AIM:To investigate the inhibitory effect of mogroside V(MV)on ferroptosis of human neuroblas-toma SH-SY5Y cells induced by RAS-selective lethal 3(RSL3),and to explore its possible mechanism.METHODS:To establish a model of ferroptosis,the SH-SY5Y cell was induced by RSL3.The cell viability and cellular morphology were determined by MTT assay and inverted microscopy,respectively.The intracellular ferrous ion content was measured by ferrous ion fluorescence probe FerrOrange.Mitochondrial membrane potential(MMP)was detected by mitochondrial red fluorescent probe MitoTracker Red CMXRos.The intracellular and mitochondrial reactive oxygen species(ROS)were de-tected by superoxide anion fluorescent probe dihydroethidium and mitochondrial superoxide red fluorescent probe MitoSOX Red,respectively.The cellular glutathione(GSH)and malondialdehyde(MDA)levels were tested by microplate assay.The protein levels of acyl-coenzyme A synthetase long-chain family member 4(ACSL4),cyclooxygenase-2(COX-2),glu-tathione peroxidase 4(GPX4)and solute carrier family 7 member 11(SLC7A11)were detected by Western blot.Molecu-lar docking techniques were employed to predict the targeting relations between MV and ACSL4/COX-2/GPX4/SLC7A11.RESULTS:Compared with control group,the SH-SY5Y cell viability,the MMP and the GSH level in RSL3 group were significantly reduced(P<0.01),while the intracellular ferrous ion level,the intracellular and mitochondrial ROS levels and the MDA level were significantly increased(P<0.05 or P<0.01).The protein levels of ACSL4 and COX-2 in RSL3 group were significantly increased,while the protein levels of GPX4 and SLC7A11 were significantly decreased(P<0.01),indicating the establishment of cell ferroptosis model.Compared with RSL3 group,the viability of SH-SY5Y cells,the MMP,the GSH level,and the GPX4 and SLC7A11 protein levels in RSL3+MV groups were significantly in-creased(P<0.05 or P<0.01),while the intracellular ferrous ion level,the intracellular and mitochondrial ROS levels,the MDA level,and the ACSL4 and COX-2 protein levels were significantly decreased(P<0.05 or P<0.01).The binding sites between MV and ferroptosis core proteins(ACSL4,COX-2,GPX4 and SLC7A11)were found by molecular docking.CONCLUSION:Treatment with MV alleviates RSL3-induced ferroptosis of SH-SY5Y cells,and the underlying mecha-nism may be associated with the activation of SLC7A11/GPX4 and the inhibition of ACSL4/COX-2.

[Objective] To analyze the prevalence of human T-lymphocyte leukemia virus (HTLV) among blood donors in Guangzhou from 2016 to 2021, and provide a basis for blood collection and supply management in this region. [Methods] A total of 2 116 951 voluntary blood donors were screened for anti-HTLV by enzyme-linked immunosorbent assay (ELISA) from March 2016 to December 2021 in Guangzhou, and the reactive cases were further confirmed by Western blotting (WB). Qualitative data were analyzed by χ2 with spss19 software. The trend of the total positive rate of HTLV confirmation test by WB from 2016 to 2021 was analyzed with the Joinpoint software, and the annual percent change (APC) was used to determine whether the trend changes were statistically significant. [Results] From March 2016 to December 2021, the total positive rate for anti-HTLV by ELISA among voluntary blood donors in Guangzhou was 0.019 7% (416/ 2116 951), and the WB confirmed positive rate was 0.001 1% (23/2 116 951). The total positive rate of HTLV among individual voluntary blood donors in the six main districts (0.002 12%, 19/895 301) was higher than that among group voluntary blood donors (0.000 32%, 3/951 947) (P<0.05). There was no significant difference in the total positive rate of HTLV confirmation between the six main districts (0.001 19%) and the three non-main districts (0.000 37%) (P>0.05). The trend of the total positive rate of HTLV infection in the six main districts and the Guangzhou area(including the six main districts and three non-main districts) showed no significant increase or decrease. [Conclusion] The prevalence of HTLV among blood donors in Guangzhou remains at a low level.

【Objective】 To explore the correlation between serological screening of human T-lymphotropic virus antibodies (anti HTLV) and Western blot(WB) confirmatory tests among blood donors, so as to explore the infection status of HTLV Ⅰ/Ⅱ in Guangzhou. 【Methods】 The anti HTLV Ⅰ/Ⅱ enzyme-linked immunosorbent assay(ELISA) kit was used to screen voluntary blood donors from Guangzhou Blood Center from July 2016 to August 2022. WB was used to confirm 395 reactive blood samples by ELISA. The correlation between the S/CO values of anti HTLV Ⅰ/Ⅱ ELISA reagents and the confirmatory test was analyzed using ROC curves. 【Results】 The results showed that 25 out of 395 initially screened reactive blood donor samples were confirmed as HTLV positive by WB, while 16 were uncertain. ROC curve analysis showed a correlation between the S/CO values by ELISA and the confirmatory test results: the S/CO value at the highest Youden index was 3.789, which was the optimal threshold. The S/CO value had a certain correlation with the predicted positive rate of confirmatory results (P<0.05): the larger the S/CO value, the higher the predicted positive value. The overall prevalence of HTLV in Guangzhou is relatively low. 【Conclusion】 The prevalence of HTLV among blood donors in Guangzhou is low.Since the false positive rate of HTLV Ⅰ/Ⅱ antibody by ELISA serological screening is high, the confirmatory testing is particularly important.

【Objective】 To learn the situation of the evolution process of HCV virus population and the selection pressure of HCV NS5B in intravenous drug users (IDUs) in Guangdong. 【Methods】 141 blood samples from hepatitis C virus (HCV) RNA-positive blood donors and 58 from HCV patients in Guangdong were randomly collected for HCV NS5B sequence amplification, combined with HCV NS5B sequences from blood donors and IDUs obtained by sequencing previously(between 2009 and 2011). Homology analysis was performed by Molecular Evolutionary Genetics Analysis (MEGA) software, evolutionary analysis were performed by Bayesian Evolutionary Analysis Sampling Trees (BEAST) software package. Selection pressure analysis was performed on sequences isolated from IDUs by Datamonkey online software package with Mixed Effects Model Evolution (MEME) method, and the population expansion of species were analyzed using Tajima and Fu neutrality test by Arlequin software. 【Results】 The comparison results of internal homology among different subtypes of IDUs in this group were as follows : HCV-3b had the highest homology (97%), followed by HCV-3a (96%), HCV-6a (95%) and HCV-1b (94%); HCV evolution rate analysis showed that HCV-1b had the fastest evolution rate [2.17E-03 substitutions/site/year (y/y/y)], followed by HCV-3b (2.12E-0 y/y/y), HCV-3a (1.58E-03 y/y/y) and HCV-6a (1.28E-03 y/y/y). The analysis on effective population of HCV: 1980~1990 was rapid growth period for HCV-6a, 1990~1995 period for HCV-1b, and 2000~2007 period for HCV-3a. HCV population genetic characteristics was as follows: HCV-1b, 3a, 3b and 6a experienced population expansion, among which 3a and 3b were the most obvious. As to the analysis of HCV selection pressure, two positive selection sites (235 and 243)were found in the 339 nucleotide fragment of the NS5B sequence in injecting drug users, but mutation only occurred at position 316 [mutation rate 1.24% (14/1 130)] among 5 direct antiviral drug (DAA) sites in this gene. 【Conclusion】 The evolution of HCV-3b in Guangdong has showed an obvious trend of population expansion, with a high proportion and homology especially in the local IDUs. HCV-3b should be the focus of HCV prevention and control in this region. Given that the positively selected sites of the HCV NS5B gene region of IDUs in Guangdong are non-DAA binding sites, DAA is expected to demonstrate a good effect on these patients.