Structural and functional characterization of sulfurtransferase from Frondihabitans sp. PAMC28461

Sulfurtransferases transfer of sulfur atoms from thiols to acceptors like cyanide. They are categorized as thiosulfate sulfurtransferases (TSTs) and 3-mercaptopyruvate sulfurtransferases (MSTs). TSTs transfer sulfur from thiosulfate to cyanide, producing thiocyanate. MSTs transfer sulfur from 3-mercaptopyruvate to cyanide, yielding pyruvate and thiocyanate. The present study aimed to isolate and characterize the sulfurtransferase FrST from Frondihabitans sp. PAMC28461 using biochemical and structural analyses. FrST exists as a dimer and can be classified as a TST rather than an MST according to sequence-based clustering and enzyme activity. Furthermore, the discovery of activity over a wide temperature range and the broad substrate specificity exhibited by FrST suggest promising prospects for its utilization in industrial applications, such as the detoxification of cyanide.

Optimization of Culture medium for the Production of an Exopolysaccharide (p-CY02) with Cryoprotective Activity by Pseudoalteromonas sp. RosPo-2 from the Antarctic Sea

When cells are exposed to freezing temperatures, high concentrations of cryoprotective agents (CPA) prevent ice crystal formation, thus enhancing cell survival. However, high concentrations of CPAs can also cause cell toxicity. Exopolysaccharides from polar marine environments exhibit lower toxicity and display effects similar to traditional CPA. To address these issues, this study focused on selecting strains that produce EPS with novel cryoprotective activity and optimizing culture conditions for EPS production. Sixty-six bacteria producing mucous substances were isolated from the Ross Sea (Antarctic Ocean) using solid marine agar plates. Among them, Pseudoalteromonas sp. RosPo-2 was ultimately selected based on the rheological properties of the produced EPS (p-CY02). Cryoprotective activity experiments demonstrated that p-CY02 exhibited significantly cryoprotective activity at a concentration of 0.8% (w/v) on mammalian cells (HaCaT). This activity was further improved when combined with various concentrations of dimethyl sulfoxide (DMSO) compared to using DMSO alone. Moreover, the survival rate of HaCaT cells treated with 5% (v/v) DMSO and 0.8% (w/v) p-CY02 was measured at 87.9 ± 2.8% after freezing treatment. it suggests that p-CY02 may be developed more effective, less toxic as a novel non-permeating CPA. To enhance the production of EPS with cryoprotective activity, Response Surface Methodology (RSM) was implemented, resulting in a 1.64-fold increase in production of EPS with cryoprotective activity.

A novel exopolysaccharide (p-CY01) from the Antarctic bacterium Pseudoalteromonas sp. strain CY01 cryopreserves human red blood cells

Cryopreservation of human red blood cells (RBCs) is vital for regenerative medicine and organ transplantation, but current cryoprotectants (CPAs) like glycerol and hydroxyethyl starch (HES) have limitations. Glycerol requires post-thaw washing due to cell membrane penetration, while HES causes high viscosity. To address these issues, we explored exopolysaccharides (EPS) from Antarctic Pseudoalteromonas sp. strain CY01 as a non-penetrating CPA for RBC cryopreservation. The EPS, p-CY01, consisted mainly of repeating (1-4) glucose and (1-6) galactose linkages with a molecular mass of 1.1 × 107 Da. Through mild acid hydrolysis, we obtained low molecular weight p-CY01 (p-CY01 LM) with a molecular weight of 2.7 × 105 Da, offering reduced viscosity, improved solubility, and cryoprotective properties. Notably, combining low concentrations of penetrating CPAs (>1% glycerol and dimethyl sulfoxide) with 2.5% (w/v) p-CY01 LM demonstrated significant cryoprotective effects. These findings highlight the potential of p-CY01 LM as a highly effective CPA for human RBC cryopreservation, replacing HES and glycerol and enabling the long-term storage of biological materials.

Arctic Sea Ice Microalga Chlamydomonas latifrons KNF0041: Identification and Statistical Optimization of Medium for Enhanced Biomass and Omega-3/Omega-6

Polar microorganisms produce biologically active compounds that enable them to survive in harsh environments. These compounds have potential biomedical applications. The green microalga Chlamydomonas latifrons KNF0041, isolated from Arctic sea ice, has been found to produce polyunsaturated fatty acids (PUFAs), including omega-3 and omega-6, which have antioxidant properties. To improve the biomass production of strain KNF0041, statistical methods such as the Plackett-Burman design, Box-Behnken design, and response surface methodology (RSM) were utilized for medium optimization. The optimized medium was designed with increased potassium phosphate content and reduced acetic acid (AcOH) content. The use of the optimized medium resulted in an increase in the cell number as biomass of strain KNF0041 by 34.18% and the omega-3 and omega-6 fatty acid (FA) content by 10.04% and 58.29%, respectively, compared to that in normal TAP medium, which is known as the growth medium for Chlamydomonas culture. In this study, Chlamydomonas latifrons was discovered for the first time in the polar region and identified using morphology and molecular phylogenetic analyses, the secondary structures of the internal transcribed spacers, and optimized culture conditions. The results of this study provide an efficient method for the application of polar microalgae for the production of bioactive compounds.

[Developing traditional medical heritage for further achievements in medical history and literature research-Commemorating the establishment of China Institute for History of Medicine and Medical Literature in the China Academy of Traditional Chinese Medicine]

The Institute of Chinese Medical History and Literature in the China Academy of Traditional Chinese Medicine was officially established on May 28, 1982. Its predecessor was the Medical History Research Office in the Chinese Medicine Institute of the Central Institute of Health, the Editorial Office of the China Academy of Traditional Chinese Medicine, and the Theory and Literature Research Office of the Institute of Acupuncture and Moxibustion. Before that, the Research Office of Chinese Medical History and Literature in the China Academy of Traditional Chinese Medicine was established in 1971. It made remarkable achievements in scientific research, personnel training and discipline construction in terms of medical history and literature. It was upgraded to the Institute with the approval of the Ministry of Health in 1980. After its establishment, the institute has benefited from great achievements.

P11.37.B When to resect or biopsy for patients with supratentorial glioblastoma: a multivariable prediction model

Background

The prospects of a patient with suspected glioblastoma may rely heavily on the indication for surgical resection versus biopsy only. Biopsy percentages vary considerably across hospitals and guidelines for treatment of glioblastoma lack criteria for surgical decision-making. To identify patient and tumor characteristics associated with the decision to resect or biopsy a glioblastoma and to develop and validate a prediction model for decision support.

Material and Methods

Clinical data and pre-operative MRI scans were collected for adults who underwent first-time surgery for supratentorial glioblastoma from a registry-based cohort study of 12 hospitals from the Netherlands, Germany, France, Italy, and the United States between 1st of January 2007 and 31st of December 2011. The main outcome was the type of surgical procedure: surgical resection or biopsy only. Predictors were patient- and tumor-related characteristics. Radiological factors were extracted from MRI using an automated tumor segmentation method. A prediction model was constructed using multivariable logistic regression analysis. The model was cross-validated and externally validated with a leave-one-hospital-out approach.

Results

Out of 1053 patients treated for glioblastoma, 28% underwent biopsy only. Biopsy rates varied from 15-40% across hospitals. The prediction model showed excellent discrimination with an average area under the curve of 0.86. Of the patient-related characteristics, younger age was associated more with resection and Karnofsky Performance Score of 60 or less with biopsy. Of the tumor-related characteristics, a location in the right hemisphere, unifocality, no tumor midline crossing, and no involvement of the cortical spinal tract, were associated with resection, as well as a high expected resectability index, a location in the right occipital lobe, and a higher percentage of tumor in Schaefer’s dorsal or ventral attention, limbic, and default networks. External validation proved acceptable to outstanding discrimination with areas under the curve ranging between 0.79 and 0.92 for hospitals.

Conclusion

A prediction model is presented and validated to support the decision to resect or to biopsy a patient with a suspected supratentorial glioblastoma. In this prediction model, tumor-related characteristics were more informative than patient-related factors. This may support surgical decision-making for individual patients, or facilitate comparisons of patient cohorts between surgeons or institutions.

Importance of rigidity of ice-binding protein (FfIBP) for hyperthermal hysteresis activity and microbial survival

Ice-binding proteins (IBPs) are well-characterized proteins responsible for the cold-adaptation mechanisms. Despite extensive structural and biological investigation of IBPs and antifreeze proteins, only a few studies have considered the relationship between protein stabilization and thermal hysteresis (TH) activity as well as the implication of hyperactivity. Here, we investigated the important role of the head capping region in stabilization and the hyper-TH activity of FfIBP using molecular dynamics simulation. Data comparison revealed that residues on the ice-binding site of the hyperactive FfIBP are immobilized, which could be correlated with TH activity. Further comparison analysis indicated the disulfide bond in the head region is mainly involved in protein stabilization and is crucial for hyper-TH activity. This finding could also be generalized to known hyperactive IBPs. Furthermore, in mimicking the physiological conditions, bacteria with membrane-anchored FfIBP formed brine pockets in a TH activity-dependent manner. Cells with a higher number of TH-active IBPs showed an increased number of brine pockets, which may be beneficial for short- and long-term survival in cold environments by reducing the salt concentration. The newly identified conditions for hyper-TH activity and their implications on bacterial survival provide insights into novel mechanistic aspects of cold adaptation in polar microorganisms.

Stereocalpin B, a New Cyclic Depsipeptide from the Antarctic Lichen Ramalina terebrata

Stereocalpin B, a new cyclic depsipeptide (1), and a new dibenzofuran derivative (3), were isolated from the Antarctic lichen, Ramalina terebrata (Ramalinaceae), along with a known cyclic depsipeptide (2). The structures of new compounds were characterized by comprehensive spectrometric analyses; high-resolution fast atom bombardment mass spectrometry (HR-FABMS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Stereocalpin B (1) existed in a rotameric equilibrium, which was confirmed using nuclear Overhauser effect spectroscopy (NOESY)/exchange spectroscopy (EXSY) spectrum. Absolute configurations of the amino acid units in 1 were assigned using the advanced Marfey’s method and subsequent NOESY analysis of the 5-hydroxy-2,4-dimethyl-3-oxo-decanoic acid residue confirmed the complete stereochemistry of 1. Compounds 1-3 exhibited moderate antimicrobial activities against E. coli, with the IC₅₀ values ranging from 18–30 μg/mL. Compound 2 exhibited cell growth inhibition against HCT116 cell lines, with the IC₅₀ value of 20 ± 1.20 μM, and compounds 1 and 2 also showed potent anti-inflammatory activities against lipopolysaccharide (LPS)-induced RAW264.7 macrophages with the IC₅₀ values ranging from 5–7 μM.

Potential of Ramalin and Its Derivatives for the Treatment of Alzheimer's Disease

The pathogenesis of Alzheimer's disease (AD) is still unclear, and presently there is no cure for the disease that can be used for its treatment or to stop its progression. Here, we investigated the therapeutic potential of ramalin (isolated from the Antarctic lichen, Ramalina terebrata), which exhibits various physiological activities, in AD. Specifically, derivatives were synthesized based on the structure of ramalin, which has a strong antioxidant effect, BACE-1 inhibition activity, and anti-inflammatory effects. Therefore, ramalin and its derivatives exhibit activity against multiple targets associated with AD and can serve as potential therapeutic agents for the disease.

Isolation of Sesquiterpenoids and Steroids from the Soft Coral Sinularia brassica and Determination of Their Absolute Configuration

Two undescribed rearranged cadinane-type sesquiterpenoids (1-2), named sinulaketol A-B, together with one new chlorinated steroid (3), one new gorgosterol (4), one known sesquiterpene (5), one known dibromoditerpene (6) and two known polyhydroxylated steroids (7-8) were isolated from the soft coral Sinularia brassica. The structures of these compounds were established by extensive spectroscopic analysis, including HRESIMS, 1D, and 2D NMR spectroscopy. Their absolute configurations were also determined by the ECD calculations and DP4+ probability analysis. Antileishmanial activity of compounds 1-8 was evaluated in vitro against the amastigote forms of Leishmania donovani, in which compounds 3, 6, and 7 inhibited the growth of L. donovani by 58.7, 74.3, 54.7%, respectively, at a concentration of 50 μM. Antimicrobial effect of the isolated compounds were also evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli. Compound 6, a brominated diterpene, exhibited antimicrobial effect against S. aureus.

Mitochondrial genome of the Antarctic microalga Micractinium simplicissimum KSF0127 (Chlorellaceae, Trebouxiophyceae)

We report the first mitochondrial genome of the Antarctic microalga Micractinium simplicissimum KSF0127. The circular mitochondrial genome was 67,923 bp in length and contained 45 protein-coding genes, one ribosomal RNA gene, and 60 transfer RNA genes. The phylogenetic tree was constructed with eight previously reported mitogenome sequences and showed the phylogenetic position of M. simplicissimum KSF0127 within the Chlorellaceae family.

Anti-inflammatory effects of methanol extracts from the Antarctic lichen, Amandinea sp. in LPS-stimulated raw 264.7 macrophages and zebrafish

The aim of the present study was to determine the anti-inflammatory effect of an extracts isolated from the lichen. Amandinea sp. was collected from the Antarctic and extracted with methanol. The basic screening of the anti-inflammatory property of the extracts was done using the NO assay. The extracts showed very little cytotoxicity, and reduced NO production in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. Furthermore, the extracts inhibited LPS-induced release of pro-inflammatory cytokines such as interleukin-6 (IL-6), and tumor necrosis factor-α(TNF-α), and inflammatory mediators inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). The extracts also reduced the cytosolic p-IκB-α level and the level of the nuclear factor p65. We examined the anti-inflammatory effects of the extracts using zebrafish in vivo. The extracts reduced the amount of reactive oxygen species (ROS) in LPS-induced zebrafish larvae and inhibited the mRNA expression of inflammatory cytokines and mediators in a tail-cutting induced model. These results are similar to those obtained in vitro with RAW 264.7 cells. Collectively, the data suggest that the extracts may contain one of more compounds with anti-inflammatory effects. Further studies are required to identify the candidate compound/s and to understand the mechanism of action of the extract.

[Tour of the History Exhibition Hall of the Chinese Academy of Chinese Medical Sciences: To commemorate the 65th anniversary of the Chinese Academy of Chinese Medical Sciences]

In 2015, 60th anniversary of China Academy of Chinese Medical Sciences(CACMS), the History Exhibition Hall of it was opened to the public. The History Exhibition Hall collecting 29504 pages of documents, and 26386 pictures, 1050 materials, reveal the history of founding and development of CACMS. 2020 is the 65th anniversary of CACMS. Taking the 87 groups representative collections as examples, briefly review the development history of CACMS from five aspects: figures, scientific research, medical treatment, education and industry.

[The preliminary clinical study on radical prostatectomy without preoperative prostate biopsy]

Objective: To investigate the feasibility and safety of minimally invasive radical prostatectomy for prostate cancer patients without preoperative prostate biopsy in the new era of the continuous development of comprehensive new imaging diagnostic mode and minimally invasive surgery technology. Methods: From August 2018 to October 2019, 17 patients with prostate cancer were enrolled in this study in the Cancer Hospital, Chinese Academy of Medical Sciences. All patients were highly suspected of prostate cancer by PSMA-PET/CT-based imaging diagnostic techniques and underwent 3D laparoscopic radical prostatectomy without prostate biopsy. The perioperative data, postoperative pathology, postoperative complications and follow-up results were recorded and analyzed. Results: The average age of 17 patients with prostate cancer was (65±7) years. The body mass index (BMI) average was (24.4±3.0) kg/m(2). The American Society of Anesthesiologists (ASA) score was 1 (1-2) and the Charlson comorbidity index (CCI) score was 1 (0-4). The preoperative value of PSA was (19±11) μg/L. The PSMA PET/CT showed abnormally high expression foci and the great possibility of prostate cancer for all the 17 patients. Prostate puncture biopsy: the results of prostate biopsy were negative in 3 cases. The digital rectal examination found that the prostate volume was Ⅰ or Ⅱ degree large, 10 cases touched hard and the nodule was touched in two cases. Three patients had undergone a previous prostate biopsy, but prostate cancer was not found. All the 17 operations were successfully performed without conversion to open surgery. The surgery time was (85±21) (range from 45 to 120) min, the estimated blood loss was (25±18) (range from5 to 100) ml, the time of intake of liquid diet was (14.3±4.4) h, the intestinal recovery time was (23±10) h, the postoperative activity time was (22±7) h, the drainage duration was (3.7±0.8) d, the postoperative hospital stay was (4.9±1.2) days, and the catheter removal time was (7.4±1.5) days. In the early postoperative period (within 30 days after surgery), no obvious complications occurred. The postoperative final pathology confirmed that all the 17 specimens were prostate cancer. After a median follow-up of 6.5 months, the patient's urinary control rate reached 81.3% at postoperative 1 month, 92.3% at postoperative 3 months after surgery, and the urinary control rate reached 100% at postoperative 6 months. Postoperative PSA value was (0.08±0.08) μg/L, significantly lower than preoperative PSA level (P<0.001). There was significant difference between the preoperative and postoperative QOL (Quality of life) score (57±5 and 47±5 respectively, P<0.001) which indicated that the patients' postoperative quality of life was greatly improved. Conclusions: It is safe and feasible to perform minimally invasive radical prostatectomy without preoperative prostate biopsy for patients with highly suspected prostate cancer by comprehensive diagnostic mode based on modern new imaging technology.

Distinguishing Extravascular from Intravascular Ferumoxytol Pools within the Brain: Proof of Concept in Patients with Treated Glioblastoma

BACKGROUND AND PURPOSE

Glioblastoma-associated macrophages are a major constituent of the immune response to therapy and are known to engulf the iron-based MR imaging contrast agent, ferumoxytol. Current ferumoxytol MR imaging techniques for localizing macrophages are confounded by contaminating intravascular signal. The aim of this study was to assess the utility of a newly developed MR imaging technique, segregation and extravascular localization of ferumoxytol imaging, for differentiating extravascular-from-intravascular ferumoxytol contrast signal at a delayed 24-hour imaging time point.

MATERIALS AND METHODS

Twenty-three patients with suspected post-chemoradiotherapy glioblastoma progression underwent ferumoxytol-enhanced SWI. Segregation and extravascular localization of ferumoxytol imaging maps were generated as the voxelwise difference of the delayed (24 hours) from the early (immediately after administration) time point SWI maps. Continuous segregation and extravascular localization of ferumoxytol imaging map values were separated into positive and negative components. Image-guided biologic correlation was performed.

RESULTS

Negative segregation and extravascular localization of ferumoxytol imaging values correlated with early and delayed time point SWI values, demonstrating that intravascular signal detected in the early time point persists into the delayed time point. Positive segregation and extravascular localization of ferumoxytol imaging values correlated only with delayed time point SWI values, suggesting successful detection of the newly developed extravascular signal.

CONCLUSIONS

Segregation and extravascular localization of ferumoxytol MR imaging improves on current techniques by eliminating intrinsic tissue and intravascular ferumoxytol signal and may inform glioblastoma outcomes by serving as a more specific metric of macrophage content compared with uncorrected T1 and SWI techniques.

Diagnostic impact of preoperative corticosteroids in primary central nervous system lymphoma

PURPOSE

High dose corticosteroids are an effective tool for rapidly alleviating neurologic symptoms caused by intracranial mass lesions. However, there is concern that preoperative corticosteroids limit the ability to obtain a definitive pathologic diagnosis, particularly if imaging features suggest primary central nervous system lymphoma (PCNSL).

METHODS

To explore the impact of preoperative corticosteroids in newly diagnosed PCNSL patients, from 2009 to 2018 treated at our institution.

RESULTS

We identified 54 patients; 18 had received corticosteroids prior to biopsy or resection. Only in one case did the patient have a prior non-diagnostic biopsy, requiring a second procedure. The cumulative doses of preoperative dexamethasone ranged from 4 mg to 120 mg (mean 32 mg, median 24 mg), given over 1-14 days (mean 2 days, median 1 day), and the majority had received corticosteroids for only 1-2 days. There was a trend for a larger diameter of lesional T1 contrast enhancement for patients who received steroids (39 mm vs. 34 mm, p = 0.11). In this series of cases with pathologically and clinically proven PCNSL, preoperative corticosteroids had been given in a third of cases, suggesting that they may be given for symptomatic relief without compromising pathologic diagnosis.

CONCLUSIONS

Despite the commonly held tenet that preoperative corticosteroids can obscure the pathologic diagnosis in PCNSL, this is likely not the case in the majority of patients who receive a short course preoperatively. Obtaining a second stereotactic scan to confirm continued presence of the lesion prior to tissue sampling may also mitigate these concerns.

Co-production of biodiesel and bioethanol using psychrophilic microalga Chlamydomonas sp. KNM0029C isolated from Arctic sea ice

BACKGROUND

Biofuels, generated using microalgae as sustainable energy, have received a lot of attention. Microalgae can be cultivated at low cost with CO₂ and solar energy without competition from edible crops. Psychrophilic microalgae can be a suitable feedstock to produce biofuels without the environmental constraints of low temperatures, because they can grow below 10 °C. However, there is a lack of efficient strategies using psychrophilic microalgae to produce biodiesel and bioethanol. Therefore, the current study aimed to optimize the production of biodiesel and bioethanol from Arctic Chlamydomonas sp. KNM0029C at low temperatures.

RESULTS

After incubation in a 20-L photobioreactor, fatty acid methyl ester (FAME) was extracted using modified FAME extraction methods, producing a maximum yield of 0.16-g FAME/g KNM0029C. Residual biomass was pretreated for bioethanol production, and the yields from different methods were compared. The highest bioethanol yield (0.22-g/g residual biomass) was obtained by pretreatment with enzyme (amyloglucosidase) after sonication. Approximately 300-mg biofuel was obtained, including 156-mg FAME biodiesel and 144-mg bioethanol per g dried cells, representing the highest recorded yield from psychrophilic microalgae.

CONCLUSIONS

This is the first to attempt at utilizing biomass from psychrophilic Arctic microalga Chlamydomonas sp. KNM0029C for the co-production of bioethanol and biodiesel, and it yielded the highest values among reported studies using psychrophilic organisms. These results can be used as a source for the efficient biofuel production using polar microalgae.

P1026Risk factors for the occurrence of stroke after atrial fibrillation ablation

Background

Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES.

Methods

We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation.

Results

A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation.

Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation.

K-M curve for stroke-free survival

Conclusions

Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.

[Clinical analysis of 555 outpatients with hand, foot and mouth diseases caused by different enteroviruses]

Objective: To study the clinical characteristics of outpatients with hand, foot and mouth disease (HFMD) caused by different serotypes of enteroviruses. Methods: This was a prospective study. From February 2017 to March 2018, 563 outpatients with HFMD were enrolled by systematic sampling in the Department of Infectious Diseases, Henan Children's Hospital. Throat swabs were collected to determine the serotypes via PCR. Demographic, clinical, and laboratory data were collected by standard questionnaire. All cases were followed up twice at 2 and 9 weeks after the initial outpatient visit through telephone interview. A total of 563 cases were enrolled and 555 (98.6%) cases were positive for human enteroviruses, including 338 (60.9%) males. Analyses were stratified by enterovirus serotypes, Chi square test or Fisher's exact test, Rank sum test was used for comparison among different groups. Results: The age of 555 cases was 24.2 (16.4, 41.3) months. Among them 44.0% (224 cases) were identified as coxsackievirus (CV)-A6, while 189 cases, 35 cases, 14 cases and 73 cases were identified as CV-A16, enterovirus (EV)-A71, CV-A10 and other serotypes, respectively. Fever (≥37.5 ℃) was present in 51.4% (285/555) of laboratory confirmed cases. The proportions of fever in cases of CV-A6 (68.9%(168/244)) and CV-A10 (12/14) were significantly higher than those in cases of CV-A16 (31.7%(60/189),χ(2)=57.344,14.313,both P=0.000), other serotypes (43.8%(32/73),χ(2)=15.101 and 8.242, P=0.000 and 0.004) and EV-A71 (37.1%(13/35), χ(2)=13.506 and 9.441, P=0.000 and 0.002) respectively. There was no significant difference between CV-A6 and CV-A10 in presentation of fever (χ(2)=1.785, P=0.182). There were 359 cases (64.7%) with eruptions in mouth, hands, feet and buttocks. Cases infected with EV-A71 had the highest proportions (74.3%(26/35)) of rash emerging simultaneously in mouth, hands, feet, and buttocks. The proportion in cases of CV-A16, CV-A6, CVA10 and other serotype were 73.5% (139/189), 61.9% (151/244), 7/14 and 49.3% (36/73), respectively. The proportion of rash on other parts of body, such as face, limbs or torso in cases infected with CV-A6 (16.8% (41/244)) was the higherest and the proportion in cases of CV-A16, EV-A71, CV-A10 or other serotypes were 8.5% (16/189) , 5.7% (2/35) , 1/14, 6.8% (5/73) , respectively. None of these cases developed serious complications. Desquamation occurred in 45.5% (179/393) cases 7.5 (5.0, 9.0) days after disease onset and 13.5% (53/393) cases showed onychomadesis 31.0 (18.0, 33.5) days after disease onset. The proportion of desquamation and onychomadesis associated with CV-A6 (64.2% (95/148) and 31.8% (47/148)) was significantly higher than CV-A16 (31.8% (49/154) and 1.3% (2/154), χ(2)=33.601 and 52.482, both P=0.000) and other serotypes (38.0%(19/50) and 6.0%(3/50),χ(2)=10.236 and 12.988, P=0.001 and 0.000). Desquamation appeared more in cases of CV-A6 than in cases of CV-A10 (2/11,χ(2)=9.386, P=0.002), with the proportion of onychomadesis higher in CV-A6 than in EV-A71 (3.3% (1/30),χ(2)=11.088, P=0.001). Conclusion: Clinical manifestation such as fever, rash emerging parts, desquamation and onychomadesis are different among outpatient HFMD cases infected with CV-A16, CV-A6, EV-A71, CV-A10 and other enteroviruses.

Lipid Production by Arctic Microalga Chlamydomonas sp. KNF0008 at Low Temperatures

A lipid-producing microalga, Chlamydomonas sp. KNF0008, collected from the Arctic was capable of growing at temperatures ranging from 4 to 20 °C, and the highest cell density was measured at 15 °C and 100 μmol photons m^-2 s^-1 light intensity under continuous shaking and external aeration. KNF0008 showed the elevated accumulation of lipid bodies under nitrogen-deficient conditions, rather than under nitrogen-sufficient conditions. Fatty acid production of KNF0008 was 4.2-fold (104 mg L^-1) higher than that of C. reinhardtii CC-125 at 15 °C in Bold's Basal Medium. The dominant fatty acids were C16:0, C16:4, C18:1, and C18:3, and unsaturated fatty acids (65.69%) were higher than saturated fatty acids (13.65%) at 15 °C. These results suggested that Arctic Chlamydomonas sp. KNF0008 could possibly be utilized for production of biodiesel during periods of cold weather because of its psychrophilic characteristics.

Total Syntheses of Lobaric Acid and Its Derivatives from the Antarctic Lichen Stereocaulon alpinum

The first total syntheses of the natural products lobaric acid (1) and its derivatives isolated from the Antarctic lichen Stereocaulon alpinum are reported in this study. Lobarin (3), with a pseudodepsidone structure, was synthesized first in 11 steps by utilizing an Ullmann aryl ether coupling reaction, and lobaric acid was synthesized in an additional three steps by a seven-membered lactonization reaction. Various derivatives were also obtained from the prepared lobaric acid, and the synthetic compounds exhibited significant PTP1B inhibitory activities.

Anti-Cancer Activity of Lobaric Acid and Lobarstin Extracted from the Antarctic Lichen Stereocaulon alpnum

Lobaric acid and lobarstin, secondary metabolites derived from the antarctic lichen Stereocaulon alpnum, exert various biological activities, including antitumor, anti-proliferation, anti-inflammation, and antioxidant activities. However, the underlying mechanisms of these effects have not yet been elucidated in human cervix adenocarcinoma and human colon carcinoma. In the present study, we evaluated the anticancer effects of lobaric acid and lobarstin on human cervix adenocarcinoma HeLa cells and colon carcinoma HCT116 cells. We show that the proliferation of Hela and HCT116 cells treated with lobaric acid and lobarstin significantly decreased in a dose- and time-dependent manner. Using flow cytometry analysis, we observed that the treatment with these compounds resulted in significant apoptosis in both cell lines, following cell cycle perturbation and arrest in G2/M phase. Furthermore, using immunoblot analysis, we investigated the expression of cell cycle and apoptosis-related marker genes and found a significant downregulation of the apoptosis regulator B-cell lymphoma 2 (Bcl-2) and upregulation of the cleaved form of the poly (ADP-ribose) polymerase (PARP), a DNA repair and apoptosis regulator. These results suggest that lobaric acid and lobarstin could significantly inhibit cell proliferation through cell cycle arrest and induction of apoptosis via the mitochondrial apoptotic pathway in cervix adenocarcinoma and colon carcinoma cells. Taken together, our data suggests that lobaric acid and lobarstin might be novel agents for clinical treatment of cervix adenocarcinoma and colon carcinoma.

Anticancer activities of ethanol extract from the Antarctic freshwater microalga, Botryidiopsidaceae sp

Background

Cancer is a leading cause of human death around the world and occurs through the highly complex coordination of multiple cellular pathways. Recent studies have revealed that microalgal extracts exhibit considerable pharmaceutical activities, including those against various cancer cells. Thus, microalgae are promising candidates as novel cancer therapeutic drugs. In this study, we evaluated the biological functions of the ethanolic extract of the Antarctic freshwater microalga, Botryidiopsidaceae sp., such as its antioxidant, anti-proliferative, apoptotic and anti-invasive properties.

Methods

To estimate antioxidant capacity of ethanol extract of Botryidiopsidaceae sp. (ETBO), free radical 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used. The anti-proliferative activity of ETBO was assessed in several cancer cell lines (A375, Hs578T and HeLa) and non-tumorigenic keratinocyte cells (HaCaT), using MTT assay. In addition, Annexin V binding was performed to detect ETBO-induced apoptotic cells, and the expression levels of apoptosis-regulating proteins, caspase-3, p53, and Bcl-2, were determined by western blot. Boyden chamber assays were used to determine anti-migratory and anti-invasive properties of ETBO.

Results

ETBO exhibited antioxidant activity and concentration-dependent anticancer activities, such as anti-proliferation and pro-apoptotic activities against cancer cells. Furthermore, the expression of the apoptosis-inducing proteins, p53 and caspase-3, significantly increased in response to ETBO, whereas the expression of the anti-apoptotic protein, Bcl-2, decreased. These data imply that ETBO induces apoptosis by caspase activation through the modulation of pro-apoptotic and anti-apoptotic gene, p53 and Bcl-2, respectively. In addition, ETBO significantly inhibited migration and invasion of cervical cancer cells in a concentration-dependent manner.

Conclusion

In this study, ETBO exhibited considerable anticancer activities, such as inhibition of proliferation, invasion, and migration, as well as induction of apoptosis. These data suggest that ETBO is a promising therapeutic agent in cancer therapy and drug discovery.

Anticancer Activity of Ramalin, a Secondary Metabolite from the Antarctic Lichen Ramalina terebrata, against Colorectal Cancer Cells

Colorectal cancer is a leading cause of death worldwide and occurs through the highly complex coordination of multiple cellular pathways, resulting in carcinogenesis. Recent studies have increasingly revealed that constituents of lichen extracts exhibit potent pharmaceutical activities, including anticancer activity against various cancer cells, making them promising candidates for new anticancer therapeutic drugs. The main objective of this study was to evaluate the anticancer capacities of ramalin, a secondary metabolite from the Antarctic lichen Ramalina terebrata, in the human colorectal cancer cell line HCT116. In this study, ramalin displayed concentration-dependent anticancer activity against HCT116 cells, significantly suppressing proliferation and inducing apoptosis. Furthermore, ramalin induced cell cycle arrest in the gap 2/mitosis (G2/M) phase through the modulation of hallmark genes involved in the G2/M phase transition, such as tumour protein p53 (TP53), cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin-dependent kinase 1 (CDK1) and cyclin B1 (CCNB1). At both the transcriptional and translational level, ramalin caused a gradual increase in the expression of TP53 and its downstream gene CDKN1A, while decreasing the expression of CDK1 and CCNB1 in a concentration-dependent manner. In addition, ramalin significantly inhibited the migration and invasion of colorectal cancer cells in a concentration-dependent manner. Taken together, these data suggest that ramalin may be a therapeutic candidate for the targeted therapy of colorectal cancer.

Comprehensive Expression Profiling and Functional Network Analysis of Porphyra-334, One Mycosporine-Like Amino Acid (MAA), in Human Keratinocyte Exposed with UV-radiation

Mycosporine-like amino acids (MAAs) have been highlighted as pharmacologically active secondary compounds to protect cells from harmful UV-radiation by absorbing its energy. Previous studies have mostly focused on characterizing their physiological properties such as antioxidant activity and osmotic regulation. However, molecular mechanisms underlying their UV-protective capability have not yet been revealed. In the present study, we investigated the expression profiling of porphyra-334-modulated genes or microRNA (miRNAs) in response to UV-exposure and their functional networks, using cDNA and miRNAs microarray. Based on our data, we showed that porphyra-334-regulated genes play essential roles in UV-affected biological processes such as Wnt (Wingless/integrase-1) and Notch pathways which exhibit antagonistic relationship in various biological processes; the UV-repressed genes were in the Wnt signaling pathway, while the activated genes were in the Notch signaling. In addition, porphyra-334-regulated miRNAs can target many genes related with UV-mediated biological processes such as apoptosis, cell proliferation and translational elongation. Notably, we observed that functional roles of the target genes for up-regulated miRNAs are inversely correlated with those for down-regulated miRNAs; the former genes promote apoptosis and translational elongation, whereas the latter function as inhibitors in these processes. Taken together, these data suggest that porphyra-334 protects cells from harmful UV radiation through the comprehensive modulation of expression patterns of genes involved in UV-mediated biological processes, and that provide a new insight to understand its functional molecular networks.

Enzymatic modification by point mutation and functional analysis of an omega-6 fatty acid desaturase from Arctic Chlamydomonas sp

Arctic Chlamydomonas sp. is a dominant microalgal strain in cold or frozen freshwater in the Arctic region. The full-length open reading frame of the omega-6 fatty acid desaturase gene (AChFAD6) was obtained from the transcriptomic database of Arctic Chlamydomonas sp. from the KOPRI culture collection of polar micro-organisms. Amino acid sequence analysis indicated the presence of three conserved histidine-rich segments as unique characteristics of omega-6 fatty acid desaturases, and three transmembrane regions transported to plastidic membranes by chloroplast transit peptides in the N-terminal region. The AChFAD6 desaturase activity was examined by expressing wild-type and V254A mutant (Mut-AChFAD6) heterologous recombinant proteins. Quantitative gas chromatography indicated that the concentration of linoleic acids in AChFAD6-transformed cells increased more than 3-fold [6.73 ± 0.13 mg g^-1 dry cell weight (DCW)] compared with cells transformed with vector alone. In contrast, transformation with Mut-AChFAD6 increased the concentration of oleic acid to 9.23 ± 0.18 mg g^-1 DCW, indicating a change in enzymatic activity to mimic that of stearoyl-CoA desaturase. These results demonstrate that AChFAD6 of Arctic Chlamydomonas sp. increases membrane fluidity by enhancing denaturation of C18 fatty acids and facilitates production of large quantities of linoleic fatty acids in prokaryotic expression systems.

Depression, Impulse Control Disorder, and Life Style According to Smartphone Addiction

We examined depression, impulse control disorder, and life style by degree of smartphone addiction. Chi-square tests and ANOVA were used to identify significant variables. CART was used to generate a decision making diagram of variables affecting smartphone addiction. The severe smartphone addiction group had rates of depression and impulse control disorder than the initial smartphone group.

Bioactivities of ethanol extract from the Antarctic freshwater microalga, Chloromonas sp. Int J Med Sci 2017;14. [PMID: 28638272 PMCID: PMC5479125 DOI: 10.7150/ijms.18702]

Cancer is the principal cause of human death and occurs through highly complex processes that involve the multiple coordinated mechanisms of tumorigenesis. A number of studies have indicated that the microalgae extracts showed anticancer activity in a variety of human cancer cells and can provide a new insight in the development of novel anti-cancer therapy. Here, in order to investigate molecular mechanisms of anticancer activity in the Antarctic freshwater microalga, Chloromonas sp., we prepared ethanol extract of Chloromonas sp. (ETCH) and performed several in vitro assays using human normal keratinocyte (HaCaT) and different types of cancer cells including cervical, melanoma, and breast cancer cells (HeLa, A375 and Hs578T, respectively). We revealed that ETCH had the antioxidant capacity, and caused significant cell growth inhibition and apoptosis of cancer cells in a dose-dependent manner, whereas it showed no anti-proliferation to normal cells. In addition, ETCH had a significant inhibitory effect on cell invasion without the cytotoxic effect. Furthermore, ETCH-induced apoptosis was mediated by increase in pro-apoptotic proteins including cleaved caspase-3 and p53, and by decrease in anti-apoptotic protein, Bcl-2 in ETCH-treated cancer cells. Taken together, this work firstly explored the antioxidant and anticancer activities of an Antarctic freshwater microalga, and ETCH could be a potential therapeutic candidate in the treatment of human cancer.

Proteomic and transcriptomic investigations on cold-responsive properties of the psychrophilic Antarctic bacterium Psychrobacter sp. PAMC 21119 at subzero temperatures

Psychrobacter sp. PAMC 21119, isolated from Antarctic permafrost soil, grows and proliferates at subzero temperatures. However, its major mechanism of cold adaptation regulation remains poorly understood. We investigated the transcriptomic and proteomic responses of this species to cold temperatures by comparing profiles at -5°C and 20°C to understand how extreme microorganisms survive under subzero conditions. We found a total of 2,906 transcripts and 584 differentially expressed genes (≥ twofold, P <0.005) by RNA-seq. Genes for translation, ribosomal structure and biogenesis were upregulated, and lipid transport and metabolism was downregulated at low temperatures. A total of 60 protein spots (≥ 1.8 fold, P < 0.005) showed differential expression on two-dimensional gel electrophoresis and the proteins were identified by mass spectrometry. The most prominent upregulated proteins in response to cold were involved in metabolite transport, protein folding and membrane fluidity. Proteins involved in energy production and conversion, and heme protein synthesis were downregulated. Moreover, isoform exchange of cold-shock proteins was detected at both temperatures. Interestingly, pathways for acetyl-CoA metabolism, putrescine synthesis and amino acid metabolism were upregulated. This study highlights some of the strategies and different physiological states that Psychrobacter sp. PAMC 21119 has developed to adapt to the cold environment in Antarctica.

Characterization of Stearoyl-CoA Desaturases from a Psychrophilic Antarctic Copepod, Tigriopus kingsejongensis

Stearoyl-CoA desaturase is a key regulator in fatty acid metabolism that catalyzes the desaturation of stearic acid to oleic acid and controls the intracellular levels of monounsaturated fatty acids (MUFAs). Two stearoyl-CoA desaturases (SCD, Δ9 desaturases) genes were identified in an Antarctic copepod, Tigriopus kingsejongensis, that was collected in a tidal pool near the King Sejong Station, King George Island, Antarctica. Full-length complementary DNA (cDNA) sequences of two T. kingsejongensis SCDs (TkSCDs) were obtained from next-generation sequencing and isolated by reverse transcription PCR. DNA sequence lengths of the open reading frames of TkSCD-1 and TkSCD-2 were determined to be 1110 and 681 bp, respectively. The molecular weights deduced from the corresponding genes were estimated to be 43.1 kDa (TkSCD-1) and 26.1 kDa (TkSCD-2). The amino acid sequences were compared with those of fatty acid desaturases and sterol desaturases from various organisms and used to analyze the relationships among TkSCDs. As assessed by heterologous expression of recombinant proteins in Escherichia coli, the enzymatic functions of both stearoyl-CoA desaturases revealed that the amount of C16:1 and C18:1 fatty acids increased by greater than 3-fold after induction with isopropyl β-D-thiogalactopyranoside. In particular, C18:1 fatty acid production increased greater than 10-fold in E. coli expressing TkSCD-1 and TkSCD-2. The results of this study suggest that both SCD genes from an Antarctic marine copepod encode a functional desaturase that is capable of increasing the amounts of palmitoleic acid and oleic acid in a prokaryotic expression system.

Enhanced production of protease by Pseudoalteromonas arctica PAMC 21717 via statistical optimization of mineral components and fed-batch fermentation

The objective of this study was to statistically optimize the mineral components of the nutritional medium required for enhancing the production of a cold-active extracellular serine-type protease, W-Pro21717, by the Antarctic bacterium Pseudoalteromonas arctica PAMC 21717. Skim milk was identified as the major efficient inducer. Among the 12 components included in the unoptimized medium, skim milk, NaCl, Na2SO4, Fe(C6H5O7) (ferric citrate), and KCl were determined, by the Plackett-Burman and Box-Behnken design, to have a major effect on W-Pro21717 production. Fed-batch fermentation (5 L scale) using the mineral-optimized medium supplemented with concentrated skim milk (critical medium component) resulted in a W-Pro21717 activity of 53.4 U/L, a 15-fold increment in production over that obtained using unoptimized flask culture conditions. These findings could be applied to scale up the production of cold-active protease.

HMGB1 in the pathogenesis of ultraviolet-induced ocular surface inflammation

High-mobility group box 1 (HMGB1) functions as a transcription-enhancing nuclear protein as well as a crucial cytokine that regulates inflammation. This study demonstrated that secretion of HMGB1 due to ultraviolet (UV) radiation inducing ocular surface inflammation-mediated reactive oxygen species (ROS) production. After treating conjunctival epithelial cells with UV radiation, HMGB1 was translocated from the nucleus to the cytoplasm and then eventually to the extracellular space. HMGB1 played a crucial role in UV-induced conjunctival neutrophil infiltration, which subsided when mice were pretreated with the HMGB1 inhibitors soluble receptor for advanced glycation endproducts (sRAGEs) and HMGB1 A box protein. In case of using ROS quencher, there was decrease in UV-induced HMGB1 secretion in conjunctival epithelial cells and mice. Considering that UV-induced chronic inflammation causes ocular surface change as pterygium, we have confirmed high HMGB1 translocation and ROS expression in human pterygium. Our findings therefore revealed a previously unknown mechanism of UV-induced ocular inflammation related to ROS and HMGB1 suggesting a new medical therapeutic target.

Microalgal lipid production using the hydrolysates of rice straw pretreated with gamma irradiation and alkali solution

BACKGROUND

Lignocellulosic biomass has long been recognized as a potential sustainable source of sugars for biofuels. However, many physicochemical structural and compositional factors inhibit the enzymatic digestibility of the lignocellulosic biomass. In this study, efficient pretreatment method of rice straw (RS) was developed and the RS hydrolysate was applied in the cultivation of microalgae for lipid production.

RESULTS

Gamma ray irradiation (GRI) and alkali solution were used for the pretreatment, and saccharification was carried out with lignocellulolytic enzymes. When RS was pretreated by combined GRI and alkali method, the glucose and xylose saccharification yield after enzymatic hydrolysis increased up to 91.65 and 98.84 %, respectively. The enzymatic hydrolysate from the RS pretreated with the combined method was used to cultivate Chlorella protothecoides for lipid production. The maximum concentrations of biomass and fatty acid methyl ester of cells were 6.51 and 2.95 g/L, respectively. The lipid content of C. protothecoides from RS hydrolysate was comparable to that from glucose, and the lipid composition was similar between different carbon sources.

CONCLUSION

These results demonstrate that the combined pretreatment with gamma irradiation was highly effective in preparing hydrolysate, and the rice straw hydrolysate could be used as an alternative carbon source for microalgal lipid production for biofuel.

Mating system patterns of natural populations of Pinus koraiensis along its post-glacial colonization route in northeastern China

To understand the genetic mechanisms underlying the endangerment of Pinus koraiensis, we studied the mating system of 49 families of this species in 3 natural populations along its post-glacial colonization route across ~1500 km in northeastern China using the chloroplast simple sequence repeat technique. We analyzed 11 polymorphic loci with clear and repeating bands, and we calculated the multi-locus outcrossing rate (tm), single-locus outcrossing rate, inbreeding index, and fixation index (F). Intra-population variation was not observed, but a large inter-population variation was observed in the outcrossing rate, and the tm increased from 0.767 (the south population) to 0.962 (the north population) along the post-glacial colonization route. The tm values within a population did not change with time over 2 consecutive years. The F values for the 3 populations were <0, which indicates an excess of heterozygotes. The mean effective number of alleles, Shannon diversity index, and Nei's genetic diversity index did not show a south-north pattern. The north population had the highest outcrossing rate but the lowest genetic diversity. The average genetic differentiation of P. koraiensis populations was 0.1251, which was within the average range of woody plants with outcrossing and wind pollination. This study suggests that the current endangerment of P. koraiensis is not related to its genetic structure; perhaps it is mainly caused by man-made and natural disturbances such as deforestation and fire. Therefore, reducing disturbances and enhancing habitats, rather than the genetic aspects, play more important roles in the long-term protection of P. koraiensis.

Enhancing extracellular lipolytic enzyme production in an arctic bacterium, Psychrobacter sp. ArcL13, by using statistical optimization and fed-batch fermentation

A strain isolated from seawater samples in the Chuckchi Sea and exhibiting extracellular lipolytic activity was identified using 16S rRNA gene sequence analysis as Psychrobacter sp. ArcL13. The lipolytic enzyme exhibited cold-active properties and high hydrolytic activity toward p-nitrophenyl caprylate (C8), p-nitrophenyl decanoate (C10), and sunflower oil. Statistical optimization of the medium components was performed to enhance the production of cold-active extracellular lipolytic activity. Glucose, yeast extract (YE), and NaCl were selected as the main efficient nutrient sources. Fed-batch fermentation using optimized medium with concentrated YE as the main feeding material showed a maximum lipolytic activity of 10.7 U/mL, which was a 21-fold increase in production over unoptimized flask culture conditions. The information obtained in the present study could prove applicable to the production of cold-active lipase on a large scale.

Extracellular visfatin activates gluconeogenesis in HepG2 cells through the classical PKA/CREB-dependent pathway

Adipokines reportedly affect hepatic gluconeogenesis, and the adipokine visfatin is known to be related to insulin resistance and type 2 diabetes. However, whether visfatin contributes to hepatic gluconeogenesis remains unclear. Visfatin, also known as nicotinamide phosphoribosyltransferase (NAMPT), modulates sirtuin1 (SIRT1) through the regulation of nicotinamide adenine dinucleotide (NAD). Therefore, we investigated the effect of extracellular visfatin on glucose production in HepG2 cells, and evaluated whether extracellular visfatin affects hepatic gluconeogenesis via an NAD+-SIRT1-dependent pathway. Treatment with visfatin significantly increased glucose production and the mRNA expression and protein levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in HepG2 cells in a time- and concentration-dependent manner. Knockdown of SIRT1 had no remarkable effect on the induction of gluconeogenesis by visfatin. Subsequently, we evaluated if extracellular visfatin stimulates the production of gluconeogenic enzymes through the classical protein kinase A (PKA)/cyclic AMP-responsive element (CRE)-binding protein (CREB)-dependent process. The phosphorylation of CREB and PKA increased significantly in HepG2 cells treated with visfatin. Additionally, knockdown of CREB and PKA inhibited visfatin-induced gluconeogenesis in HepG2 cells. In summary, extracellular visfatin modulates glucose production in HepG2 cells through the PKA/CREB pathway, rather than via SIRT1 signaling.

Purification, crystallization and preliminary X-ray crystallographic studies of FMN-bound and FMN-free forms of aromatic acid decarboxylase (CpsUbiX) from the psychrophilic bacterium Colwellia psychrerythraea 34H

The ubiX gene (UniProtKB code Q489U8) of Colwellia psychrerythraea strain 34H has been annotated as a putative flavin mononucleotide (FMN)-dependent aromatic acid decarboxylase. Based on previous studies of homologous proteins, CpsUbiX is thought to catalyze the decarboxylation of 3-octaprenyl-4-hydroxybenzoate to produce 2-polyprenylphenol in the ubiquinone-biosynthesis pathway using a noncovalently bound FMN molecule as a cofactor. However, the detailed mechanisms of this important enzyme are not yet clear and need to be further elucidated. In this study, it was found that the V47S single mutation resulted in a loss of FMN binding, resulting in the production of FMN-free CpsUbiX protein. This mutation is likely to destabilize FMN-protein interactions without affecting the overall structural folding. To fully characterize the conformational changes upon FMN binding and the enzymatic mechanism at the molecular level, the wild-type (FMN-bound) and V47S mutant (FMN-free) CpsUbiX proteins were purified and crystallized using the sitting-drop vapour-diffusion method. Furthermore, complete diffraction data sets for FMN-bound (space group C222(1)) and FMN-free (space group P23) forms were obtained to 2.0 and 1.76 Å resolution, respectively.

Photochemically crosslinked collagen annulus plug: a potential solution solving the leakage problem of cell-based therapies for disc degeneration

Intra-disc injection of mesenchymal stem cells (MSCs) to treat disc degeneration may lead to unfavorable complications, particularly osteophyte formation. Development of an effective method to block the injection portal, prevent the leakage of injected cells and materials and, hence, prevent osteophyte formation is of the utmost importance before MSC-based therapies can be applied in a clinical setting. Here we seek to alleviate the cell leakage problem and the associated complication osteophyte formation by developing an injectable annulus plug to block the injection portal during intra-disc delivery. Specifically, we fabricated a needle-shaped collagen plug by photochemical crosslinking and successfully delivered it intra-discally, in association with MSCs in collagen microsphere carriers, using a custom-made delivery device. The mechanical performance of the plug and its effectiveness in reducing cell leakage were evaluated ex vivo under compression and in torsion push-out tests. The results demonstrate that the plug survived physiologically relevant loadings and significantly reduced leakage and enhanced retention of the injected materials. Finally, a pilot in vivo study in rabbits was conducted to evaluate the performance of the plug. Microcomputed tomography imaging and histology revealed that the plug significantly reduced osteophyte formation. This work suggests the potential of the annulus plug as an adjunct or annulus closure device for intra-disc delivery of cells and materials.

Recombinant tagging system using ribosomal frameshifting to monitor protein expression

For rapid and accurate quantitation of recombinant proteins during expression and after purification, we introduce a new tagging strategy that expresses both target proteins and limitedly tagged target proteins together in a single cell at a constant ratio by utilizing cis-elements of programmed -1 ribosomal frameshifting (-1RFS) as an embedded device. -1RFS is an alternative reading mechanism that effectively controls protein expression by many viruses. When a target gene is fused to the enhanced green fluorescent protein (EGFP) gene with a -1RFS element implanted between them, the unfused target and the target-GFP fusion proteins are expressed at a fixed ratio. The expression ratio between these two protein products is adjustable simply by changing -1RFS signals. This limited-tagging system would be valuable for the real-time monitoring of protein expression when optimizing expression condition for a new protein, and in monitoring large-scale bioprocesses without a large metabolic burden on host cells. Furthermore, this strategy allows for the direct measurement of the quantity of a protein on a chip surface and easy application to proteomewide study of gene products.

Ramalin, a novel nontoxic antioxidant compound from the Antarctic lichen Ramalina terebrata

Ramalin (γ-glutamyl-N'-(2-hydroxyphenyl)hydrazide), a novel compound, was isolated from the methanol-water extract of the Antarctic lichen Ramalina terebrata by several chromatographic methods. The molecular structure of ramalin was determined by spectroscopic analysis. The experimental data showed that ramalin was five times more potent than commercial butylated hydroxyanisole (BHA) in scavenging 1-diphenyl-2-picryl-hydazil (DPPH) free radicals, 27 times more potent in scavenging 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid free radicals (ABTS(+)) than the vitamin E analogue, trolox, and 2.5 times more potent than BHT in reducing Fe(3+) to Fe(2+) ions. Similarly, ramalin was 1.2 times more potent than ascorbic acid in scavenging superoxide radicals and 1.25 times more potent than commercial kojic acid in inhibiting tyrosinase enzyme activity, which ultimately leads to whitening of skin cells. Ramalin showed no or very little cytotoxicity in human keratinocyte and fibroblast cells at its antioxidant concentration. Furthermore, ramalin was assessed to determine its antioxidant activity in vivo. One microgram per milliliter ramalin significantly reduced the released nitric oxide (NO) and 0.125 μg/ml ramalin reduced the produced hydrogen peroxide (H(2)O(2)) in LPS (lipopolysaccharide)-stimulated murine macrophage Raw264.7 cells. Considering all the data together, ramalin can be a strong therapeutic candidate for controlling oxidative stress in cells.