Intervertebral disc degeneration (IDD) is largely attributed to impaired endogenous repair. Nucleus pulposus-derived stem cells (NPSCs) senescence leads to endogenous repair failure. Small extracellular vesicles/exosomes derived from mesenchymal stem cells (mExo) have shown great therapeutic potential in IDD, while whether mExo could alleviate NPSCs senescence and its mechanisms remained unknown. We established a compression-induced NPSCs senescence model and rat IDD models to evaluate the therapeutic efficiency of mExo and investigate the mechanisms. We found that mExo significantly alleviated NPSCs senescence and promoted disc regeneration while knocking down thioredoxin (TXN) impaired the protective effects of mExo. TXN was bound to various endosomal sorting complex required for transport (ESCRT) proteins. Autocrine motility factor receptor (AMFR) mediated TXN K63 ubiquitination to promote the binding of TXN on ESCRT proteins and sorting of TXN into mExo. Knocking down exosomal TXN inhibited the transcriptional activity of nuclear factor erythroid 2-related factor 2 (NRF2) and activator protein 1 (AP-1). NRF2 and AP-1 inhibition reduced endogenous TXN production that was promoted by exosomal TXN. Inhibition of NRF2 in vivo diminished the anti-senescence and regenerative effects of mExo. Conclusively, AMFR-mediated TXN ubiquitination promoted the sorting of TXN into mExo, allowing exosomal TXN to promote endogenous TXN production in NPSCs via TXN/NRF2/AP-1 feed-forward circuit to alleviate NPSCs senescence and disc degeneration.

AIM:To investigate the improvement effect of blood flow-limited resistance training on renal fibro-sis in type 2 diabetes mellitus(T2DM)rats and its potential mechanism to attenuate renal fibrosis by inhibiting the trans-forming growth factor β1(TGF-β1)/Smad3 signaling pathway.METHODS:The T2DM model was prepared by combining a high-fat diet and streptozotocin(STZ),and after successful modeling,the rats were randomly divided into a T2DM con-trol group,a low-load resistance training group,a high-load resistance training group,a blood flow restriction group and a blood flow restriction combined with resistance training group for 8 weeks of exercise.The renal index,fasting blood glu-cose(FBG),serum creatinine(SCr),and blood urea nitrogen(BNU)were recorded in each group.The morphological changes of the kidneys were observed by hematoxylin and eosin(HE)and Masson's trichrome staining,and the collagen volume fraction was calculated.The mRNA expression levels of renal Klotho,TGF-β1,and α-smooth muscle actin(α-SMA)were detected by RT-qPCR.The protein expression levels of renal Klotho,TGF-β1,Smad3,phosphorylated Smad3(p-Smad3),α-SMA and connective tissue growth factor(CTGF)were detected using Western blot.RESULTS:Compared with the other groups,FBG,SCr,BNU,and renal collagen volume fraction were significantly decreased in the blood flow restriction combined with resistance training group of rats(P<0.05),Klotho expression was significantly in-creased(P<0.05),and the expression of TGF-β1,p-Smad3,CTGF and α-SMA was significantly decreased(P<0.05),and there was no significant change in the expression level of Smad3(P>0.05).CONCLUSION:Blood flow restriction combined with resistance training attenuates renal fibrosis in T2DM rats,the mechanism of which may be related to the up-regulation of Klotho expression,disruption of the TGF-β1/Smad3 signaling pathway,and inhibition of the deposition of epi-thelial-mesenchymal transformation.

Objective To evaluate the quality and authenticity of Ophiopogon japonicus in Shengmaiyin,establish ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)for the determination of three characteristic components(methylophiopogonanone A,liriopeside B and liriope muscari baily saponin C),and provide technical support for drug supervision.Methods Samples were analyzed on a Phenomenex Kinetex F5 C18 column(100 mm×3.0 mm,2.6 μm)in a gradient elution mode with 0.1％formic acid water and-0.1％formic acid acetonitrile as the mobile phase at a flow rate of 0.4 mL/min,the column temperature was 30 ℃,and the injection volume was 1 μL.Mass spectrometer detector,electro spray ion source of positive and negative ions,and multi-reaction monitoring mode were used.Results The linear ranges of methylophiopogonanone A,liriopeside B and liriope muscari baily saponin C were 0.016 7-1.666 0,0.039 7-15.872 0 and 0.022 5～8.988 0 ng(r＞0.999 9),respectively.The average recovery rates of these three components were 85.16％,86.95％and 95.07％,respectively,with RSSDs of 2.65％,1.45％and 1.14％(n=6).The content of methylophiopogonanone A in thirty-eight batches was quite different.Seven batches of liriopeside B or liriope muscari baily saponin C were detected.Conclusion The method is simple and sensitive,and suitable for determining of three characteristic components in Shengmaiyin,which provides references for the quality control of Ophiopogon japonicus in Shengmaiyin.

OBJECTIVE To optimize the extraction process and to primarily evaluate the anti-anxiety and anti-depression efficacy of polysaccharide from Baihe dihuang decoction. METHODS Based on Plackett-Burman experimental design， using the comprehensive score of yield and content of polysaccharide as indicators， with extraction time， water amount， alcohol precipitation concentration as factors， Box-Behnken response surface methodology was used to optimize the extraction process of polysaccharide from Baihe dihuang decoction； and the validation test was conducted. Forty ICR mice were divided into control group， venlafaxine group [positive control， 13.5 mg/（kg·d）]， Baihe dihuang polysaccharide high-dose and low-dose groups [5.28， 2.64 g/（kg·d），by raw material]， with 10 mice in each group （half male and half female）. Administration groups were given corresponding drug solution intragastrically， and control group was given water 10 mL/kg intragastrically， once a day， for 7 test， forced swimming test and tail suspension test were used to evaluate the effects of the extract prepared by the optimal process on the anxiety-like and depression-like behavior of mice； enzyme-linked immunosorbent assay was used to detect the effects of the extract on the levels of neurotransmitter in cerebral tissue of mice. RESULTS The optimal extraction process of Baihe dihuang decoction was： the water amount of 25 times， extract time of 1.5 hours， and alcohol precipitation concentration of 70%. In 3 times of validation test， the average yield and content of polysaccharide were 33.10% and 0.62 mg/mg， the relative deviations of which from the predicted values （36.14% and 0.65 mg/mg） were 8.40% and 4.62% respectively （RSD＜2%， n＝3）. The polysaccharide extract of Baihe dihuang decoction could effectively increase the percentages of open-arms entry， the percentages of open-arms time， the total distance of voluntary activities and the activity distance in central area， and significantly shortened the immobility time of forced swimming test and tail suspension test （P＜0.05 or P＜0.01）. The polysaccharide extract could significantly increase the levels of 5-hydroxytryptamine， norepinephrine （except for the Baihe dihuang polysaccharide low-dose group） and gamma-aminobutyric acid in cerebral tissue of mice， while significantly decrease the levels of glutamic acid （except for the Baihe dihuang polysaccharide low-dose group） （P＜0.05 or P＜ 0.01）. CONCLUSIONS The optimized extraction process of polysaccharide from Baihe dihuang decoction is stable and feasible， and the obtained polysaccharide extract has obvious anti-anxiety and anti-depression effect in vivo.

Background Imidacloprid is a neonicotinoid insecticide that is widely used in agricultural production, with a high detection rate in human biological samples. Previous studies have shown a high correlation between imidacloprid exposure and liver injury, but the specific mechanism is still unknown. Objective To observe potential toxic effects of HepG2 cells and its perturbation of non-targeted metabolic profile after imidacloprid exposure, and to explore possible molecular mechanisms of hepatotoxicity of imidacloprid by analyzing invovlved biological processes and signaling pathways. Methods HepG2 cell suspension was prepared and seeded in a 96-well plate, which was divided into blank control group, dimethyl sulfoxide (DMSO) solvent control group and imidacloprid exposure groups with multiple concentrations. Each group was set with 5 parallel samples. The viability of HepG2 cells viability were determined after 8 h of exposure to different concentrationsof imidacloprid (1, 2.5, 5, 7.5, 10 mmol·L⁻¹), and the dose-effect relationship was analyzed. A proper concentration (3 mmol·L⁻¹ with 80% viability) was chosen for imidacloprid exposure, non-targeted metabolomic analysis was applied to the cultivated HepG2 cells using UHPLC-Q-TOF/MS technology, the differential metabolites between groups were screened, and the bioprocess and related signaling pathways of their enrichment were annotated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Results Compared to the other two groups, the survival rates of HepG2 cells in the imidacloprid exposure groups decreased. A survival rate of about 86% of HepG2 cells was found in HepG2 cells exposed to 2.5 mmol·L⁻¹ imidacloprid exposure. The non-targeted metabolomics studies showed that 61 metabolites were significantly affected in HepG2 cells after 3 mmol·L⁻¹ imidacloprid exposure, including creatine (variable importance in projection VIP=1.11, P<0.001), arginine (VIP=1.47, P=0.048), taurine (VIP=4.28, P=0.001), and α-D-glucose (VIP=1.90, P=0.006). The differential metabolites enriched in bioprocess and related signaling pathways were mainly directed to mTOR signaling pathways (P<0.001), arginine and proline metabolism (P=0.002), and galactose metabolism (P=0.015). Conclusion Imidacloprid exposure can significantly inhibit the survival rate of HepG2 cells, and interfere with the mTOR signaling pathway, arginine and proline metabolism, galactose metabolism, and so on.

Objective:To explore the effects of genotypes of one-carbon metabolism (OCM)-related enzyme single nucleotide polymorphisms (SNPs) sites and anti-epileptic drugs on OCM metabolite levels in epileptic patients, and to screen valproic acid (VPA) teratogenic susceptibility genes.Methods:Three hundred and seventy-two epileptic patients, admitted to our hospital from January 2019 to December 2020, were enrolled in the study; patients taking VPA, levetiracetam (LEV), lamotrigine (LTG) or oxcarbazepine (OXC) for more than 6 months without attack during regular medication were classified as VPA group ( n=95), LEV group ( n=61), LTG group ( n=57) and OXC group ( n=70); firstly diagnosed epileptic patients who had never taken antiepileptic drugs or had not taken antiepileptic drugs in the previous 6 months were assigned into blank control group ( n=89). Plasma folic acid (FA), vitamin B12 (VitB 12) and homocysteine (Hcy) levels were determined by automatic chemiluminescence immunoassay, and genotypes of OCM-related enzyme SNPs sites were detected by Sequenom iPLEX. Results:(1) As compared with LEV group and blank control group, VPA group had significantly decreased FA level and significantly increased Hcy level ( P<0.05). (2) Patients with DNA methyltransferase (DNMT) 3a rs12987326(-178G>A) GA type had significantly higher Hcy level than those with GG type ( P<0.05); patients with DNMT1 rs2288350(82G>C) GC type had significantly higher Hcy level than those with GG type ( P<0.05); patients with DNMT1 rs75616428 (55850G>C) GC type had significantly lower VitB 12 level than those with GG type ( P<0.05). Patients with DNMT1 rs1863771(128G>A) GA+AA type had significantly higher FA level than those with GG type, patients with folate receptor 2 rs2298444(59T>C) CT+CC type had significantly higher Hcy level than those with TT type, patients with 5,10-methylenetetrahydrofolate reductase rs1801131(1298A>C) AC+CC type had significantly higher Hcy level than those with AA type, and patients with DNMT3a rs6722613(2327C>T) CT+TT type had significantly lower VitB 12 level than those with CC type ( P<0.05). Conclusions:Decreased FA and increased Hcy levels can be noted in epileptic patients who used VPA; some gene variations in SNPs of OCM also affect the OCM metabolite levels in epileptic patients. Epileptic patients during pregnancy should avoid using VPA or detecting SNPs genotypes before medication to reduce the incidence of fetal malformation.

Objective:To establish an inductively coupled plasma mass spectrometry (ICP-MS) for platinum antineoplastic drugs in the environment.Methods:The platinum antineoplastic drugs in the environmental table were eluted by wiping and collecting pure water, and the supernatant was taken by centrifugation and inductively coupled plasma mass spectrometry for detection.Results:The concentration range of 0-8.0 μg/L was good, the correlation coefficient was 1.000, the detection limit was 0.0006 μg/L, the lower quantitative limit was 0.002 μg/L, the method precision was between 0.9%-1.3%, and the sample standard recovery rate was between 97.0%-98.5%.Conclusion:This method has low detection limit, high accuracy and precision, and simple sample pretreatment, which is suitable for the determination of platinum antineoplastic drugs in environmental tables.

Objective:To establish an inductively coupled plasma mass spectrometry (ICP-MS) for platinum antineoplastic drugs in the environment.Methods:The platinum antineoplastic drugs in the environmental table were eluted by wiping and collecting pure water, and the supernatant was taken by centrifugation and inductively coupled plasma mass spectrometry for detection.Results:The concentration range of 0-8.0 μg/L was good, the correlation coefficient was 1.000, the detection limit was 0.0006 μg/L, the lower quantitative limit was 0.002 μg/L, the method precision was between 0.9%-1.3%, and the sample standard recovery rate was between 97.0%-98.5%.Conclusion:This method has low detection limit, high accuracy and precision, and simple sample pretreatment, which is suitable for the determination of platinum antineoplastic drugs in environmental tables.

Objective:To establish a LC-MS/MS method for determination of paraquat and diquat in plasma and urine samples.Methods:Plasma is precipitated by acetonitrile then diluent with phosphate buffer (pH=7) , urine is diluent with phosphate buffer (pH=7) , then diluent samples extracted with Oasis WCX solid-phase extraction column. Samples were analyzed using LC-MS/MS in multiple reaction monitoring (MRM) mode. The analytical column was XBridge?BEH-HILIC (100 mm×2.1 mm×2.5 μm) and the mobile phase were 100 mmol ammonium formate add 0.5% formic acid and acetonitrile. Paraquat was quantified by internal standard method and diquat by external standard method.Results:The calibration curves of paraquat and diquat were linear in the concentration range of 10.0~120.0 μg/L, the correlation coefficient (r) were 0.9985~0.9994. The limit of detection of paraquat in plasma and urine were 1.98 μg/L and 1.00 μg/L, respectively, the recovery rate were 100.2%~107.3%, the RSD were 1.6%~3.3%. The limit of detection of diquat in plasma and urine were 1.80 μg/L and 2.77 μg/L, respectively, the recovery rate were 85.3%~93.1%, the RSD were 1.8%~5.5%. Conclusion:This method is sensitive and accurate, and can simultaneously determine paraquat and diquat in plasma and urine.

Objective:To establish a LC-MS/MS method for determination of paraquat and diquat in plasma and urine samples.Methods:Plasma is precipitated by acetonitrile then diluent with phosphate buffer (pH=7) , urine is diluent with phosphate buffer (pH=7) , then diluent samples extracted with Oasis WCX solid-phase extraction column. Samples were analyzed using LC-MS/MS in multiple reaction monitoring (MRM) mode. The analytical column was XBridge?BEH-HILIC (100 mm×2.1 mm×2.5 μm) and the mobile phase were 100 mmol ammonium formate add 0.5% formic acid and acetonitrile. Paraquat was quantified by internal standard method and diquat by external standard method.Results:The calibration curves of paraquat and diquat were linear in the concentration range of 10.0~120.0 μg/L, the correlation coefficient (r) were 0.9985~0.9994. The limit of detection of paraquat in plasma and urine were 1.98 μg/L and 1.00 μg/L, respectively, the recovery rate were 100.2%~107.3%, the RSD were 1.6%~3.3%. The limit of detection of diquat in plasma and urine were 1.80 μg/L and 2.77 μg/L, respectively, the recovery rate were 85.3%~93.1%, the RSD were 1.8%~5.5%. Conclusion:This method is sensitive and accurate, and can simultaneously determine paraquat and diquat in plasma and urine.