Author: screening library

Evidence has suggested that the deficiency of PARP-1 results in DNA repair defects, genomic instability, failure of induction of cell death, and modulation of gene transcription, thereby contributing to carcinogenesis. This polymorphism is located in the sixth helix of the COOH-terminal NAD-binding region with all of the catalytic activities of the full-length enzyme. This amino acid change contributes to low polyation activities in a dosage-dependent manner, thereby impairing DNA repair and enhancing the susceptibility of variant allele carriers to damage caused by environmental carcinogens and cancer risk. Thus far, molecular epidemiological studies have indicated the genetic association of Val762Ala with the risk of many cancer types, including cancers of the breast, stomach, lung, cervix, brain, and colorectum, as well as other types of malignancies. However, these studies have not yet produced consistent results. The discrepancies of the findings are partially attributed to the limited power of individual studies with small sample sizes and differences in the baseline characteristics of included patients. Although the PARP-1 Val762Ala polymorphism and susceptibility to cancers have been discussed, all of the eligible studies have not been included, particularly case-control studies published in the past two years. Therefore, these meta-studies are disputed because of the limited number of included studies and relatively small sample size. The present meta-analysis aimed to update previous meta-analyses and derive a reliable conclusion regarding the effect of the V762A polymorphism on the function of PARP-1 in cancer. This meta-analysis also aimed to quantify the potential of heterogeneity between studies. Prolactin is a hormone secreted mainly by lactotropes in the anterior pituitary gland. This hormone is involved in several physiological functions, including mammopoiesis, lactogenesis and reproduction although it has also been implicated in the development of various peripheral tumors. In breast and prostate cancers, where local PRL production has been demonstrated, its proliferative potential via an autocrine/paracrine mechanisms has been proposed to contribute to tumor development and progression. Prolactinomas are benign tumors that constitute approximately one third of pituitary tumors. One of the main characteristics of prolactinomas is that they rarely undergo malignant transformation or local invasiveness. It has been proposed that prolactinomas have a monoclonal origin and that alterations in cell cycle regulation lead to expansion of an original mutated cell. Although several oncogenes are expressed in these adenomas, and various mutations have been associated with familial cases of anterior pituitary tumors, the mechanisms leading to sporadic adenoma formation are currently unknown.

The key endogenous fluorophores in tissues are collagen, elastin, Nicotinamide adenine dinucleotide, keratin, melanin and hemoglobin which are extensively being investigated using LIF. Collagen being the major component of the extracellular matrix plays a key role during tissue remodeling, which if monitored noninvasively, will provide an opportunity to assess the wound healing progression and hence will help in the planning of subsequent treatment. The prospective of second harmonic generation microscopy as a non-invasive imaging tool to monitor collagen near the wound boundaries during tissue regeneration is very well documented. Likewise, Raman spectroscopy and histological techniques have also been employed to evaluate native collagen in wounds. The basic purpose of adopting LIF here is to monitor collagen non-invasively during tissue regeneration by measuring the corresponding autofluorescence and testing the performance of the technique. The actual motivation for the present work came from the outcome of our previous study, wherein, for the first time we demonstrated the usefulness of ex vivo autofluorescence in assessing endogenous collagen in granulation tissue during the wound healing progression following laser therapy. In that study, the wound granulation tissue shown a gradual increase in the collagen fluorescence during all the post-wounding days along with the microscopic evidence of collagen deposition as shown by the quantitative scoring of the histological features highlighting the capability of the technique in collagen monitoring. Since collagen staining by Masson’s trichome stain used in that report had limitations of being unable to differentiate between different types of collagen fibers, and failed to differentiate between thin elastin and collagen fibers. To overcome these, we have utilized Picro-Sirius red in the present study for the identification of different collagen fibers along with the information on their occurrence and orientations. In the present study, in addition to the qualitative scoring of the Picro-Sirius red stained histological sections for thicknes, occurrence and orientation, a quantitative assessment for total collagen deposition in the tissue was also perfomed using image analysis along with its comparision with spectroscopic findings of endogenous collagen. Histological sections were examined in a blinded fashion and scored qualitatively for the thickness of the collagen fiber, their occurrence and orientations by an expert pathologist. The scores for different histological parameters of un-wounded control, unilluminated control and laser treatment groups were listed separately in tables 2, 3 and 4 respectively. Presently available methods of examining collagen in biological tissues are histochemistry and immunohistochemistry wherein both techniques involve several steps in tissue processing and it introduce undesirable structural variations in the collagenous matrix.

To date there are few studies regarding the pathophysiology of lamin A DE11, hence the spliceswitching method here may offer an inducible model to further study this disease. Given that the lamin A DE11 product, like progerin, is presumably permanently farnesylated and that restrictive dermopathy demonstrates similar nuclear abnormalities to HGPS, it is possible that lamin A DE11 will have similar downstream effects to those caused by progerin. Lamin A DE11 is probably as deleterious as, if not more so, progerin in HGPS, considering the extreme phenotype of restrictive dermopathy. Indeed, the fact that accumulation of progerin and lamin A DE11 can both cause restrictive dermopathy suggests that HGPS and restrictive dermopathy belong to the same clinical spectrum of diseases caused by farnesylated prelamin A. Therefore, although there is a mixture of cryptic splicing activation and exon 11 skipping in the AO treated myogenic cells in the present study, it is our belief that the induced products, progerin and lamin A DE11, exert similar effects in cells to cause accelerated ageing. Consistent with this hypothesis, similarly mis-shapen myonuclei were found in myogenic cells treated with the PMOs that induced progerin alone and both progerin and lamin A DE11. Premature ageing can be induced in fibroblasts and human midbrain dopamine neurons derived from induced pluripotent stem cells by transfection with a synthetic RNA that encodes progerin tagged with GFP. Enhanced expression of progerin was only achieved after 3 and 5 repeats of daily transfection in iPSfibroblasts and iPS-neurons respectively. In contrast, 36 hours after transfection. It will be interesting to evaluate the consequences of progerin expression arising from PMO induced splice switching in iPS-fibroblasts and iPS-neurons. In conclusion, we have shown that AOs targeting the putative ESEs/ESSs within exon 11 of LMNA or the donor site, can be used to redirect splicing in human myogenic cells, and lead to the production of two distinctive, yet functionally similar, farnesylated prelamin A isoforms. The PMO chemistry was found to be more effective than the 2OMe chemistry in terms of specificity and progerin production. The PMOs increased production of progerin and induced the nuclear changes associated with premature ageing, similar to those that occur in HGPS. Atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased considerably since the industrial revolution, and are still increasing annually by about 0.5%, 1.1% and 0.3%, respectively. Worldwide concerns about the increased greenhouse gases concentrations in the atmosphere and its effects on our future environment require a better understanding of the cause of these emissions. Agricultural lands occupy 37% of the earth’s land surface; about 13.5% of global anthropogenic GHG was emitted from agricultural production.

Nevertheless, the studies did not extent the evaluation of DA to brain areas other than striatum or were performed with a drug exposure schedule not adjusted to mephedrone pharmacokinetics. The aim of this paper was to investigate the neurotoxicity profile of mephedrone in mice, addressing some of the limitations in the literature. Most authors described the neurotoxic effects of methamphetamine three days after exposition and those of MDMA seven days after. We examined the neurotoxic injury induced by mephedrone at 3 and 7 days after finishing the exposition. Obtaining as much mechanistic information as possible regarding mephedrone, as well as on its neurotoxic effects, is of the essence. In this regard, we have evaluated the in vivo effect of this cathinone following different dosage schedule whilst complementing it by performing in vitro experiments. With regards to MDMA, it is described that the magnitude of the acute hyperthermic response plays a major role in determining the severity of the consequences of its misuse, in such a way that ingesting the drug in hot, crowded dance club conditions, increases the possibility of subsequent cerebral neurotoxic effects. To simulate these usual conditions of drug exposure, the neurotoxicity studies with amphetamine-derivatives are usually performed at elevated ambient temperatures. Accordingly, present experiments were carried out at high room temperatures. This condition was not considered in previous published papers. In the present study we used adolescent mice, a feature that correlates with young adult consumers. We demonstrate that mephedrone induces an injury at nerve endings in the frontal cortex at a schedule of drug exposure that mimics human “weekend consumption”. The easy availability of cathinones and their initial status as legal highs may have contributed to their increasing popularity as drugs of abuse. Because of the relatively short history of the use of cathinones as recreational drugs, their effects among long-term users have yet to be determined. Based on its structural similarity to well established neurotoxic psychostimulants such as methamphetamine and MDMA, it was hypothesized that mephedrone would exert neuronal damage. However, there are important discrepancies concerning the neurotoxicity induced by cathinones. The inconsistent results could be attributed to differences in species, dosage. Some cases of aggressive behavior, even cannibalism, as a consequence of exposure to new designer drugs have been recently reported in the media. However, these cases have been poorly documented. In the present study, all mephedrone schedules induced the appearance of initial stereotypy consisting in repeated self-licking that was followed by aggressive behavior which leads to self-injuries. This is an especially important factor to be taken into account, seeing as it required animals to be housed individually.

Exosomes mediate cell-to-cell communication and induce different effects on target cells depending on the cell origin and exosome content. The function of placental-derived exosomes during normal or pathological pregnancy remains to be established. Delorme-Axfold et al.,, however, recently reported that specific miRNAs are transported in exosome released by trophoblast cells to protect the developing fetus against viral infection. In addition, we have previously reported that exosomes released from cytotrophoblast cells primary culture contain biologically active proteins that can interact with the maternal endothelium and regulate their function. Furthermore, the release of exosome from placental mesenchymal stem cells and cytotrophoblast cells is regulated by the oxygen tension. In this study, we used the PLAP ratio as a measure of the contribution of placental exosomes to total exosomes in maternal blood. We observed that PLAP ratio was similar in both first and second trimesters but decreased dramatically in third trimester. Several factors may contribution to this decrease, including: decreased release of PLAP +ve exosomes from the placenta; decreased circulating half-live of PLAP +ve exosomes; increased released of PLAP-ve exosomes; or a combination of these events. While it is not possible to precisely establish what causes the late gestational decreased in PLAP ratio in this study, the data afford opportunity of further hypothesis testing and, in particular, to establish the clinical utility of PLAP ratio as am indicator of placental function. The release of placental exosomes into maternal blood may result from a change in: the de novo rate of secretion of exosomes; placental mass; placental perfusion; the numbers and/or surface area of syncytotrophoblasts exposed to maternal blood or a combination of these factors. In this study, the concentration of placental exosomes in maternal plasma correlated with placental mass ; and placental perfusion. The association between placental-derived exosomes and placental blood flow was assessed using Doppler velocimetry. Mean uterine pulsatility index declined gradually during pregnancy and strongly correlated with exosomes number and PLAP concentration in maternal blood. Exosomes isolated from peripheral plasma were biologically active, as assessed by their ability to increase endothelial cell migration in vitro. The bioactivity of exosomes was greatest during first trimester and gradually declined with advancing gestational age. This change in bioactivity may reflect a change in the cellular origins, and/or content of exosomes While the role of placental cell-derived exosomes in regulating maternal and/or fetal vascular responses in normal and pathological pregnancies remains to be elucidated, it is tempting to speculate that exosomes released from the syncytitotrophoblast may contribute to maternal vascular adaptation during pregnancy.