BACKGROUND: Upregulation of the RNA-binding protein HuR (human antigen R) has been reported in patients with chronic kidney disease (CKD), but its pathogenic role remains incompletely understood. We hypothesized that HuR promotes renal and vascular injury in hypertensive CKD and that pharmacological inhibition of HuR attenuates disease progression. We therefore investigated the role of HuR in deoxycorticosterone acetate (DOCA) plus Ang II (angiotensin II)-induced CKD and evaluated the therapeutic efficacy of the HuR inhibitor, KH3 . METHODS: Male mice underwent uninephrectomy followed by DOCA+Ang II infusion with 1% NaCl in drinking water and were treated with KH3 or vehicle for 3 weeks. Control mice received saline without DOCA or Ang II. RESULTS: DOCA+Ang II markedly increased HuR expression in circulating exosomes and kidney tissues, which was attenuated by KH3 treatment. KH3 reduced albuminuria, improved renal function, and attenuated kidney hypertrophy, glomerular, and tubulointerstitial fibrosis. These renoprotective effects were associated with reduced podocyte and tubular injury, decreased macrophage infiltration, and suppression of NF-κB (nuclear factor-kappa B) p65, Nox2 (NADPH oxidase 2), AKT (protein kinase B) phosphorylation, TGFβ1 (transforming growth factor β1), and Wisp1 (WNT1-inducible signaling pathway protein 1) signaling. KH3 also partially lowered arterial blood pressure in DOCA+Ang II–treated mice. Further studies in vascular smooth muscle cells and mesenteric resistance arteries suggested that HuR inhibition may suppress vascular profibrotic signaling associated with SGLT2 (sodium-glucose cotransporter 2). CONCLUSIONS: HuR is upregulated in renal and vascular tissues in DOCA+Ang II–induced CKD and contributes to renal inflammation, oxidative stress, fibrosis, and vascular dysfunction. Pharmacological inhibition of HuR attenuates renal and vascular injury, supporting HuR as a promising therapeutic target for CKD.
BACKGROUND: Abnormal mechanoreflex function from skeletal muscle significantly contributes to the heightened circulatory response during exercise in type 2 diabetes (T2DM). However, the underlying mechanisms remain unclear. We hypothesized that the abnormal cardiovascular responses in T2DM are mediated by mechanoreflex-induced exaggerations resulting from enhanced Piezo1-mediated mechanosensitivity of muscle afferents. METHODS: T2DM rats (Sprague-Dawley rats) were given a high-fat diet in combination with a low dose of streptozotocin. Using an in vivo decerebrated rat model and an ex vivo single-fiber recording preparation, we measured muscle mechanoreflex responses, mechanosensitivity of muscle afferents, and Piezo1-mediated responses. Piezo1 protein levels in the membrane fraction were detected by Western blotting in human embryonic kidney 293 (HEK293) cells. RESULTS: Blood pressure and sympathetic nerve activity responses to mechanoreflex activation, as well as group IV muscle afferent firing to mechanical stimulation and the Piezo1 agonist (Yoda1), were significantly greater in T2DM rats. More importantly, Piezo1 agonist-induced blood pressure changes and group IV afferent firing were significantly potentiated by administration of lipopolysaccharide, a gut-derived inflammatory endotoxin. Furthermore, lipopolysaccharide significantly increased Piezo1 protein in the cell membrane, which was attenuated by a PKA (protein kinase A) inhibitor. CONCLUSIONS: These findings suggest that activation of the lipopolysaccharide-Piezo1 pathway may contribute to enhanced responsiveness of group IV muscle afferents and may be associated with exaggerated circulatory responses to muscle mechanoreflex activation in T2DM.
BACKGROUND: The transcriptional mechanisms governing macrophage glutamine metabolism in pulmonary arterial hypertension remain incompletely understood. We investigated the role of ZEB1 (zinc finger E-box-binding homeobox 1)-mediated transcriptional regulation in macrophage metabolic reprogramming and the development of pulmonary arterial hypertension. METHODS: Clinical samples and multiomics data sets were analyzed to characterize ZEB1 expression in pulmonary arterial hypertension. Myeloid-specific ZEB1 conditional knockout mice were subjected to hypoxia-induced pulmonary hypertension. Transcriptomic sequencing, metabolomic profiling, chromatin immunoprecipitation-quantitative polymerase chain reaction, dual-luciferase reporter assays, and coimmunoprecipitation were integrated to define ZEB1-dependent molecular, metabolic, and inflammatory programs in pulmonary and bone marrow-derived macrophages. Therapeutic potential was further evaluated using pharmacological interventions and adenoviral ZEB1 silencing in monocrotaline-induced pulmonary hypertension in rats. RESULTS: ZEB1 was upregulated in pulmonary arterial hypertension and enriched in recruited disease-associated macrophages. Myeloid-specific ZEB1 deletion attenuated macrophage inflammation, pulmonary vascular remodeling, and right ventricular dysfunction. Mechanistically, ZEB1 bound the GLS (glutaminase) promoter and recruited BRD4 (bromodomain-containing protein 4), enhancing histone H3 lysine 27 acetylation at the GLS promoter and promoting GLS transcription and glutamine metabolic reprogramming. Restoration of GLS partially reversed the metabolic and inflammatory effects of ZEB1 deficiency. Pharmacological targeting of ZEB1, combined BRD4 and GLS inhibition, and adenoviral ZEB1 silencing ameliorated experimental pulmonary hypertension. CONCLUSIONS: ZEB1 promotes macrophage glutamine metabolic reprogramming by recruiting BRD4 and enhancing histone H3 lysine 27 acetylation-dependent GLS transcription. This ZEB1-driven metabolic program promotes macrophage inflammation and pulmonary vascular remodeling, identifying the ZEB1-BRD4-GLS regulatory axis as a potential therapeutic target in pulmonary arterial hypertension.
BACKGROUND: Catheter-based intravascular renal denervation produces modest, variable blood pressure reductions, partly because renal sympathetic nerves lie at variable depths within the periarterial adventitia and because accessory or early branching arteries are inaccessible to intraluminal catheters. We developed an extravascular renal denervation system (HyperQure) delivering circumferential radiofrequency energy from outside the artery and assessed its safety and efficacy. Here, we report the primary 3-month outcomes. METHODS: This prospective, multicenter, single-arm, first-in-human pilot trial enrolled 10 patients with resistant hypertension (office blood pressure ≥140/90 mm Hg and daytime ambulatory systolic blood pressure [SBP] ≥135 mm Hg despite ≥3 antihypertensive agents) across 7 Korean centers. All underwent bilateral extravascular renal denervation on stable antihypertensive regimens. The primary end point was 3-month change in 24-hour ambulatory SBP; safety outcomes were assessed through 3 months. RESULTS: All 10 patients (median age, 52.5 years; 7 men) completed follow-up. Seven patients (70%) had accessory or early branching arteries <3 mm typically ineligible for intravascular renal denervation; all were successfully ablated. Median 24-hour ambulatory SBP decreased by 25.0 mm Hg ( P =0.008) and median office SBP by 39.5 mm Hg ( P =0.002). Seven of 10 (70%) achieved office SBP <140 mm Hg despite a reduction in median antihypertensive burden from 6.0 to 4.5 agents. No major or procedure-related adverse events occurred; follow-up computed tomography angiography showed no vascular complications and renal function was preserved. CONCLUSIONS: Extravascular renal denervation using the HyperQure renal denervation System warrants evaluation in a larger controlled trial, particularly in patients with complex renal arterial anatomy.
BACKGROUND: The adrenal zona glomerulosa (zG) is the primary site of aldosterone synthesis. Inducible genetic tools are important for investigating zG cell function and fate in adult mice. This study aimed to generate and validate a tamoxifen-inducible, zG-specific aldosterone synthase–CreERT2 mouse model and investigate the zG-specific role of NPC1 (Niemann-Pick type C1) in aldosterone synthesis. METHODS: Aldosterone synthase-CreERT2 mice were generated by clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat–associated 9 knock-in of P2A (porcine teschovirus-1 2A peptide)-CreERT2 into the Cyp11b2 locus. Cre specificity and efficiency were validated by quantitative polymerase chain reaction, immunofluorescence, and lineage tracing. The model was then used to conditionally delete Npc1 in the zG. RESULTS: Cre expression and activity were confined to the zG. Heterozygous aldosterone synthase–CreERT2 mice showed normal adrenal morphology and hormone levels despite reduced Cyp11b2 expression. Homozygosity of the CreERT2 allele significantly reduced Cyp11b2 expression and aldosterone levels and increased renin in both sexes, indicating a gene-dosage effect. Lineage tracing confirmed the centripetal migration of zG cells to the zona fasciculata, which was faster in female mice. Strikingly, zG-specific Npc1 deletion reduced aldosterone in female mice under a normal-sodium diet, whereas increased renin and decreased aldosterone-to-renin ratio were observed in male mice under a high-sodium diet, indicating a sex-dependent effect. CONCLUSIONS: The aldosterone synthase–CreERT2 mouse provides a powerful and specific platform for spatiotemporally controlled dissection of zG biology, with the heterozygous line recommended for use to avoid Cre-associated dosage effects. Using this model, we identify a sex-dependent effect of zG-specific Npc1 deletion on aldosterone regulation, providing new insight into sex differences in adrenal physiology and aldosterone-related disorders.
