In vitro screening system for hepatotoxicity: Comparison of bone‐marrow‐derived mesenchymal stem cells and Placenta‐derived stem cells

Stem cells have unique properties such as self‐renewal, plasticity to generate various cell types, and availability of cells of human origin. The characteristics are attentive in the toxicity screening against chemical toxicants. Placenta‐derived stem cells (PDSCs) have been spotlighted as a new cell source in stem cell research recently because they are characterized by their capacity to differentiate into multilineages. However, the use of PDSCs as an in vitro screening model for potential drug candidates has not yet been studied. Here, we analyzed the potentials for bone‐marrow‐derived mesenchymal stem (BM‐MSCs), which is a representative adult stem cells and PDSCs as an in vitro hepatotoxicity screening system, using well‐known hepatotoxicants. BM‐MSCs and PDSCs were analyzed to the potential for hepatogenic differentiation and were cultured with different concentrations of hepatotoxicants for time courses. The viability and ATP‐binding cassette (ABC) transporters were measured by the MTT assay and RT‐PCR, respectively. The sensitivities of PDSCs to hepatotoxicants are more sensitive than those of BM‐MSCs. The viability (IC₅₀) to in PDSCs was less than that of BM‐MSCs after 48 and 72 h (P < 0.05) of CCl₄ exposure. The toxicities of CCl₄ were decreased by fourfold in hepatogenic differentiation inducing PDSCs compared to the undifferentiated cells. The alteration of ABCGs was observed in PDSCs during differentiation. These findings suggest that the naïve PDSCs expressing ABCGs can be used as a source for in vitro screening system as well as the expression patterns of ABCG1 and ABCG2 might be involved in the sensitivity of PDSCs to hepatotoxicants. J. Cell. Biochem. 112: 49–58, 2011. © 2010 Wiley‐Liss, Inc.     

Genetic assessment of safflower (Carthamus tinctorius L.) collection with microsatellite markers acquired via pyrosequencing method

A genetic evaluation of safflower germplasm collections derived from different geographical regions and countries will provide useful information for sustainable conservation and the utilization of genetic diversity. However, the molecular marker information is limited for evaluation of genetic diversity of safflower germplasm. In this study, we acquired 509 putative genomic SSR markers for sufficient genome coverage using next‐generation sequencing methods and characterized thirty polymorphic SSRs in safflower collection composed of 100 diverse accessions. The average allele number and expected heterozygosity were 2.8 and 0.386, respectively. Analysis of population structure and phylogeny based on thirty SSR profiles revealed genetic admixture between geographical regions contrary to genetic clustering. However, the accessions from Korea were genetically conserved in distinctive groups in contrast to other safflower gene pool. In conclusion, these new genomic SSRs will facilitate valuable studies to clarify genetic relationships as well as conduct population structure analyses, genetic map construction and association analysis for safflower.     

Light and Electron Microscopy of the European Beaver (Castor fiber) Stomach Reveal Unique Morphological Features with Possible General Biological Significance

Anatomical, histological, and ultrastructural studies of the European beaver stomach revealed several unique morphological features. The prominent attribute of its gross morphology was the cardiogastric gland (CGG), located near the oesophageal entrance. Light microscopy showed that the CGG was formed by invaginations of the mucosa into the submucosa, which contained densely packed proper gastric glands comprised primarily of parietal and chief cells. Mucous neck cells represented <0.1% of cells in the CGG gastric glands and 22–32% of cells in the proper gastric glands of the mucosa lining the stomach lumen. These data suggest that chief cells in the CGG develop from undifferentiated cells that migrate through the gastric gland neck rather than from mucous neck cells. Classical chief cell formation (i.e., arising from mucous neck cells) occurred in the mucosa lining the stomach lumen, however. The muscularis around the CGG consisted primarily of skeletal muscle tissue. The cardiac region was rudimentary while the fundus/corpus and pyloric regions were equally developed. Another unusual feature of the beaver stomach was the presence of specific mucus with a thickness up to 950 µm (in frozen, unfixed sections) that coated the mucosa. Our observations suggest that the formation of this mucus is complex and includes the secretory granule accumulation in the cytoplasm of pit cells, the granule aggregation inside cells, and the incorporation of degenerating cells into the mucus.     

Risk Factors for Developing Hyponatremia in Thyroid Cancer Patients Undergoing Radioactive Iodine Therapy

Background

Due to the alarming increase in the incidence of thyroid cancer worldwide, more patients are receiving postoperative radioactive iodine (RAI) therapy and these patients are given a low-iodine diet along with levothyroxine withdrawal to induce a hypothyroid state to maximize the uptake of RAI by thyroid tissues. Recently, the reported cases of patients suffering from life-threatening severe hyponatremia following postoperative RAI therapy have increased. This study aimed to systematically assess risk factors for developing hyponatremia following RAI therapy in post-thyroidectomy patients.

Methods

We reviewed the medical records of all thyroid cancer patients who underwent thyroidectomy and postoperative RAI therapy from July 2009 to February 2012. Demographic and biochemical parameters including serum sodium and thyroid function tests were assessed along with medication history.

Results

A total of 2229 patients (47.0±11.0 years, female 76.3%) were enrolled in the analysis. Three hundred seven patients (13.8%) of all patients developed hyponatremia; 44 patients (2.0%) developed moderate to severe hyponatremia (serum Na⁺≤130 mEq/L) and another 263 (11.8%) patients showed mild hyponatremia (130 mEq/L<serum Na⁺≤135 mEq/L). In univariate analysis, old age, female sex, presence of hypertension, presence of diabetes, use of thiazide diuretics, use of angiotensin receptor blocker or angiotensin-converting enzyme inhibitors, lung metastasis, and hyponatremia and lower estimated glomerular filtration rate at the start of RAI therapy were significantly associated with hyponatremia in patients undergoing RAI therapy after total thyroidectomy. Multivariate analysis showed that old age, female sex, use of thiazide diuretics, and hyponatremia at the initiation of RAI therapy were independent risk factors for the development of hyponatremia.

Conclusion

Our data suggest that age greater than 60 years, female sex, use of thiazide, and hyponatremia at the initiation of RAI therapy are important risk factors for developing hyponatremia following RAI therapy in post-thyroidectomy patients.     

Profiles of photosynthetic pigment accumulation and expression of photosynthesis-related genes in the marine cyanobacteria Synechococcus sp.: Effects of LED wavelengths

Light quality is a significant environmental factor that influences photosynthetic pigments in cyanobacteria. In the present study, we illuminated the marine cyanobacteria Synechococcus sp. with white (350 ～ 700 nm), red (630 nm), green (530 nm), and blue (450 nm) light emitting diodes (LEDs) and measured pigment levels (chlorophyll, carotenoid, and phycobiliprotein) and expression of photosynthesis-related genes (pebA, psbB, and psaE). The amount of photosynthetic pigments (total pigments, chlorophyll, and phycobiliproteins) was higher in the green and blue LED groups than in the white and red LED groups after 8 days of culture. The cells were prepared in a 1.5 mL solution for the analysis of the total pigments, chlorophyll, and carotenoid, and in a 2 mL for analysis of phycobiliproteins. The mRNA expression levels of pebA and psbB significantly increased after 8 days of cultivation under green and blue light, while the mRNA expression levels of psaE decreased. These results indicate that green and blue light increase the accumulation of photosynthetic pigments. In contrast red light induced mRNA expression of psaE and stimulated cell growth in Synechococcus sp.     

Salicortin suppresses lipopolysaccharide-stimulated inflammatory responses via blockade of NF-κB and JNK activation in RAW 264.7 macrophages

We isolated the phenolic glucoside salicortin from a Populus euramericana bark extract, and examined its ability to suppress inflammatory responses as well as the molecular mechanisms underlying these abilities, using lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Salicortin inhibited iNOS expression and the subsequent production of NO in a dose-dependent manner in the LPS-stimulated RAW 264.7 cells. Salicortin significantly suppressed LPS-induced signal cascades of NF-κB activation, such as IKK activation, IκBα phosphorylation and p65 phosphorylation in RAW 264.7 cells. In addition, salicortin inhibited the LPS-induced activation of JNK, but not ERK or p38 MAPK. Furthermore, salicortin significantly inhibited production of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6 in the LPS-stimulated RAW 264.7 cells. These findings suggest that salicortin may show its anti-inflammatory activity by suppressing the LPS-induced expression of pro-inflammatory mediators through inhibition of NF-κB and JNK MAPK signaling cascades in macrophages. [BMB Reports 2014; 47(6): 318-323]     

Bacterial community composition and diversity of a full-scale integrated fixed-film activated sludge system as investigated by pyrosequencing

The integrated fixed-film activated sludge (IFAS) system is a variation of the activated sludge wastewater treatment process, in which hybrid suspended and attached biomass is used to treat wastewater. Although the function and performance of the IFAS system are well studied, little is known about its microbial community structure. In this study, the composition and diversity of the bacterial community of suspended and attached biomass samples were investigated in a full-scale IFAS system using a highthroughput pyrosequencing technology. Distinct bacterial community compositions were examined for each sample and appeared to be important for its features different from conventional activated sludge processes. The abundant bacterial groups were Betaproteobacteria (59.3%), Gammaproteobacteria (8.1%), Bacteroidetes (5.2%), Alphaproteobacteria (3.9%), and Actinobacteria (3.2%) in the suspended sample, whereas Actinobacteria (14.6%), Firmicutes (13.6%), Bacteroidetes (11.6%), Betaproteobacteria (9.9%), Gammaproteobacteria (9.25%), and Alphaproteobacteria (7.4%) were major bacterial groups in the attached sample. Regarding the diversity, totals of 3,034 and 1,451 operational taxonomic units were identified at the 3% cutoff for the suspended and attached samples, respectively. Rank abundance and community analyses demonstrated that most of the diversity was originated from rare species in the samples. Taken together, the information obtained in this study will be a base for further studies relating to the microbial community structure and function of the IFAS system.     

Simulation of sequential batch reactor (SBR) operation for simultaneous removal of nitrogen and phosphorus

Modeling of the operation of sequential batch reactor (SBR) was performed to find out optimum design parameters for simultaneous removal of nitrogen and phosphorus in a small-scale wastewater treatment plant. The models were set up with material balances on SBR operation and Monod kinetics. The model parameters were obtained to best fit the experimental results in a small scale SBR. The models were useful in optimizing hydraulic retention time (HRT) and successfully simulated operations of SBR in a larger scale. Especially the model predicted well the reactions occurring in the filling period as well as the effect of dilution, and evaluated the performance of SBR process under diverse operating conditions.