Tanshinone IIA prevents LPS-induced inflammatory responses in mice via inactivation of succinate dehydrogenase in macrophages

Metabolic reprogramming is associated with NLRP3 inflammasome activation in activated macrophages, contributing to inflammatory responses. Tanshinone IIA (Tan-IIA) is a major constituent from Salvia miltiorrhiza Bunge, which exhibits anti-inflammatory activity. In this study, we investigated the effects of Tan-IIA on inflammation in macrophages in focus on its regulation of metabolism and redox state. In lipopolysaccharides (LPS)-stimulated mouse bone marrow-derived macrophages (BMDMs), Tan-IIA (10 μM) significantly decreased succinate-boosted IL-1β and IL-6 production, accompanied by upregulation of IL-1RA and IL-10 release via inhibiting succinate dehydrogenase (SDH). Tan-IIA concentration dependently inhibited SDH activity with an estimated IC50 of 4.47 μM in LPS-activated BMDMs. Tan-IIA decreased succinate accumulation, suppressed mitochondrial reactive oxygen species production, thus preventing hypoxia-inducible factor-1α (HIF-1α) induction. Consequently, Tan-IIA reduced glycolysis and protected the activity of Sirtuin2 (Sirt2), an NAD+-dependent protein deacetylase, by raising the ratio of NAD+/NADH in activated macrophages. The acetylation of α-tubulin was required for the assembly of NLRP3 inflammasome; Tan-IIA increased the binding of Sirt2 to α-tubulin, and thus reduced the acetylation of α-tubulin, thus impairing this process. Sirt2 knockdown or application of Sirt2 inhibitor AGK-2 (10 μM) neutralized the effects of Tan-IIA, suggesting that Tan-IIA inactivated NLRP3 inflammasome in a manner dependent on Sirt2 regulation. The anti-inflammatory effects of Tan-IIA were observed in mice subjected to LPS challenge: pre-administration of Tan-IIA (20 mg/kg, ip) significantly attenuated LPS-induced acute inflammatory responses, characterized by elevated IL-1β but reduced IL-10 levels in serum. The peritoneal macrophages isolated from the mice displayed similar metabolic regulation. In conclusion, Tan-IIA reduces HIF-1α induction via SDH inactivation, and preserves Sirt2 activity via downregulation of glycolysis, contributing to suppression of NLRP3 inflammasome activation. This study provides a new insight into the anti-inflammatory action of Tan-IIA from the respect of metabolic and redox regulation.

Genetic variability of Myzus persicae nicotianae densovirus based on partial NS and VP gene sequences

We previously described a novel densovirus [Myzus persicae nicotianae densovirus (MpnDV)] infecting M. persicae nicotianae (Hemiptera: Aphididae) with 34% prevalence. This single-stranded DNA virus has a 5480-nucleotide ambisense genome and belongs to the Densovirinae subfamily within the family Parvoviridae. In the present study, we estimated the genetic diversity of MpnDV using partial nonstructural protein (NS) and capsid protein (VP) gene sequences from 10 locations in China. First, we identified MpnDV-positive samples by amplifying a 445-bp fragment with primers MpDVF/MpDVR. Subsequently, we amplified and sequenced COI genes with primers MpCOIF/ MpCOIR, and partial NS and VP sequences with primers MpnDVF1/MpnDVR1. The respective 655-, 1461-, and 423-bp COI, NS, and VP fragments were used to analyze the genetic diversity of MpnDV using MEGA 6.0 and DnaSP 5.0. The high level of identity shared by all COI sequences (>99%) suggested that the aphids sampled were of the same species, and indicated population homogeneity across the 10 locations investigated. The nucleotide diversity of MpnDV sequences (0.0020 ± 0.0025) was significantly higher than that of the COI genes (0.0002 ± 0.0005). The pairwise fixation index for MpnDV was 0.832, and the total gene flow was 0.05. Phylogenetic analysis revealed that the MpnDV haplotypes clustered according to geographical location, except for those from the Liaoning and Shanxi provinces. In conclusion, MpnDV demonstrated a low level of gene flow and high genetic diversity, suggesting that it is vertically transmitted, and implying that endosymbiotic viruses could be used as markers in studies of insect population genetics.

Modulation of BCRP mediated atypical multidrug resistance phenotype by RNA interference

Multidrug resistance (MDR) in human cancers is one of the major causes of failure of chemotherapy. The emergence of breast cancer resistance protein (BCRP), a member of the ABC transporter family, has necessitated the development of antagonists. To overcome the BCRP-mediated atypical multidrug drug resistance, two small interfering RNA constructs (RNAi) targeting two different regions of BCRP mRNA were designed to inhibit the atypical MDR expression by transfecting them into MCF-7/MX100 cell lines. The multidrug resistance index to mitoxantrone and the intensity of mitoxantrone fluorescence of MCF-7/MX100 decreased after transfected by pSUPER-BCRP-A and pSUPER-BCRP-B respectively; the BCRP mRNA level and the BCRP protein level of MCF-7/MX100 decreased after treated with pSUPER-BCRPs. The two constructed RNAi plasmids could reverse the atypical mutidrug resistance mediated by BCRP, but neither can reversed it completely, this may be due to low transfection efficiency and transient transfection.

[Determination of the pKa value of icariin and its content in the Chinese herb medicine epimedium grandiflorum morr. by capillary electrophoresis]

Knowledge of dissociation constants is important for prediction and understanding the migration behavior of analytes in capillary electrophoresis. Icariin is the active component of the Chinese herb medicine Epimedium grandiflorum Morr.. In order to determine the dissociation constant of icariin and to show many important pharmacology activities, a CZE method has been used to determine the ion mobility (mu A-) and the pKa value of icariin based on the non-linear relation between mu eff and [H+] and the linear relation between the reciprocal of effective mobility of the solute (1/mu eff) and the [H+] of the buffer solution. In addition, the change of pKa of icariin with the increase of ethanol concentration in the buffer was also investigated. Under the buffer condition of 24 mmol/L phosphate + 30% ethanol, the content of the active component icariin in Chinese herb Epimedium grandiflorum Morr. was quantitatively determined. The linear correlation equation was Y = 6.96 x 10(-3) + 17.0X, and the linear range is 0.032 g/L-0.354 g/L.

[Determination of the active components in Chinese herb Aloe vera L. var. chinensis (Haw.) Berger by capillary zone electrophoresis]

It has been proved that the Chinese herb Aloe vera L. var. chinensis (Haw.) Berger as well as its active components showed many important pharmacology activities. In order to find an easy and low-cost method to control the quality of the herb, a CZE method for the determination of the active components aloin and aloe-emodin in Aloe vera L. var. chinensis (Haw.) Berger was developed in this work. Under the buffer conditions of 24 mmol/L phosphate (pH 10.52), applied voltage of 15 kV and detector wavelength of 254 nm, baseline separation of the active compounds in Aloe vera L. var. chinensis (Haw.) Berger was achieved and the active components were quantitatively analyzed. The linear calibration equations of the two components are: Y= -0.140 + 57.2X (r = 0.997) for aloin and Y = -0.393 + 1.08 x 10(2) X (r = 0.999) for aloe-emodin respectively. In addition, the effects of buffer pH value and organic modifier on the migration behavior of the solutes were also investigated.

[Comparative study of the effect of wei-yan-ning and furazolidone in the treatment of gastritis and gastric ulcer caused by pyloric Campylobacter]

Wei-Yan-Ning and Furazolidone were used separately in the treatment of 62 cases of gastritis and gastric ulcer caused by pyloric campylobacteria. The examinations one month later proved, through the gastrofiberscopy and pathological test as well as the urease test, that, among the 40 cases of Wei-Yan-Ning group, there were 25 cures (62.5%), prominent effect for 9 cases (22.5%), improvement for 3 cases (7.5%). The total effective rate was 92.5%. Among the 22 cases of the Furazolidone group, there were 7 cures (31.8%), prominent effect for 5 cases (22.7%), improvement for 4 cases (18.2%). The total effective rate was 72.7%. As for the improvement of symptom, the average time for the Wei-Yan-Ning group was 12.5 +/- 8.12 days; and the Furazolidone group was 21.63 +/- 7.87 days. Therefore, the effect of Wei-Yan-Ning group was superior to that of the Furazolidone group (P less than 0.05).