LRRC8/VRAC anion channels are required for late stages of spermatid development in mice.

Spermatogenesis is a highly complex developmental process that occurs primarily in seminiferous tubules of the testes and requires additional maturation steps in the epididymis and beyond. Mutations in many different genes can lead to defective spermatozoa and hence to male infertility. Some of these genes encode for ion channels and transporters that play roles in various processes such as cellular ion homeostasis, signal transduction, sperm motility, and the acrosome reaction. Here we show that germ cell-specific, but not Sertoli cell-specific, disruption of Lrrc8a leads to abnormal sperm and male infertility in mice. LRRC8A (leucine-rich repeat containing 8A) is the only obligatory subunit of heteromeric volume-regulated anion channels (VRACs). Its ablation severely compromises cell volume regulation by completely abolishing the transport of anions and osmolytes through VRACs. Consistent with impaired volume regulation, the cytoplasm of late spermatids appeared swollen. These cells failed to properly reduce their cytoplasm during further development into spermatozoa and later displayed severely disorganized mitochondrial sheaths in the midpiece region, as well as angulated or coiled flagella. These changes, which progressed in severity on the way to the epididymis, resulted in dramatically reduced sperm motility. Our work shows that VRAC, probably through its role in cell volume regulation, is required in a cell-autonomous manner for proper sperm development and explains the male infertility of Lrrc8a-/- mice and the spontaneous mouse mutant ébouriffé.

Real world data of a German Parkinson's disease population: effectiveness and safety of safinamide in routine clinical practice.

BACKGROUND: Parkinson's Disease (PD) is a common progressive neurodegenerative disorder that leads to an imbalance of various neurotransmitters and affects cognitive, motor and non-motor function. Safinamide inhibits monoamine oxidase B in a highly selective and reversible manner and beyond that has anti-glutamatergic properties, with positive effects on motor and non-motor symptoms. The aim of the study was to obtain data about the effectiveness and tolerability of safinamide under routine clinical practice conditions in unselected patients with Parkinson's disease (PD). METHODS: A post-hoc analysis of the German cohort of the European SYNAPSES study (a non-interventional cohort study). Patients were treated with safinamide as an add-on to levodopa and followed-up for 12 months. Analyses were done in the total cohort and in clinically relevant subgroups (patients older than 75 years; with relevant comorbidities; with psychiatric conditions). RESULTS: 181 PD patients were eligible for analysis. Motor symptoms included bradykinesia (76.8%), rigidity (77.3%), tremor (58.6%), and postural instability (27.1%). Non-motor symptoms were reported in 161 patients (89.0%), mainly psychiatric symptoms (43.1%), sleep disorders (35.9%), fatigue (30.9%), and pain (27.6%). 28.7% of patients were aged 75 years or older, 84.5% had relevant comorbidities, and 38.1% had psychiatric conditions. During treatment, the rate of motor complications decreased from 100.0% to 71.1%. UPDRS scores improved under safinamide, with a clinically important effect in 50% in the total score and 45% in the motor score. The positive effect on motor complications occurred already at the 4-month visit and was maintained over 12 months. At least one adverse event (AE)/adverse drug reaction (ADR) was reported by 62.4%/25.4% of patients, AEs were generally mild or moderate, and completely resolved. Only 5 (1.5%) AEs had a definite relationship to safinamide. CONCLUSIONS: The benefit-risk profile of safinamide was favourable and consistent with the total cohort of the SYNAPSES study. In the subgroups, findings were congruent with the total population, which allows the clinical utilisation of safinamide also in more vulnerable patient groups.