Analytical techniques used for the characterization and authentification of six ancient religious manuscripts (XVIII-XIX centuries).
Microsc Res Tech. 2014 Oct 21;
Authors: Vornicu N, Deselnicu V, Bibire C, Ivanov D, Doroftei F
This article presents the experimental results of a research on six manuscripts (three of the XVIII century and three of XIX century) belonging collection of old religious books to the Moldovan Metropolitan Church of Romania. Non-invasive techniques (optical microscopy [OM], scanning electron microscopy/energy dispersive X-ray system, X-ray fluorescence analysis, shrinkage temperature, and Fourier transform infrared spectroscopy/attentuated total reflectance) provided information on the degree of degradation and identification of the leather bookbinding type. Moreover, visual assessment and OM revealed the extent of the surface degradation (wane, biological attack, change color, etc.). The degradation extent of the skin bindings was determined on the 12 samples. The insight on the mechanism of degradation was accomplished by analyzing the deterioration of collagen fibers in terms of shrinkage temperature and chemical modifications induced by oxidative and hydrolytic processes. Shrinkage temperature values were lower compared with the literature data for collagen, indicating that the leather bookbinding suffered intrinsic damage. Morphological analysis was accomplished by microscopy and allowed the identification of skin type and provided information about its processing technique. Mineral elements were identified for leather composition and contributed to the information regarding the origin and the extent of degradation of the leather bookbinding, of the studied manuscripts. The analyzed results were useful in determining the state of preservation and were able to provide an increased efficiency of further restoration. The correlation of the obtained data brought new contributions to the knowledge of the leather covers for the book technique in the XVIII and XIX centuries in monastic workshops of Eastern Europe. Microsc. Res. Tech., 2014. © 2014 Wiley Periodicals, Inc.
PMID: 25331722 [PubMed - as supplied by publisher]
Comparative study of decalcification versus nondecalcification for histological evaluation of one-wall periodontal intrabony defects in dogs.
Microsc Res Tech. 2014 Oct 21;
Authors: Park SH, Choi HM, Han JS, Park YB
Biological reactions between biomaterials and surrounding tissues, analyzed by histology, may be important predictors of clinical healing pattern and selection of slide preparation techniques requires a careful consideration regarding sample properties. In this study, we compared histology of bone specimens prepared with or without decalcification and performed histological and histomorphometrical assessments. For the histological evaluation, one-wall intrabony defects were created around the mandibular molars of six adult dogs, filled with biphasic calcium phosphate, synthetic bone graft material/recombinant human bone morphogenic protein-2, and healing pattern was histologically evaluated at 4 and 12 weeks. New bone formation in 5 × 4 × 4 mm defects and the length of new cementum, connective tissue attachments around the teeth and number of osteoclasts were measured by histomorphometric analysis. After decalcification, new cementum was easily observed and was significantly increased at week 4. In nondecalcified samples, significantly increased connective tissue attachments were seen at week 12. After 12 weeks, the number of countable multinucleated osteoclasts was significantly increased by 62% in nondecalcified versus calcified tissue sections (P = 0.030). Histomorphometric results may be significantly affected by histological preparation method and therefore, selecting the most appropriate histological preparation method is essential for reliable diagnosis and evaluation of bony samples in studies analyzing tissue regeneration. Microsc. Res. Tech., 2014. © 2014 Wiley Periodicals, Inc.
PMID: 25331781 [PubMed - as supplied by publisher]
Small Molecules Targeting c-Myc Oncogene: Promising Anti-Cancer Therapeutics.
Int J Biol Sci. 2014;10(10):1084-1096
Authors: Chen BJ, Wu YL, Tanaka Y, Zhang W
The nuclear transcription factor c-Myc is a member of the Myc gene family with multiple functions and located on band q24.1 of chromosome 8. The c-Myc gene is activated by chromosomal translocation, rearrangement, and amplification. Its encoded protein transduces intracellular signals to the nucleus, resulting in the regulation of cell proliferation, differentiation, and apoptosis, and has the ability to transform cells and bind chromosomal DNA. c-Myc also plays a critical role in malignant transformation. The abnormal over-expression of c-Myc is frequently observed in some tumors, including carcinomas of the breast, colon, and cervix, as well as small-cell lung cancer, osteosarcomas, glioblastomas, and myeloid leukemias, therefore making it a possible target for anticancer therapy. In this minireview, we summarize unique characteristics of c-Myc and therapeutic strategies against cancer using small molecules targeting the oncogene, and discuss the prospects in the development of agents targeting c-Myc, in particular G-quadruplexes formed in c-Myc promoter and c-Myc/Max dimerization. Such information will be of importance for the research and development of c-Myc-targeted drugs.
PMID: 25332683 [PubMed - as supplied by publisher]
Cationicity-Enhanced Analogues of the Antimicrobial Peptides, AcrAP1 and AcrAP2, from the Venom of the Scorpion, Androctonus crassicauda, Display Potent Growth Modulation Effects on Human Cancer Cell Lines.
Int J Biol Sci. 2014;10(10):1097-107
Authors: Du Q, Hou X, Ge L, Li R, Zhou M, Wang H, Wang L, Wei M, Chen T, Shaw C
The non disulphide-bridged peptides (NDBPs) of scorpion venoms are attracting increased interest due to their structural heterogeneity and broad spectrum of biological activities. Here, two novel peptides, named AcrAP1 and AcrAP2, have been identified in the lyophilised venom of the Arabian scorpion, Androctonus crassicauda, through “shotgun” molecular cloning of their biosynthetic precursor-encoding cDNAs. The respective mature peptides, predicted from these cloned cDNAs, were subsequently isolated from the same venom sample using reverse phase HPLC and their identities were confirmed by use of mass spectrometric techniques. Both were found to belong to a family of highly-conserved scorpion venom antimicrobial peptides – a finding confirmed through the biological investigation of synthetic replicates. Analogues of both peptides designed for enhanced cationicity, displayed enhanced potency and spectra of antimicrobial activity but, unlike the native peptides, these also displayed potent growth modulation effects on a range of human cancer cell lines. Thus natural peptide templates from venom peptidomes can provide the basis for rational analogue design to improve both biological potency and spectrum of action. The diversity of such templates from such natural sources undoubtedly provides the pharmaceutical industry with unique lead compounds for drug discovery.
PMID: 25332684 [PubMed - in process]
Dexmedetomidine-induced Contraction Involves Phosphorylation of Caldesmon by JNK in Endothelium-denuded Rat Aortas.
Int J Biol Sci. 2014;10(10):1108-15
Authors: Baik J, Ok SH, Cho H, Yu J, Kim W, Nam IK, Choi MJ, Lee HK, Sohn JT
Caldesmon, an inhibitory actin binding protein, binds to actin and inhibits actin-myosin interactions, whereas caldesmon phosphorylation reverses the inhibitory effect of caldesmon on actin-myosin interactions, potentially leading to enhanced contraction. The goal of this study was to investigate the cellular signaling pathway responsible for caldesmon phosphorylation, which is involved in the regulation of the contraction induced by dexmedetomidine (DMT), an alpha-2 adrenoceptor agonist, in endothelium-denuded rat aortas. SP600125 (a c-Jun NH2-terminal kinase [JNK] inhibitor) dose-response curves were generated in aortas that were pre-contracted with DMT or phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) activator. Dose-response curves to the PKC inhibitor chelerythrine were generated in rat aortas pre-contracted with DMT. The effects of SP600125 and rauwolscine (an alpha-2 adrenoceptor inhibitor) on DMT-induced caldesmon phosphorylation in rat aortic vascular smooth muscle cells (VSMCs) were investigated by western blot analysis. PDBu-induced caldesmon and DMT-induced PKC phosphorylation in rat aortic VSMCs was investigated by western blot analysis. The effects of GF109203X (a PKC inhibitor) on DMT- or PDBu-induced JNK phosphorylation in VSMCs were assessed. SP600125 resulted in the relaxation of aortas that were pre-contracted with DMT or PDBu, whereas rauwolscine attenuated DMT-induced contraction. Chelerythrine resulted in the vasodilation of aortas pre-contracted with DMT. SP600125 and rauwolscine inhibited DMT-induced caldesmon phosphorylation. Additionally, PDBu induced caldesmon phosphorylation, and GF109203X attenuated the JNK phosphorylation induced by DMT or PDBu. DMT induced PKC phosphorylation in rat aortic VSMCs. These results suggest that alpha-2 adrenoceptor-mediated, DMT-induced contraction involves caldesmon phosphorylation that is mediated by JNK phosphorylation by PKC.
PMID: 25332685 [PubMed - in process]
The steroid receptor coactivator-3 is required for developing neuroendocrine tumor in the mouse prostate.
Int J Biol Sci. 2014;10(10):1116-27
Authors: Tien JC, Liao L, Liu Y, Liu Z, Lee DK, Wang F, Xu J
Neuroendocrine tumor cells (NETCs) are commonly observed in prostate cancer. Their presence is associated with castration resistance, metastasis and poor prognosis. Cellular and molecular mechanisms for NETC initiation and growth are unknown. TRAMP mice develop heterogeneous adenocarcinomas induced by expression of the SV40-T/t oncogene in prostate epithelial cells. Here, we demonstrate prostate tumors in TRAMP mice with a mixed genetic background are characterized mostly by atypical hyperplasia (AH) containing steroid receptor coactiator-3-positive, androgen receptor-positive and synaptophysin-negative (SRC-3+/AR+/Syp-) cells. Few SRC-3+/AR-/Syp+ NETCs are present in their prostates. We generated TRAMP mice in which SRC-3 was specifically ablated in AR+/Syp- prostatic epithelial cells (termed PE3KOT mice). In these animals, we observed a substantial reduction in SRC-3-/AR+/Syp- AH tumor growth. There was a corresponding increase in SRC-3-/AR+/Syp- phyllodes lesions, suggesting SRC-3 knockout can convert aggressive AH tumors with mostly epithelial tumor cells into less aggressive phyllodes lesions with mostly stromal tissue. Surprisingly, PE3KOT mice developed many more SRC-3+/AR-/Syp+ NETCs versus control TRAMP mice, indicating SRC-3 expression was retained in NETCs. In contrast, TRAMP mice with global SRC-3 knockout did not develop any NETC, indicating SRC-3 is required for developing NETC. Analysis of cell-differentiating markers revealed that these NETCs might not be derived from the mature AR-/Syp+ neuroendocrine cells or the AR+/Syp- luminal epithelial tumor cells. Instead, these NETCs might originate from the SV40-T/t-transformed intermediate/progenitor epithelial cells. In summary, SRC-3 is required for both AR+/Syp- AH tumor growth and AR-/Syp+ NETC development, suggesting SRC-3 is a target for inhibiting aggressive prostate cancer containing NETCs.
PMID: 25332686 [PubMed - in process]
Defect in MAPK signaling as a cause for monogenic obesity caused by inactivating mutations in the melanocortin-4 receptor gene.
Int J Biol Sci. 2014;10(10):1128-37
Authors: He S, Tao YX
The melanocortin-4 receptor (MC4R) is a Family A G protein-coupled receptor that plays an essential role in regulating energy homeostasis, including both energy intake and expenditure. Mutations leading to a reduced MC4R function confer a major gene effect for obesity. More than 170 distinct mutations have been identified in humans. In addition to the conventional Gs-stimulated cAMP pathway, the MC4R also activates MAPKs, especially ERK1/2. We also showed there is biased signaling in the two signaling pathways, with inverse agonists in the Gs-cAMP pathway acting as agonists for the ERK1/2 pathway. In the current study, we sought to determine whether defects in basal or agonist-induced ERK1/2 activation in MC4R mutants might potentially contribute to obesity pathogenesis in patients carrying these mutations. The constitutive and ligand-stimulated ERK1/2 activation were measured in wild type and 73 naturally occurring MC4R mutations. We showed that nineteen mutants had significantly decreased basal pERK1/2 level, and five Class V variants (where no functional defects have been identified previously), C40R, V50M, T112M, A154D and S295P, had impaired ligand-stimulated ERK1/2 activation. Our studies demonstrated for the first time that decreased basal or ligand-stimulated ERK1/2 signaling might contribute to obesity pathogenesis caused by mutations in the MC4R gene. We also observed biased signaling in 25 naturally occurring mutations in the Gs-cAMP and ERK1/2 pathways.
PMID: 25332687 [PubMed - in process]
Interaction between HIV-1 Tat and DNA-PKcs modulates HIV transcription and class switch recombination.
Int J Biol Sci. 2014;10(10):1138-49
Authors: Zhang SM, Zhang H, Yang TY, Ying TY, Yang PX, Liu XD, Tang SJ, Zhou PK
HIV-1 tat targets a variety of host cell proteins to facilitate viral transcription and disrupts host cellular immunity by inducing lymphocyte apoptosis, but whether it influences humoral immunity remains unclear. Previously, our group demonstrated that tat depresses expression of DNA-PKcs, a critical component of the non-homologous end joining pathway (NHEJ) of DNA double-strand breaks repair, immunoglobulin class switch recombination (CSR) and V(D)J recombination, and sensitizes cells to ionizing radiation. In this study, we demonstrated that HIV-1 Tat down-regulates DNA-PKcs expression by directly binding to the core promoter sequence. In addition, Tat interacts with and activates the kinase activity of DNA-PKcs in a dose-dependent and DNA independent manner. Furthermore, Tat inhibits class switch recombination (CSR) at low concentrations (≤4 µg/ml) and stimulates CSR at high concentrations (≥8 µg/ml). On the other hand, low protein level and high kinase activity of DNA-PKcs promotes HIV-1 transcription, while high protein level and low kinase activity inhibit HIV-1 transcription. Co-immunoprecipitation results revealed that DNA-PKcs forms a large complex comprised of Cyclin T1, CDK9 and Tat via direct interacting with CDK9 and Tat but not Cyclin T1. Taken together, our results provide new clues that Tat regulates host humoral immunity via both transcriptional depression and kinase activation of DNA-PKcs. We also raise the possibility that inhibitors and interventions directed towards DNA-PKcs may inhibit HIV-1 transcription in AIDS patients.
PMID: 25332688 [PubMed - in process]
RNA Interference (RNAi) Induced Gene Silencing: A Promising Approach of Hi-Tech Plant Breeding.
Int J Biol Sci. 2014;10(10):1150-1158
Authors: Younis A, Siddique MI, Kim CK, Lim KB
RNA interference (RNAi) is a promising gene regulatory approach in functional genomics that has significant impact on crop improvement which permits down-regulation in gene expression with greater precise manner without affecting the expression of other genes. RNAi mechanism is expedited by small molecules of interfering RNA to suppress a gene of interest effectively. RNAi has also been exploited in plants for resistance against pathogens, insect/pest, nematodes, and virus that cause significant economic losses. Keeping beside the significance in the genome integrity maintenance as well as growth and development, RNAi induced gene syntheses are vital in plant stress management. Modifying the genes by the interference of small RNAs is one of the ways through which plants react to the environmental stresses. Hence, investigating the role of small RNAs in regulating gene expression assists the researchers to explore the potentiality of small RNAs in abiotic and biotic stress management. This novel approach opens new avenues for crop improvement by developing disease resistant, abiotic or biotic stress tolerant, and high yielding elite varieties.
PMID: 25332689 [PubMed - as supplied by publisher]
Prestress in the extracellular matrix sensitizes latent TGF-β1 for activation.
J Cell Biol. 2014 Oct 20;
Authors: Klingberg F, Chow ML, Koehler A, Boo S, Buscemi L, Quinn TM, Costell M, Alman BA, Genot E, Hinz B
Integrin-mediated force application induces a conformational change in latent TGF-β1 that leads to the release of the active form of the growth factor from the extracellular matrix (ECM). Mechanical activation of TGF-β1 is currently understood as an acute process that depends on the contractile force of cells. However, we show that ECM remodeling, preceding the activation step, mechanically primes latent TGF-β1 akin to loading a mechanical spring. Cell-based assays and unique strain devices were used to produce a cell-derived ECM of controlled organization and prestrain. Mechanically conditioned ECM served as a substrate to measure the efficacy of TGF-β1 activation after cell contraction or direct force application using magnetic microbeads. The release of active TGF-β1 was always higher from prestrained ECM as compared with unorganized and/or relaxed ECM. The finding that ECM prestrain regulates the bioavailability of TGF-β1 is important to understand the context of diseases that involve excessive ECM remodeling, such as fibrosis or cancer.
PMID: 25332161 [PubMed - as supplied by publisher]