacy.

Glioblastoma (GBM) therapy is severely impaired by the blood-brain barrier (BBB) and invasive tumor growth in the central nervous system. To improve GBM therapy, we herein presented a dual-targeting nanotheranostic for second near-infrared (NIR-II) fluorescence imaging-guided photo-immunotherapy. Firstly, a NIR-Ⅱ fluorophore MRP bearing donor-acceptor-donor (D-A-D) backbone was synthesized. Then, the prodrug nanotheranostics were prepared by self-assembling MRP with a prodrug of JQ1 (JPC) and T7 ligand-modified PEG_5k-DSPE. T7 can cross the BBB for tumor-targeted delivery of JPC and MRP. JQ1 could be restored from JPC at the tumor site for suppressing interferon gamma-inducible programmed death ligand 1 expression in the tumor cells. MRP could generate NIR-II fluorescence to navigate 808 nm laser, induce a photothermal effect to trigger in-situ antigen release at the tumor site, and ultimately elicit antitumor immunogenicity. Photo-immunotherapy with JPC and MRP dual-loaded nanoparticles remarkably inhibited GBM tumor growth in vivo. The dual-targeting nanotheranostic might represent a novel nanoplatform for precise photo-immunotherapy of GBM.