Coordinating cell proliferation and migration in the lens and cornea

Migration is a complex process for epithelial tissues, because the epithelium must move as an intact sheet to preserve its barrier function. The requirement for structural integrity is met by coupling cell-to-matrix and cell-to-cell adhesion at the cellular level, and by coordinating cell proliferation and cell migration in the tissue as a whole. Proliferation is suppressed at the migrating cell front, allowing cells in this region to remain tightly packed while advancing rapidly. At the same time, proliferation is enhanced in a region behind the advancing cell front to expand the epithelial cell sheet. This review considers the extracellular signals and intracellular signaling pathways that regulate these processes in the lens and corneal epithelium, with emphasis on the commonalities that link these tissues.     

Climatic controls of vegetation vigor in four contrasting forest types of India—evaluation from National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer datasets (1990–2000)

Ten-day advanced very high resolution radiometer images from 1990 to 2000 were used to examine spatial patterns in the normalized difference vegetation index (NDVI) and their relationships with climatic variables for four contrasting forest types in India. The NDVI signal has been extracted from homogeneous vegetation patches and has been found to be distinct for deciduous and evergreen forest types, although the mixed-deciduous signal was close to the deciduous ones. To examine the decadal response of the satellite-measured vegetation phenology to climate variability, seven different NDVI metrics were calculated using the 11-year NDVI data. Results suggested strong spatial variability in forest NDVI metrics. Among the forest types studied, wet evergreen forests of north-east India had highest mean NDVI (0.692) followed by evergreen forests of the Western Ghats (0.529), mixed deciduous forests (0.519) and finally dry deciduous forests (0.421). The sum of NDVI (SNDVI) and the time-integrated NDVI followed a similar pattern, although the values for mixed deciduous forests were closer to those for evergreen forests of the Western Ghats. Dry deciduous forests had higher values of inter-annual range (RNDVI) and low mean NDVI, also coinciding with a high SD and thus a high coefficient of variation (CV) in NDVI (CVNDVI). SNDVI has been found to be high for wet evergreen forests of north-east India, followed by evergreen forests of the Western Ghats, mixed deciduous forests and dry deciduous forests. Further, the maximum NDVI values of wet evergreen forests of north-east India (0.624) coincided with relatively high annual total precipitation (2,238.9 mm). The time lags had a strong influence in the correlation coefficients between annual total rainfall and NDVI. The correlation coefficients were found to be comparatively high (R²=0.635) for dry deciduous forests than for evergreen forests and mixed deciduous forests, when the precipitation data with a lag of 30 days was correlated against NDVI. Using multiple regression approach models were developed for individual forest types using 16 different climatic indices. A high proportion of the temporal variance (>90%) has been accounted for by three of the precipitation parameters (maximum precipitation, precipitation of the wettest quarter and driest quarter) and two of the temperature parameters (annual mean temperature and temperature of the coldest quarter) for mixed deciduous forests. Similarly, in the case of deciduous forests, four precipitation parameters and three temperature parameters explained nearly 83.6% of the variance. These results suggest differences in the relationship between NDVI and climatic variables based upon the time of growing season, time interval and climatic indices over which they were summed. These results have implications for forest cover mapping and monitoring in tropical regions of India.     

Identification of Potential Peptide Inhibitors of ACE-2 Target of SARS-CoV-2 from Buckwheat & Quinoa

International Journal of Peptide Research and Therapeutics - It is well established fact that peptides from various foods offer human health benefits displaying diverse functionalities. Millets...     

β-carotene at physiologically attainable concentration induces apoptosis and down-regulates cell survival and antioxidant markers in human breast cancer (MCF-7) cells

Mitogen-activated protein kinases (MAPKs) (ERK1/2, JNK, and p38) are upregulated in diabetic cardiomyopathy (DCM). Dual-specific phosphatase-1 (DUSP-1) has been reported to regulate the activity of MAPKs in cardiac hypertrophy; however, the role of DUSP-1 in regulating MAPKs activity in DCM is not known. MicroRNAs have been reported to regulate the expression of several genes in hypertrophied failing hearts. However, little is known about the microRNAs regulating DUSP-1 expression in diabetes-related cardiac hypertrophy. In the present study, we investigated the role of DUSP-1 and miR-200c in diabetes-induced cardiac hypertrophy. DCM was induced in Wistar rats by low-dose Streptozotocin high-fat diet for 12 weeks. Cardiac expression of ERK, p-38, JNK, DUSP-1, miR-200c, and hypertrophy markers (ANP and β-MHC) was studied in DCM in control rats and in high-glucose (HG)-treated rat neonatal cardiomyocytes. miR-200c inhibition was performed to validate DUSP-1 as target. A significant increase in phosphorylated ERK, p38, and JNK was observed in DCM model and in HG-treated cardiomyocytes (p < 0.05). Expression of DUSP-1 was significantly decreased in diabetes group and in HG-treated cardiomyocytes (p < 0.05). Increased expression of miR-200c was observed in DCM model and in HG-treated cardiomyocytes (p < 0.05). Inhibition of miR-200c induces the expression of the DUSP-1 causing decreased expression of phosphorylated ERK, p38, and JNK and attenuated cardiomyocyte hypertrophy in HG-treated cardiomyocytes. miR-200c plays a role in diabetes-associated cardiac hypertrophy by modulating expression of DUSP-1.     

Selection of herbal therapeutics against deltatoxin mediated Clostridial infections

Clostridium perfringens (a versatile pathogenic bacterium) secretes enterotoxins (the deltatoxin, virulent factor) and causes food borne gastroenteritis and gasgangrene. The organism was isolated and characterized from improperly cooked meat and poultry samples. The isolated organism showed multiple drug resistance indicating that the treatment is challenging. Hence, there is need for improved therapeutic agents. The rational design of improved therapeutics requires the crystal structure for the toxin. However, the structure for the toxin is not yet available in its native form. Thus, we modeled the toxin structure using α- hemolysin of Staphylococcus aureus (PDB: 3M4D chain A) as template. The docking of the toxin with the herbal extract curcumin (1,7-bis(4-hydroxy-3- methoxyphenyl)hepta-1,6-diene-3,5-dione) showed a binding energy of -8.6 Kcal/mol, in comparison to the known antibiotic Linezolid with binding energy of -6.1 Kcal/mol. This data finds application in the design and development of novel compounds against the deltatoxin from Clostridium perfringens.     

Structure based virtual screening of novel inhibitors against multidrug resistant superbugs

Pathogenic microorganisms are persistently expressing resistance towards present generation antibiotics and are on the verge of joining the superbug family. Recent studies revealed that, notorious pathogens such as Salmonella typhi, Shigella dysenteriae and Vibrio cholerae have acquired multiple drug resistance and the treatment became a serious concern. This necessitates an alternative therapeutic solution. Present study investigates the utility of computer aided method to study the mechanism of receptor-ligand interactions and thereby inhibition of virulence factors (shiga toxin of Shigella dysenteriae, cholera toxin of Vibrio cholerae and hemolysin-E of Salmonella typhi) by novel phytoligands. The rational designs of improved therapeutics require the crystal structure for the drug targets. The structures of the virulent toxins were identified as probable drug targets. However, out of the three virulent factors, the structure for hemolysin-E is not yet available in its native form. Thus, we tried to model the structure by homology modeling using Modeller 9v9. After extensive literature survey, we selected 50 phytoligands based on their medicinal significance and drug likenesses. The receptor-ligands interactions between selected leads and toxins were studied by molecular docking using Auto Dock 4.0. We have identified two novel sesquiterpenes, Cadinane [(1S, 4S, 4aS, 6S, 8aS)- 4- Isopropyl- 1, 6- dimethyldecahydronaphthalene] and Cedrol [(8α)-Cedran-8-ol] against Shiga (binding energy -5.56 kcal/mol) and cholera toxins (binding energy -5.33 kcal/mol) respectively which have good inhibitory properties. Similarly, a natural Xanthophyll, Violaxanthin [3S, 3'S, 5R, 5'R, 6S, 6'S)-5, 5', 6, 6'-Tetrahydro-5, 6:5', 6'-diepoxy-β, β-carotene-3, 3'-diol] was identified as novel therapeutic lead for hemolysin-E (binding energy of -5.99 kcal/mol). This data provide an insight for populating the pool of novel inhibitors against various drug targets of superbugs when all current generation drugs seem to have failed.     

CENTURY ecosystem model application for quantifying vegetation dynamics in shifting cultivation areas: A case study from Rampa Forests, Eastern Ghats (India)

In India, slash and burn agriculture is one of the major factors contributing to deforestation, especially in the hilly north-eastern region and Eastern Ghats. Studies on vegetation dynamics associated with slash and burn agricultural practices have been intensively studied in the north-eastern part of India. These have covered semi-evergreen/evergreen vegetation, but similar studies on tropical mixed dry deciduous ecosystems are not as common. In the present study, we used the century ecosystem model to study vegetation dynamics in shifting cultivation areas on the mixed dry deciduous forests covering the Eastern Ghats of India. The site-specific parameters, temperature, precipitation, biomass and nutrient pools were used, and, by collecting information from local management practices, a 12-year shifting cultivation cycle during a 70-year period from 1960 to 2030 was simulated. century estimated a total loss of 239 tonnes carbon (tC) in soil organic matter over the simulation period, and the total nitrogen content of the soil organic matter showed an initial increase followed by a decline (344.3 g m² during 1960 to less than 318.3 g m² during 2030). century estimated that 66 tC ha^–1 would be lost from the forest system, reducing the initial forest system carbon level from 118.5 tC ha^–1. An increase in productivity from 0.49 tC ha^–1 during 1960 to 1.2 tC ha^–1 during the initial forest slash and burn in 1962 was observed, but thereafter productivity declined to 0.7 tC ha^–1 during the year 2030. Results obtained in other studies of similar types of agricultural practices are also reviewed.