Menaquinone-4 exerts a protective effect against carbon tetrachloride-induced acute liver injury in mice by alleviating ferroptosis / 临床肝胆病杂志

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.

Effect of Toll-like receptor 4 on liver regeneration during acetaminophen-induced liver injury in mice / 临床肝胆病杂志

Objective To investigate whether Toll-like receptor 4 (TLR4) inhibition affects liver regeneration during acetaminophen (APAP)-induced liver injury in mice, as well as the mechanism of TLR4 involved in liver regeneration. Methods A total of 78 male CD-1 mice were divided into nine groups using a random number table, i.e., three control groups (normal control group, solvent control group, inhibitor control group) with 6 mice in each group and six experimental groups (APAP 24-hour group, TAK-242+APAP 24-hour group, APAP 48-hour group, TAK-242+APAP 48-hour group, APAP 72-hour group, TAK-242+APAP 72-hour group) with 10 mice in each group. The mice in the experimental groups were given a single dose of intraperitoneally injected APAP (300 mg/kg), and TAK-242 was intraperitoneally injected at a dose of 3 mg/kg at 3 hours before APAP administration. Serum and liver tissue samples were collected at different time points. The biochemical method was used to measure the serum level of alanine aminotransferase (ALT); HE staining was used to observe liver pathological changes; RT-PCR, Western blot, and immunohistochemistry were used to measure the expression levels of Cyclin D1, PCNA, Ki-67, STAT3, and p-STAT3. The t -test was used for comparison of normally distributed continuous data between two groups; a one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t -test was used for further comparison between two groups. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups, and the Kruskal-Wallis H test was used for comparison between multiple groups and further comparison between two groups. Results Compared with the normal control group, the APAP 24-hour and 48-hour groups had a significantly higher serum level of ALT (both P < 0.05), and the TAK-242+APAP 24-hour and 48-hour groups had a significantly higher serum level of ALT than the APAP group at the same time point (both P < 0.05). HE staining showed typical central lobular necrosis in the liver of APAP-treated mice, and the TAK-242+APAP 24-hour and 48-hour groups had a significantly larger necrotic area than the APAP group at the same time point (both P < 0.05). RT-PCR, Western blot, and immunohistochemistry showed that the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had significantly lower mRNA and protein expression levels of Cyclin D1 than the APAP group at the same time point (all P < 0.05); the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had a significantly lower mRNA expression level of PCNA than the APAP group at the same time point (all P < 0.05), and the TAK-242+APAP 24-hour and 48-hour groups had a significantly lower protein expression level of PCNA than the APAP group at the same time point (all P < 0.05); the TAK-242+APAP 24-hour and 72-hour groups had a significantly lower mRNA expression level of Ki-67 than the APAP group at the same time point (all P < 0.05), and the TAK-242+APAP 24-hour, 48-hour, and 72-hour groups had a significantly lower protein expression level of Ki-67 than the APAP group at the same time point (all P < 0.05). In addition, the TAK-242+APAP 24-hour and 48-hour groups had a significantly lower phosphorylation level of STAT3 than the APAP group at the same time point (both P < 0.05). Conclusion TLR4 may promote liver regeneration by increasing the phosphorylation level of STAT3 during APAP-induced liver injury in mice.

The Expression of Metallothionein-1 in Mouse Kidney / 天津医药

Objective To investigate the expression and cellular localization of metallothionein-1 (MT-1) in mouse kidney. Methods The adult male CD-1 mice were selected as experimental animals. The protein of MT-1 in mouse renal cortex and medulla was detected by Western blot assay. Immunohistochemistry and immunofluorescence methods were ap-plied to observe the location of MT-1 in renal tubules and collecting ducts of mouse kidney. Double-immunofluorescence and confocal laser scanning microscopy were used to observe the subcellular localization of MT-1 in the epithelial cells of re-nal tubules and collecting ducts of mouse kidney. Results The expression of MT-1 was detected in cortex and medulla of mouse kidney. The expression of MT-1was mainly found in proximal convoluted tubules and distal convoluted tubules of cor-tical labyrinth, and proximal straight tubules, distal straight tubules and collecting ducts of ray medullary and medulla of kid-ney. The strongest expression of MT-1 was found in proximal tubules, secondary in distal tubules and last in collecting ducts. The intracellular location of MT-1 was in brush border of proximal tubules and intracytoplasm, in the distal tubule epi-thelial cell cytoplasm and in the basolateral membranes of collecting duct epithelial cells. The subcellular localization was found in the lysosome. Conclusion The different locations of MT-1 expressed in proximal tubules, distal tubules and col-lecting ducts may determine different roles of them in kidney.

Effects of various combinations of cryoprotectants and cooling speed on the survival and further development of mouse oocytes after vitrification / 대한생식의학회지

OBJECTIVE: The objectives of this study were to analyze efficacy of immature and mature mouse oocytes after vitrification and warming by applying various combinations of cryoprotectants (CPAs) and/or super-rapid cooling using slush nitrogen (SN2). METHODS: Four-week old ICR female mice were superovulated for GV- and MII-stage oocytes. Experimental groups were divided into two groups. Ethylene glycol (EG) only group: pre-equilibrated with 1.5 M EG for 2.5 minutes and then equilibrated with 5.5 M EG and 1.0 M sucrose for 20 seconds. EG+dimethylsulfoxide (DMSO) group: pre-equilibrated with 1.3 M EG+1.1 M DMSO for 2.5 minutes and equilibrated with 2.7 M EG+2.1 M DMSO+0.5 M sucrose for 20 seconds. The oocytes were loaded onto grids and plunged into SN2 or liquid nitrogen (LN2). Stored oocytes were warmed by a five-step method, and then their survival, maturation, cleavage, and developmental rates were observed. RESULTS: The EG only and EG+DMSO groups showed no significant difference in survival of immature oocytes vitrified after warming. However, maturation and cleavage rates after conventional insemination were greater in the EG only group than in the EG+DMSO group. In mature oocytes, survival, cleavage, and blastocyst formation rates after warming showed no significant difference when EG only or EG+DMSO was applied. Furthermore, cleavage and blastocyst formation rates of MII oocytes vitrified using SN2 were increased in both the EG only and EG+DMSO groups. CONCLUSION: A combination of CPAs in oocyte cryopreservation could be formulated according to the oocyte stage. In addition, SN2 may improve the efficiency of vitrification by reducing cryoinjury.

CpG oligodeoxynucletide potently enhances cellular immune responses in suckling mice infected with human rotavirus / 中华传染病杂志

Objective To investigate the effects of CpG oligodeoxynucleotide (ODN) on cellular immune responses in suckling mice infected with human rotavirus (HRV). Methods Forty ICR suckling mice were randomly divided into four groups: control group. HRV infection group, CpG ODN pretreatment group and CpG ODN treatment group. Suckling mice were sacrificed four days after rotavirus challenge. Small intestine and spleen samples were collected under sterile condition. Thedegree of small intestinal mucosal injures was evaluated with standard scoring criteria. The spleen index was calculated and spleen lymphocyte stimulation index was detected by methyl thiazolyl tetrazolium ( MTT) assays. Levels of gamma interferon (IFN-γ), interleukin-4 ( IL-4) in the supernatant of spleen lymphocyte culture were detected by enzyme linked immunosorbent assay (ELISA). T lymphocyte subsets were analyzed by flow cytometry. The data was compared by one way ANOVA. Results The scores of mucosal injures of mice in HRV infection group, CpG ODN pretreatment group and CpG ODN treatment group were 4. 00 ±1. 31, 2. 75 ±1. 28 and 2. 87 ±0. 99, respectively, and the differences among groups were statistically significant (F=ll. 32,P＜0. 01). The scores of mucosal injures in CpG ODN pretreatment group and CpG ODN treatment group were both lower than that in HRV infection group (P＜0. 05). Compared with control group, spleen lymphocyte stimulation index and the percentage of CD8+ T lymphocytes were higher, the percentage of CD4+ T lymphocyte and ratio of CD4+ /CD8+ T cells were lower, levels of T helper (Th)1 type cytokine IFN-y increased significantly in HRV infection group; while the spleen index, spleen lymphocyte stimulation index, percentages of CD4+ and CD8+ T lymphocytes, IFN-y levels were all increased in CpG ODN pretreatment group and CpG ODN treatment group (P＜0. 05). The spleen index, spleen lymphocyte stimulation index, the percentage of CD4+ T lymphocytes, CD4+/CD8+ ratios and IFN-y levels in CpG ODN pretreatment group and CpG ODN treatment group were all significantly higher than HRV infection group (P＜0. 05). Conclusion CpG ODN potently enhances cellular immune responses in ICR suckling mice infected with HRV and CpG ODN could induce dominant Th1 response.

Detection of expression of mouse MN/CA9 gene with reverse transcriptase-polymerase chain reaction / 吉林大学学报(医学版)

Objective To clone and analyze the MN/CA9 gene sequence in ICR mice and detect the expressions of MN/CA9 gene in various tissues of ICR mice.Methods The fresh tissues of small intesine, uterrus, skin, musle, liver, pancreas, heart, lung, thymus, spleen, kidney, ovary, stomach ,urinary bladder from ICR mice were obtained , the total RNA was extracted by GIT method, the 1st strand and 2nd strand of cDNA were synthesized, the EcoRⅠ adapters were lingated,the EcoRⅠ ends were phosphorylated, digested with XhoⅠ ,cDNA was ligated into the ZAP expression vector, packaged, planted, screened.The expressions of MN/CA 9 gene in various tissues in mice were detected by RT-PCR.Results A fragment of human MN/CA9 gene was used as probe, and 1.47?10~3 clones were screened with radioactive isotopic ~ 32 P labeled probe, after hybridizations, one positive signal of cDNA was detected and the complete nucleotide sequence contained 1 671 bp was determined (GenBank:AB086322), The nucleotide similarity between mouse and human cDNA (GenBank:Z54349) was 69.1%.The MN/CA9 gene detected by RT-PCR assay (primer: P521-P1193) strongly expressed in small intesine,uterus, musle, pancreas, heart, lung, thymus, spleen, kidney, ovary, stomach,and urinary bladder,meanwhile did not express in skin and liver. Conclusion The expressions of MN/CA9 gene in some tissues of ICR mice are similar to that of human, it can be used to further functional analysis of MN/CA9 gene.