Genetic evidence for involvement of neuronally expressed S1P₁ receptor in nociceptor sensitization and inflammatory pain

Sphingosine-1-phosphate (S1P) is a key regulator of immune response. Immune cells, epithelia and blood cells generate high levels of S1P in inflamed tissue. However, it is not known if S1P acts on the endings of nociceptive neurons, thereby contributing to the generation of inflammatory pain. We found that the S1P₁ receptor for S1P is expressed in subpopulations of sensory neurons including nociceptors. Both S1P and agonists at the S1P₁ receptor induced hypersensitivity to noxious thermal stimulation in vitro and in vivo. S1P-induced hypersensitivity was strongly attenuated in mice lacking TRPV1 channels. S1P and inflammation-induced hypersensitivity was significantly reduced in mice with a conditional nociceptor-specific deletion of the S1P₁ receptor. Our data show that neuronally expressed S1P₁ receptors play a significant role in regulating nociceptor function and that S1P/S1P₁ signaling may be a key player in the onset of thermal hypersensitivity and hyperalgesia associated with inflammation.     

Cation-Mediated Interplay of Loops in Chaperonin-10

Abstract

The ubiquitously occurring chaperonins consist of a large tetradecameric Chaperonin-60, forming a cylindrical assembly, and a smaller heptameric Chaperonin-10. For a functional protein folding cycle, Chaperonin-10 caps the cylindrical Chaperonin-60 from one end forming an asymmetric complex. The oligomeric assembly of Chaperonin-10 is known to be highly plastic in nature. In Mycobacterium tuberculosis, the plasticity has been shown to be modulated by reversible binding of divalent cations. Binding of cations confers rigidity to the metal binding loop, and also promotes stability of the oligomeric structure. We have probed the conformational effects of cation binding on the Chaperonin-10 structure through fluorescence studies and molecular dynamics simulations. Fluorescence studies show that cation binding induces reduced exposure and flexibility of the dome loop. The simulations corroborate these results and further indicate a complex landscape of correlated motions between different parts of the molecule. They also show a fascinating interplay between two distantly spaced loops, the metal binding “dome loop” and the GroEL-binding “mobile loop”, suggesting an important cation-mediated role in the recognition of Chaperonin-60. In the presence of cations the mobile loop appears poised to dock onto the Chaperonin-60 structure. The divalent metal ions may thus act as key elements in the protein folding cycle, and trigger a conformational switch for molecular recognition.     

Overexpression of phytochelatin synthase (<Emphasis Type="Italic">AtPCS</Emphasis>) in rice for tolerance to cadmium stress

Phytoremediation is an important strategy adapted by plants to sequester and/or detoxify pollutants. Phytochelatins, a family of cysteine-rich thiol-reactive peptides, bind to various heavy metals and metalloids making them good candidates for phytoremediation. Phytochelatin synthase catalyses the final step in the biosynthesis of phytochelatins and can be used as a strategy to improve tolerance against heavy metals. In the present study, an AtPCS gene was overexpressed in rice following the in planta transformation approach. Stringent screening strategies were standardized to select putative transformants under a Cd stress of 125 μM at both seedling and plant levels. Molecular analysis by PCR in 18 tolerant plants confirmed the transgene integration and absence of Agrobacterium. Genomic Southern analysis further confirmed the integration of the T-DNA as a single copy. The stability of the T-DNA in the progeny of 5 selected T₁ generation plants was confirmed by tolerance assay, molecular characterization and biochemical analysis for the reduced glutathione, phytochelatin content and lipid peroxidation. This strategy is discussed as a potential mechanism to enhance the tolerance of rice plants to Cd stress.     

Molecular stacking of two codon-modified genes encoding Bt insecticidal proteins,Cry1AcF and Cry2Aa for management of resistance development in Helicoverpa armigera

Journal of Plant Biochemistry and Biotechnology - Concurrent expression of multiple insecticidal toxins as pyramided genes in the same host plant is one of the tangible strategies to delay the...     

Evaluation of antioxidant and neuroprotective effect of date palm (Phoenix dactylifera L.) against bilateral common carotid artery occlusion in rats

The cerebral ischemia in rats was induced by occluding bilateral common carotid arteries (BCCAO) for 30 min., followed by 45 min reperfusion. BCCAO caused significant depletion in superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and significant increase in lipid peroxidation along with severe neuronal damage in the brain. All the alterations except depletion in glutathione peroxidase and glutathione-S-transferase levels induced by cerebral ischemia were significantly attenuated by 15 days pretreatment with methanolic extract of P. dactylifera fruits (100, 300 mg/kg), whereas 30 mg/kg dose was insignificant in this regard. These results suggest the possible use P. dactylifera against bilateral common carotid artery occlusion induced oxidative stress and neuronal damage.     

A sensitive and specific LC-MS/MS method for rapid diagnosis of Niemann-Pick C1 disease from human plasma

Niemann-Pick type C1 (NPC1) disease is a rare, progressively fatal neurodegenerative disease for which there are no FDA-approved therapies. A major barrier to developing new therapies for this disorder has been the lack of a sensitive and noninvasive diagnostic test. Recently, we demonstrated that two cholesterol oxidation products, specifically cholestane-3β,5α,6β-triol (3β,5α,6β-triol) and 7-ketocholesterol (7-KC), were markedly increased in the plasma of human NPC1 subjects, suggesting a role for these oxysterols in diagnosis of NPC1 disease and evaluation of therapeutics in clinical trials. In the present study, we describe the development of a sensitive and specific LC-MS/MS method for quantifying 3β,5α,6β-triol and 7-KC human plasma after derivatization with N,N-dimethylglycine. We show that dimethylglycine derivatization successfully enhanced the ionization and fragmentation of 3β,5α,6β-triol and 7-KC for mass spectrometric detection of the oxysterol species in human plasma. The oxysterol dimethylglycinates were resolved with high sensitivity and selectivity, and enabled accurate quantification of 3β,5α,6β-triol and 7-KC concentrations in human plasma. The LC-MS/MS assay was able to discriminate with high sensitivity and specificity between control and NPC1 subjects, and offers for the first time a noninvasive, rapid, and highly sensitive method for diagnosis of NPC1 disease.     

Synchrony during acoustic interactions in the bushcricket <Emphasis Type="Italic">Mecopoda</Emphasis> ‘Chirper’ (Tettigoniidae:Orthoptera) is generated by a combination of chirp-by-chirp resetting and change in intrinsic chirp rate

In several bushcricket species, individual males synchronise their chirps during acoustic interactions. Synchrony is imperfect with the chirps of one male leading or lagging the other by a few milliseconds. Imperfect synchrony is believed to have evolved in response to female preferences for leading chirps. We investigated the mechanism underlying synchrony in the bushcricket species Mecopoda ‘Chirper’ from Southern India using playback experiments and simulations of pairwise interactions. We also investigated whether intrinsic chirp period is a good predictor of leading probability during interactions between males. The mechanism underlying synchrony in this species differs from previously reported mechanisms in that it involves both a change in the oscillator’s intrinsic rate and resetting on a chirp-by-chirp basis. The form of the phase response curve differs from those of previously reported firefly and bushcricket species including the closely related Malaysian species Mecopoda elongata. Simulations exploring oscillator properties showed that the outcome of pairwise interactions was independent of initial phase and alternation was not possible. Solo intrinsic chirp period was a relatively good predictor of leading probability. However, changing the intrinsic period during interactions could enable males with longer periods to lead during acoustic interactions.     

Growth and nutritional status of the Bharia--a primitive tribe of Madhya Pradesh

This study is an attempt to understand the physical growth and nutritional status of Bharia, a primitive tribe of Central India. A cross sectional study was conducted on 551 children (283 boys and 268 girls) aged 4 to 18 years. Body weight, height, sitting height, head circumference, upper arm circumference, chest circumference, biceps, triceps, sub scapular and calf skin fold thickness were measured. Body Mass Index was calculated as weight/height2 to calculate chronic energy deficiency. All anthropometric measurements except skin fold measurement exhibit uniform increase with age in both the sexes. Age-specific Body Mass Index (BMI) indicated substantial changes and falls during pre-school age and rise in adolescence. The BMI according to the Indian standard was normal, but when the data was compared with the International standard malnutrition in both sexes was noticed in childhood. Boys remained undernourished after adolescence, while girls reached the normal growth patterns.