TOR2A Variants in Blepharospasm.

Background: Genetic factors have been implicated in the pathogenesis of blepharospasm (BSP), a dystonia characterized by excessive blinking and involuntary eyelid closure. Previous research identified a co-segregating deleterious TOR2A variant (GRCh38/hg38, NC_000009.12: g.127733410G>A, NM_001085347.3:c.568C>T, p. Arg190Cys) in three subjects with BSP and three carriers within a multi-generation pedigree. Other TOR2A variants have been reported in patients with dystonia. Methods: Sanger sequencing was used to screen a cohort of 307 subjects with isolated BSP or BSP-plus dystonia affecting additional anatomical segments (BSP+). We also utilized computational tools to uniformly assess the deleteriousness and potential pathogenicity of previously reported TOR2A variants. Results: There were no highly deleterious TOR2A variants in the coding or contiguous splice site regions of TOR2A within our cohort of 307 subjects. Discussion: Highly deleterious variants in TOR2A are rare in patients with BSP/BSP+ phenotypes. Highlights: Over 300 patients with BSP were screened for variants in TOR2A, a TOR1A (DYT1) homologue. No highly deleterious variants were identified in our cohort. The role of TOR2A in BSP and other forms of dystonia remains indeterminant.

Upregulated expression of a TOR2A gene product-salusin-ß in the paraventricular nucleus enhances sympathetic activity and cardiac sympathetic afferent reflex in rats with chronic heart failure induced by coronary artery ligation.

AIM: Enhanced cardiac sympathetic afferent reflex (CSAR) promotes sympathetic hyperactivation in chronic heart failure (CHF). Salusin-ß is a torsin family 2 member A (TOR2A) gene product and a cardiovascular active peptide closely associated with cardiovascular diseases. We aimed to determine the roles of salusin-ß in the paraventricular nucleus (PVN) in modulating enhanced CSAR and sympathetic hyperactivation in rats with CHF induced by coronary artery ligation and elucidate the underlying molecular mechanisms. METHODS: CSAR was evaluated based on the responses of mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) to the epicardial administration of capsaicin in rats under anesthesia. RESULTS: Salusin-ß protein expression was upregulated in the PVN of the CHF compared with sham-operated rats. Salusin-ß microinjection into the PVN dose-dependently increased MAP and RSNA and enhanced CSAR, while anti-salusin-ß IgG exerted opposite effects. The effect of salusin-ß was inhibited by reactive oxygen species (ROS) scavenger or NAD(P)H oxidase inhibitor but promoted by superoxide dismutase inhibitor. The effect of anti-salusin-ß IgG was interdicted by nitric oxide (NO) synthase inhibitor. Furthermore, chronic salusin-ß gene knockdown in PVN attenuated CSAR, reduced sympathetic output, improved myocardial remodeling and cardiac function, decreased NAD(P)H oxidase activity and ROS levels, and increased NO levels in the CHF rats. CONCLUSION: Increased salusin-ß activity in the PVN contributes to sympathetic hyperactivation and CSAR in CHF by inhibiting NO release and stimulating NAD(P)H oxidase-ROS production. Reducing endogenous central salusin-ß expression might be a novel strategy for preventing and treating CHF in the future.

Saluisn-ß contributes to endothelial dysfunction in monocrotaline-induced pulmonary arterial hypertensive rats.

BACKGROUND: The endothelial dysfunction and the consequent attenuated pulmonary vasodilatation are the major causes of elevated pulmonary arterial resistance and pressure in pulmonary arterial hypertension (PAH). Current study aimed to explore the effects of a TOR2A gene product, salusin-ß, on endothelium-dependent vascular relaxation and the progression of PAH in monocrotaline (MCT)-induced PAH rats as well as the relevant signaling pathway. METHODS: Acetylcholine (ACh)-induced dose-dependent relaxation was used to evaluate the endothelium-dependent vasodilatation function. RESULTS: The salusin-ß level in plasma and pulmonary artery (PA) in MCT-PAH rats were significantly increased, while the ACh-induced endothelium-dependent vasodilatation was attenuated. After salusin-ß incubation or overexpression of salusin-ß gene, the endothelium-dependent relaxation was further deteriorated, while anti-salusin-ß IgG incubation or knockdown of salusin-ß improved it in PAH rats. The superoxide anions scavenger NAC or the antioxidant apocynin inhibited the effect of salusin-ß, while the SOD inhibitor DETC further enhanced it. The nitric oxide (NO) synthase inhibitor L-NAME almost blocked the effect of anti-salusin-ß IgG. Silencing of salusin-ß in PAH rats decreased right ventricular (RV) systolic pressure, RV hypertrophy index, NAD(P)H oxidase activity and ROS level, and increased the eNOS activity and NO level of PA. Overexpression of salusin-ß played opposite roles. CONCLUSIONS: The elevated saluisn-ß level in PAH rats plays important roles in the reduction of endothelium-dependent vasodilatation and participates in the progression of PAH through stimulating NAD(P)H oxidase-ROS production and inhibiting eNOS-NO release.