Digoxin Suppresses Pyruvate Kinase M2-Promoted HIF-1α Transactivation in Steatohepatitis

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The Effects of Two Polymorphisms on p21cip1 Function and Their Association with Alzheimer’s Disease in a Population of European Descent

With the exception of ApoE4, genome-wide association studies have failed to identify strong genetic risk factors for late-onset Alzheimer’s disease, despite strong evidence of heritability, suggesting that many low penetrance genes may be involved. Additionally, the nature of the identified genetic risk factors and their relation to disease pathology is also largely obscure. Previous studies have found that a cancer-associated variant of the cell cycle inhibitor gene p21^cip1 is associated with increased risk of Alzheimer’s disease. The aim of this study was to confirm this association and to elucidate the effects of the variant on protein function and Alzheimer-type pathology. We examined the association of the p21^cip1 variant with Alzheimer’s disease and Parkinson’s disease with dementia. The genotyping studies were performed on 719 participants of the Oxford Project to Investigate Memory and Ageing, 225 participants of a Parkinson’s disease DNA bank, and 477 participants of the Human Random Control collection available from the European Collection of Cell Cultures. The post mortem studies were carried out on 190 participants. In the in-vitro study, human embryonic kidney cells were transfected with either the common or rare p21^cip1 variant; and cytometry was used to assess cell cycle kinetics, p21^cip1 protein expression and sub-cellular localisation. The variant was associated with an increased risk of Alzheimer’s disease, and Parkinson’s disease with dementia, relative to age matched controls. Furthermore, the variant was associated with an earlier age of onset of Alzheimer’s disease, and a more severe phenotype, with a primary influence on the accumulation of tangle pathology. In the in-vitro study, we found that the SNPs reduced the cell cycle inhibitory and anti-apoptotic activity of p21^cip1. The results suggest that the cancer-associated variant of p21^cip1 may contribute to the loss of cell cycle control in neurons that may lead to Alzheimer-type neurodegeneration.     

Cool-dry season depression in gas exchange of canopy leaves and water flux of tropical trees at the northern limit of Asian tropics

Trees on the northern boundary of Asian tropics experience hot-humid and cool-dry seasons, but little is known about their seasonal dynamics in canopy physiology. We used a canopy crane to reach the canopy of nine tropical tree species and measured canopy leaf gas exchange, water status, and trunk sap flux during the hot-humid and cool-dry seasons in Xishuangbanna, China. We found that most tree species exhibited significant reductions in maximum photosynthetic rate (A_max), stomatal conductance (g_smax), predawn and midday leaf water potentials, and maximum sap flux density in the cool-dry season. Compared to the hot-humid season, A_max declined by 19–60%, and maximum water flux declined by ?14% (an increase) to 42%. The cool-dry season decline in A_max of four species can be partly explained by an increased stomatal limitation (decreased g_smax and intercellular CO₂ concentrations). Therefore, a predicted increase in drought in this region may decrease the carbon sequestration and productivity of these forests. We did not find a tradeoff between performance (A_max in the hot-humid season) and persistence through the cool-dry season; species with higher A_max in the hot-humid season did not show higher percent seasonal declines in the cool-dry season. A_max was significantly and positively associated with the trunk sap flux for both seasons, but the association was weaker in the cool-dry season. Thus, our results suggest that some tradeoffs and trait associations are environment dependent. Our results are important for understanding carbon and water fluxes of seasonal tropical forests and their responses to environmental changes.

     

Expression and purification of the rifamycin amide synthase, RifF, an enzyme homologous to the prokaryotic arylamine N-acetyltransferases.

The assembly of the polyketide backbone of rifamycin B by the type I rifamycin polyketide synthase, encoded by the rifA-rifE genes, is terminated by the product of the rifF gene, an amide synthase that releases the completed undecaketide as its macrocyclic lactam. The sequence of the RifF protein from Amycolatopsis mediterranei shows 26% identity and 40% homology with the members of the arylamine N-acetyltransferase (NAT) family of proteins. Based on the homology of the primary structures and the similarity of the reactions catalyzed by the two enzymes, we have compared the RifF protein with members of the NAT family. We have modeled the three-dimensional (3D) structure of RifF using NAT from Salmonella typhimurium and Mycobacterium smegmatis as a template. Proteolytic digestions of RifF revealed accessible regions in the protein which are in agreement with the modeled structure. We have expressed the whole protein and individual domains of the protein based on comparison with NAT from S. typhimurium and have purified the proteins by affinity chromatography using a hexahistidine tag. RifF has been further purified using ion-exchange (Mono Q) chromatography. An antiserum has been generated using the C-terminal nona- and tridecapeptides of RifF and has been shown to recognize RifF uniquely. It does not cross-react with any other member of the NAT family.     

Novel Non-Peptide Inhibitors against SmCL1 of Schistosoma mansoni: In Silico Elucidation,Implications and Evaluation via Knowledge Based Drug Discovery

Schistosomiasis is a major endemic disease known for excessive mortality and morbidity in developing countries. Because praziquantel is the only drug available for its treatment, the risk of drug resistance emphasizes the need to discover new drugs for this disease. Cathepsin SmCL1 is the critical target for drug design due to its essential role in the digestion of host proteins for growth and development of Schistosoma mansoni. Inhibiting the function of SmCL1 could control the wide spread of infections caused by S. mansoni in humans. With this objective, a homology modeling approach was used to obtain theoretical three-dimensional (3D) structure of SmCL1. In order to find the potential inhibitors of SmCL1, a plethora of in silico techniques were employed to screen non-peptide inhibitors against SmCL1 via structure-based drug discovery protocol. Receiver operating characteristic (ROC) curve analysis and molecular dynamics (MD) simulation were performed on the results of docked protein-ligand complexes to identify top ranking molecules against the modelled 3D structure of SmCL1. MD simulation results suggest the phytochemical Simalikalactone-D as a potential lead against SmCL1, whose pharmacophore model may be useful for future screening of potential drug molecules. To conclude, this is the first report to discuss the virtual screening of non-peptide inhibitors against SmCL1 of S. mansoni, with significant therapeutic potential. Results presented herein provide a valuable contribution to identify the significant leads and further derivatize them to suitable drug candidates for antischistosomal therapy.     

Markers of atopic dermatitis,allergic rhinitis and bronchial asthma in pediatric patients: correlation with filaggrin,eosinophil major basic protein and immunoglobulin E

Background

Allergic reactions have been implicated as contributions in a number of atopic disorders, including atopic dermatitis (AD), allergic rhinitis (AR) and bronchial asthma (BA). However, the potential for filaggrin protein, eosinophil major basic protein (MBP) and immunoglobulin E (IgE) to elicit allergic response or to contribute to atopic disorders remains largely unexplored in pediatric patients. This study was undertaken to investigate the status and contribution of filaggrin protein, eosinophil MBP and total IgE in pediatric patients with AD, AR and BA.

Methods

Sera from 395 pediatric patients of AD, AR or BA with varying levels of disease activity according to the disease activity index and 410 age-matched non-atopic healthy controls were evaluated for serum levels of atopic markers, including filaggrin, eosinophil MBP and IgE.

Results

Serum analysis showed that filaggrin levels were remarkably high in pediatric patients with AD, followed by BA and AR, whereas its levels were low in non-atopic pediatric controls. Eosinophil MBP levels in sera of atopic patients were significantly high as compared with their respective controls, but its levels were highest in AR patients, followed by AD and BA. Total IgE in sera of AD patients was markedly high, followed by AR and BA patients, whereas its levels were low in non-atopic pediatric controls. Interestingly, not only was an increased number of subjects positive for filaggrin protein, eosinophil MBP or total IgE, but also their levels were statistically significantly higher among those atopic patients whose disease activity scores were higher as compared with atopic patients with lower disease activity scores.

Conclusions

These findings strongly support a role of filaggrin protein, eosinophil MBP and IgE in the onset of allergic reactions in pediatric patients with AD, AR and BA. The data suggest that filaggrin, eosinophil MBP or IgE might be useful in evaluating the progression of AD, AR or BA and in elucidating the mechanisms involved in the pathogenesis of these pediatric disorders.

     

Exploration and local utilization of medicinal vegetation naturally grown in the Deusai plateau of Gilgit,Pakistan

In the study area, the traditional knowledge regarding the uses of local wild medicinal plants for the health care of human and domestic animals is totally in hold of old people. The young ones are unaware about such an indispensable practices. The objective of the current study was to transfer this sort of precious knowledge from old members of the community to young generations in documented form.