Jawaharlal Nehru Centre For Advanced Scientific Research

Huntington's disease (HD) is caused by the expansion of poly-glutamine repeats in the Huntingtin (Htt) gene and is associated with a wide variety of motor and physiological (sleep, metabolism, etc.) perturbations. Studies from diverse model organisms have proposed that modulation of autophagy (a key protein homeostatic pathway) can mitigate the toxic effects of mutant HTT protein. However, consistent changes are not observed across studies, and the improvements in phenotypes can be associated with changes in specific circuits/neurons affected by the mutant HTT protein. They suggest that not all neurons respond effectively to autophagy modulation. Hence, it remains to be understood whether diverse circuits/neurons affected by mutant HTT protein respond effectively to this intervention. Using a genetic approach, we expressed mutant HTT protein independently in diverse sets of neurons in male Drosophila melanogaster and asked whether genetic modulation of autophagy pathway through Atg8a overexpression can mitigate the toxic effect of mutant HTT protein. We found that in male flies, not all neurons/circuits expressing mutant HTT protein respond effectively to ATG8a protein. Circadian neurons and neurons regulating carbohydrate and lipid metabolism (Dilp2 ^+ve) showed improvement, while motor and neurons responding to temperature changes showed no improvement. Using cellular markers we also showed that these phenotypes can be attributed to specific changes in mutant HTT and Ref(2)P proteins (autophagy marker). Our study suggests that not all circuits respond effectively to autophagy modulation and suggests a potential cause for low success of autophagy modulators in clinical trials..

Beta actin is a cytoskeletal protein that contributes to a wide range of cellular processes. Here we generated beta actin reporter knock-in in BJNhem20 human embryonic stem cell line by CRISPR Cas9 gene editing. The reporter mEGFP is integrated at the beta actin locus, tagging the N-terminal of the protein via a linker. The reporter line is a valuable tool to study beta actin dynamics during cellular process in human embryonic stem cells and to track cells by live imaging.

In the present work, DFT/TD-DFT methods have been implemented to study the theor. concept of how a change in aromaticity supports the presence of the ESIPT process.The representative mol. used was 2,2′-bipyridyl-3,3′-diol-5,5′-dicarboxylic acid Et ester (BP(OH)₂DCEt), consisting of a double proton transfer via (N-H) intramol. hydrogen bonding.The solvent effect on the ESIPT process was also investigated with the help of polar Water (H₂O) and non-polar Cyclohexane (CYH) solvent.It was observed that intramol. hydrogen bonding was strengthening in the S₁ state, which was more prominent for polar solvents.MCI aromaticity index explained the decrease in stability of mols. upon excitation.Further charge redistribution, NICS(1)_zz anal. and HOMA index of the mol. reinforced the occurrence of the ESIPT process supported by the aromatic behavior of the mol.Furthermore, the stability of the mol. in S₀ and S₁ states as enol and keto form resp. was confirmed by PES plots.