De novo Semi-Synthetic Platform for Monitoring Protein degradation in Live Cells.

We designed a platform for monitoring the degradation of exogenous proteins in live cells. We engineered a semi-synthetic platform, which consists of Enhanced Green Fluorescent Protein tagged with SpyCatcher to enable its conjugation to a SpyTag peptide bearing a Von Hippel-Lindau E3 ligand, which was delivered to live cells to promote its degradation. This platform lays the ground for studying the degradation of endogenous proteins equipped with SpyTag and for tracking the degradation of post-translationally modified proteins in live cells.

Nicotine mediated microcystic oedema in white matter of cerebellum: possible relationship to postural imbalance.

BACKGROUND: Nicotine is heavily used addictive drug that has unpleasant side- effects, e.g. dizziness, nausea, emphysema. PURPOSE: The current study was designed to find the possible relationship of nicotine mediated microcystic oedema in white matter of cerebellum to postural imbalance. METHODS: Nicotine was administered for 8 weeks orally via cannula, using dose rate (5 mg/day, 10 mg/day) to male drukrey rats. The results were compared to control adult rats, given vehicle in identical manner. After 8 weeks exposure, the cerebellum was removed and processed for histopathologic study. RESULTS: The cellular microcystic change with interstitial oedema was found in white core of cerebellum of rat received 10 mg/kg of nicotine. Cytoplasmic vacuolation was also observed in most areas of cerebellum. CONCLUSION: These findings suggest that the mature adult cerebellum is susceptible to the damaging effects of nicotine in depleting white core of cerebellum.

Clinical spectrum of Treacher Collins syndrome.

Treacher Collins syndrome (TCS) is the most common of the human mandibulofacial dysostosis disorders. It is an autosomal-dominant disorder of the craniofacial development occurring between the fifth and the eighth weeks of embryonic development with an incidence of 1/50,000 live births, range between 1-40,000 and 1-70,000. We present here the various clinical, radiographical and other diagnostic findings of the TCS to correlate the clinical assessment with the diagnostic imaging and review the various investigations and management options being carried out to improve their facial deformity.

Potentiation of neurotoxicity of Lathyrus sativus by manganese: alterations in blood-brain barrier permeability.

Environmental factors have been speculated to play an important role in potentiating the neurotoxicity of Lathyrus sativus (LS). Hence, blood-brain barrier permeability and neurotoxicity studies were carried out in manganese- and LS-exposed animals. Dietary feeding of LS (80%) plus Mn (0.4 mg/100 g diet) for 90 days to guinea pigs showed significant (p < 0.05) decrease in brain nucleotidase and ATPase activities when compared to control or LS alone treated groups. Combined treatment of LS and Mn showed a significant (p < 0.05) decrease in neuronal aryl hydrocarbon hydroxylase (36-40%), ethoxyresorufin-O-deethylase (40-45%), glutathione-S-transferase (27-31%), and quinone reductase (24-25%) activities when compared to control and LS alone treated animals. Lipid peroxidation, a marker for membrane damage, was found to be relatively more enhanced (58-141%) along with significant (p < 0.05) depletion of GSH levels in LS+Mn-treated animals when compared to control, Mn alone, and LS alone treated groups. The neuronal catalase activity of lathyrus plus Mn-treated animals showed a pronounced decrease (37-49%) when compared to control, Mn, and lathyrus alone treated groups. On the contrary, glutathione peroxidase in brain of Mn and lathyrus alone treated animals indicated a respective increase (p < 0.05) of 18% and 20%, while the combined effect of lathyrus plus Mn exhibited an increase of almost 50% when compared to control guinea pigs. Single parenteral administration of Mn (15 mg/kg b.wt) to guinea pigs followed by single oral intubation of beta-N-oxalyl-L-alpha, beta-diamino propionic acid (ODAP, 75 mg/guinea pig) resulted in a significant increase (143%) in neuronal ODAP content. ODAP (50 mg/kg,iv) treatment to mice pretreated with MnCl2 (10 mg/kg b.wt for 3 days or 40 mg/kg b.wt for 1 day), caused an enhancement in blood-brain barrier (BBB) permeability (129-196%), while ODAP and Mn alone showed relatively less enhancement (66-87%). The lumbar region of LS+Mn showed a number of vacuolated areas of variegated size and chromatolytic neurons, along with a few degenerated neurons. These results suggest that Mn may potentiate the neurotoxicity of lathyrus/ODAP by altering the BBB permeability.

Influence of age on aluminum induced lipid peroxidation and neurolipofuscin in frontal cortex of rat brain: a behavioral, biochemical and ultrastructural study.

Aluminum exposure is known to be associated with oxidative stress and cognitive decline in experimental animals but the precise mechanism of its neurotoxicity has not yet been delineated. The present study attempts to assess the learning and memory capacity of rats using Y-maze test for cognitive functioning. The markers of oxidative stress, e.g. lipid peroxides and endogenous antioxidants as well as metals (Al, Fe, Cu, Zn and Se) were measured in the brain frontal cortex of young and aged rats fed with AlCl(3) (100 mg/kg b.w.) for 90 days and normal saline treated controls. We observed significant changes between young and aged Al treated rats and their controls in terms of lipid peroxides and endogenous antioxidants. Lipofuscin content was significantly increased in Al treated aged rats along with higher concentration of Al, Fe and Zn with concomitantly low levels of Cu, and Se. Ultrastructural studies of the frontal cortex of exposed rats revealed that the changes were more pronounced in the aged treated rats in terms of presence of spongiform lipofuscin, vacuolization and lysosomal degradation. Changes in synaptic morphology and decreased number of synapses were detected in the frontal cortex of Al treated aged rats. On the basis of the results of the present study, we conclude that Al may be linked with neurolipofuscinogenesis and alteration in neurobehavioral activity and these changes may be responsible for the development of age related disorders, such as Alzheimer's disease.

Aluminum-mediated metabolic changes in rat serum and urine: a proton nuclear magnetic resonance study.

The toxic effects of Al(3+) have been studied in 90-days AlCl(3) orally treated male albino rats (n = 7) using (1)H NMR spectroscopy-based metabolic profile of rat serum and urine, serum enzyme tests, behavioral impairment, and histopathology of kidney and liver. Metabolic profile of 90-days Al(3+)-treated rat sera showed significantly elevated levels of alanine, glutamine, beta-hydroxy-butyrate, and acetoacetate and significantly decreased level of acetone when compared with that of control rats. However, metabolic profile of 90-days Al(3+)-treated rat urine showed significantly decreased levels of citrate, creatinine, allantoin, trans-aconitate, and succinate and significantly increased level of acetate when compared to control rats. The overall perturbations observed in the metabolic profile of serum and urine demonstrate the impairment in the tricarboxylic acid cycle, liver and kidney metabolism, which was further reinstated by clinical chemistry and histopathological observations. Moreover, "in vivo" behavioral impairment has also been observed as the indication of aluminum neurotoxicity.