Tau-tubuline kinases (TTBK) are a family of serine/threonine and tyrosine kinases recently discovered and implicated in the phosphorylation of important substrates such as tau, tubuline or TDP-43. Its two homologs, TTBK1 and TTBK2, show different expression patterns and different involvements in physiological mechanisms of great importance such as mitosis, ciliogenesis and neurotransmission. Their phosphorylation activity has also linked them to the development of neurodegenerative diseases like Alzheimer's disease, amyotrophic lateral sclerosis or spinocerebellar ataxia type 11. There are currently only three inhibitors of these kinases described in the literature. This review intends to give an overview of the structure, expression, physiological and pathological mechanisms of both kinases as well as an extended analysis on the molecules that can inhibit them. The final analysis of all this information led us to propose TTBK1 as a new target for the treatment of neurodegenerative diseases and its selective inhibitors as potential effective drugs for the treatment of these severe unmet disorders.

The unprecedent situation generated by the COVID-19 global emergency has prompted us to actively work to fight against this pandemic by searching for repurposable agents among FDA approved drugs to shed light into immediate opportunities for the treatment of COVID-19 patients. In the attempt to proceed toward a proper rationalization of the search for new antivirals among approved drugs, we carried out a hierarchical in silico/in vitro protocol which successfully combines virtual and biological screening to speed up the identification of host-directed therapies against COVID-19 in an effective way. To this end a multi-target virtual screening approach focused on host-based targets related to viral entry, followed by the experimental evaluation of the antiviral activity of selected compounds, has been carried out. As a result, five different potentially repurposable drugs interfering with viral entry—cepharantine, clofazimine, metergoline, imatinib and efloxate—have been identified.

A potent cell division cycle 7 (CDC7) kinase inhibitor, known as PHA-767491, has been described to reduce the transactive response DNA binding protein of 43 KDa (TDP-43) phosphorylation in vitro and in vivo, which is one of the main proteins found to aggregate and accumulate in the cytoplasm of motoneurons in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) patients. However, the main drawback of this compound is its low permeability to the central nervous system (CNS), limiting its use for the treatment of neurological conditions. In this context, the use of drug delivery systems like nanocarriers has become an interesting approach to improve drug release to the CNS. In this study, we prepared and characterized biodegradable nanoparticles in order to encapsulate PHA-767491 and improve its permeability to the CNS. Our results demonstrate that poly (lactic-co-glycolic acid) (PLGA) nanoparticles with an average radius between 145 and 155 nm could be used to entrap PHA-767491 and enhance the permeability of this compound through the blood–brain barrier (BBB), becoming a promising candidate for the treatment of TDP-43 proteinopathies such as ALS.