Efficient Bioproduction of Indigo and Indirubin by Optimizing a Novel Terpenoid Cyclase XiaI in Escherichia coli.

Blue indigo dye, an important natural colorant, is used for textiles and food additives worldwide, while another red isomer, indirubin, is the major active ingredient of a traditional Chinese medicine named "Danggui Longhui Wan" for treating various diseases including granulocytic leukemia, cancer, and Alzheimer's disease. In this work, we constructed a new and highly efficient indigoid production system by optimizing a novel terpenoid cyclase, XiaI, from the xiamycin biosynthetic pathway. Through introducing the flavin-reducing enzyme Fre, tryptophan-lysing and -importing enzymes TnaA and TnaB, and H2O2-degrading enzyme KatE and optimizing the fermentation parameters including temperature, the concentration of isopropyl-ß-d-thiogalactopyranoside, and feeding of the l-tryptophan precursor, the final maximum productivity of indigoids by the recombinant strain Escherichia coli BL21(DE3) (XiaI-Fre-TnaAB-KatE) was apparently improved to 101.9 mg/L, an approximately 60-fold improvement to that of the starting strain E. coli BL21(DE3) (XiaI) (1.7 mg/L). In addition, when the fermentation system was enlarged to 1 L in the flask (feeding with 5 mM tryptophan and 10 mM 2-hydroxyindole), the indigoid productivity further increased to 276.7 mg/L at 48 h, including an indigo productivity of 26.0 mg/L and an indirubin productivity of 250.7 mg/L, which has been the highest productivity of indirubin so far. This work provided a basis for the commercial production of bio-indigo and the clinical drug indirubin in the future.

Serum Folic Acid and Erectile Dysfunction: A Systematic Review and Meta-Analysis.

INTRODUCTION: The association between folic acid (FA) and erectile dysfunction (ED) was contradictory in the published original articles, and no meta-analysis was conducted to pool these data. AIM: To verify the role of FA in the pathology of ED and explore the treatment efficacy of FA for ED patients. METHODS: An extensive search was performed on PubMed, Cochrane Library, and Web of Science to obtain all relevant studies published up to October 31, 2020. Studies comparing the serum FA level between ED patients and healthy controls, or comparing the score of the IIEF-5, or IIEF before and after folic acid therapy alone or combination in ED patient were eligible for our meta-analysis. The Newcastle-Ottawa Scales (NOS) was used to qualify included studies. MAIN OUTCOME MEASURES: The standardized mean differences (SMD) and their corresponding 95% confidence intervals (95% CIs) were calculated to pool our data. RESULTS: Nine studies were eligible for our meta-analysis to verify the association between FA and ED, and to explore the treatment efficacy of FA for ED patients. The pooled SMD of the FA level difference between ED patients and healthy subjects was -0.94 (95% CI: -1.59, -0.30, P = .004). Moreover, the level of folic acid in healthy subjects, Mild ED patients, Moderate ED patients and Severe ED patients was 11.847 (95%CI = 9.671, 14.022), 9.496 (95%CI = 8.425, 10.567), 6.597 (95%CI = 5.187, 8.007) and 5.623 (95%CI = 3.535, 7.711) respectively. The SMD of changes in score of IIEF-5 was 1.89 with 95%CI (1.60, 2.17) after FA administration in ED patients. Our analysis also showed that combination therapy of FA plus tadalafil changed the score of IIEF with 0.90 (95%CI = 0.44, 1.36) comparing to combination of placebo plus tadalafil. CONCLUSION: This novel meta-analysis demonstrated that FA was an independent risk factor for ED and FA supplement may have potentially positive effects in the treatment of ED patients. Zhang Y, Zhang W, Dai Y, et al. Serum Folic Acid and Erectile Dysfunction: A Systematic Review and Meta-Analysis. Sex Med 2021;9:100356.

Molecular identification of an androgen receptor and the influence of long-term aggressive interaction on hypothalamic genes expression in black rockfish (Sebastes schlegelii).

This study aims to explore the mechanism on how aggressive interaction alters reproductive physiology by testing whether aggressive interaction can activate the reproductive neuroendocrine function via the hypothalamus-pituitary-gonadal (HPG) axis in black rockfish (Sebastes schlegelii). The expressions of the androgen receptor gene (ar) and gonadotropin-releasing hormone genes (gnrhs), the concentration of plasma androgens, and GSI (the ratio of testes mass to body mass) were compared between the interaction group (dominant males or subordinate males) and the isolation group in male black rockfish after 3 weeks. A full-length cDNA encoding an androgen receptor (AR) of 766 amino acids was isolated. Transcripts encoding this AR were detected at a high relative abundance in the liver, kidney, testis, ovary, muscle, and intestine tissue. Further evaluation of brain genes transcripts abundance revealed that the mRNA levels of gnrh I and ar genes were significantly different between the interaction group and the isolation group in the hypothalamus. However, no significant difference was detected in testosterone, 11-keto-testosterone, and GSI between these two groups. This study indicates that a long-term aggressive interaction affect the expression of hypothalamic gnrh I and ar but may not change the physiological function of the HPG axis in an all-male condition.

Defective transition metal hydroxide-based nanoagents with hypoxia relief for photothermal-enhanced photodynamic therapy.

Recently, phototherapy has attracted much attention due to its negligible invasiveness, insignificant toxicity and excellent applicability. The construction of a newly proposed nanosystem with synergistic photothermal and photodynamic tumor-eliminating properties requires a delicate structure design. In this work, a novel therapeutic nanoplatform (denoted as BCS-Ce6) based on defective cobalt hydroxide nanosheets was developed, which realized hypoxia-relieved photothermal-enhanced photodynamic therapy against cancer. Defective cobalt hydroxide exhibited high photothermal conversion efficacy at the near-infrared region (49.49% at 808 nm) as well as enhanced catalase-like activity to produce oxygen and greatly boost the singlet oxygen generation by a photosensitizer, Ce6, realizing efficacious dual-modal phototherapy. In vivo and in vitro experiments revealed that BCS-Ce6 can almost completely extinguish implanted tumors in a mouse model and present satisfactory biocompatibility during the treatment. This work sets a new angle of preparing photothermal agents and constructing comprehensive therapeutic nanosystems with the ability to modulate the hypoxic tumor microenvironment for efficient cancer therapy.

Inhibitory effect of chestnut (Castanea mollissima Blume) inner skin extract on the activity of α-amylase, α-glucosidase, dipeptidyl peptidase IV and in vitro digestibility of starches.

This study aimed to investigate the inhibitory effect of chestnut inner skin extract (CISE) on the activity of postprandial blood sugar-related enzymes. In total, 12 flavonoids were identified by HPLC-TOF-MS. CISE showed strong and weak inhibition on α-amylase and α-glucosidase, with the IC50 of 27.2 and 2.3 µg/mL, respectively. The inhibition modes of CISE against α-amylase and α-glucosidase were mixed-type and non-competitive type, respectively. Epicatechin gallate noncompetitively inhibited α-amylase, α-glucosidase and dipeptidyl peptidase IV (DPP-IV). Analysis by ultraviolet-visible spectroscopy, fluorescence spectroscopy and circular dichroism suggested that flavonoids altered the hydrophobicity and microenvironment of these enzymes. CISE decreased the starch bioavailability by reducing the enzymatic hydrolysis rate and increasing the fraction of undigested starch. The extract reduced the rapidly digestible starch and increased the resistant starch after incorporation into A-, B- or C- crystallinity starch. Thus, the chestnut inner skin is a useful resource for regulating postprandial blood sugar level.

Correction: A facile strategy to realize a single/double photon excitation-dependent photosensitizer for imaging-guided phototherapy against HeLa cancer cells at separate irradiation channels.

Correction for 'A facile strategy to realize a single/double photon excitation-dependent photosensitizer for imaging-guided phototherapy against HeLa cancer cells at separate irradiation channels' by Lin Kong et al., Chem. Commun., 2020, 56, 571-574.

A facile strategy to realize a single/double photon excitation-dependent photosensitizer for imaging-guided phototherapy against HeLa cancer cells at separate irradiation channels.

A novel difluoroboron fluorophore with an electron donor-acceptor conjugated structure was synthesized with 26.5% fluorescence quantum yield, 18 035 GM two-photon absorbing cross-section, and undetectable two-photon fluorescence, resulting in 25% 1O2 quantum yield. The unique optical behavior of CNFBBN enabled one-photon fluorescence imaging and two-photon phototherapy against HeLa cancer cells, irradiated at separate wavelengths.

Ginkgo biloba Pretreatment Attenuates Myocardial Ischemia-Reperfusion Injury via mitoBKCa.

Ginkgo biloba extracts (EGb) alleviate myocardial ischemia/reperfusion (MI/R) injury. However, the underlying mechanisms have not yet been characterized. This study aimed to investigate whether activation of large-conductance Ca2+-activated K+ channels at the inner mitochondrial membrane (mitoBKCa) of cardiomyocytes is involved in Ginkgo biloba extract-mediated cardioprotection. Shuxuening injection (SXNI, 12.5ml/kg/d), a widely prescribed herbal medicine containing Ginkgo biloba extracts in China, or vehicle, was administered to C57BL/6 mice via tail vein injection for one week prior to surgical procedures. The mitoBKCa blocker paxilline (PAX) (1ml/kg, 115 nM) was administered via tail vein injection 30min prior to the onset of ischemia. The mice were randomly divided into the following groups: Sham, MI/R, MI/R+SXNI, and MI/R+SXNI+PAX. MI/R was induced by ligating the left anterior descending coronary artery for 30min with subsequent reperfusion for 24h. SXNI pretreatment conferred cardioprotective effects against MI/R injury as evidenced by reduced infarct size, improved cardiac function, and improved mitochondrial function. However, these effects were abrogated by co-administration with PAX. In addition, activation of mitoBKCa by Ginkgo biloba extract EGb761 reduced hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury in vitro through the inhibition of mitochondrial fragmentation, restoration of the mitochondrial membrane potential, decreased generation of superoxide, and inhibition of apoptosis which is associated with alleviating mitochondrial Ca2+ overload. These results indicated that Ginkgo biloba extracts pretreatment protected against MI/R injury via activation of mitoBKCa.

Evaluation of hyperbaric oxygen therapy for spinal cord injury in rats with different treatment course using diffusion tensor imaging.

STUDY DESIGN: Animal study. OBJECTIVES: To evaluate the efficacy of hyperbaric oxygen (HBO) therapy for spinal cord injury (SCI) in rats with different treatment course using diffusion tensor imaging (DTI). SETTING: Hospital in Fuzhou, China. METHODS: Fifty adult Sprague-Dawley rats were grouped as: (A) sham-operated group (n = 10); (B) SCI without HBO therapy group (n = 10); (C) SCI with HBO therapy for 2 weeks (SCI+HBO2W) group (n = 10); (D) SCI with HBO therapy for 4 weeks (SCI+HBO4W) group (n = 10); (E) SCI with HBO therapy for 6 weeks (SCI+HBO6W) group (n = 10). Basso Beattie Bresnahan (BBB) scores and diffusion tensor imaging parameters including fractional anisotropy (FA), mean diffusivity (MD), radial diffusion (RD), and axial diffusion (AD) values in the injury epicenter, as well as 2 mm rostral and caudal to the injury epicenter were collected and analyzed 6 weeks post-injury. RESULTS: Higher BBB score and FA values were found in the SCI+HBO4W group than in the SCI and SCI+HBO2W groups (all P < 0.05), whereas no significant differences of these metrics were observed between the SCI+HBO4W and SCI+HBO6W groups. MD and RD values of the SCI+HBO4W group were significantly lower than those of the SCI group (all P < 0.01). FA values were positively correlated with BBB scores. MD and RD values were negatively correlated with BBB scores. CONCLUSION: DTI parameters, especially FA, could non-invasively and quantifiably evaluate the efficacy of HBO treatment for rats with SCI and 4 weeks may be the more appropriate treatment course.

[CH4 Fluxes During the Algal Bloom in the Pengxi River].

Emissions of greenhouse gases in the Three Gorges Reservoir have been attracting attention in the recent years. This study was conducted to reveal the CH4 emission and removal during the process of algal growth at different nitrogen and phosphorus concentrations in the Pengxi River in the Three Gorges Reservoir. In-situ field experiments were conducted in the Gaoyang Lake in Pengxi River. From April 22nd, 2016, to May 9th, 2016, different concentrations of nitrogen and phosphorus were added to different experimental chambers. Results showed that CH4 emission decreased sharply from the first day of the experiment to the sixth day, and after that, CH4 emission in the water samples with only added phosphorus were obviously recovered compared to the other treatment. In this experiment, algal biomass was influenced by different concentrations of N and P. The biomass of algae were not affected by N, but were promoted under suitable concentration of P, such as 1P, 10P, 1NP, and 10NP. When the P concentration was too high, the biomass of algae was also limited. The emission and removal of CH4 in the experiment were significantly related to the addition of NO3--N.

Overexpression of calmodulin-like (ShCML44) stress-responsive gene from Solanum habrochaites enhances tolerance to multiple abiotic stresses.

Calmodulin-like (CML) proteins are important Ca(2+) sensors, which play significant role in mediating plant stress tolerance. In the present study, cold responsive calmodulin-like (ShCML44) gene was isolated from cold tolerant wild tomato (Solanum habrochaites), and functionally characterized. The ShCML44 was differentially expressed in all plant tissues including root, stem, leaf, flower and fruit, and was strongly up-regulated under cold, drought and salinity stresses along with plant growth hormones. Under cold stress, progressive increase in the expression of ShCML44 was observed particularly in cold-tolerant S. habrochaites. The ShCML44-overexpressed plants showed greater tolerance to cold, drought, and salinity stresses, and recorded higher germination and better seedling growth. Transgenic tomato plants demonstrated higher antioxidant enzymes activity, gas exchange and water retention capacity with lower malondialdehyde accumulation and membrane damage under cold and drought stresses compared to wild-type. Moreover, transgenic plants exhibited reduced reactive oxygen species and higher relative water contents under cold and drought stress, respectively. Greater stress tolerance of transgenic plants was further reflected by the up-/down-regulation of stress-related genes including SOD, GST, CAT, POD, LOX, PR and ERD. In crux, these results strengthen the molecular understanding of ShCML44 gene to improve the abiotic stress tolerance in tomato.

Water-soluble polysaccharides from finger citron fruits (Citrus medica L. var. sarcodactylis).

Four water-soluble polysaccharides, FCp-1, FCp-2, FCp-3, and FCp-4 were obtained from finger citron fruits (Citrus medica L. var. sarcodactylis) by hot-water extraction and ethanol precipitation, followed by routine separation procedure. Based on the calibration curve, molecular weights of them were estimated to be 113.9, 32.6, 140.3, and 177.1 kDa respectively. The acid hydrolysis, methylation, IR, GC-MS, and NMR experiments were used for composition analysis. FCp-1 was a heteropolysaccharide composed of arabinose, galactose, glucose, rhamnose, and xylose, with a molar ratio of 3.0:7.0:4.1:1.0:1.5. FCp-2 and FCp-4 were →4)-α-D-GalpA(1→ linking galacturonan differ in molecular weights. FCp-3 was a →6)-α-D-Glcp(1→ linking glucan. According to the results of in vitro assays, FCp-3 showed significantly and moderately enhancing capacities toward the proliferation of splenocytes and thymocytes respectively. Thus, FCp-3 or analogs may have further use as immunomodulatory agents.

The immunosuppressive activity of pseudolaric acid B on T lymphocytes in vitro.

Pseudolaric acid B (PB) is a major bioactive component extracted from Pseudolarix kaempferi. Traditional medicine practitioners in China have been using the roots of this plant to treat inflammatory and microbial dermatoses for centuries. In this study, the experiments were conducted to investigate immunosuppressive activity of PB on T lymphocytes in vitro. The results show that PB has hypotoxicity on hepatocytes and renal cells assessed by Methyl thiazolyl tetrazoliym (MTT) Assay and selectively inhibits the proliferation of T lymphocytes and antigen-specific T lymphocytes stimulated by concanavalin A and dinitrophenyl-modified spleen cells, respectively. Then, PB also shows suppressive effect on T lymphocytes in mixed lymphocyte reaction. Moreover, PB can depress the production of interleukin-2 (IL-2) secreted by concanavalin A-activated T lymphocytes or dinitrophenyl-modified spleen cells-activated antigen-specific T lymphocytes. It is first found that PB exhibits the inhibitory action on antigen-specific T lymphocytes and on the production of IL-2 from antigen-specific T lymphocytes and selectively inhibits the proliferation of T lymphocytes and the production of IL-2 as well. PB is in need of further study because of its potent immunosuppressive function.

Differential modulation of photosynthesis, signaling, and transcriptional regulation between tolerant and sensitive tomato genotypes under cold stress.

The wild species Solanum habrochaites is more cold tolerant than the cultivated tomato (S. lycopersicum). To explore the mechanisms underlying cold tolerance of S. habrochaites, seedlings of S. habrochaites LA1777 introgression lines (ILs), as well as the two parents, were evaluated under low temperature (4°C). The IL LA3969 and its donor parent LA1777 were found to be more cold tolerant than the recurrent parent S. lycopersicum LA4024. The differences in physiology and global gene expression between cold-tolerant (LA1777 and LA3969) and -sensitive (LA4024) genotypes under cold stress were further investigated. Comparative transcriptome analysis identified 1613, 1456, and 1523 cold-responsive genes in LA1777, LA3969, and LA4024, respectively. Gene ontology (GO) term enrichment analysis revealed that more GO biological process terms were significantly enriched among the up-regulated genes in the two tolerant genotypes, whereas more biological processes were significantly repressed by cold stress in the sensitive one. A total of 92 genes with significant differential expression between tolerant and sensitive genotypes under cold stress were identified. Among these, many stress-related GO terms were significantly enriched, such as 'response to stimulus' and 'response to stress'. Moreover, GO terms 'response to hormone stimulus', 'response to reactive oxygen species (ROS)', and 'calcium-mediated signaling' were also overrepresented. Several transcripts involved in hormone or ROS homeostasis were also differentially expressed. ROS, hormones, and calcium as signaling molecules may play important roles in regulating gene expression in response to cold stress. Moreover, the expression of various transcription factors, post-translational proteins, metabolic enzymes, and photosynthesis-related genes was also specifically modulated. These specific modifications may play pivotal roles in conferring cold tolerance in tomato. These results not only provide new insights into the molecular mechanisms of cold tolerance in tomato, but also provide potential candidate genes for genetic improvement.

[Separation and determination of selenium polysaccharide in enriched-Se cordyceps militaris].

In the present paper, the water soluble selenium polysaccharide was extracted, and isolated and purified preliminarily. The traditional method was used to extract selenium polysaccharide, which was extracted by water and sank by ethanol. The work also focused on the determination of the experiment conditions, optimizing the experiment conditions such as proportion of extract solution, extract temperature, extract times, proportion of ethanol, and standing time. The recovery of selenium polysaccharide under these conditions is 5.76%. Polysaccharide content in the powder is 46.6%, and selenium content is 92.3 mg x kg(-1).