Heterologous expression of Chlorophytum borivilianum Squalene epoxidase in tobacco modulates stigmasterol production and alters vegetative and reproductive growth

KEYMESSAGE

CbSE overexpression increased stigmasterol levels and altered plant morphology. The genes upstream and downstream of CbSE were found to be upregulated, which confirms its regulatory role in the saponin biosynthetic pathway. Chlorophytum borivilianum is a high-value medicinal plant with many promising preclinical applications that include saponins as a major active ingredient. Squalene epoxidase (SE) is one of the major rate-limiting enzymes of the saponin biosynthetic pathway. Here, we functionally characterized C. borivilianum SE (CbSE) by over-expressing heterologously in Nicotiana tabacum. The heterologous expression of CbSE resulted in stunted pant growth with altered leaf and flower morphology. Next, RT-qPCR analysis of transgenic plants overexpressing CbSE revealed increased expression levels of Cycloartenol synthase (CAS), Beta amyrin synthase (βAS), and cytochrome P450 monooxygenase 51 (CYP51) (Cytochrome P450), which encode key enzymes for triterpenoid and phytosterol biosynthesis in C. borivilianum. Further, Methyl Jasmonate (MeJa) treatment upregulated Squalene synthase (SQS), SE, and Oxidosqualene cyclases (OSCs) to a significant level. GC-MS analysis of the leaf and hairy roots of the transformants showed an increased stigmasterol content (0.5-1.0 fold) compared to wild type (WT) plants. These results indicate that CbSE is a rate-limiting gene, which encodes an efficient enzyme responsible for phytosterol and triterpenoid production in C. borivilianum.

Genome-wide analysis of Catalase gene family reveal insights into abiotic stress response mechanism in Brassica juncea and B. rapa

Environmental stresses affect the yield and productivity of Brassica crops. Catalases are important antioxidant enzymes involved in reducing excess hydrogen peroxide produced by environmental stresses. In the present study, nine and seven CAT family members in two oilseed Brassica species (B. juncea and B. rapa) were identified with complete characterization based on gene and protein structure. Phylogenetic classification categorized CAT proteins into three classes and differentiated the monocot and dicot-specific CAT proteins. Further, the gene and protein characterizations revealed a high degree of conservation across the CAT family members. Differences were observed in the CAT-HEME binding affinity in CAT1, CAT2, and CAT3 isozymes, which could suggest their differential enzyme activities in different conditions. Furthermore, protein-protein interaction with other antioxidant proteins suggested their coordinated role in ROS scavenging mechanisms. Notably, the differential gene expression of BjuCATs and BraCATs and CAT enzyme activities suggested their crucial roles in major abiotic stresses faced by Brassica species. Promoter analysis in BjuCATs and BraCATs suggested the presence of abiotic-stress responsive cis-regulatory elements. Gene regulatory network analysis suggested miRNA and TF mediated stress response in BjuCATs and BraCATs. CAT family screening and characterization in Brassica sp. has established a basic ground for further functional validation in abiotic and heavy-metal stresses which can help in developing stress tolerant crops.

Arterial stiffness and age moderate the association between physical activity and global cognition in the older adults

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Merck Sharp & Dohme Corp Program of the Faculty of Medicine of the Université de Montréal The Canadian Institutes of Health Research (CIHR)

Background

The growing concern on the impact of higher arterial stiffness on cognitive decline in older adults, leads to the question of whether non-pharmacological interventions like physical activity should be introduced to correct or diminish the progression of arterial stiffness.

Purpose

The goal of this study is to elaborate a model for arterial stiffness as a moderator for the physical activity and global cognition relationship in function of age. 

Methods

One hundred ten healthy older adults aged 60 to 75 years old (46 men and 64 women) were examined for arterial stiffness (carotid-femoral Pulse Wave Velocity (cf-PWV)), global cognition (Montreal Cognitive Assessment and Mini Mental State Examination) and self-reported physical activity (PACED diary). The double moderation analysis used PROCESS macro for SPSS, where physical activity was included as the independent variable (X), global cognition as the dependent variable (Y), arterial stiffness as moderator 1 (W), and age moderator 2 (Z). This study used a cf-PWV cutoff of 8.5 m/s to identify micro-structural damage in the brain related to arterial stiffness.

Results

Results found that the arterial stiffness x age interaction moderated the effect of physical activity on global cognition (β = -.89, SE = .42, p = .037) (Model: R2 = .15, p = .018). Physical activity had a positive effect on cognition in younger-older adults (aged 60 to 68.5 years) with high arterial stiffness i.e. cf-PWV > 8.5 m/s (β = .57, SE = .222, p = .011, 95% CI .133 to 1.014), and in older-older adults (aged 68.6 to 75 years) with low arterial stiffness i.e. cf-PWV < 8.5 m/s (β = .49, SE = .190, p = .010, 95% CI = .116 to .869). 

Conclusions

These results support targeted physical activity interventions based on age and degree of arterial stiffness, furthering the notion that even daily life physical activity could play an important role in older adults’ cognitive performances.

Physical activity on global cognition Conditional effects of physical activity on global cognition Moderators cf-PWV Age Effect SE p CI < 8.5 m/s < 68.5 years .171 .245 .487 -.315 to .657 < 8.5 m/s > = 68.5 years .574 .222 .011* .133 to 1.014 > = 8.5 m/s < 68.5 years .492 .190 .010* .116 to .868 > = 8.5 m/s > = 68.5 years .002 .180 .990 -.355 to .359 Physical activity conditional effects on global cognition at determined values of arterial stiffness and age. SE: Standard Error, CI: Confidence Interval, cf-PWV: carotid-femoral Pulse Wave Velocity, *p-value<.05.

Identification of novel microRNAs and their targets in Chlorophytum borivilianum by small RNA and degradome sequencing

Plant specific miRNAs (Novel miRNAs) are well known to perform distinctive functions in biological processes. Identification of new miRNAs is necessary to understand their gene regulation. Degradome provides an opportunity to explore the miRNA functions by comparing the miRNA population and their degraded products. In the present study, Small RNA sequencing data was used to identify novel miRNAs. Further, degradome sequencing was carried out to identify miRNAs targets in the plant, Chlorophytum borivilianum. The present study supplemented 40 more novel miRNAs correlating degradome data with smallRNAome. Novel miRNAs, complementary to mRNA partial sequences obtained from degradome sequencing were actually targeting the later. A big pool of miRNA was established by using Oryza sativa, Arabidopsis thaliana, Populus trichocarpa, Ricinus communis, and Vitis vinifera genomic data. Targets were identified for novel miRNAs and total 109 targets were predicted. BLAST2GO analysis elaborate about localization of novel miRNAs’ targets and their corresponding KEGG (Kyoto Encyclopedia for Genes and Genomes) pathways. Identified targets were annotated and were found to be involved in significant biological processes like Nitrogen metabolism, Pyruvate metabolism, Citrate cycle (TCA cycle), photosynthesis, and Glycolysis/Gluconeogenesis. The present study provides an overall view of the miRNA regulation in multiple metabolic pathways that are involved in plant growth, pathogen resistance and secondary metabolism of C. borivilianum.

Computing Resonant Inelastic X-Ray Scattering Spectra Using The Density Matrix Renormalization Group Method

We present a method for computing the resonant inelastic x-ray scattering (RIXS) spectra in one-dimensional systems using the density matrix renormalization group (DMRG) method. By using DMRG to address this problem, we shift the computational bottleneck from the memory requirements associated with exact diagonalization (ED) calculations to the computational time associated with the DMRG algorithm. This approach is then used to obtain RIXS spectra on cluster sizes well beyond state-of-the-art ED techniques. Using this new procedure, we compute the low-energy magnetic excitations observed in Cu L-edge RIXS for the challenging corner shared CuO4 chains, both for large multi-orbital clusters and downfolded t-J chains. We are able to directly compare results obtained from both models defined in clusters with identical momentum resolution. In the strong coupling limit, we find that the downfolded t-J model captures the main features of the magnetic excitations probed by RIXS only after a uniform scaling of the spectra is made.

Development of Spectrofluorimetric and HPLC Methods for In vitro Analysis of Repaglinide

Spectrofluorimetric and high-performance liquid chromatography methods for estimation of repaglinide were developed. These methods were validated for estimation of repaglinide in tablets as well as in receptor fluid obtained during in vitro permeation studies. Repaglinide was observed to exhibit emission and excitation wavelengths, respectively, at 379 nm and 282 nm with linearity in the concentration range of 5-80 µg/ml. High-performance liquid chromatography analysis of repaglinide yielded retention time of 6.14 min with linearity ranging from 0.1-1.2 µg/ml concentration. Spectrofluorimetric analysis of repaglinide in tablets yielded results comparable to high performance liquid chromatography.

Phosphorylation of Crk on tyrosine 251 in the RT loop of the SH3C domain promotes Abl kinase transactivation

Here, we report the identification and characterization of a novel tyrosine phosphorylation site in the carboxy-terminal Src Homology 3 (SH3) (SH3C) domain of the Crk adaptor protein. Y251 is located in the highly conserved RT loop structure of the SH3C, a region of Crk involved in the allosteric regulation of the Abl kinase. Exploiting kinase assays to show that Y251 is phosphorylated by Abl in vitro, we generated affinity-purified antisera against phosphorylated Y251 in Crk and showed that Abl induces phosphorylation at Y251 in vivo, and that the kinetics of phosphorylation at Y251 and the negative regulatory Y221 site in vitro are similar. Y251 on endogenous Crk was robustly phosphorylated in chronic myelogenous leukemia cell lines and in A431 and MDA-MB-468 cells stimulated with epidermal growth factor. Using streptavidin-biotin pull downs and unbiased high-throughput Src Homology 2 (SH2) profiling approaches, we found that a pY251 phosphopeptide binds specifically to a subset of SH2 domains, including Abl and Arg SH2, and that binding of pY251 to Abl SH2 induces transactivation of Abl 1b. Finally, the Y251F Crk mutant significantly abrogates Abl transactivation in vitro and in vivo. These studies point to a yet unrealized positive regulatory role resulting from tyrosine phosphorylation of Crk, and identify a novel mechanism by which an adaptor protein activates a non-receptor tyrosine kinase by SH2 domain displacement.

Effect of different non-steroidal anti-inflammatory drugs, aspirin, nimesulide and celecoxib on the disaccharide hydrolases and histoarchitecture of the rat intestinal brush border membrane

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause gastrointestinal damage. New anti-inflammatory drugs have been developed in an attempt to improve their gastrointestinal side effect profile which however failed to do so. Therefore, the objective of the present study was to compare the effect of three different NSAIDs, aspirin, nimesulide and celecoxib on the intestinal brush border membrane (BBM) marker enzymes and correlate these alterations to the histoarchitecture of the intestine using electron microscopic study. Female Wistar rats were divided into four different groups viz: Group I (Control), Group II (aspirin treated), Group III (nimesulide treated) and Group IV (celecoxib treated). The Group II, III and IV received the corresponding drugs dissolved in water orally at a dose of 40 mg/kg body weight, while the control received the vehicle only. After 28 days, all the treatment groups demonstrated significant alterations in the activities of intestinal disaccharide hydrolases and alkaline phosphatase in both the crude homogenates and BBM preparations as well. The histopathological observations also showed considerable changes in the intestinal mucosa. It was suggested that NSAIDs like aspirin, nimesulide and celecoxib pose intestinal side effects due to initial changes in the enzymatic composition of the intestinal apical membranes. It was further concluded that newly discovered NSAIDs such as celecoxib has better safety profiles but studies are still required to comment decisively on the suitability of various NSAIDs depending upon their cyclooxygenase enzyme specificity.

Do food stamps cause obesity? Evidence from immigrant experience

I use changes in immigrant eligibility for food stamps under the 1996 federal law and heterogeneous state responses to set up a natural experiment research design to study the effect of food stamps on Body Mass Index (BMI) of adults in immigrant families. I find that in the post-1996 period food stamps use by foreign-born unmarried mothers with a high school or lower education was 10 percentage points higher in states with substitute programs than in states that implemented the federal ban. However, this increase in FSP participation was not associated with any statistically significant difference in BMI. I find that FSP participation was associated a statistically insignificant 0.3% increase in BMI among low-educated unmarried mothers.

In vitro clonal multiplication of an apple rootstock by culture of shoot apices and axillary buds

In vitro clonal multiplication of apple rootstock MM 111 using axillary buds and shoot apices were carried out. Vegetative axillary buds of the size of 0.2-2.0 cm and shoot apices measuring 4 mm in length were initiated to shoot proliferation on MS medium supplemented with BA (0.5 - 1.0 mgl(-1)), GA3(0.5 mgl(-1)), with or without IBA(0.05 - 0.1 mgl(-1)). Small size explants showed less phenol exudation and less contamination. Following establishment phase, the small shoots emerged from explants were subcultured on MS medium supplemented with different combinations and concentrations of growth regulators. BA (1.0 mgl(-1)) and GA3 (0.5 mgl(-1)) combination showed highest multiplication rate (1:5), andcl also produced longer shoots. Two step rooting was done by transferring microcuttings to auxin free solid medium after root initiation in dark on 1/2 strength MS liquid medium containing IBA (0.5 mgl(-1) ). Rooted plantlets were transferred to peat containing paper cups and resulting plants of MM 111 acclimated successfully for transfer to field.

Maternal CA-125 levels in pregnancy and the puerperium

OBJECTIVE

To determine the levels of CA-125 throughout pregnancy and the puerperium to establish a baseline, thereby indicating what values may be indicative of the pathologic conditions usually associated with elevated CA-125 levels.

STUDY DESIGN

A prospective, longitudinal study was carried out on a consecutive series of pregnant women to determine their CA-125 levels throughout pregnancy and during the puerperium. Blood was drawn at four- to six-week intervals for clinically indicated tests. The residual sera were kept frozen, and subsequently CA-125 measurements were determined by radioimmunoassay.

RESULTS

Of 34 women enrolled in the study, 20 completed the evaluations throughout pregnancy and in the puerperium. The remaining 14 had evaluations for varying portions of their pregnancies but not throughout pregnancy or during the puerperium. The results in these two groups were compared and found not to be statistically significantly different. For the group as a whole, the levels of CA-125 were high, with wide fluctuations in the first trimester; the levels in the early first trimester (five to eight weeks) were particularly high, with a mean of 55.8 and median of 36.2 (range, 6.9-251.2) U/mL. The levels then dropped and remained < 35 U/mL through the rest of pregnancy (including immediately prior to delivery). Another peak, with wide fluctuations, occurred soon after delivery, with a mean of 39.8 and median of 41.9 (range, 10.7-296.7) U/mL. In the late postpartum period (2-10 weeks after delivery) there was a return to baseline levels in all subjects.

CONCLUSION

This study showed that there is a distinct pattern in CA-125 levels during pregnancy and the puerperium. Due to the wide fluctuations in CA-125 levels in very early pregnancy and the immediate postpartum period, CA-125 values during these periods are not useful for clinical correlation with the pathologic conditions known to be associated with elevated levels of CA-125. However, further study is needed to determine whether extreme values in the first trimester or elevated levels after the first trimester are diagnostic or predictive of any conditions related to pregnancy.

Effect of graded head-up tilt on parasympathetic reactivity

Thirteen healthy subjects were tested for parasympathetic reactivity during head-up tilt and reversal of the tilt. Head-up tilt (70 degrees) resulted in significant increase in baseline heart rate and diastolic blood pressure. Head-up tilt also led to increased parasympathetic reactivity as measured by Valsalva manoeuvre and hand grip test. Heart rate response to deep breathing test did not change. The reversal of the tilt led to returning of heart responses to original values. Responses indicate towards enhanced parasympathetic reactivity during head-up tilt position.

Effect of lead acetate administration on ATPases of brain and its mitochondrial and synaptosomal fractions in adult mice

The effects of oral administration of lead acetate on the activities of cation-transport ATPases and on the brain and its mitochondrial and synaptosomal fractions of male mice were studied at doses of 1, 5, and 20 mg lead acetate per 100 g body weight per day for 4, 8, 12, and 16 weeks. The activities of Na(+)-ATPase, K(+)-ATPase, total-ATPase, and Na(+)-K(+)-ATPase decreased significantly at doses of 1 and 5 mg lead acetate after 12 and 16 weeks of treatment; changes in the activities were not marked after 4 and 8 weeks of lead administration. However, the 20-mg dose significantly reduced enzyme activities at all treatment intervals.