Therapeutic Potential of Melatonin, Erythropoietin, and TRPV4 Antagonism in a Preclinical Model of Genetic Hydrocephalus
Symptomatic hydrocephalus is a neuropathological disorder of cerebrospinal fluid (CSF) homeostasis characterized by abnormal accumulation of CSF and progressive ventricular enlargement. Current treatment relies primarily on surgical CSF diversion, which is invasive and associated with substantial rates of treatment failure and surgical revisions. Congenital hydrocephalus can be caused by genetic pathologies; for example, a point mutation in the Meckel-Gruber type 3, Tmem67, gene produces a congenital hydrocephalus phenotype in rats, characterized by progressive ventriculomegaly. Here, we evaluated a combinatorial cocktail therapeutic strategy consisting of erythropoietin (EPO), melatonin (MLT), and the transient receptor potential vanilloid 4 (TRPV4) antagonist, RN1734 (RN), in the Tmem67-- rat model of congenital hydrocephalus. Magnetic Resonance Imaging (MRI) demonstrated marked progression of ventriculomegaly in untreated Tmem67-- rats between postnatal (P) 7 and P15. RN1734 and EPO+MLT+RN1734 (triple therapy) from P7-P14 prevented further ventricular expansion. Hydrocephalus is associated with structural disruption of the periventricular white matter (WM) and ependymal lining (EL), accompanied by regionally increased TLR4 and NLRP3-associated inflammatory signaling. EPO+MLT, RN1734, or triple therapy differentially attenuated these inflammatory responses. The triple combination reduced both TLR4 and NLRP3 protein abundance within the affected periventricular region and ameliorated the structural alterations. These findings support a combined therapeutic approach that addresses ventricular pathology, inflammation and periventricular structural consequences of congenital hydrocephalus.