Oligodendrocyte Dysfunction in Tauopathy: A Less Explored Area in Tau-Mediated Neurodegeneration.

Aggregation of the microtubule-associated protein tau (MAPT) is the hallmark pathology in a spectrum of neurodegenerative disorders collectively called tauopathies. Physiologically, tau is an inherent neuronal protein that plays an important role in the assembly of microtubules and axonal transport. However, disease-associated mutations of this protein reduce its binding to the microtubule components and promote self-aggregation, leading to formation of tangles in neurons. Tau is also expressed in oligodendrocytes, where it has significant developmental roles in oligodendrocyte maturation and myelin synthesis. Oligodendrocyte-specific tau pathology, in the form of fibrils and coiled coils, is evident in major tauopathies including progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick's disease (PiD). Multiple animal models of tauopathy expressing mutant forms of MAPT recapitulate oligodendroglial tau inclusions with potential to cause degeneration/malfunction of oligodendrocytes and affecting the neuronal myelin sheath. Till now, mechanistic studies heavily concentrated on elucidating neuronal tau pathology. Therefore, more investigations are warranted to comprehensively address tau-induced pathologies in oligodendrocytes. The present review provides the current knowledge available in the literature about the intricate relations between tau and oligodendrocytes in health and diseases.

Designing one-compartment H2O2 fuel cell using electroactive phenalenyl-based [Fe2(hnmh-PLY)3] complex as the cathode material.

The sustainable chemical energy of H2O2 as a fuel and an oxidant in an advantageous single-compartment fuel cell design can be converted into electric energy, which requires molecular engineering to design suitable cathodes for lowering the high overpotential associated with H2O2 reduction. The present work covers the synthesis and structural characterization of a novel cathode material, [FeIII2(hnmh-PLY)3] complex, 1, designed from a PLY-derived Schiff base ligand (E)-9-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazineyl)-1H-phenalen-1-one, hnmh-PLYH2. Complex 1, when coated on the surface of a glassy carbon electrode (GC-1) significantly catalyzed the reduction of H2O2 in an acidic medium. Therefore, a complex 1 modified glassy carbon electrode was employed in a one-compartment H2O2 fuel cell operated in 0.1 M HCl with Ni foam as the corresponding anode to produce a high open circuit potential (OCP) of 0.65 V and a peak power density (PPD) of 2.84 mW cm-2. CV studies of complex 1 revealed the crucial participation of two Fe(III) centers for initiating H2O2 reduction, and the role of coordinated redox-active PLY units is also highlighted. In the solid state, the π-conjugated network of coordinating (hnmh-PLY) ligands in complex 1 has manifested interesting face-to-face π-π stacking interactions, which have helped the reduction of the complex and facilitated the overall catalytic performance.