Guidance of myogenic cell migration by oriented deposits of fibronectin

Fibronectin mediates myoblast-substratum attachment; one region of the molecule binds directly to the cell surface, while others bind to collagen, glycosaminoglycans, and other fibronectin molecules. There is evidence to suggest that fibronectin-containing extracellular matrices guide cell migration in vivo. We describe a method for producing regular deposits of fibronectin in vitro that can serve as a model system for studying cell-substrate interactions, cell orientation, and contact guidance. The novel culture substrate is prepared by allowing an aqueous solution of fibronectin and urea to dry in a culture dish and then washing away the urea crystals. Myogenic cells in vitro adhere to, align with, and migrate along, parallel streaks of fibronectin. This leads to the formation of myotubes that are long and thin, with little branching. Myogenic clones are highly elongated in the direction of the deposits, in contrast with the roughly circular clones seen in conventional cultures. Fibroblasts and limb bud mesenchymal cells align with fibronectin deposits, assuming a bipolar shape.     

A non-invasive approach to determining pine marten abundance and predation

A non-invasive approach was used to investigate variation in pine marten (Martes martes) abundance between the midlands and east of Ireland, and to determine the frequency of occurrence of squirrels and other small mammals in the diet. Remotely plucked hair samples were genotyped to differentiate between individual animals, and real-time polymerase chain reaction (PCR) was used to identify predator and prey DNA in scats. Macro analysis of prey remains was carried out on a sub sample of scats and the results from both methods are compared. Non-invasive techniques were successful in determining the presence and relative abundance of the pine marten at woodland level. As expected, abundance was found to be higher in the core population of the midlands than in the east. Pine martens were found to reach higher numbers per km² of forested habitat in Ireland than their British or European counterparts. Both traditional hard part analysis and molecular dietary analysis of mammalian prey yielded similar results. We provide the first evidence of the European pine marten predating upon the North American grey squirrel (Sciurus carolinensis) in its invasive range. While the grey squirrel was not available as a prey item in any of the midlands sites, it was available in the east, where it featured significantly more frequently in the diet than the native red squirrel. In both the midlands and the east the woodmouse is the most frequently occurring mammal in the diet.     

Keratin 19-like immunoreactivity in receptor cells of mammalian taste buds

Three monoclonal antibodies, 4.62, LPZK and 170.2.14, were usedto evaluate keratin 19-like immunoreactivity in gustatory epithelia.Keratin 19-like immunoreactivity was restricted to the intragemmalcells for all types of mammalian taste buds examined. Thesetaste buds included fungiform, foliate and vallate taste budsin rat, gerbil and rabbit, and nasopalatine, epiglottal andpalatine taste buds in rat. There was no keratin 19-like immunoreactivityin basal cells or in perigemmal cells lateral to the immunoreactivetaste receptor cells. Denervation of the rat vallate papillaeliminated all taste buds, as well as all immunoreactive tastecells. That the immunoreactive material in the taste cells waskeratin 19 was supported by the comparable staining of rat tastebuds with each of three monoclonal antibodies specific for keratin19. Furthermore, as predicted, these antibodies selectivelystained luminal cells of ral bile ducts, bladder, salivary ducts,trachea, ureter and uterus. It was concluded that monoclonalantibodies against keratin 19 can usefully distinguish intragemmaltaste receptor cells from keratinocytes, and from the perigemmaland basal cells of gustatory epithelia. Anti-keratin 19 antibodiesmay serve to identify differentiated taste cells in gustatoryepithelia undergoing taste bud development, renewal, degenerationor regeneration.     

siRNA against presenilin 1 (PS1) down regulates amyloid β42 production in IMR-32 cells

Background  

One of the pathological hallmarks of Alzheimer's disease (AD) is the deposition of the ~4 kDa amyloid β protein (Aβ) within lesions known as senile plaques. Aβ is also deposited in the walls of cerebral blood vessels in many cases of AD. A substantial proportion of the Aβ that accumulates in the AD brain is deposited as Amyloid, which is highly insoluble, proteinaceous material with a β-pleated-sheet conformation and deposited extracellularly in the form of 5-10 nm wide straight fibrils. As γ-secretase catalyzes the final cleavage that releases the Aβ42 or 40 from amyloid β -protein precursor (APP), therefore, it is a potential therapeutic target for the treatment of AD. γ-Secretase cleavage is performed by a high molecular weight protein complex containing presenilins (PSs), nicastrin, Aph-1 and Pen-2. Previous studies have demonstrated that the presenilins (PS1 and PS2) are critical components of a large enzyme complex that performs γ-secretase cleavage.     

High vapor pressure deficit drives salt‐stress‐induced rice yield losses in India

Flooded rice is grown across wide geographic boundaries from as far north as Manchuria and as far south as Uruguay and New South Wales, primarily because of its adaptability across diverse agronomic and climatic conditions. Salt‐stress damage, a common occurrence in delta and coastal rice production zones, could be heightened by the interactions between high temperature and relative humidity (vapor pressure deficit – VPD). Using temporal and spatial observations spanning 107 seasons and 19 rice‐growing locations throughout India with varying electrical conductivity (EC), including coastal saline, inland saline, and alkaline soils, we quantified the proportion of VPD inducing salinity damage in rice. While controlling for time‐invariant factors such as trial locations, rice cultivars, and soil types, our regression analysis indicates that EC has a nonlinear detrimental effect on paddy rice yield. Our estimates suggest these yield reductions become larger at higher VPD. A one standard deviation (SD) increase in EC from its mean value is associated with 1.68% and 4.13% yield reductions at median and maximum observed VPD levels, respectively. Yield reductions increase roughly sixfold when the one SD increase is taken from the 75th percentile of EC. In combination, high EC and VPD generate near catastrophic crop loss as predicted yield approaches zero. If higher VPD levels driven by global warming materialize in conjunction with rising sea levels or salinity incursion in groundwater, this interaction becomes an important and necessary predictor of expected yield losses and global food security.     

Modeling of human CCR5 as Target for HIV-I and Virtual Screening with Marine Therapeutic compounds

Marine derivatives are of great pharmaceutical interest as inhibitory compound and search of bioactive compounds from Marine organism which is relatively new to medicinal chemistry. Our main aim in the study is to screen possible inhibitors against CCR5 which acts as co-receptor M-tropic HIV-1, through virtual screening of 122 Marine derived compounds from various organisms known to have biological activity. Homology Model of CCR5 was constructed using MODELLER and the Model was energy minimized and validated using PROCHECK to obtain a stable structure, which was further used for virtual screening of Marine derived compounds through molecular Docking studies using GOLD. The Docked complexes were validated and Enumerated based on the GOLD Scoring function to pick out the best Marine inhibitor based on GOLD score. Thus from the entire 122 Marine compounds which were Docked, we got best 4 of them with optimal GOLD Score. (LAMIVUDINE: 45.0218, BATZELLINE-D: 44.3852.ACYCLOVIR: 43.1362 and THIIOACETAMIDE: 42.7412) Further the Complexes were analyzed through LIGPLOT for their interaction for the 4 best docked Marine compounds. Thus from the Complex scoring and binding ability its deciphered that these Marine compounds could be promising inhibitors for M-tropic HIV-1 using CCR5 as Drug target yet pharmacological studies have to confirm it.     

Variations among cell lines in the synthesis of sphingolipids in de novo and recycling pathways

There are several pathways for the incorporation of sugars into glycosphingolipids (GSL). Sugars can be added to ceramide that contains sphinganine (dihydrosphingosine) synthesized de novo (pathway 1), to ceramide synthesized from sphingoid bases produced by hydrolysis of sphingolipids (pathway 2), and into GSL recycling from the endosomal pathway through the Golgi (pathway 3). We reported previously the surprising observation that SW13 cells, a human adrenal carcinoma cell line, synthesize most of their GSL in pathway 2. We now present data on the synthesis of GSL in four additional cell lines. Approximately 90% of sugar incorporation took place in pathway 2, and 10% or less in pathway 1, in human foreskin fibroblasts and NB41A3 neuroblastoma cells. In contrast, approximately 50-90% of sugar incorporation took place in pathway 1 in C2C12 myoblasts. The C2C12 cells divide more rapidly and synthesize 10-14 times as much GSL as the other three cell lines. In C6 glioma cells, approximately 30% of sugar incorporation occurred in pathway 1 and 60% in pathway 2. There was no relation between the utilization of pathways for GSL and sphingomyelin synthesis in foreskin fibroblasts and C2C12 cells. In both cells pathways 1 and 2 each accounted for 50% of incorporation of choline into sphingomyelin. In five of the six cell lines that we have studied, most GSL synthesis takes place in pathway 2. We suggest that when the need for synthesis is relatively low, as in slowly dividing cells, GSL are synthesized predominantly from sphingoid bases salvaged from the hydrolytic pathway. When cells are dividing more rapidly, the need for increased synthesis is met by upregulating the de novo pathway.      

Ultrastructural comparison of the tailed and tailless P-protein crystals respectively of runner bean (Phaseolus multiflorus) and garden pea (Pisum sativum) with tilting stage electron microscopy

Summary The periodicity of striation, discovered to measure 12 nm in the tailless P-protein crystal ofPisum sativum, is compared with that known in the central body of the tailed P-protein crystal ofPhaseolus multiflorus. A preliminary model advanced to explain the coarse striation in tails accounts for both the wavy outline in longitudinal section and the nearcircular outline in transverse section.