Endothelial-Mesenchymal Transition in Heart Failure With a Preserved Ejection Fraction: Insights Into the Cardiorenal Syndrome.

BACKGROUND: The management of clinical heart failure with a preserved ejection fraction (HFpEF) is often complicated by concurrent renal dysfunction, known as the cardiorenal syndrome. This, combined with the notable lack of evidence-based therapies for HFpEF, highlights the importance of examining mechanisms and targetable pathways in HFpEF with the cardiorenal syndrome. METHODS: HFpEF was induced in mice by uninephrectomy, infusion of d-aldosterone (HFpEF; N=10) or saline (Sham; N=8), and given 1% NaCl drinking water for 4 weeks. Renal fibrosis and endothelial-mesenchymal transition (endo-MT) were evident once HFpEF developed. Human aortic endothelial cells were treated for 4 days with 10% serum obtained from patients with chronically stable HFpEF with the cardiorenal syndrome (N=12) and compared with serum-treated human aortic endothelial cells from control subjects (no cardiac/renal disease; N=12) to recapitulate the in vivo findings. RESULTS: Kidneys from HFpEF mice demonstrated hypertrophy, interstitial fibrosis (1.9-fold increase; P<0.05) with increased expression of endo-MT transcripts, including pdgfrß (platelet-derived growth factor receptor ß), snail, fibronectin, fsp1 (fibroblast-specific protein 1), and vimentin by 1.7- (P=0.004), 1.7- (P=0.05), 1.8- (P=0.005), 2.6- (P=0.001), and 2.0-fold (P=0.001) versus Sham. Immunostaining demonstrated co-localization of CD31 and ACTA2 (actin α2) in kidney sections suggesting evidence of endo-MT. Similar to the findings in HFpEF mice, comparable endo-MT markers were also significantly elevated in human aortic endothelial cells treated with serum from patients with HFpEF compared with human aortic endothelial cells treated with serum from control subjects. CONCLUSIONS: These translational findings demonstrate a plausible role for endo-MT in HFpEF with cardiorenal syndrome and may have therapeutic implications in drug development for patients with HFpEF and concomitant renal dysfunction.

Sympathetic Regulation of the NCC (Sodium Chloride Cotransporter) in Dahl Salt-Sensitive Hypertension.

Increased sympathoexcitation and renal sodium retention during high salt intake are hallmarks of the salt sensitivity of blood pressure. The mechanism(s) by which excessive sympathetic nervous system release of norepinephrine influences renal sodium reabsorption is unclear. However, studies demonstrate that norepinephrine can stimulate the activity of the NCC (sodium chloride cotransporter) and promote the development of SSH (salt-sensitive hypertension). The adrenergic signaling pathways governing NCC activity remain a significant source of controversy with opposing studies suggesting a central role of upstream α1- and ß-adrenoceptors in the canonical regulatory pathway involving WNKs (with-no-lysine kinases), SPAK (STE20/SPS1-related proline alanine-rich kinase), and OxSR1 (oxidative stress response 1). In our previous study, α1-adrenoceptor antagonism in norepinephrine-infused male Sprague-Dawley rats prevented the development of norepinephrine-evoked SSH in part by suppressing NCC activity and expression. In these studies, we used selective adrenoceptor antagonism in male Dahl salt-sensitive rats to test the hypothesis that norepinephrine-mediated activation of the NCC in Dahl SSH occurs via an α1-adrenoceptor dependent pathway. A high-salt diet evoked significant increases in NCC activity, expression, and phosphorylation in Dahl salt-sensitive rats that developed SSH. Increases were associated with a dysfunctional WNK1/4 dynamic and a failure to suppress SPAK/OxSR1 activity. α1-adrenoceptor antagonism initiated before high-salt intake or following the establishment of SSH attenuated blood pressure in part by suppressing NCC activity, expression, and phosphorylation. Collectively, our findings support the existence of a norepinephrine-activated α1-adrenoceptor gated pathway that relies on WNK/SPAK/OxSR1 signaling to regulate NCC activity in SSH.

Treatment of Patients with Vocal Fold Atrophy and Comorbid Essential Voice Tremor: Long-Term Injection Augmentation Outcomes After Successful Diagnostic Vocal Fold Injection Augmentation.

OBJECTIVE: Vocal fold injection augmentation (VFIA) is employed diagnostically for patients with subtle glottic insufficiency. Its use in patients with both vocal fold atrophy and benign essential voice tremor (EVT) has been reported but not after durable augmentation. This study intends to evaluate the success of durable VFIA using either autologous fat or calcium hydroxylapatite in patients with both vocal fold atrophy and comorbid EVT. METHODS/DESIGN: Retrospective review. Subjects included demonstrated subtle glottic insufficiency from true vocal fold atrophy and comorbid EVT with no other vocal fold pathology. Voice Handicap Index (VHI-10), aerodynamic data including subglottic pressure and airflow, and the tremor scoring scale were evaluated before diagnostic VFIA with carboxymethylcellulose and after durable VFIA with calcium hydroxylapatite or autologous fat. RESULTS: Seven patients met inclusion criteria. Six subjects went on to durable VFIA. Three of six demonstrated meaningful improvement in the VHI-10 score. Subglottic pressure improved significantly in those subjects with meaningful VHI-10 improvement compared to those that did not. The tremor did not resolve completely in any subject, but patient satisfaction and function was improved in four of the six. CONCLUSIONS: VFIA for EVT in the setting of true vocal fold atrophy appears to offer benefit and may be an alternative treatment pathway for EVT patients. More than half of the subjects who underwent durable VFIA after successful diagnostic VFIA reported improvement in their communication despite inconsistent objective outcomes. Subglottic pressure improved significantly in half of the subjects who also reported a substantive improvement in their VHI-10.

Sympathetic regulation of NCC in norepinephrine-evoked salt-sensitive hypertension in Sprague-Dawley rats.

Salt sensitivity of blood pressure is characterized by inappropriate sympathoexcitation and renal Na+ reabsorption during high salt intake. In salt-resistant animal models, exogenous norepinephrine (NE) infusion promotes salt-sensitive hypertension and prevents dietary Na+-evoked suppression of the Na+-Cl- cotransporter (NCC). Studies of the adrenergic signaling pathways that modulate NCC activity during NE infusion have yielded conflicting results implicating α1- and/or ß-adrenoceptors and a downstream kinase network that phosphorylates and activates NCC, including with no lysine kinases (WNKs), STE20/SPS1-related proline-alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1). In the present study, we used selective adrenoceptor antagonism in NE-infused male Sprague-Dawley rats to investigate the differential roles of α1- and ß-adrenoceptors in sympathetically mediated NCC regulation. NE infusion evoked salt-sensitive hypertension and prevented dietary Na+-evoked suppression of NCC mRNA, protein expression, phosphorylation, and in vivo activity. Impaired NCC suppression during high salt intake in NE-infused rats was paralleled by impaired suppression of WNK1 and OxSR1 expression and SPAK/OxSR1 phosphorylation and a failure to increase WNK4 expression. Antagonism of α1-adrenoceptors before high salt intake or after the establishment of salt-sensitive hypertension restored dietary Na+-evoked suppression of NCC, resulted in downregulation of WNK4, SPAK, and OxSR1, and abolished the salt-sensitive component of hypertension. In contrast, ß-adrenoceptor antagonism attenuated NE-evoked hypertension independently of dietary Na+ intake and did not restore high salt-evoked suppression of NCC. These findings suggest that a selective, reversible, α1-adenoceptor-gated WNK/SPAK/OxSR1 NE-activated signaling pathway prevents dietary Na+-evoked NCC suppression, promoting the development and maintenance of salt-sensitive hypertension.

Evaluation of a Shorter Follow-up Time to Capture Benefit of a Trial Vocal Fold Augmentation.

OBJECTIVE: Trial vocal fold injection (TVFI) is employed diagnostically for patients with subtle glottic insufficiency to explore potential for improvement. Clinical experience demonstrates the time to and length of peak benefit of the TVFI is variable. Previous studies collected data 4 weeks or more after TVFI. The aim of this study was to compare subjectively successful and unsuccessful TVFI patient groups. It is hypothesized that patients with subjectively reported success will also have significant improvements in Voice Handicap Index-10 (VHI-10), phase closure percentage, and aerodynamic measures 2 weeks after trial augmentation. METHODS/DESIGN: Subjects with glottic insufficiency were included in this retrospective review if they underwent office-based, per-oral vocal fold injection augmentation specifically for trial purposes. Patients were divided into "successful" and "unsuccessful" groups based on their subjective experience during the 2-week post-TVFI period. VHI-10, subjective report, phase closure evaluation using frame-by-frame analysis, and aerodynamic data were collected pre- and 2 weeks post-TVFI. RESULTS: Of the subjects, 15 of 23 (65%) reported a successful subjective improvement of their symptom, whereas 8 (35%) were unsuccessful (only partial improvement or no improvement). The number of subjects with an improvement in VHI-10 by 5 or more points was not significantly different between groups. The number of subjects that demonstrated complete, long phase closure was significantly higher in the successful group (P = 0.021). CONCLUSIONS: The understanding of how to more precisely determine the success of TVFI remains incomplete. Subjective improvement of successful TVFI was captured with basic clinical questioning, yet the VHI-10 was unable to confidently demonstrate this reported success 2 weeks after TVFI.