Nocardia cavernae sp. nov., a novel actinobacterium isolated from a karst cave sample.

A novel actinobacterial strain, designated YIM A1135T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic, Gram-stain-positive and partially acid-alcohol-fast. Strain YIM A1135T shared 98.3 % 16S rRNA gene sequence similarity with Nocardia jejuensis NBRC 103114T and 97.6 % with Nocardia alba YIM 30243T. DNA-DNA hybridization values between strain YIM A1135T and related type strains of the genus Nocardia were less than 70 %. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. The whole-cell sugars were fructose, mannose, galactose and glucose. The major isoprenoid quinone was MK-8(H4,ω-cycl), while the major fatty acids (>10 %) were C16 : 0, C18 : 1ω9c, C18 : 0 10-methyl and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. Mycolic acids were present. The genomic DNA G+C content of strain YIM A1135T was 66.7 mol%. Based on the results of the molecular studies supported by its morphological, physiological, chemotaxnomic and other differential phenotypic characteristics, strain YIM A1135T is considered to represent a novel species within the genus Nocardia, for which the name Nocardia cavernae sp. nov. is proposed. The type strain is YIM A1135T (=KCTC 39595T=CCTCC AA 2017030T).

Nonomuraea cavernae sp. nov., a novel actinobacterium isolated from a karst cave sample.

A novel actinobacterial strain, designated SYSU K10005T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-west China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic and Gram-stain-positive. On the basis of 16S rRNA gene sequence analysis, strain SYSU K10005T was most closely related to the type strains of the genus Nonomuraea, and shared highest sequence similarity of 98.4 % with Nonomuraea candida HMC10T. DNA-DNA hybridization values between the two strains were less than 70 %. The whole-cell hydrolysates of strain SYSU K10005T contained meso-diaminopimelic acid (diagnostic diamino acid), and arabinose, madurose and rhamnose (whole-cell sugars). The major isoprenoid quinone was MK-9(H4), while the major fatty acids were iso-C16 : 0, 10-methyl C17 : 0, C17 : 1ω8c and C17 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, hydroxyl-phosphatidylethanolamine, lyso-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, an unidentified lipid, two unidentified ninhydrin-positive phosphoglycolipids and two unidentified phospholipids. The genomic DNA G+C content of strain SYSU K10005T was 64.2 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K10005T can be characterized to represent a novel species of the genus Nonomuraea, for which the name Nonomuraea cavernae sp. nov. is proposed. The type strain is SYSU K10005T (=KCTC 39805T=CGMCC 4.7368T).

Lentzea cavernae sp. nov., an actinobacterium isolated from a karst cave sample, and emended description of the genus Lentzea.

A novel actinobacterial strain, designated SYSU K10001T, was isolated from a limestone sample collected from a karst cave in Xingyi county, Guizhou province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic and Gram-stain-positive. On the basis of 16S rRNA gene sequence analysis, strain SYSU K10001T was most closely related to the type strains of the genus Lentzea, Lentzea albida NBRC 16102T (98.8 % similarity) and Lentzea waywayandensis NRRL B-16159T (98.6 %), and is therefore considered to represent a member of the genus Lentzea. DNA-DNA hybridization values between strain SYSU K10001T and related type strains of the genus Lentzea were less than 70 %. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The whole-cell sugars were arabinose, fructose, mannose and xylose. The major isoprenoid quinone was MK-9(H4), while the major fatty acids (>10 %) were iso-C16 : 0 and C14 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid and one unidentified lipid. The genomic DNA G+C content of strain SYSU K10001T was 69.4 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain SYSU K10001T represents a novel species of the genus Lentzea, for which the name Lentzea cavernae sp. nov. is proposed. The type strain is SYSU K10001T (=KCTC 39804T=CGMCC 4.7367T=NBRC 112394T).

Nocardioides cavernae sp. nov., an actinobacterium isolated from a karst cave.

A novel actinobacterial strain, designated YIM A1136T, was isolated from a soil sample collected from a karst cave in Xingyi county, Guizhou province, south-western China. The taxonomic position of the strain was investigated using a polyphasic approach. Cells of the strain were aerobic, Gram-staining-positive and rod-shaped. Colonies of the strain were circular, convex, opaque and yellowish-white in colour. On the basis of 16S rRNA gene sequence analysis, strain YIM A1136T was most closely related to the type strains Nocardioides ganghwensis JC2055T (98.3 % sequence similarity), Nocardioides exalbidus RC825T (98.2 %), Nocardioides alpinus Cr7-14T (98.2 %), Nocardioides hwasunensis HFW-21T (98.0 %), Nocardioides oleivorans DSM 16090T (97.9 %) and Nocardioides furvisabuli SBS-26T (97.8 %) and is therefore considered to represent a member of the genus Nocardioides. DNA-DNA hybridization values between strain YIM A1136T and related type strains of the genus Nocardioides were less than 70 %. ll-Diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The whole-cell sugars were galactose, glucose, mannose, rhamnose and ribose. The major isoprenoid quinone was MK-8(H4), while the major fatty acids (>10 %) were C16 : 0, summed feature 3 and summed feature 8. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unidentified phospholipids. The genomic DNA G+C content was 71.4 mol%. On the basis of phenotypic, genotypic and phylogenetic data, strain YIM A1136T merits representation of a novel species of the genus Nocardioides, for which the name Nocardioides cavernae sp. nov. is proposed. The type strain is YIM A1136T (=KCTC 39551T=DSM 29950T).

Streptomyces xinjiangensis sp. nov., an actinomycete isolated from Lop Nur region.

A novel actinobacterial strain, designated LPA192(T), was isolated from a soil sample collected from Lop Nur, Xinjiang Uygur Autonomous Region, Northwest China. A polyphasic approach was used to investigate the taxonomic position of strain LPA192(T). The isolate showed morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. Peptidoglycan was found to contain LL-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H6) and MK-10(H4). Polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylinositol. Major cellular fatty acids consist of C16:0, anteiso-C15:0 and C18:1 ω9c. The sugar in whole-cell hydrolysates was mannose. Phylogenetic analysis indicated that strain LPA192(T) is closely related to Streptomyces tanashiensis LMG 20274(T) (99.3 %), Streptomyces gulbargensis DAS131(T) (99.3 %), Streptomyces nashvillensis NBRC 13064(T) (99.3 %), Streptomyces roseolus NBRC 12816(T) (99.2 %) and Streptomyces filamentosus NBRC 12767(T) (99.1 %) while showing below 98.5 % sequencing similarities with other validly published Streptomyces species. However, DNA-DNA relatedness values between LPA192(T) and the closely related type strains were below 40 %, which are much lower than 70 % threshold value for species delineation. The genomic DNA G + C content of strain LPA192(T) was 69.3 mol %. Based on the differences in genotypic and phenotypic characteristics from the closely related strains, strain LPA192(T) is considered to represent a novel species of the genus Streptomyces for which the name Streptomyces xinjiangensis sp. nov. is proposed. The type strain is LPA192(T) (=KCTC 39601(T) = CGMCC 4.7288(T)).

Stackebrandtia cavernae sp. nov., a novel actinobacterium isolated from a karst cave sample.

A novel actinobacterial strain, YIM ART06T, was isolated from a rock sample of karst cave located at Guizhou province, south-west China, and was characterized by a polyphasic taxonomic approach. The morphological and chemotaxonomic properties of strain YIM ART06T were in accordance with those of the genus Stackebrandtia. The 16S rRNA gene sequence of strain YIM ART06T showed highest similarity to Stackebrandtia nassauensis JCM 14905T (98.0 %). The DNA-DNA hybridization value between strains YIM ART06T and S. nassauensis JCM 14905T was, however, moderately high (62.9 %) but below the 70 % limit for species identification. Strain YIM ART06T contained meso-diaminopimelic acid as the diagnostic diamino acid, and mannose, ribose and xylose in the whole-cell hydrolysates. The predominant menaquinones detected were MK-10(H4), MK-10(H6), MK-11(H4) and MK-11(H6), while the cell membrane polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine and three unidentified phospholipids. The genomic DNA G+C content of strain YIM ART06T was 71 mol%. The major fatty acids were anteiso-C17 : 0, iso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. Based on the taxonomic characteristics from the genotypic and phenotypic results, strain YIM ART06T merits recognition as a representative of a novel species of the genus Stackebrandtia, for which the name Stackebrandtia cavernae sp. nov. is proposed. The type strain is YIM ART06T ( = KCTC 39599T = CCTCC AA 2015021T = DSM 100594T).

Scorpion Venom Heat-Resistant Peptide Attenuates Glial Fibrillary Acidic Protein Expression via c-Jun/AP-1.

Scorpion venom has been used in the Orient to treat central nervous system diseases for many years, and the protein/peptide toxins in Buthus martensii Karsch (BmK) venom are believed to be the effective components. Scorpion venom heat-resistant peptide (SVHRP) is an active component of the scorpion venom extracted from BmK. In a previous study, we found that SVHRP could inhibit the formation of a glial scar, which is characterized by enhanced glial fibrillary acidic protein (GFAP) expression, in the epileptic hippocampus. However, the cellular and molecular mechanisms underlying this process remain to be clarified. The results of the present study indicate that endogenous GFAP expression in primary rat astrocytes was attenuated by SVHRP. We further demonstrate that the suppression of GFAP was primarily mediated by inhibiting both c-Jun expression and its binding with AP-1 DNA binding site and other factors at the GFAP promoter. These results support that SVHRP contributes to reducing GFAP at least in part by decreasing the activity of the transcription factor AP-1. In conclusion, the effects of SVHRP on astrocytes with respect to the c-Jun/AP-1 signaling pathway in vitro provide a practical basis for studying astrocyte activation and inhibition and a scientific basis for further studies of traditional medicine.

Neuroprotection by scorpion venom heat resistant peptide in 6-hydroxydopamine rat model of early-stage Parkinson's disease.

Neuroprotective effect of scorpion venom on Parkinson's disease (PD) has already been reported. The present study was aimed to investigate whether scorpion venom heat resistant peptide (SVHRP) could attenuate ultrastructural abnormalities in mitochondria and oxidative stress in midbrain neurons of early-stage PD model. The early-stage PD model was established by injecting 6-hydroxydopamine (6-OHDA) (20 µg/3 µL normal saline with 0.1% ascorbic acid) into the striatum of Sprague Dawley (SD) rats unilaterally. The rats were intraperitoneally administered with SVHRP (0.05 mg/kg per day) or vehicle (saline) for 1 week. Two weeks after 6-OHDA treatment, the rats received behavior tests for validation of model. Three weeks after 6-OHDA injection, the immunoreactivity of dopaminergic neurons were detected by immunohistochemistry staining, and the ultrastructure of neuronal mitochondria in midbrain was observed by electron microscope. In the meantime, the activities of monoamine oxidase-B (MAO-B), superoxide dismutase (SOD) and content of malondialdehyde (MDA) in the mitochondria of the midbrain neurons, as well as the inhibitory ability of hydroxyl free radical and the antioxidant ability in the serum, were measured by corresponding kits. The results showed that 6-OHDA reduced the optical density of dopaminergic neurons, induced damage of mitochondrial ultrastructure of midbrain neurons, decreased SOD activity, increased MAO-B activity and MDA content, and reduced the antioxidant ability of the serum. SVHRP significantly reversed the previous harmful effects of 6-OHDA in early-stage PD model. These findings indicate that SVHRP may contribute to neuroprotection by preventing biochemical and ultrastructure damage changes which occur during early-stage PD.

Transferrin receptor 1 promotes hepatocellular carcinoma progression and metastasis by activating the mTOR signaling pathway.

BACKGROUND: Aberrant iron metabolism is commonly observed in multiple tumor types, including hepatocellular carcinoma (HCC). However, as the key regulator of iron metabolism involved in iron absorption, the role of transferrin receptor (TFRC) in HCC remains elusive. METHODS: The mRNA and protein expression of TFRC were evaluated in paired HCC and adjacent non-tumor specimens. The correlation between TFRC level and clinicopathological features or prognostic significance was also analyzed. The role of TFRC on biological functions was finally studied in vitro and in vivo. RESULTS: The TFRC level was remarkably upregulated in HCC tissues compared to paired peritumor tissues. Overexpressed TFRC positively correlated with serum alpha-fetoprotein, carcinoembryonic antigen, and poor tumor differentiation. Multivariate analysis demonstrated that upregulated TFRC was an independent predictive marker for poorer overall survival and disease-free survival in HCC patients. Loss of TFRC markedly impaired cell proliferation and migration in vitro and notably suppressed HCC growth and metastasis in vivo, while overexpression of TFRC performed an opposite effect. Mechanistically, the mTOR signaling pathway was downregulated with TFRC knockdown, and the mTOR agonist MHY1485 completely reversed the biological inhibition in HCC cells caused by TFRC knockdown. Furthermore, exogenous ferric citrate (FAC) or iron chelator reversed the changed biological functions and signaling pathway expression of HCC cells caused by TFRC knockdown or overexpression, respectively. CONCLUSIONS: Our study indicates that TFRC exerts an oncogenic role in HCC and may become a promising therapeutic target to restrain HCC progression.

Alterations in gut microbiome and metabolomics in chronic hepatitis B infection-associated liver disease and their impact on peripheral immune response.

Gut dysbiosis has been reported in chronic hepatitis B (CHB) infection, however its role in CHB progression and antiviral treatment remains to be clarified. Herein, the present study aimed to characterize gut microbiota (GM) in patients with chronic hepatitis B virus infection-associated liver diseases (HBV-CLD) by combining microbiome with metabolome analyses and to evaluate their effects on peripheral immunity. Fecal samples from HBV-CLD patients (n = 64) and healthy controls (n = 17) were collected for 16s rRNA sequencing. Fecal metabolomics was measured with untargeted liquid chromatography-mass spectrometry in subgroups of 58 subjects. Lineage changes of peripheral blood mononuclear cells (PBMCs) were determined upon exposure to bacterial extracts (BE) from HBV-CLD patients. Integrated analyses of microbiome with metabolome revealed a remarkable shift of gut microbiota and metabolites in HBV-CLD patients, and disease progression and antiviral treatment were found to be two main contributing factors for the shift. Concordant decreases in Turicibacter with 4-hydroxyretinoic acid were detected to be inversely correlated with serum AST levels through host-microbiota-metabolite interaction analysis in cirrhotic patients. Moreover, depletion of E.hallii group with elevated choline was restored in patients with 5-year antiviral treatment. PBMC exposure to BE from non-cirrhotic patients enhanced expansion of T helper 17 cells; however, BE from cirrhotics attenuated T helper 1 cell count. CHB progression and antiviral treatment are two main factors contributing to the compositional shift in microbiome and metabolome of HBV-CLD patients. Peripheral immunity might be an intermediate link in gut microbe-host interplay underlying CHB pathogenesis.

Integrated analyses of microbiome with metabolomics revealed a remarkable shift of gut microbiota and metabolites in HBV-CLD patients. Disease progression and entecavir treatment were found to be two main contributing factors for the shift. Novel host-microbiota-metabolite interplay was investigated (red, positive correlation; blue, negative correlation). Ex vivo results showed that exposure of PBMCs to BE from non-cirrhotic patients promoted expansion of T helper 17 cells whilst BE from cirrhotic patients attenuated T helper 1 cell count, suggesting peripheral immunity may be one of mechanisms by which overall bacterial products exert profibrotic effects and have an impact on prognosis of HBV-CLD patients. Our research confers new insights into the role of gut dysbiosis and metabolomics in the pathogenesis of HBV-CLD, and underscores that disrupted peripheral immunity homeostasis during the microbe-host interplay may contribute to fibrosis progression in HBV-CLD. CHB, chronic hepatitis B (treatment-naive); Crrh, cirrhosis; ETV, entecavir; HBV-CLD, chronic hepatitis B virus infection-associated liver diseases; HCs, healthy controls; MCFAs, medium chain fatty acids; NC, non-cirrhosis; Th1, T helper 1; Th17, T helper 17.Abbreviations: ALB, albumin; ALP, alkaline phosphatase; ANOISM, analysis of similarities; AST, aspartate aminotransferase; BE, bacterial extracts; BMI, body mass index; CC, compensated cirrhosis; CHB, chronic hepatitis B; DB, direct bilirubin; DC, decompensated cirrhosis; DCA, deoxycholic acid; ETV, entecavir; FDR, false discovery rate; GGT, γ-glutamyl transpeptidase; GM, gut microbiota; HBV, hepatitis B virus; HBV-CLD, chronic hepatitis B virus infection-associated liver diseases; HCs, healthy controls; HCC, hepatocellular carcinoma; LC-MS, liquid chromatography-mass spectrometry; LRE, liver-related events; LS, liver stiffness; ImP, imidazole propionate; IQR, interquartile range; MCFAs, medium chain fatty acids; OCT, organic cation transporter; OPLS-DA, orthogonal partial least square discriminant analysis; PBMCs, peripheral blood mononuclear cells; PERMANOVA, permutational multivariate analysis of variance; PLS-DA, partial least square discriminant analysis; PCA, principal component analysis; PcoA, principal coordinates analysis; PT, prolonged prothrombin time; SDs, standard deviations; TB, total bilirubin; Tregs, regulatory T cells; Th1, T helper 1; Th17, T helper 17.

Shengmai San for Treatment of Cardiotoxicity from Anthracyclines: A Systematic Review and Meta-Analysis.

OBJECTIVE: To systematically evaluate the efficacy of Shengmai San in patients with cardiotoxicity of anthracyclines. METHODS: Randomized controlled trials (RCTs) were identified by searching China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Biomedical Literature Database (CBM), PubMed, Cochrane Library, and Embase Databases from the inceptions until December 2020. The Cochrane Handbook was used to evaluate the risk of bias in the included studies. Data analysis was conducted using RevMan 5.3 software. RESULTS: Totally 19 RCTs with 2,331 participants were included in this review. Results showed that in improving arrhythmia (13 RCTs, n=1,877, RR=0.37, 95%CI 0.25 to 0.52, P<0.00001), the treatment group was superior to the control group. In terms of reducing left ventricular end-diastolic diameter (LVEDD, 2 RCTs, n=128, MD=-0.79, 95%CI -0.93 to -0.65, P<0.00001) and left ventricular end systolic diameter (LVESD, 2 RCTs, n=128, MD=-0.58, 95%CI -0.82 to -0.35, P<0.00001), the treatment group was also better than the control group. In reducing myocardial enzymes such as creatine kinase (CK) [(3 RCTs, n=256, SMD=-0.80, 95%CI -1.16 to -0.44, P<0.0001), (2 RCTs, n=126, SMD=-0.62, 95%CI -0.98 to -0.26, P=0.0007)], the treatment group was superior to the control group. CONCLUSION: Shengmai San has a positive effect on the treatment of cardiotoxicity from anthracyclines. However, in the future, it is still necessary to conduct high-quality RCTs to verify its efficacy.

TMA/TMAO in Hypertension: Novel Horizons and Potential Therapies.

Hypertension is the most prevalent chronic disease and a risk factor for various diseases. Although its mechanisms and therapies are constantly being updated and developed, they are still not fully clarified. In recent years, novel gut microbiota and its metabolites have attracted widespread attention. It is strongly linked with physiological and pathological systems, especially TMA and TMAO. TMA is formed by intestinal microbial metabolism of choline and L-carnitine and converted into TMAO by FMO3. This paper collected and collated the latest researches and mainly discussed the following four parts. It introduced gut microbiota; provided a focus on TMA, TMA-producing bacteria, and TMAO; summarized the alternations in hypertensive patients and animals; discussed the mechanisms of TMAO with two respects; and summarized the regulatory factors may be as new interventions and therapies of hypertension. And, more relevant studies are still prospected to be accomplished between hypertension and TMA/TMAO for further clinical services.

[Inhibition of sodium channels in acutely isolated hippocampal neurons by scorpion venom heat resistant protein].

The effects of scorpion venom heat resistant protein (SVHRP) on sodium channel were studied in freshly isolated hippocampal neurons in rat using the whole-cell patch-clamp technique. The results indicated that tetrodotoxin-sensitive voltage-dependent sodium current in hippocampal neurons was inhibited by SVHRP in a dose-dependent manner. The half-inhibition concentration (IC(50)) was (0.0034+/-0.0004) microg/mL, Hill constant (n) was 0.4361+/-0.0318. After SVHRP application, a clear shift of the activation curve of Na(+) channel was shown towards more depolarized potential, resulting in channel opening at more positive membrane potentials. In the presence of 0.1 mug/mL SVHRP, the voltage for half-activation (V(1/2)) and the slope factor of the activation curve were (-23.96+/-0.41) mV and 3.73+/-0.08 (n=8, P<0.05) compared with the control recordings of (-34.38+/-0.62) mV and 4.52+/-0.52 (n=16), respectively. Averaged and normalized curve of steady-state inactivation of Na(+) channel was shifted towards negative potential after treatment of 0.1 and 0.01 mug/mL SVHRP. In the presence of 0.1 mug/mL SVHRP, the voltage for half-inactivation (V(1/2)) and the slope factor determined by a sigmoid fit of the inactivation curve were (-50.69+/-2.55) mV (n=8, P<0.01) and 5.49+/-0.72 (n=8, P<0.05) compared with the control recordings of (-32.60+/-1.52) mV and 6.73+/-0.51 (n=16), respectively. These results suggest that SVHRP blocks the voltage-dependent sodium currents and alters the sodium channel kinetics to decrease the excitability of neurons. This might be an interpretation for the antiepileptic effects of SVHRP.

Inhibitory effects of scorpion venom heat resistant protein on the excitability of acutely isolated rat hippocampal neurons.

The effects of scorpion venom heat resistant protein (SVHRP) (National invention patent of China, 2004-10-20, No. ZL01 1 06166.92) on the excitability of acutely isolated rat hippocampal neurons were observed by whole-cell recording and the potential molecular mechanisms underlying its antiepileptic effect were investigated further. The results showed that SVHRP could decrease the excitability of hippocampal neurons. SVHRP (1x 10(-2) microg/mL) altered the action potential (AP) firing mode and decreased the AP firing frequency. Out of 52 neurons observed, 45 (86.54%) generated phasic firing, and 7 (13.46%) generated repetitive firing. Among the 45 neurons generating phasic firing, 8 (17.78%) neurons could still be induced phasic firing after treatment with 1x 10(-2) microg/mL SVHRP and 37 (82.22%) neurons had no responses to the stimulation. The AP firing of neurons was dramatically different after treatment with SVHRP (P<0.01, n=45). Among the 7 repetitive firing neurons, all of them could only generate 1 or 0 AP instead of repetitive firing when SVHRP was applied. The number of APs was 14.57 +/- 1.00 and 0.57 +/- 0.20 before and after SVHRP treatment (P<0.01, n=7). The AP rheobase was (75.10 +/- 8.99) pA and (119.85 +/- 12.73) pA before and after 1x 10(-4) microg/mL SVHRP application, respectively (P<0.01, n=8). The AP threshold was increased from (-41.17 +/- 2.15) mV to (-32.40 +/- 1.48) mV after 1x 10(-4) microg/mL SVHRP treatment (P<0.01, n=8). The peak amplitude of AP was (68.49 +/- 2.33) mV for the neurons before treatment with 1x 10(-4) microg/mL SVHRP and (54.71 +/- 0.81) mV after treatment (P<0.01, n=8). These results showed that SVHRP could decrease the AP firing frequency, increase the AP rheobase and threshold, but decrease the AP peak amplitude of hippocampal neurons. In other words, SVHRP can decrease the excitability of hippocampal neurons. SVHRP probably alters the excitability of hippocampal neurons by affecting sodium channels and this may be one of the underlying molecular mechanisms for its antiepileptic effect.

[The rate of hepatitis B virus resistance to adefovir dipivoxil (ADV) and the evolution of hepatitis B virus in lamivudine-resistant chronic hepatitis B patients with ADV monotherapy].

OBJECTIVE: To study the resistant rate of hepatitis B virus (HBV) to ADV and the dynamic evolution of HBV in lamivudine (Lam)-resistant chronic hepatitis B (CHB) patients. METHODS: Twenty-three Lam-resistant CHB patients were assigned to a 10mg/d ADV monotherapy for 68-116 weeks. The baseline and different time point blood samples after ADV monotherapy were analyzed for ADV-resistant mutations using direct sequencing of PCR products; the evolution of HBV mutations was examined by clonal analysis of serial samples from one patient infected with ADV-associated resistant HBV strains. RESULTS: The cumulative incidence of genotypic ADV resistance at weeks 48 and 96 was 4.3% and 10.5% respectively respectively. The evolution analysis of HBV mutant strains in an ADV-resistant CHB patient showed that the proportion of YMDD mutants gradually decreased with rtA181S mutants increasing over time after ADV monotherapy, and that rtA181S+N236T mutants became the predominant strains during prolonged ADV monotherapy. The addition of Lam to the ongoing ADV treatment had poorer antiviral response in the patient with rtA181S or rtA181S+N236T mutant infection; one clone with multi-drug resistant mutations was selected during Lam and ADV combination therapy. CONCLUSION: Increased risk of adefovir resistance and selection of multi-drug resistant mutations are associated with long-term ADV monotherapy in patients with Lam-resistant chronic hepatitis B.

Scorpion Venom Heat-Resistant Peptide Protects Transgenic Caenorhabditis elegans from ß-Amyloid Toxicity.

Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Our previous studies found SVHRP could enhance neurogenesis and inhibit microglia-mediated neuroinflammation in vivo. Here, we use the transgenic CL4176, CL2006, and CL2355 strains of Caenorhabditis elegans which express the human Aß1-42 to investigate the effects and the possible mechanisms of SVHRP mediated protection against Aß toxicity in vivo. The results showed that SVHRP-fed worms displayed remarkably decreased paralysis, less abundant toxic Aß oligomers, reduced Aß plaque deposition with respect to untreated animals. SVHRP also suppressed neuronal Aß expression-induced defects in chemotaxis behavior and attenuated levels of ROS in the transgenic C. elegans. Taken together, these results suggest SVHRP could protect against Aß-induced toxicity in C. elegans. Further studies need to be conducted in murine models and humans to analyze the effectiveness of the peptide.

The role of microglia in paraquat-induced dopaminergic neurotoxicity.

The herbicide paraquat (PQ) has been implicated as a potential risk factor for the development of Parkinson's disease. In this study, PQ (0.5-1 microM) was shown to be selectively toxic to dopaminergic (DA) neurons through the activation of microglial NADPH oxidase and the generation of superoxide. Neuron-glia cultures exposed to PQ exhibited a decrease in DA uptake and a decline in the number of tyrosine hydroxylase-immunoreactive cells. The selectivity of PQ for DA neurons was confirmed when PQ failed to alter gamma-aminobutyric acid uptake in neuron-glia cultures. Microglia-depleted cultures exposed to 1 microM PQ failed to demonstrate a reduction in DA uptake, identifying microglia as the critical cell type mediating PQ neurotoxicity. Neuron-glia cultures treated with PQ failed to generate tumor necrosis factor-alpha and nitric oxide. However, microglia-enriched cultures exposed to PQ produced extracellular superoxide, supporting the notion that microglia are a source of PQ-derived oxidative stress. Neuron-glia cultures from NADPH oxidase-deficient (PHOX-/-) mice, which lack the functional catalytic subunit of NADPH oxidase and are unable to produce the respiratory burst, failed to show neurotoxicity in response to PQ, in contrast to PHOX+/+ mice. Here we report a novel mechanism of PQinduced oxidative stress, where at lower doses, the indirect insult generated from microglial NADPH oxidase is the essential factor mediating DA neurotoxicity.

[The alterations of apoptosis factor Bcl-2/Bax in the early Parkinson's disease rats and the protective effect of scorpion venom derived activity peptide].

OBJECTIVE: To explore the alterations of apoptosis factor Bcl-2/Bax in the early Parkinson's disease (PD) rats and the protective effect of scorpion venom derived bioactive peptide. METHODS: Healthy male SD rats (180-220 g) were randomly divided into 4 groups (n = 10): early PD model group, sham operation group, scorpion venom derived bioactive peptide control group, scorpion venom derived bioactive peptide therapy group. 6-hydroxydopamine (6-OHDA) was used to prepare the early PD rat model. The immunohistochemistry was used to detect the expression of Bax and Bcl-2 and further explore the mechanism of anti-apoptosis regarding the neuroprotective effect of scorpion venom derived bioactive peptide. RESULTS: The results indicated that compared with the control rats, the immunostaining of Bax in the brain increased significantly while that of Bcl-2 decreased significantly in the lesion side of 6-OHDA treated rats. Interestingly, scorpion venom derived bioactive peptide could attenuate the above abnormal changes. CONCLUSION: Up-regulation of Bax and down-regulation of Bcl-2 could participate in the early stage of PD and the anti-apoptotic mechanism could be involved in the neuroprotective effect exerted by scorpion venom derived activity peptide regarding the dopaminergic neuron in the early stage.

Effects of chronic administration of PL017 and beta-funaltrexamine hydrochloride on susceptibility of kainic acid-induced seizures in rats.

There is evidence that 5-7 d after acute seizure episodes induced by kainic acid (KA) the rats develop a long-lasting increase in the susceptibility to seizures followed by spontaneous recurrent seizures (SRS). The present study was focused on the role of hippocampal mu opioid receptors (MORs) in the susceptibility of rats to seizures with the KA model of epilepsy. The rats received a convulsant dose of KA (10 mg/kg, i.p.) were continuously infused with a selective MOR agonist PL017 (2.09, 2.59, 3.29 microg/microl), or a selective MOR antagonist beta-funaltrexamine hydrochloride (beta-FNA, 0.88, 1.10, and 1.35 microg/microl) into ventral hippocampus by means of mini-osmotic pumps. Seven days later, the susceptibility of rats to seizures was checked by a subconvulsant dose of KA (5 mg/kg, i.p.). PL017 infusion shortened the latency and increased the stage of seizures induced by subconvulsant dose of KA in a dose-dependent manner. In contrast, infusion of beta-FNA exhibited a dose-dependent effect against seizures challenged by subconvulsant dose of KA. These results indicate that hippocampal MOR may exert a promoting effect on the susceptibility of rats to KA-induced seizures.

Scorpion venom heat-resistant peptide (SVHRP) enhances neurogenesis and neurite outgrowth of immature neurons in adult mice by up-regulating brain-derived neurotrophic factor (BDNF).

Scorpion venom heat-resistant peptide (SVHRP) is a component purified from Buthus martensii Karsch scorpion venom. Although scorpions and their venom have been used in Traditional Chinese Medicine (TCM) to treat chronic neurological disorders, the underlying mechanisms of these treatments remain unknown. We applied SVHRP in vitro and in vivo to understand its effects on the neurogenesis and maturation of adult immature neurons and explore associated molecular mechanisms. SVHRP administration increased the number of 5-bromo-2'-dexoxyuridine (BrdU)-positive cells, BrdU-positive/neuron-specific nuclear protein (NeuN)-positive neurons, and polysialylated-neural cell adhesion molecule (PSA-NCAM)-positive immature neurons in the subventricular zone (SVZ) and subgranular zone (SGZ) of hippocampus. Furthermore immature neurons incubated with SVHRP-pretreated astrocyte-conditioned medium exhibited significantly increased neurite length compared with those incubated with normal astrocyte-conditioned medium. This neurotrophic effect was further confirmed in vivo by detecting an increased average single area and whole area of immature neurons in the SGZ, SVZ and olfactory bulb (OB) in the adult mouse brain. In contrast to normal astrocyte-conditioned medium, higher concentrations of brain-derived neurotrophic factor (BDNF) but not nerve growth factor (NGF) or glial cell line-derived neurotrophic factor (GDNF) was detected in the conditioned medium of SVHRP-pretreated astrocytes, and blocking BDNF using anti-BDNF antibodies eliminated these SVHRP-dependent neurotrophic effects. In SVHRP treated mouse brain, more glial fibrillary acidic protein (GFAP)-positive cells were detected. Furthermore, immunohistochemistry revealed increased numbers of GFAP/BDNF double-positive cells, which agrees with the observed changes in the culture system. This paper describes novel effects of scorpion venom-originated peptide on the stem cells and suggests the potential therapeutic values of SVHRP.