The neuronal ceroid lipofuscinoses (NCLs) constitute a group of rare and fatal autosomal pediatric neurodegenerative disorders. The most prevalent subtype, CLN3, is characterized by a mutation in the CLN3 gene that encodes for the CLN3 protein. No treatment options for this disease exist. Although common pathological hallmarks have been identified, the pathophysiology of CLN3 disease is poorly understood, limiting pharmacological target identification. These hallmarks include the accumulation of lipofuscin and subunit c of mitochondrial ATP synthase, mitochondrial dysfunction, and attenuated Bcl-2 expression. Herein, we report the synthesis and characterization of strategically designed bicyclic analogues of the bioisosteric non-opioid analgesics Flupirtine and Retigabine, previously shown to exhibit neuroprotective effects. Metabolic action on the parent structures leads to the formation of reactive diamine/diimine intermediates that result in adverse effects, including hepatotoxicity. 1H-benzo[d]imidazoles incapable of forming the known toxicophore demonstrate enhanced protective effects in a highly phenotypic CLN3 patient-derived induced pluripotent stem cell (iPSC) model. Selected lead compounds 9b and 38b afford significant protective effects and have a mechanism of action to activate autophagy which results in the capability of rescuing a CLN3 disease hallmark, the accumulation of subunit c of mitochondrial ATP synthase. Furthermore, both compounds possess ‘drug-like’ pharmacokinetics and represent promising compounds for CLN3 drug discovery.

Colorectal cancer (CRC) remains a leading cause of cancer-related deaths worldwide, despite advancements in diagnosis. The main reason for this is that many newly diagnosed CRC patients will suffer from metastasis to other organs. Thus, the development of new therapies is of critical importance. Claudin-1 protein is a component of tight junctions in epithelial cells, including those found in the lining of the colon. It plays a critical role in the formation and maintenance of tight junctions, which are essential for regulating the passage of molecules between cells. In CRC, claudin-1 is often overexpressed, leading to an increase in cell adhesion, which can contribute to the development and progression of the disease. Studies show that high levels of claudin-1 are associated with poor prognosis in CRC patients and targeting claudin-1 may have therapeutic potential for the treatment of CRC. Previously, we have identified a small molecule that inhibits claudin-1 dependent CRC progression. Reported herein are our lead optimization efforts around this scaffold to identify the key SAR components and the discovery of a key new compound that exhibits enhanced potency in SW620 cells.

Neuronal ceroid lipofuscinosis type 6 (CLN6) is a fatal, autosomal recessive neurodegenerative disorder characterized by cognitive/motor impairment, vision loss, as well as neuronal loss and gliosis in the brain, and premature death. Onset typically occurs in childhood. No approved pharmacological treatments exist that halt or reverse disease progression. A novel flupirtine benzyl carbamate was orally administered to male and female Cln6^nclf mice from 4 to 28 weeks of age to evaluate its neuroprotective and antispastic effects. Drug treatment produced significant, sex-dependent phenotypic improvements. Treated mice of both sexes exhibited reduced hindlimb spasticity, but only treated males demonstrated diminution in locomotor hyperactivity and recovery of visuospatial performance. In the brains of male and female Cln6^nclf mice, flupirtine benzyl carbamate significantly decreased astrocytosis, microgliosis and mitochondrial ATP synthase subunit C (SCMAS) accumulation, increased neuronal marker expression and reduced the number of TUNEL-positive cells. The treatment failed to rescue photoreceptor loss or clear retinal SCMAS storage. These outcomes result in distinct sex-specific differences in neuronal vulnerability and drug responsiveness. Overall, these findings demonstrate that flupirtine benzyl carbamate diminishes key motor, visual and pathological deficits in CLN6 disease, highlighting its promise as a potential disease-modifying therapy for CLN6 in humans despite sex-specific differences.