[Effect of SIRT1 on delay of D-gal-induced premature ovarian failure in mice with ginsenoside Rg_1].

To explore the effect of slient mating type information regulation 2 homolog 1(SIRT1) on the delay of D-galactose(D-gal) induced premature ovarian failure in mice with ginsenoside Rg_1(Rg_1). Fifty-four female SPF BALB/c mice were randomly divided into PBS group, D-gal group, and Rg_1 group. In the D-gal group, D-galactose(200 mg·kg~(-1)·d~(-1)) was injected subcutaneously into the neck and back for 42 days. In the PBS group, the equal amount of phosphate buffered saline(PBS) was injected into the neck and back for 42 days. In addition to the therapy of D-gal group, Rg_1 group was given Rg_1(20 mg·kg~(-1)·d~(-1)) through the intraperitoneal injection on the 15 th day for 28 days. At the same time, the D-gal group and the PBS group were also given an equal amount of PBS through hintraperitoneal injection on the 15 th day for 28 days. The changes in body weight and ovarian weight coefficient of mice were detected. Expressions of estradiol 2(E_2), luteinizing hormone(LH), superoxide dismutase(SOD), catalase(CAT) and follicle-stimulating hormone(FSH) in peripheral blood were detected. Morphological changes of ovaries were detected by HE staining. Changes in expression of aging regulator SIRT1 were detected by fluorescent quantitative PCR and Western blot. The results showed that compared with the PBS group, the body weight growth rate of the D-gal group was significantly slowed, the ovarian weight coefficient was decreased, the serum levels of E_2, LH, SOD, CAT were significantly reduced, and FSH was significantly increased. After the administration with Rg_1, the body weight growth rate, ovarian weight coefficient, serum levels of E_2, LH, SOD, and CAT in the mice were higher than those in the D-gal group, while FSH was lower than those in the D-gal group. HE staining showed that the follicular morphology and structure of the PBS group were normal; the number of follicles in the D-gal group was reduced, the corpus luteum was vacuolated, and the number of atretic follicles was increased. Compared with the D-gal group, the number of follicles in the Rg_1 group was increased, whereas the number of corpus luteum was decreased. Compared with the PBS group, SIRT1 expression was down-regulated in the D-gal group, while SIRT1 expression was up-regulated in the Rg_1 group compared with the D-gal group. The results suggested that Rg_1 could delay D-gal-induced premature ovarian failure in a mouse model of premature ovarian failure, and SIRT1 played an important role in this.

Effect of ginsenoside Rg_1 in delaying premature ovarian failure induced by D-gal in mice through PI3K/Akt/mTOR autophagy pathway / 中国中药杂志

The aim of this paper was to study the role of phosphoinositide 3-kinase(PI3 K), protein kinase B(Akt) and mamma-lian target of rapamycin(mTOR) in the inhibition of premature ovarian failure induced by D-galactose(D-gal) in mice model by ginsenoside Rg_1(Rg_1). Fifty-four female SPF BALB/c mice were randomly divided into PBS group, D-gal group, and Rg_1 group. In the D-gal group, D-galactose(200 mg·kg~(-1)·d~(-1)) was injected subcutaneously into the neck and back for 42 days. In the PBS group, an equal amount of phosphate buffered saline(PBS) was injected into the neck and back for 42 days. In addition to the therapy of D-gal group, Rg_1 group was given Rg_1(20 mg·kg~(-1)·d~(-1)) through intraperitoneal injection since the 15 th day for 28 days, at the same time, the D-gal group and the PBS group were also given an equal amount of PBS through intraperitoneal injection since the 15 th day for 28 days. After the treatment, the estrous cycle changes of the mice were detected, and the ovarian SA-β-Gal staining was used to detect the changes of ovarian aging. Western blot was used to detect the changes in protein expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). Fluorescence quantitative PCR was used to detect the changes in mRNA expressions of PI3 K, Akt, mTOR, S6 k, LC3-Ⅱ and P16~(INK4 a). According to the findings, compared with the PBS group, the D-gal group began to show estrous cycle disorder in the 3 rd week,the ovarian SA-β-Gal staining positive granulosa cells increased in the D-gal group, the expression of senescence marker P16~(INK4 a) increased, while the expression of autophagy signaling molecule LC3-Ⅱ decreased. After treatment with Rg_1, the positive rate of ovarian SA-β-Gal staining in Rg_1 group decreased, the expression level of autophagy signaling molecule LC3-Ⅱ in Rg_1 group was higher than that in D-gal group, while the expression level of senescence marker P16~(INK4 a) was lower than that in D-gal group. Compared with the PBS group, the protein and mRNA expressions of PI3 K, Akt, mTOR and S6 k in the D-gal group were up-regulated, the protein expressions of Akt, mTOR and S6 k in the Rg_1 group were up-regulated, and the mRNA expressions of PI3 K and mTOR were up-regulated. After treatment with Rg_1, the protein expressions of PI3 K, Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group, while the mRNA expressions of Akt, mTOR and S6 k in the Rg_1 group were lower than those in the D-gal group. The finding ssuggested that Rg_1 has the effect in delaying ovarian premature failure in D-gal-induced mouse models, and PI3 K/Akt/mTOR autophagy signaling pathways play an important role.

Ginsenoside Rg_1 induces leukemia stem cell senescence via SIRT1/TSC_2 signal axis / 中国中药杂志

The aim of this paper was to investigate the effect of SIRT1/TSC_2 signal axis on leukemia stem cell senescence induced by ginsenoside Rg_1. CD34~+CD38~- leukemia stem cells(CD34~+CD38~-LSCs) was isolated by magnetic cell sorting(MACS) and divided into two groups. The control group cells were routinely cultured, 40 μmol·L~(-1) ginsenoside Rg_1 was added to the control group for co-culture in Rg_1 group. The effect of Rg_l to induce CD34~+CD38~-LSCs senescence were evaluated by senescence-associated β-Galactosidase(SA-β-Gal) staining, cell cycle assay, CCK-8 and Colony-Assay. The expression of senescence associated SIRT1, TSC_2 mRNA and protein was examined by Real-time fluorescence quantitative PCR(FQ-PCR) and Western blot. The results showed that the CD34~+CD38~-LSCs could effectively be isolated by MACS, and the purity of CD34~+CD38~-LSCs is up to(95.86±3.04)%. Compared with the control group, the percentage of positive cells expressed SA-β-Gal in the Rg_1 group is increased, the senescence morphological changes were observed in the CD34~+CD38~-LSCs in the Rg_1 group. The proliferation inhibition rate and the number of cells entered G_0/G_1 phase in the Rg_1 group were increased, but the colony-formed ability was decreased, Rg_1 could significantly inhibit the proliferation and self-renewal ability of CD34~+CD38~-LSCs. The expression of SIRT1 and TSC_2 mRNA and protein were down regulated in the Rg_1 group compared with the control group. Our research implied that Rg_1 may induce the senescence of CD34~+CD38~-LSCs and SIRT1/TSC_2 signal axis plays a significant role in this process.

Infection by the nematode Angiostrongylus cantonensis induces differential expression of miRNAs in mouse brain.

BACKGROUND: The parasitic nematode Angiostrongylus cantonensis is the primary pathogen causing eosinophilic meningitis and meningoencephalitis in nonpermissive hosts. The larval parasites are eliminated by the host's immune responses in the central nervous system (CNS) through infiltration of eosinophils and lymphocytes. This study aimed to determine primary alterations of microRNA (miRNA) during A. cantonensis infection in mice. METHODS: miRNA array was used to analyze the expression of miRNA in uninfected and A. cantonensis-infected mouse brains at 21 days postinfection (dpi). Target genes were predicted by miRDB software, and protein-protein interaction network was analyzed using STRING v9.1. Expression levels of selected miRNAs and cytokine production were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Twenty-five mature miRNAs showed differential expression in infected mouse brains, of which 24 were upregulated and one was downregulated compared to the uninfected control. These 25 miRNAs were divided into five clusters, and the first upregulated cluster was selected for further bioinformatics analysis. Target gene prediction and gene ontology (GO) enrichment analysis revealed that the miRNAs were mainly related to the immune response. Furthermore, six target genes of mmu-miR-146a-5p were predicted to interact with tumor necrosis factor alpha (TNF-α). The in vitro study suggested that transfected mmu-miR-146a-5p inhibitor upregulated TNF-α and its target gene Traf6 in microglia following stimulation with A. cantonensis larval antigen. CONCLUSION: This study suggested a critical role of miRNAs in the host defense during A. cantonensis infection, providing new insights into the molecular mechanisms underlying the interaction between mmu-miR-146a-5p and TNF-α in angiostrongyliasis in nonpermissive hosts.

Bacillus Calmette-Guérin-inoculation at different time points influences the outcome of C57BL/6 mice infected with Plasmodium chabaudi chabaudi AS.

Bacillus Calmette-Guérin (BCG) is an attenuated Mycobacterium tuberculosis vaccine. We performed a series of co-infection experiments with BCG-Plasmodium chabaudi chabaudi Landau, 1965 AS using C57BL/6 mice to analyse whether BCG can affect the development of protective immunity to infection with Plasmodium spp. and the mechanism of this protection. We divided mice into four groups: BCG-inoculation 4 weeks prior to P. c. chabaudi AS infection (B-4w-Pc); simultaneous BCG-inoculation and P. c. chabaudi AS infection (Pc+B); BCG-inoculation 3 days post P. c. chabaudi AS (Pc-3-B) infection; and mono-P. c. chabaudi AS infection as control (Pc). The parasitemia level in the B-4w-Pc group was noticeably higher than control group at 6-19 days post infection (dpi). Compared with the control group, the proportion of CD4(+)CD69(+) T cells was significantly reduced 5, 8 and 12 dpi, but the proportion of CD4(+)CD25(+)Foxp3(+) Tregs was significantly increased in the B-4w-Pc group on 5 and 8 dpi. The B-4w-Pc group also demonstrated reduced levels of IFN-γ and TNF-α on 5 and 8 dpi and significantly elevated level of IL-10 on 12 dpi. There were significantly fewer mDCs (CD11c(+)CD11b(+)) and pDCs (CD11c(+)B220(+)) in the B-4w-Pc group than the control group at all the time points post infection and the expression of MHC II was noticeably reduced on day 8 pi. Our findings confirmed that BCG inoculation prior to Plasmodium infection resulted in excessive activation and proliferation of Tregs and upregulation of anti-inflammatory mediators, which inhibited establishment of a Th1-dominant immune response during the early stages of Plasmodium infection by inhibiting dendritive cells response. BCG inoculation prior to P. c. chabaudi AS infection may contribute to overgrowth of parasites as well as mortality in mice.

Application of a real-time PCR method for detecting and monitoring hookworm Necator americanus infections in Southern China.

OBJECTIVE: To develop a quantitative PCR method for detecting hookworm infection and quantification. METHODS: A real-time PCR method was designed based on the intergenic region II of ribosomal DNA of the hookworm Necator americanus. The detection limit of this method was compared with the microscopy-based Kato-Katz method. The real-time PCR method was used to conduct an epidemiological survey of hookworm infection in southern Fujian Province of China. RESULTS: The real-time PCR method was specific for detecting Necator americanus infection, and was more sensitive than conventional PCR or microscopy-based method. A preliminary survey for hookworm infection in villages of Fujian Province confirmed the high prevalence of hookworm infections in the resident populations. In addition, the infection rate in women was significantly higher than that of in men. CONCLUSIONS: A real-time PCR method is designed, which has increased detection sensitivity for more accurate epidemiological studies of hookworm infections, especially when intensity of the infection needs to be considered.