148 research outputs found
Excessive HDAC activation is critical for neurodegeneration in the rd1 mouse
Inherited retinal degenerations, collectively termed retinitis pigmentosa (RP), constitute one of the leading causes of blindness in the developed world. RP is at present untreatable and the underlying neurodegenerative mechanisms are unknown, even though the genetic causes are often established. Acetylation and deacetylation of histones, carried out by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively, affects cellular division, differentiation, death and survival. We found acetylation of histones and probably other proteins to be dramatically reduced in degenerating photoreceptors in the rd1 human homologous mouse model for RP. Using a custom developed in situ HDAC activity assay, we show that overactivation of HDAC classes I/II temporally precedes photoreceptor degeneration. Moreover, pharmacological inhibition of HDACs I/II activity in rd1 organotypic retinal explants decreased activity of poly-ADP-ribose-polymerase and strongly reduced photoreceptor cell death. These findings highlight the importance of protein acetylation for photoreceptor cell death and survival and propose certain HDAC classes as novel targets for the pharmacological intervention in RP
TRPM2 channel deficiency prevents delayed cytosolic ZnĀ²āŗ accumulation and CA1 pyramidal neuronal death after transient global ischemia
Transient ischemia is a leading cause of cognitive dysfunction. Postischemic ROS generation and an increase in the cytosolic ZnĀ²āŗ level ([ZnĀ²āŗ]c) are critical in delayed CA1 pyramidal neuronal death, but the underlying mechanisms are not fully understood. Here we investigated the role of ROS-sensitive TRPM2 (transient receptor potential melastatin-related 2) channel. Using in vivo and in vitro models of ischemia-reperfusion, we showed that genetic knockout of TRPM2 strongly prohibited the delayed increase in the [ZnĀ²āŗ]c, ROS generation, CA1 pyramidal neuronal death and postischemic memory impairment. Time-lapse imaging revealed that TRPM2 deficiency had no effect on the ischemia-induced increase in the [ZnĀ²āŗ]c but abolished the cytosolic ZnĀ²āŗ accumulation during reperfusion as well as ROS-elicited increases in the [ZnĀ²āŗ]c. These results provide the first evidence to show a critical role for TRPM2 channel activation during reperfusion in the delayed increase in the [ZnĀ²āŗ]c and CA1 pyramidal neuronal death and identify TRPM2 as a key molecule signaling ROS generation to postischemic brain injury
The use of mesenchymal stem cells for cartilage repair and regeneration: a systematic review.
BACKGROUND: The management of articular cartilage defects presents many clinical challenges due to its avascular, aneural and alymphatic nature. Bone marrow stimulation techniques, such as microfracture, are the most frequently used method in clinical practice however the resulting mixed fibrocartilage tissue which is inferior to native hyaline cartilage. Other methods have shown promise but are far from perfect. There is an unmet need and growing interest in regenerative medicine and tissue engineering to improve the outcome for patients requiring cartilage repair. Many published reviews on cartilage repair only list human clinical trials, underestimating the wealth of basic sciences and animal studies that are precursors to future research. We therefore set out to perform a systematic review of the literature to assess the translation of stem cell therapy to explore what research had been carried out at each of the stages of translation from bench-top (in vitro), animal (pre-clinical) and human studies (clinical) and assemble an evidence-based cascade for the responsible introduction of stem cell therapy for cartilage defects. This review was conducted in accordance to PRISMA guidelines using CINHAL, MEDLINE, EMBASE, Scopus and Web of Knowledge databases from 1st January 1900 to 30th June 2015. In total, there were 2880 studies identified of which 252 studies were included for analysis (100 articles for in vitro studies, 111 studies for animal studies; and 31 studies for human studies). There was a huge variance in cell source in pre-clinical studies both of terms of animal used, location of harvest (fat, marrow, blood or synovium) and allogeneicity. The use of scaffolds, growth factors, number of cell passages and number of cells used was hugely heterogeneous. SHORT CONCLUSIONS: This review offers a comprehensive assessment of the evidence behind the translation of basic science to the clinical practice of cartilage repair. It has revealed a lack of connectivity between the in vitro, pre-clinical and human data and a patchwork quilt of synergistic evidence. Drivers for progress in this space are largely driven by patient demand, surgeon inquisition and a regulatory framework that is learning at the same pace as new developments take place
Fn14-Fc suppresses germinal center formation and pathogenic B cells in a lupus mouse model via inhibition of the TWEAK/Fn14 Pathway
The global impact of non-communicable diseases on macro-economic productivity: a systematic review
Ā© 2015, The Author(s). Non-communicable diseases (NCDs) have large economic impact at multiple levels. To systematically review the literature investigating the economic impact of NCDs [including coronary heart disease (CHD), stroke, type 2 diabetes mellitus (DM), cancer (lung, colon, cervical and breast), chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD)] on macro-economic productivity. Systematic search, up to November 6th 2014, of medical databases (Medline, Embase and Google Scholar) without language restrictions. To identify additional publications, we searched the reference lists of retrieved studies and contacted authors in the field. Randomized controlled trials, cohort, caseācontrol, cross-sectional, ecological studies and modelling studies carried out in adults (>18Ā years old) were included. Two independent reviewers performed all abstract and full text selection. Disagreements were resolved through consensus or consulting a third reviewer. Two independent reviewers extracted data using a predesigned data collection form. Main outcome measure was the impact of the selected NCDs on productivity, measured in DALYs, productivity costs, and labor market participation, including unemployment, return to work and sick leave. From 4542 references, 126 studies met the inclusion criteria, many of which focused on the impact of more than one NCD on productivity. Breast cancer was the most common (nĀ =Ā 45), followed by stroke (nĀ =Ā 31), COPD (nĀ =Ā 24), colon cancer (nĀ =Ā 24), DM (nĀ =Ā 22), lung cancer (nĀ =Ā 16), CVD (nĀ =Ā 15), cervical cancer (nĀ =Ā 7) and CKD (nĀ =Ā 2). Four studies were from the WHO African Region, 52 from the European Region, 53 from the Region of the Americas and 16 from the Western Pacific Region, one from the Eastern Mediterranean Region and none from South East Asia. We found large regional differences in DALYs attributable to NCDs but especially for cervical and lung cancer. Productivity losses in the USA ranged from 88 million US dollars (USD) for COPD to 20.9 billion USD for colon cancer. CHD costs the Australian economy 13.2 billion USD per year. People with DM, COPD and survivors of breast and especially lung cancer are at a higher risk of reduced labor market participation. Overall NCDs generate a large impact on macro-economic productivity in most WHO regions irrespective of continent and income. The absolute global impact in terms of dollars and DALYs remains an elusive challenge due to the wide heterogeneity in the included studies as well as limited information from low- and middle-income countries.WHO; NestleĀ“ Nutrition (Nestec Ltd.); Metagenics Inc.; and AX
Study protocol of guided mobile-based perinatal mindfulness intervention (GMBPMI) - a randomized controlled trial
202308 bcchVersion of RecordRGCPublishe
Carbon isotope composition of long chain leaf wax n-alkanes in lakesediments: A dual indicator of paleoenvironment in the Qinghai-TibetPlateau
The carbon isotope composition (d13C values) of long chain n-alkanes in lake sediments has been considered a reliable means of tracking changes in the terrigenous contribution of plants with C3 and C4 photosynthetic pathways. A key premise is that long chain leaf wax components used for isotope analysis are derived primarily from terrigenous higher plants. The role of aquatic plants in affecting d13C values of long chain n-alkanes in lacustrine sediments may, however, have long been underestimated. In this study, we found that a large portion of long chain n-alkanes (C27 and C29) in nearshore sediments of the Lake Qinghai catchment was contributed by submerged aquatic plants, which displayed a relatively positive carbon isotope composition (e.g. 26.7‰ to 15.7‰ for C29) similar to that of terrestrial C4 plants. Thus, the use of d13C values of sedimentary C27 and C29 n-alkanes for tracing terrigenous vegetation composition may create a bias toward significant overestimation/underestimation of the proportion of terrestrial C4 plants. For sedimentary C31, however, the contribution from submerged plants was minor, so that the d13C values for C31 n-alkane in surface sediments were in accord with those of the modern terrestrial vegetation in the Lake Qinghai region. Moreover, we found that changes in the d13C values of sedimentary C27 and C29 n-alkanes were closely related to water depth variation. Downcore analysis further demonstrated the significant influence of endogenous lipids in lake sediments for the interpretation of terrestrial C4 vegetation and associated environment/climate reconstruction. In conclusion, our results suggest that the d13C values of sedimentary long chain n-alkanes (C27, C29 and C31) may carry different environmental signals. While the d13C values of C31 were a reliable proxy for C4/C3 terrestrial vegetation composition, the d13C values of C27 and C29 n-alkanes may have recorded lake ecological conditions and sources of organic carbon, which might be affected by lake water depth.</p
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