Pollen morphology of some taxa of Vicia L. subgenus Vicia (Fabaceae) from Turkey

In this study, the pollen morphology of 11 taxa belonging to Atossa (Alef.) Asch. & Graebner, Hypechusa (Alef.) Asch. & Graebner, Peregrinae Kupicha, Wiggersia (Alef.) Maxted, Vicia L. and Narbonensis (Radzhi) Maxted sections of the genus Vicia L. subgenus Vicia (Fabeae, Fabaceae) naturally growing in Turkey has been studied using Light Microscopy (LM) and Scanning Electron Microscopy (SEM) to evaluate the taxonomic relevance of pollen characters. Twelve morphometric characters are analysed with one-way analysis of variance and Tukey’s honestly significant difference test for multiple comparisons. Of the taxa studied V. narbonensis var. narbonensis (sect. Narbonensis) has the largest pollen grains (P = 51.98 μm × E = 30.52 μm) and V. lathyroides (sect. Wiggersia) has the smallest pollen grains (P = 27.71 μm × E = 20.14 μm). The pollen grains are subprolate to perprolate (P/E = 1.16–2.11), but the prolate shape occurs in the majority of the taxa. The regular pollen grains of all taxa are trizonocolporate, isopolar, and released in monads. Ornamentation of the mesocolpium is psilate-perforate in V. lathyroides (sect. Wiggersia), reticulate-rugulate in V. narbonensis var. narbonensis (sect. Narbonensis), (micro)reticulate in V. sericocarpa var. sericocarpa (sect. Hypechusa), V. sativa subsp. sativa (sect. Vicia) and V. grandiflora var. grandiflora (sect. Vicia), and reticulate-perforate in the remaining taxa. The apocolpium and colpus area are psilate or perforate in all taxa except V. sericocarpa var. sericocarpa (sect. Hypechusa) and V. sativa subsp. sativa (sect. Vicia), which exhibit the obscurely reticulate-perforate pattern. Several palynological features have taxonomic importance in sectional level: polar axis, equatorial diameter, pollen shape (P/E ratio), colpus length, colpus width, size of pori, porus length/width ratio, lumina diameter, muri thickness and ornamentation. The results also indicate that pollen characters can be useful in distinguishing the examined taxa.     

S-Allyl cysteine attenuates free fatty acid-induced lipogenesis in human HepG2 cells through activation of the AMP-activated protein kinase-dependent pathway

S-Allyl cysteine (SAC), a nontoxic garlic compound, has a variety of pharmacological properties, including antioxidant and hepatoprotective properties. In this report, we provide evidence that SAC prevented free fatty acid (FFA)-induced lipid accumulation and lipotoxicity in hepatocytes. SAC significantly reduced FFA-induced generation of reactive oxygen species, caspase activation and subsequent cell death. Also, SAC mitigated total cellular lipid and triglyceride accumulation in steatotic HepG2 cells. SAC significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) in HepG2 cells. Additionally, SAC down-regulated the levels of sterol regulatory element binding protein-1 (SREBP-1) and its target genes, including ACC and fatty acid synthase. Use of a specific inhibitor showed that SAC activated AMPK via calcium/calmodulin-dependent kinase kinase (CaMKK) and silent information regulator T1. Our results demonstrate that SAC activates AMPK through CaMKK and inhibits SREBP-1-mediated hepatic lipogenesis. Therefore, SAC has therapeutic potential for preventing nonalcoholic fatty liver disease.     

Massively parallel sequencing of Chikso (Korean brindle cattle) to discover genome-wide SNPs and InDels

Since the completion of the bovine sequencing projects, a substantial number of genetic variations such as single nucleotide polymorphisms have become available across the cattle genome. Recently, cataloguing such genetic variations has been accelerated using massively parallel sequencing technology. However, most of the recent studies have been concentrated on European Bos taurus cattle breeds, resulting in a severe lack of knowledge for valuable native cattle genetic resources worldwide. Here, we present the first whole-genome sequencing results for an endangered Korean native cattle breed, Chikso, using the Illumina HiSeq 2,000 sequencing platform. The genome of a Chikso bull was sequenced to approximately 25.3-fold coverage with 98.8% of the bovine reference genome sequence (UMD 3.1) covered. In total, 5,874,026 single nucleotide polymorphisms and 551,363 insertion/deletions were identified across all 29 autosomes and the X-chromosome, of which 45% and 75% were previously unknown, respectively. Most of the variations (92.7% of single nucleotide polymorphisms and 92.9% of insertion/deletions) were located in intergenic and intron regions. A total of 16,273 single nucleotide polymorphisms causing missense mutations were detected in 7,111 genes throughout the genome, which could potentially contribute to variation in economically important traits in Chikso. This study provides a valuable resource for further investigations of the genetic mechanisms underlying traits of interest in cattle, and for the development of improved genomics-based breeding tools.     

Inactivation and conformational changes in methyl parathion hydrolase in 2,2,2-trifluoroethanol solutions: Inactivation kinetics and molecular dynamics simulation

Many improvements have been made in the understanding of functional and structural characteristics of proteins in a denaturant-based microenvironment. This study reports the chemical denaturation of methyl parathion hydrolase (MPH, EC 3.1.8.1) using 2,2,2-trifluoroethanol (TFE). MPH is an important enzyme that catalyzes the hydrolysis of organophosphorus agents. However, the regulation of MPH activity and structural changes during unfolding are not well studied, particularly for TFE unfolding. We investigated MPH unfolding with TFE for the first time. In this study, changes in enzymatic activity and unfolding of MPH at different TFE concentrations were investigated by enzyme activity measurements, intrinsic fluorescence and by 1-anilino-8-naphthalenesulfonate (ANS) fluorescence emission spectral scans. The results showed TFE inactivated MPH in a dose-dependent manner. A Lineweaver–Burk plot analysis revealed that the type of inhibition was reversible noncompetitive inhibition. Intrinsic fluorescence and ANS-binding fluorescence showed that TFE induced obvious tertiary structural changes in MPH by exposing hydrophobic groups. Furthermore, we conducted a docking simulation between MPH and TFE. The computer simulation successfully showed the binding structure and we estimated stability by calculating the binding energy (lowest binding energy: -3.18 kcal/mol). The results demonstrate that MPH can be inactivated by TFE, and provide new insights into the mechanism of TFE-induced unfolding of MPH and inhibition of ligand binding.     

Improving of Catalase Stability Properties by Encapsulation in Alginate/Fe3O4 Magnetic Composite Beads for Enzymatic Removal of H2O2

The aim of this study was enhancing of stability properties of catalase enzyme by encapsulation in alginate/nanomagnetic beads. Amounts of carrier (10–100 mg) and enzyme concentrations (0.25–1.5 mg/mL) were analyzed to optimize immobilization conditions. Also, the optimum temperature (25–50°C), optimum pH (3.0–8.0), kinetic parameters, thermal stability (20–70°C), pH stability (4.0–9.0) operational stability (0–390 min), and reusability were investigated for characterization of the immobilized catalase system. The optimum pH levels of both free and immobilized catalase were 7.0. At the thermal stability studies, the magnetic catalase beads protected 90% activity, while free catalase maintained only 10% activity at 70°C. The thermal profile of magnetic catalase beads was spread over a large area. Similarly, this system indicated the improving of the pH stability. The reusability, which is especially important for industrial applications, was also determined. Thus, the activity analysis was done 50 times in succession. Catalase encapsulated magnetic alginate beads protected 83% activity after 50 cycles.     

Formation of an Antral Follicle-Like Structure by Bovine Cumulus-Oocyte Complexes Embedded with Fragmin/Protamine Microparticles

Fragmin/protamine microparticles (F/P MPs) approximately 0.5-1 µM in diameter were prepared by the simple mixing of fragmin with protamine. This study investigated the effects of F/P MP-containing collagen gels as a hormone carrier on the formation of antral follicle-like structures and on the development of growing bovine oocytes. The supplementation of F/P MPs in collagen gels contributed to the beneficial effects of follicle stimulating hormone (FSH) on the formation and size of antral follicle-like structures. The F/P MPs may serve as potential hormone carriers for the growth of cultured bovine oocytes from early antral follicles.     

SIGN-R1, a C-type lectin,enhances apoptotic cell clearance through the complement deposition pathway by interacting with C1q in the spleen

Complements, such as C1q and C3, and macrophages in the splenic marginal zone (MZMs) play pivotal roles in the efficient uptake and processing of circulating apoptotic cells. SIGN-R1, a C-type lectin that is highly expressed in a subpopulation of MZMs, regulates the complement fixation pathway by interacting with C1q, to fight blood-borne Streptococcus pneumoniae. Therefore, we examined whether the SIGN-R1-mediated classical complement pathway plays a role in apoptotic cell clearance and immune tolerance. SIGN-R1 first-bound apoptotic cells and this binding was significantly enhanced in the presence of C1q. SIGN-R1–C1q complex then immediately mediated C3 deposition on circulating apoptotic cells in the MZ, leading to the efficient clearance of them. SIGN-R1-mediated C3 deposition was completely abolished in the spleen of SIGN-R1 knockout (KO) mice. Given that SIGN-R1 is not expressed in the liver, we were struck by the finding that C3-deposited apoptotic cells were still found in the liver of wild-type mice, and dramatically reduced in the SIGN-R1 KO liver. In particular, SIGN-R1 deficiency caused delayed clearance of apoptotic cells and aberrant secretion of cytokines, such as TNF-α, IL-6, and TGF-β in the spleen as well as in the liver. In addition, anti-double- and single-stranded DNA antibody level was significantly increased in SIGN-R1-depleted mice compared with control mice. These findings suggest a novel mechanism of apoptotic cell clearance which is initiated by SIGN-R1 in the MZ and identify an integrated role of SIGN-R1 in the systemic clearance of apoptotic cells, linking the recognition of apoptotic cells, the opsonization of complements, and the induction of immune tolerance.