1.Mechanism of Yishen Tongluo Prescription in Inhibiting Endoplasmic Reticulum Stress and Improving Apoptosis of Renal Tubular Epithelial Cells Based on PERK/ATF4/CHOP
Xuan SU ; Liang ZHAO ; Mengmeng WANG ; Jing DING ; Zhenqiang ZHANG ; Xiaowei ZHANG ; Jiangyan XU ; Zhishen XIE
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(2):26-36
ObjectiveTo investigate the effect of Yishen Tongluo prescription (YSTLP) on apoptosis of renal tubular epithelial cells and explore the mechanism based on endoplasmic reticulum stress pathway of protein kinase R-like endoplasmic reticulum kinase (PERK)/activating transcription factor 4 (ATF4)/transcription factor C/EBP homologous protein (CHOP). MethodThe db/db mice were randomly divided into model group, valsartan group (10 mg·kg-1), and low, middle, high-dose YSTLP groups (1, 2.5, 5 g·kg-1). Samples were collected after eight weeks of drug intervention. In addition, db/m mice in the same litter served as the control group. Human renal tubular epithelial cells (HK-2) were cultured in vitro and divided into the control group, advanced glycated end-product (AGE) group, and AGE + low, middle, and high-dose YSTLP groups (100, 200, 400 mg·L-1). TdT-mediated dUTP nick end labeling (TUNEL) staining was used to detect the apoptosis rate of HK-2 cells. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was conducted to detect the viability of HK-2 cells. Calcium fluorescence probe staining and luciferase reporter gene method were adopted to detect the luciferase activity of folded protein response element (UPRE) and endoplasmic reticulum stress. Immunohistochemical (IHC) analysis was carried out to measure the protein expressions of phosphorylated PKR (p-PERK), CHOP, and ATF4. Real-time polymerase chain reaction (Real-time PCR) was used to measure the mRNA expression levels of CHOP and X-box binding protein 1 (XBP1) in mouse kidney and HK-2 cells. Western blot was used to detect the protein expression level of p-PERK, PERK, CHOP, ATF4, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleaved Caspase-3 in mouse kidney and HK-2 cells. ResultIn the cellular assay, HK-2 cell viability was significantly reduced, and the apoptosis rate was elevated in the AGE group compared with the control group (P<0.01). The mRNA and protein expression levels of apoptosis-related factor Bcl-2 were significantly reduced (P<0.01), and those of Bax were significantly increased (P<0.01). The protein expression level of cleaved Caspase-3 was significantly increased (P<0.01). Compared with the AGE group, YSTLP administration treatment resulted in elevated cell viability and reduced apoptosis rate (P<0.01). The mRNA and protein expression levels of Bcl-2 were significantly elevated in a time- and dose-dependent manner (P<0.01), and those of Bax were significantly reduced in a time- and dose-dependent manner. The protein expression level of cleaved Caspase-3 was significantly reduced in a time- and dose-dependent manner (P<0.01). The intracellular Ca2+ imbalance and UPRE luciferase fluorescence intensity were increased in the AGE group compared with the control group (P<0.01). The mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 were significantly increased (P<0.01), and the protein expression levels of p-PERK, CHOP, and ATF4 were significantly increased (P<0.05). Compared with the AGE group, YSTLP effectively improved intracellular Ca2+ imbalance in HK-2 cells and decreased UPRE luciferase fluorescence intensity in a dose-dependent manner (P<0.01). It reduced the mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 (P<0.01) and the protein expression levels of intracellular p-PERK, CHOP, and ATF4 in a dose- and time-dependent manner (P<0.01). In animal experiments, the protein expression level of Bcl-2 was significantly reduced(P<0.01), and that of cleaved Caspase-3 and Bax was significantly increased in the model group compared with the control group (P<0.05). The protein expression level of Bcl-2 was dose-dependently elevated, and that of cleaved Caspase-3 and Bax was dose-dependently decreased in the YSTLP groups compared with the model group (P<0.01). Compared with the control group, the mRNA expression levels of CHOP and XBP1 were significantly elevated in the model group (P<0.05, P<0.01), and the protein expression levels of p-PERK, CHOP, and ATF4 were significantly increased (P<0.05). Compared with the model group, YSTLP significantly decreased the mRNA expression levels of CHOP and XBP1 (P<0.01) and the protein expression levels of p-PERK, CHOP, and ATF4 (P<0.01). ConclusionYSTLP can effectively inhibit endoplasmic reticulum stress and improve apoptosis of renal tubular epithelial cells, and its mechanism may be related to the regulation of the PERK/AFT4/CHOP pathway.
2.Study on the mechanism of astragaloside Ⅰ inhibiting podocyte pyroptosis in diabetic kidney disease
Yafei DUAN ; Xiancong SHI ; Liang ZHAO ; Mingzhen LYU ; Xinqi REN ; Yulei GU ; Jiangyan XU ; Zhenqiang ZHANG ; Jinxin MIAO ; Zhishen XIE ; Xiaowei ZHANG
Journal of Beijing University of Traditional Chinese Medicine 2024;47(10):1408-1415
Objective To investigate the mechanism of astragaloside Ⅰ,the active constituent of milkvetch root,in inhibiting podocyte injury and improving diabetic kidney disease.Methods According to the body weight,60 male db/db mice were randomly divided into the model group,astragaloside Ⅰ low-dose group(10 mg/kg),astragaloside Ⅰ medium-dose group(20 mg/kg),astragaloside Ⅰ high-dose group(40 mg/kg),and valsartan group(10mg/kg),with 12 mice per group.Twelve db/db littermate control db/m mice were used as the control group.The drug was administered by gavage for 8 weeks.Transmission electron microscope was used to observe the ultrastructure of the kidney;immunohistochemistry and Western blotting were used to detect the expression of nephrotic protein(nephrin),a marker of renal podocytes;enzyme-linked immunosorbent assay was used to detect the contents of interleukin-1β(IL-1β)and interleukin-18(IL-18)in the serum of mice;Western blotting was used to detect the protein expressions of NOD-like receptor thermoprotein domain-related protein 3(NLRP3),cysteinyl aspartate specific proteinase 1(Caspase-1),and Gasdermin D(GSDMD)in kidney tissue.Results Compared with the control group,the glomeruli of the model group showed obvious podocyte loss and foot process fusion;the protein expression of nephrin was decreased(P<0.05);the contents of IL-1 β and IL-18 in serum were increased(P<0.05);the protein expressions of NLRP3,Cleaved-Caspase-1,and GSDMD-N were increased(P<0.05).Compared with the model group,the renal pathological damage in the astragaloside Ⅰ administration groups were alleviated;the protein expression of nephrin was increased(P<0.05);the contents of IL-1β and IL-18 in serum were decreased(P<0.05);the protein expressions of NLRP3,Cleaved-Caspase-1,and GSDMD-N were decreased(P<0.05).Conclusion Astragaloside Ⅰ may play a role in intervening diabetic kidney disease by inhibiting pyroptosis and improving podocyte injury.
3.Shugan Jianpi Yangxin Prescription Regulates Orexin-A and Its Receptors in Mouse Model of Insomnia
Zhen WANG ; Jie ZHANG ; Feixiang LIU ; Jiangyan SUN ; Yahui GAO ; Yuxin ZHENG ; Min ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(10):54-61
ObjectiveTo investigate the interventional effects of Shugan Jianpi Yangxin prescription on the expression of orexin-A (OXA), orexin-1 receptor (OX1R), and orexin-2 receptor (OX2R) in the mouse model of insomnia. MethodThe mouse model of insomnia was established by intraperitoneal injection of DL-4-chlorophenylalanine (PCPA). Fifty BALB/c mice were randomized into a blank group, a model group, an eszopiclone (0.13 mg·kg-1) group, and low- and high-dose (8.4 and 33.6 g·kg-1, respectively) Shugan Jianpi Yangxin prescription groups and treated with the corresponding drugs for 14 consecutive days. The weight changes of mice were monitored, and Morris water maze and pentobarbital-induced sleep tests were conducted. Immunohistochemistry (IHC) was employed to examine the expression of OXA in the hypothalamus. Enzyme-linked immunosorbent assay was used to measure the levels of OXA and 5-hydroxytryptamine (5-HT) in the hypothalamus, serum, and spleen. Real-time fluorescence quantitative polymerase chain reaction was employed to determine the mRNA levels of OXA, OX1R, and OX2R in the hypothalamus. ResultCompared with the blank group, the model group had decreased body weight (P<0.01), increased escape latency (P<0.01), increased sleep latency (P<0.01), shortened sleep duration (P<0.01), elevated OXA level and lowered 5-HT level in the hypothalamus, serum, and spleen (P<0.05), and up-regulated mRNA levels of OXA, OX1R, and OX2R in the hypothalamus (P<0.01). Compared with the model group, the low- and high-dose groups of Shugan Jianpi Yangxin prescription showed increased body weight (P<0.05, P<0.01), shortened escape latency (P<0.05), shortened sleep latency and prolonged sleep duration (P<0.01), and lowered OXA level and elevated 5-HT level in the hypothalamus, serum, and spleen (P<0.05, P<0.01). Moreover, the two doses of Shugan Jianpi Yangxin prescription down-regulated the mRNA levels of OXA, OX1R, and OX2R in the hypothalamus (P<0.01). ConclusionShugan Jianpi Yangxin prescription exerts sedative and hypnotic effects in mice by increasing the content of 5-HT in the brain and inhibiting the expression of OXA and its receptors in the hypothalamus.
4.Expression of interleukin-36 and its regulatory effect on monocyte function in patients with diabetic kidney disease
Jiangyan LI ; Yakun KONG ; Jianlin ZHAO ; Lichao ZHAO ; Chengyun XIONG ; Yanhong ZHOU
Chinese Journal of Endocrinology and Metabolism 2024;40(1):30-36
Objective:To analyze the level of interleukin-36(IL-36) family cytokines in peripheral blood, and explore the regulatory role of recombinant human IL-36α in monocyte function in patients with diabetic kidney disease(DKD).Methods:A total of 41 type 2 diabetes mellitus(T2DM) patients, 36 DKD patients, and 20 controls were consecutively enrolled. Plasma and peripheral blood mononuclear cells(PBMCs) were isolated. Enzyme-linked immunosorbent assay(ELISA) was used to measure plasma levels of IL-36α, IL-36β, IL-36γ, and IL-36 receptor antagonist(IL-36Ra). PBMCs were sorted, and real-time quantitative PCR was performed to detect the mRNA expression of IL-36 receptor subunits in monocytes. Monocytes were stimulated with recombinant IL-36α, and levels of cytotoxic molecules and cytokines in the culture supernatant were measured. Flow cytometry was used to assess the expressions of programmed death receptor-1(PD-1) and cytotoxic T-lymphocyte-associated protein 4(CTLA-4). Co-culture of monocytes with Vero cells was performed to evaluate monocyte cytotoxicity.Results:Plasma levels of IL-36α and IL-36β in the T2DM and DKD groups were significantly higher than those in the control group. The DKD group also showed higher plasma levels of IL-36α compared to the T2DM group( P<0.05). There were no significant differences in IL-36γ and IL-36Ra levels among the three groups( P>0.05). The mRNA expression of IL-36 receptor subunits in monocytes was comparable among the three groups( P>0.05). The DKD group had higher level of tumor necrosis factor-alpha(TNF-α) compared to the control and T2DM groups( P<0.05). The levels of PD-1 and CTLA-4 were lower in the DKD group than those in the control and T2DM groups( P<0.05). The proportion of monocyte-induced Vero cell death was significantly higher in the DKD group compared to the control and T2DM groups( P<0.05). After stimulation with recombinant human IL-36α, monocytes from DKD patients showed a significant increase in the secretion of granzyme B and TNF-α( P<0.05), as well as an increased proportion of monocyte-induced Vero cell death( P=0.024). Conclusion:In DKD patients, elevated IL-36α and granzyme B levels in monocytes enhance monocyte function.
5.Salvianolic Acid F Regulates Bax/Caspase-3/GSDME Signaling Pathway to Inhibit Pyroptosis of HK-2 Cells
Xiancong SHI ; Zhishen XIE ; Liang ZHAO ; Jiajun WANG ; Yafei DUAN ; Pan WANG ; Zhenqiang ZHANG ; Xiaowei ZHANG ; Jiangyan XU
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(9):56-64
ObjectiveTo investigate the mechanism of salvianolic acid F (Sal F) in repairing the high glucose-induced injury in human kidney-2 (HK-2) cells via the B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax)/cysteinyl aspartate-specific proteinase 3 (Caspase-3)/gasdermin-E (GSDME) pathway. MethodThe cell counting kit-8 (CCK-8) was used to measure the relative viability of HK-2 cells exposed to high glucose and different concentrations (2.5, 5, 10, 20 μmol·L-1) of Sal F and the relative viability of HK-2 cells treated with Sal F for different time periods. The levels of lactate dehydrogenase (LDH) and interleukin-1β (IL-1β) in the supernatant of the cell culture were measured by the LDH assay kit and enzyme-linked immunosorbent assay (ELISA) kit, respectively. Flow cytometry combined with Annexin V-FITC/propidium iodide (PI) and Hoechst 33342/PI staining was employed to reveal the proportion of PI-positive HK-2 cells exposed to high glucose. Western blotting was employed to determine the protein levels of Bax, Bcl-2, cytochrome C, cysteinyl aspartate-specific proteinase (Caspase)-9, Caspase-3, and GSDME in the HK-2 cells exposed to high glucose and treated with Sal F. The 2,7-dichlorodihydrofluorescein diacetate fluorescence probe (DCFH-DA) and mitochondrial membrane potential assay kit (JC-1) were used to determine the production of reactive oxygen species (ROS) and the mitochondrial membrane potential in the HK-2 cells exposed to high glucose and treated with Sal F. ResultCompared with the blank group, the model group showed decreased cell viability (P<0.01), elevated levels LDH and IL-1β, increased proportion of PI-positive cells (P<0.01), up-regulated protein levels of Bax, cytochrome C, Caspase-9, Caspase-3, and GSDME (P<0.01), down-regulated protein level of Bcl-2 (P<0.01), decreased mitochondrial membrane potential, and excessive ROS accumulation. Compared with the model group, Sal F repaired the high glucose-induced injury in HK-2 cells (P<0.05), lowered the levels of LDH and IL-1β (P<0.05, P<0.01), and decreased the proportion of PI-positive cells (P<0.01). In addition, Sal F down-regulated the protein levels of Bax, cytochrome C, Caspase-9, Caspase-3, and GSDME and up-regulated the protein level of Bcl-2 (P<0.05, P<0.01), increased the mitochondrial membrane potential, and decreased the accumulation of ROS in HK-2 cells. ConclusionSal F can reduce the production of ROS, restore the balance of mitochondrial membrane potential, and inhibit pyroptosis via the Bax/Caspase-3/GSDME signaling pathway to repair the high glucose-induced injury in HK-2 cells.
6.The influence of interleukin-35 on the balance between regulatory T cells and T helper 22 cells in patients with Hashimoto′s thyroiditis
Lichao ZHAO ; Jianlin ZHAO ; Huifang CAO ; Jiangyan LI ; Yanhong ZHOU
Chinese Journal of Endocrinology and Metabolism 2024;40(8):669-675
Objective:To observe the expression of interleukin-35(IL-35) in Hashimoto's thyroiditis(HT) patients, and evaluate its regulatory effect on the balance between regulatory T cells(Treg) and T helper 22(Th22) cells.Methods:Forty-two HT patients and eighteen controls were consecutively enrolled. Plasma and peripheral blood mononuclear cells(PBMC) were isolated. Treg were purified. Plasma IL-35 and IL-22 were detected with enzyme-linked immunosorbent assay. Treg and Th22 percentages were measured using flow cytometry. Real-time quantitative PCR was used to assess mRNA levels of forhead box protein 3(FoxP3) and aryl hydrocarbon receptor(AhR). Treg were stimulated with exogenous IL-35, and were co-cultured with autologous PBMC to induce Treg-to-Th22 phenotypic differentiation, evaluating the effect of IL-35 on Treg function and differentiation.Results:There was imbalance between Treg and Th22 cells in HT group. HT group had reduced Treg percentage, plasma IL-35 and FoxP3 mRNA( P<0.001), while had elevated Th22 percentage and AhR mRNA( P<0.001). There was no significant difference in plasma IL-22 level between two groups( P=0.775). The suppressive capacity of Tregs in the HT group was diminished( P=0.013), and secretion levels of IL-35 and IL-10 were lower than those in the control group( P<0.001). The ability of Tregs in the HT group to differentiate into Th22 cells was increased, with higher levels of CCR4, CCR6, CCR10, AhR mRNA, and IL-22 secretion compared to the control group( P<0.01). IL-35 stimulation induced elevation of Treg percentage, FoxP3 mRNA, and IL-35/IL-10 secretion( P<0.05), but did not affect Th22 percentage, AhR mRNA, or IL-22 secretion( P>0.05). IL-35 stimulation enhanced Treg function in HT group, increasing proliferation inhibition and secretion of IL-35 and IL-10( P<0.05). IL-35 stimulation reduced the differentiation of Treg to Th22 phenotype in HT group, with decreased levels of CCR4, CCR6 CCR10, AhR mRNA, and IL-22 secretion( P<0.05). Conclusion:IL-35 enhances the immunosuppression of Tregs in HT patients and inhibits its differentiation into Th22 cells, thus regulating the balance between Tregs and Th22 cells.
7.Study on the mechanism of Yishen tongluo formula improving abnormal lipid metabolism based on SREBPs pathway
Liang ZHAO ; Xiaowei ZHANG ; Zhishen XIE ; Shixie XIANG ; Yafei DUAN ; Gai GAO ; Pan WANG ; Huifen MA ; Yiran SUN ; Jie CHEN ; Jiangyan XU ; Zhenqiang ZHANG
China Pharmacy 2023;34(23):2835-2840
OBJECTIVE To explore the mechanism of Yishen tongluo formula (YSTLF) in improving abnormal lipid metabolism based on the sterol regulatory element binding proteins (SREBPs) pathway. METHODS Using C57BLKS/J (db/db) mice as model and C57BLKS/J (db/m) mice as normal control, the mechanism of 1, 2.5 and 5 g/kg YSTLF improving abnormal lipid metabolism of db/db mice was investigated by determining the liver coefficient, the contents of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), observing steatosis and lipid accumulation in liver tissue of mice, detecting the protein expressions of SREBP-1 and SREBP-2 as well as mRNA transcription levels of Srebp- 1c, Srebp-2 and their downstream lipid metabolism-related target genes (Fasn, Acc1, Scd5, Fads1, Hmgcr, Dhcr24, Insig-1, Fdps) in liver tissue of mice. Using low-fat cultured human liver cancer cell HepG2 as an in vitro cell model for abnormal lipid metabolism, and 25-HC (SREBPs inhibitor, 10 μmol/L) as the control, the effects of 125, 250 and 500 μg/mL YSTLF on protein expressions of SREBP-1 and SREBP-2 as well as mRNA transcription of SREBP-1c, SREBP-2 and their downstream lipid metabolism-related target genes were investigated to verify the mechanism in vitro. RESULTS 1, 2.5, 5 g/kg YSTLF significantly reduced the levels of TC, TG and LDL, the percentage of lipid droplet-positive region in liver tissue and liver coefficient, significantly down-regulated protein expressions of Pre-SREBP-1, n-SREBP-1, Pre-SREBP-2 and n-SREBP-2, and mRNA transcription of Srebp-1c, Srebp-2 and their downstream target genes in liver tissue, while significantly increased HDL level, with statistical significance (P<0.05 or P<0.01). In the cell experiment in vitro, the expressions of the above-mentioned proteins and genes in the cells treated with YSTLF at 125, 250 and 500 μg/mL for 24 hours were consistent with those in the animal experiment; there was no significant difference in the expressions of the above-mentioned proteins and genes between inhibitor control group and 250, 500 μg/mL YSTLF groups (P>0.05). CONCLUSIONS YSTLF can regulate the expression of transcription factor SREBPs, so as to inhibit the high expression of fatty acid and cholesterol synthesis-related genes, promote the degradation of TC and TG, improve the abnormality of lipid metabolism and inhibit lipid accumulation, thus playing the role of lipid-lowering.
8.Medication law of Traditional Chinese Medicine patent compounds in the treatment of Alzheimer disease based on data mining
Shanshan LI ; Min ZHAO ; Jiangyan SUN ; Jie ZHANG ; Yuanyuan YAN ; Zhihui CUI ; Menglong SHI
International Journal of Traditional Chinese Medicine 2023;45(2):220-226
Objective:To analyze the medication law of Traditional Chinese Medicine (TCM) patent compounds for Alzheimer disease (AD) by using data mining method.Methods:The TCM compounds for the treatment of AD in the patent database were screened, and the frequency, clustering and association analysis were carried out with the help of TCM inheritance calculation platform, SPSS Statistics 21.0 and SPSS Modeler 18.0 software. The medication law was analyzed.Results:A total of 220 patent compounds were included, involving 361 kinds of Chinese materia medica; the top 10 high-frequency drugs were Acori Tatarinowii Rhizoma, Polygalae Radix, Ginseng Radix et Rhizoma, Chuanxiong Rhizoma, Astragali Radix, Lycii Fructus, Poria, Rehmanniae Radix PraeparataAngelicae Sinensis Radix, Salviae Miltiorrhizae Radix et Rhizoma; the most frequently used drugs were drugs for tonifying deficiency and promoting blood circulation to remove blood stasis; most of their properties belonged to warm, mild and cold; the tastes were mainly sweet, bitter and pungent; the meridians belonged to the five internal organs. 16 items of association data (4 combinations of two items and 12 combinations of three items) were obtained by association rule analysis, and the strongest correlation group was " Acori Tatarinowii Rhizoma- Polygalae Radix" and " Acori Tatarinowii Rhizoma- Chuanxiong Rhizoma- Polygalae Radix". Cluster analysis showed four prescription combinations and three pairs of drug compatibility, including the addition and subtraction structure of Kaixin Powder, Zuogui Pill, Bazhen decoction and so on. Conclusion:The core treatment principle of TCM patent compound treatment of AD is regulating and tonifying the five internal organs to treat its root, resolving phlegm and removing blood stasis to treat the symptoms, which accords with the theoretical basis of TCM in the treatment of AD, and can provide reference for clinical practice and new drug research and development.
9.Preliminary application of recombinase -aided amplification in detection of Clonorchis sinensis metacercariae in freshwater fish.
J CHEN ; Z WANG ; W HUANG ; J WANG ; L CHEN ; Y SUN ; L ZHAO ; Y ZHAO ; Y QIAN ; J DUAN ; Q ZHANG
Chinese Journal of Schistosomiasis Control 2023;35(5):458-463
OBJECTIVE:
To evaluate the performance of recombinase-aided amplification (RAA) assay in detection of Clonorchis sinensis metacercariae in freshwater fish samples, so as to provide insights into standardization and field application of this assay.
METHODS:
Wild freshwater fish samples were collected in the rivers of administrative villages where C. sinensis-infected residents lived in Jiangyan District, Xinghua County and Taixing County of Taizhou City, Jiangsu Province from June to September 2022. Genomic DNA was extracted from six freshwater fish specimens (5 g each) containing 0, 1, 2, 4, 8 and 16 C. sinensis metacercariae for fluorescent RAA assay, and the diagnostic sensitivity was evaluated. Fluorescent RAA assay was performed with genomic DNA from C. sinensis, Metorchis orientalis, Haplorchis pumilio and Centrocestus formosanus metacercariae as templates to evaluate its cross-reactions. In addition, the detection of fluorescent RAA assay and direct compression method for C. sinensis metacercariae was compared in field-collected freshwater fish samples.
RESULTS:
Positive amplification was found in fresh-water fish specimens containing different numbers of C. sinensis metacercariae, and fluorescent RAA assay was effective to detect one C. sinensis metacercaria in 5 g freshwater fish specimens within 20 min. Fluorescent RAA assay tested negative for DNA from M. orientalis, H. pumilio and C. formosanus metacercariae. Fluorescent RAA assay and direct compression method showed 5.36% (93/1 735) and 2.88% (50/1 735) detection rates for C. sinensis metacercariae in 1 735 field-collected freshwater fish samples, with a statistically significant difference seen (χ2 = 478.150, P < 0.001). There was a significant difference in the detection of C. sinensis metacercariae in different species of freshwater fish by both the direct compression method (χ2 = 11.20, P < 0.05) and fluorescent RAA assay (χ2 = 20.26, P < 0.001), and the detection of C. sinensis metacercariae was higher in Pseudorasbora parva than in other fish species by both the direct compression method and fluorescent RAA assay (both P values < 0.05).
CONCLUSIONS
Fluorescent RAA assay has a high sensitivity for detection of C. sinensis metacercariae in freshwater fish samples, and has no cross-reactions with M. orientalis, H. pumilio or C. formosanus metacercariae. Fluorescent RAA assay shows a higher accuracy for detection of C. sinensis infections in field-collected freshwater fish than the direct compression method.
Animals
;
Clonorchis sinensis/genetics*
;
Metacercariae/genetics*
;
Recombinases
;
Fresh Water
;
Fishes
;
DNA
;
Fish Diseases/diagnosis*
10.Characterization of a monoclonal antibody against the hemagglutinin stem of H7N9 subtype avian influenza virus.
Jiangyan ZHAO ; Yanxiao ZHU ; Jiao HU ; Zenglei HU ; Xiufan LIU
Chinese Journal of Biotechnology 2022;38(1):160-173
The conserved hemagglutinin (HA) stem region of avian influenza virus (AIV) is an important target for designing broad-spectrum vaccines, therapeutic antibodies and diagnostic reagents. Previously, we obtained a monoclonal antibody (mAb) (5D3-1B5) which was reactive with the HA stem epitope (aa 428-452) of H7N9 subtype AIV. To systematically characterize the mAb, we determined the antibody titers, including the HA-binding IgG, hemagglutination-inhibition (HI) and virus neutralizing (VN) titers. In addition, the antigenic epitope recognized by the antibody as well as the sequence and structure of the antibody variable region (VR) were also determined. Moreover, we evaluated the cross-reactivity of the antibody with influenza virus strains of different subtypes. The results showed that the 5D3-1B5 antibody had undetectable HI and VN activities against H7N9 virus, whereas it exhibited strong reactivity with the HA protein. Using the peptide-based enzyme-linked immunosorbent assay and biopanning with a phage-displayed random peptide library, a motif with the core sequence (431W-433Y-437L) in the C-helix domain in the HA stem was identified as the epitope recognized by 5D3-1B5. Moreover, the mAb failed to react with the mutant H7N9 virus which contains mutations in the epitope. The VR of the antibody was sequenced and the complementarity determining regions in the VR of the light and heavy chains were determined. Structural modeling and molecular docking analysis of the VR verified specific binding between the antibody and the C-helix domain of the HA stem. Notably, 5D3-1B5 showed a broad cross-reactivity with influenza virus strains of different subtypes belonging to groups 1 and 2. In conclusion, 5D3-1B5 antibody is a promising candidate in terms of the development of broad-spectrum virus diagnostic reagents and therapeutic antibodies. Our findings also provided new information for understanding the epitope characteristics of the HA protein of H7N9 subtype AIV.
Animals
;
Antibodies, Monoclonal
;
Antibodies, Viral
;
Hemagglutinin Glycoproteins, Influenza Virus/genetics*
;
Hemagglutinins
;
Influenza A Virus, H7N9 Subtype
;
Influenza in Birds
;
Molecular Docking Simulation

Result Analysis
Print
Save
E-mail