Glycogen synthase kinase-3beta regulates growth, calcium homeostasis, and diastolic function in the heart

Glycogen synthase kinase (GSK) 3beta is a negative regulator of stress-induced cardiomyocyte hypertrophy. It is not clear, however, if GSK-3beta plays any role in regulating normal cardiac growth and cardiac function. Herein we report that a transgenic mouse expressing wild type GSK-3beta in the heart has a dramatic impairment of normal post-natal cardiomyocyte growth as well as markedly abnormal cardiac contractile function. The most striking phenotype, however, is grossly impaired diastolic relaxation, which leads to increased filling pressures of the left ventricle and massive atrial enlargement. This is due to profoundly abnormal calcium handling, leading to an inability to normalize cytosolic [Ca2+] in diastole. The alterations in calcium handling are due at least in part to direct down-regulation of the sarcoplasmic reticulum calcium ATPase (SERCA2a) by GSK-3beta, acting at the level of the SERCA2 promoter. These studies identify GSK-3beta as a regulator of normal growth of the heart and are the first of which we are aware, to demonstrate regulation of expression of SERCA2a, a critical determinant of diastolic function, by a cytosolic signaling pathway, the activity of which is dynamically modulated. De-regulation of GSK-3beta leads to severe systolic and diastolic dysfunction and progressive heart failure. Because down-regulation of SERCA2a plays a central role in the diastolic and systolic dysfunction of patients with heart failure, these findings have potential implications for the therapy of this disorder.     

Eugenol specialty chemical production in transgenic poplar (Populus tremula × P. alba) field trials

A foundational study assessed effects of biochemical pathway introduction into poplar to produce eugenol, chavicol, p‐anol, isoeugenol and their sequestered storage products, from potentially available substrates, coniferyl and p‐coumaryl alcohols. At the onset, it was unknown whether significant carbon flux to monolignols vs. other phenylpropanoid (acetate) pathway metabolites would be kinetically favoured. Various transgenic poplar lines generated eugenol and chavicol glucosides in ca. 0.45% (~0.35 and ~0.1%, respectively) of dry weight foliage tissue in field trials, as well as their corresponding aglycones in trace amounts. There were only traces of any of these metabolites in branch tissues, even after ~4‐year field trials. Levels of bioproduct accumulation in foliage plateaued, even at the lowest introduced gene expression levels, suggesting limited monolignol substrate availability. Nevertheless, this level still allows foliage collection for platform chemical production, with the remaining (stem) biomass available for wood, pulp/paper and bioenergy product purposes. Several transformed lines displayed unexpected precocious flowering after 4‐year field trial growth. This necessitated terminating (felling) these particular plants, as USDA APHIS prohibits the possibility of their interacting (cross‐pollination, etc.) with wild‐type (native plant) lines. In future, additional biotechnological approaches can be employed (e.g. gene editing) to produce sterile plant lines, to avoid such complications. While increased gene expression did not increase target bioproduct accumulation, the exciting possibility now exists of significantly increasing their amounts (e.g. 10‐ to 40‐fold plus) in foliage and stems via systematic deployment of numerous ‘omics’, systems biology, synthetic biology and metabolic flux modelling approaches.     

Clinical proteomics of the neglected human malarial parasite Plasmodium vivax

Recent reports highlight the severity and the morbidity of disease caused by the long neglected malaria parasite Plasmodium vivax. Due to inherent difficulties in the laboratory-propagation of P. vivax, the biology of this parasite has not been adequately explored. While the proteome of P. falciparum, the causative agent of cerebral malaria, has been extensively explored from several sources, there is limited information on the proteome of P. vivax. We have, for the first time, examined the proteome of P. vivax isolated directly from patients without adaptation to laboratory conditions. We have identified 153 proteins from clinical P. vivax, majority of which do not show homology to any previously known gene products. We also report 29 new proteins that were found to be expressed in P. vivax for the first time. In addition, several proteins previously implicated as anti-malarial targets, were also found in our analysis. Most importantly, we found several unique proteins expressed by P. vivax.This study is an important step in providing insight into physiology of the parasite under clinical settings.     

Kinetics and Molecular Docking Study of an Anti-diabetic Drug Glimepiride as Acetylcholinesterase Inhibitor: Implication for Alzheimer’s Disease-Diabetes Dual Therapy

Neurochemical Research - At the present time, treatment of two most common degenerative disorders of elderly population i.e., Type 2 Diabetes Mellitus (T2DM) and Alzheimer’s disease (AD) is a...     

Common Oncogenic Mutations Are Infrequent in Oral Squamous Cell Carcinoma of Asian Origin

Objectives

The frequency of common oncogenic mutations and TP53 was determined in Asian oral squamous cell carcinoma (OSCC).

Materials and Methods

The OncoCarta^™ panel v1.0 assay was used to characterize oncogenic mutations. In addition, exons 4-11 of the TP53 gene were sequenced. Statistical analyses were conducted to identify associations between mutations and selected clinico-pathological characteristics and risk habits.

Results

Oncogenic mutations were detected in PIK3CA (5.7%) and HRAS (2.4%). Mutations in TP53 were observed in 27.7% (31/112) of the OSCC specimens. Oncogenic mutations were found more frequently in non-smokers (p = 0.049) and TP53 truncating mutations were more common in patients with no risk habits (p = 0.019). Patients with mutations had worse overall survival compared to those with absence of mutations; and patients who harbored DNA binding domain (DBD) and L2/L3/LSH mutations showed a worse survival probability compared to those patients with wild type TP53. The majority of the oncogenic and TP53 mutations were G:C > A:T and A:T > G:C base transitions, regardless of the different risk habits.

Conclusion

Hotspot oncogenic mutations which are frequently present in common solid tumors are exceedingly rare in OSCC. Despite differences in risk habit exposure, the mutation frequency of PIK3CA and HRAS in Asian OSCC were similar to that reported in OSCC among Caucasians, whereas TP53 mutations rates were significantly lower. The lack of actionable hotspot mutations argue strongly for the need to comprehensively characterize gene mutations associated with OSCC for the development of new diagnostic and therapeutic tools.     

Genetic polymorphisms of GSTM1, GSTT1 and GSTP1 and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides

GSTM1, T1 and P1 are important enzymes of glutathione S-transferases (GSTs), involved in the metabolism of many endogenous and exogenous compounds. Individual genetic variation in these metabolizing enzymes may influence the metabolism of their substrates. The present study was designed to determine the genotoxic effects using DNA damage and its association with GSTM1, GSTT1, and GSTP1 (Ile105Val) genetic polymorphisms in workers occupationally exposed to organophosphate pesticides (OPs). We examined 230 subjects including 115 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using individual PCR or PCR-RFLP. Significantly higher DNA tail moment (TM) was observed in workers as compared to control subjects (14.41 ± 2.25 vs. 6.36 ± 1.41 tail % DNA, p<0.001). The results revealed significantly higher DNA TM in workers with GSTM1 null genotype than those with GSTM1 positive (15.18 vs. 14.15 tail % DNA, p=0.03). A significantly higher DNA TM was also observed in workers with homozygous Ile-Ile GSTP1 genotype than heterozygous (Ile-Val) and mutant (Val-Val) GSTP1 genotype (p=0.02). In conclusion, the results show that null deletion of GSTM1 and homozygote wild GSTP1 genotype could be related to inter-individual differences in DNA damage arises from the gene-environment interactions in workers occupationally exposed to OPs.     

Spectral karyotyping refines cytogenetic diagnostics of constitutional chromosomal abnormalities

Karyotype analysis by chromosome banding is the standard method for identifying numerical and structural chromosomal aberrations in pre- and postnatal cytogenetics laboratories. However, the chromosomal origins of markers, subtle translocations, or complex chromosomal rearrangements are often difficult to identify with certainty. We have developed a novel karyotyping technique, termed spectral karyotyping (SKY), which is based on the simultaneous hybridization of 24 chromosome-specific painting probes labeled with different fluorochromes or fluorochrome combinations. The measurement of defined emission spectra by means of interferometer-based spectral imaging allows for the definitive discernment of all human chromosomes in different colors. Here, we report the comprehensive karyotype analysis of 16 samples from different cytogenetic laboratories by merging conventional cytogenetic methodology and spectral karyotyping. This approach could become a powerful tool for the cytogeneticists, because it results in a considerable improvement of karyotype analysis by identifying chromosomal aberrations not previously detected by G-banding alone. Advantages, limitations, and future directions of spectral karyotyping are discussed. Received: 4 August 1997 / Accepted: 8 September 1997     

The Effect of Chilling of the Physiological and Simulated Apex of 2- and 3-leaf Plants of Pisum sativum L. cv. Alaska on Lateral Shoot Growth, C-14 IAA Movement and P-32 Accumulation

The apex of a 3-leaf pea plant was chilled in cold chambers maintained at 5–7°C. The lateral shoots 1 through 5 grew, and shoot 5 eventually dominated other lateral shoots. The apex when returned to the ambient temperature did not reimpose apical dominance. The growing lateral shoots competed with the stem apex. The apices of 2- and 3-leaf plants were chilled and P-32 distribution in these plants was studied in the entire plant, at various intervals of time. Phosphorus-32 accumulation followed the growth pattern of the plant. The lateral shoots accumulated P-32 activity and very little activity was accumulated by the apex. The dominating shoots 2 and 5 accumulated the maximum amount of activity in 2- and 3-leaf plants, respectively. Labeled-IAA moved basipetally through the stem when applied to the cut stump simulating the apex. By cold treatment the translocation of IAA was influenced more than its absorption. The plant seems to metabolize this compound in the later periods of application. The plant now becomes “insensitive” to auxin and the lateral shoots grow.     

New constituents from the dried fruit of Piper nigrum Linn., and their larvicidal potential against the Dengue vector mosquito Aedes aegypti

Six bioactive compounds were isolated from the seeds extract of Piper nigrum Linn. following a larvicidal activity guided isolation against 4th instar larvae of Aedes aegypti L., a Dengue vector mosquito and a carrier of yellow fever. Their structures were elucidated using spectroscopic methods including HR-EI-MS, FAB-MS, ¹H and ¹³C NMR (Broad Bond Decoupled, & DEPT), and 2D-NMR techniques (¹H–¹H COSY, NOESY, HMQC, HMBC, & 2D-J-resolved). These include three new constituents namely pipilyasine (1), pipzubedine (2) and pipyaqubine (3), and three known constituents pellitorine (4), pipericine (5) and piperine (6). The larvicidal activity was determined by WHO method.