ABSTRACT Spironolactone (SP), a clinically used aldosterone antagonist, has been explored as an anti-HIV agent in models of HIV-1 latency for inducing transcriptional silencing of the viral reservoir. SP promotes the degradation of xeroderma pigmentosum group B (XPB) protein, a crucial component of transcription factor II H (TFIIH) required for RNA polymerase II transcriptional initiation. This study evaluated the impact of a long-acting formulation of SP on HIV replication within the context of antiretroviral therapy (ART) in the humanized mice model of HIV infection. The findings demonstrate that adding SP to ART accelerates viral decline and reduces expression of inflammation-related genes in human immune cells – genes often upregulated in chronic viral infections. Although SP treatment did not alter levels of cell-associated viral DNA, it led to a significant 4.4-fold decrease in systemic cell-associated viral RNA. This supports the role of XPB in HIV transcriptional regulation and advocates for incorporating transcriptional inhibitors like SP into primary HIV therapy. Additionally, SP treatment diminished markers of immune activation and inflammation, critical factors contributing to morbidity and mortality in individuals with chronic HIV infection. These results highlight SP’s potential to enhance HIV treatment by mitigating key aspects of viral persistence and associated immune challenges.

Controlled release 3D nanofiber scaffolds for fostering the anti-acne effect of spironolactone in an in vivo surgical testosterone-induced acne model.

The benefit of mineralocorticoid receptor blockade in the treatment of experimental autoimmune encephalomyelitis mice.

Background and ObjectivesDemyelinating diseases are neurologic disorders characterized by the loss of the myelin sheath and impaired regeneration. Retinoid X receptor γ (RXRγ) is a member of the nuclear receptor superfamily and plays a crucial role in oligodendrocyte biology and myelin formation. However, the clinical application of drugs targeting RXRγ for demyelinating diseases is limited. Selecting small-molecule drugs approved by the U.S. Food and Drug Administration (FDA) that have high binding activity to RXRγ may be an effective strategy for treating demyelinating disorders.MethodsWe used an online molecular docking tool to predict that spironolactone (SPIR), an FDA-approved drug, displays strong binding activity to RXRγ. Subsequently, we verified the impact of SPIR on oligodendrocyte precursor cell (OPC) differentiation and myelin sheath formation through in vitro OPC culture and pharmacologic experiments in mice. Furthermore, using genetic models with CRISPR-LSL-Cas9, we confirmed that the effect of SPIR on OPCs relies on RXRγ.ResultsIn this study, we identified that SPIR, an FDA-approved drug, functions as an RXRγ agonist in OPCs. RXRγ was identified as a crucial factor of myelin production. Its activation promotes the differentiation of OPCs and enhances myelin generation. We confirmed the specificity of SPIR's target, demonstrating that SPIR facilitates OPC differentiation and myelin generation in a RXRγ-dependent manner. Our findings not only identify the RXRγ agonist to promote OPC differentiation but also provide new experimental evidence for expanding the clinical indications of SPIR.DiscussionThe promotion of OPC differentiation by SPIR in animal models suggests its potential for treating demyelinating diseases.

Hyaluronic acid based light responsive long acting hydrogel for the intraocular delivery of spironolactone.

Toxicological profiling and diuretic potential of arbutin via aldosterone synthase gene inhibition.

Introduction: Obstructive sleep apnea (OSA) is characterized by repetitive obstruction in the upper airway leading to chronic intermittent hypoxia (IH). OSA is associated with increased cardiovascular morbidity with 70% of OSA individuals being obese. Previous studies suggest that mineralocorticoid receptor antagonists (MRAs) improve cardiac function. We investigated the impact of IH and obesity on coronary microvascular function and hypothesized that IH impairs coronary artery vascular reactivity, with MRAs, spironolactone (SPL), and finerenone (FIN), improving these effects. Methods: Male and female C57Bl/6J mice were fed a high-fat diet (HFD, 45% kcal of fat) or low-fat diet (LFD, 10% kcal of fat) for 10 weeks. Mice were then exposed to IH (12 cycles/hour at 6% FiO2 for 90 seconds per cycle) or room air (RA; 21% FiO2) for 12 hours per day over 16 weeks and treated with SPL, FIN or placebo mixed with the diet. Mean arterial blood pressure (MAP) was measured using the tail-cuff method. The left anterior descending coronary artery was harvested and examined for vascular reactivity in response to acetylcholine (ACh) and thromboxane A2 receptor agonist U46619. Results: MAP was increased in IH-HFD male mice, while MAP was unchanged in female mice. In males, IH and/or HFD augmented coronary vasoconstriction in response to U46619 and reduced ACh-mediated vasorelaxation. Meanwhile, in females, exacerbated vasoconstriction was observed only in the IH-HFD group and impaired vasorelaxation was shown in IH-placebo and IH-HFD groups. SPL and FIN normalized MAP in HFD, HFD-IH and LFD-IH male mice. In addition, FIN restored endothelium (Ach)-dependent relaxation in LFD-IH and HFD-IH male mice. FIN and SPL attenuated vasoconstriction only in LFD-IH group. However, in female mice, FIN or SPL did not ameliorate the enhanced vasoconstriction or the impaired vasorelaxation shown in the placebo corresponding groups. Conclusion: Findings suggest that males have a greater susceptibility to coronary dysfunction and hypertension associated with diet-induced obesity or long-term IH. Moreover, FIN, selective MRA, attenuated coronary dysfunction in IH-exposed mice, suggesting mineralocorticoid receptors as a promising therapeutic target to reduce cardiovascular consequences in OSA. NIH grants HL166617 and HL136386 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Introduction: Blood pressure-lowering medications can reduce or even reverse left ventricular (LV) hypertrophy and myocardial fibrosis induced by chronically elevated blood pressure. However, in patients with resistant hypertension (HPT), high blood pressure often remains unresponsive to anti-hypertensive treatment. Therefore, the search for novel therapeutic strategies that would help preserve or restore myocardial properties and, hence, LV function even under the effect of persistently elevated blood pressure has remained of significant importance. Hypothesis: Considering that a competitive mineralocorticoid receptor antagonist spironolactone (SL) could alleviate HPT-induced myocardial fibrosis, whereas a treatment with a heart rate-lowering drug ivabradine (IVA) was shown to mitigate the scale of concentric hypertrophy and LV dysfunction, it has been hypothesized that a combination of these two compounds might benefit myocardial properties and cardiac function even in the presence of chronically elevated blood pressure. Methods: Twenty male, 7-week-old Dahl salt-sensitive (DSS) rats were placed on a high-salt diet (8% NaCl) for 7 weeks to induce chronic, self-sustaining HPT. Then all HPT rats were switched back to a normal-salt diet (0.3% NaCl) and randomized in two experimental groups to receive ether a combined treatment (HPT-T) with IVA (10 mg/kg/day) and SL (20 mg/kg/day) or the vehicle only (HPT-V) for 8 weeks via intraperitoneal ALZET osmotic pumps. Ten age-matched male DSS rats fed a normal-salt diet only were used as control. Heart rate and peripheral blood pressure were evaluated every week in conscious rats for the duration of the study using a CODA tail-cuff plethysmography system. At the end of an experimental period, osmotic pumps were removed to terminate the treatment, and 1 week later, central (aortic) and cardiac hemodynamic parameters were assessed in isoflurane-anesthetized rats using a Millar micro-tip pressure catheter attached to a PowerLab data acquisition system. Subsequently, rats were euthanized, and their hearts were excised, weighed and processed to paraffin for histology and quantitative morphology. Statistical analysis was performed using Prism 6 software. Results: During 8 weeks of treatment, mean arterial pressure (MAP) had remained persistently elevated in both groups of HPT rats by ~27% (P≤0.001) compared to control, whereas heart rate had been solely reduced in HPT-T rats by ~38% (P≤0.001) and ~27% (P≤0.001) compared to HPT-V and control rats, respectively. After cessation of treatment, heart rate became similar in all rats, while the level of MAP remained significantly higher in HPT groups. The assessment of aortic (central) and cardiac hemodynamics revealed a marked reduction in central MAP (149.4±4.3 vs. 167.5±3.3 mmHg, P≤0.01) and peak systolic LV pressure (169.8±6.5 vs. 187.2±5.4 mmHg, P≤0.01) in rats from HPT-T group compared to HPT-V rats. Surprisingly, a decrease in central blood pressure detected in HPT-T animals coincided with an evident decline in LV contractility. The morphologic examination of the hearts revealed that chronic HPT did induce relatively comparable scale of LV hypertrophy (P≤0.001) and myocardial fibrosis (P≤0.01) in two HPT groups. However, in contrast to HPT-V group, the rats in HPT-T group showed a marked increase in myocardial density of CD68-positive monocytes/macrophages (228.8±12.5 vs 62.4±7.1 cells/mm 2 , P≤0.0001). Conclusion: Our findings demonstrate that a cotreatment of chronically HPT rats with IVA and SL did not improve myocardial tissue properties but led to a sustained decrease in LV and central blood pressure that was corresponded with myocardial inflammation and reduction in LV contractility. Supported by Camden Health Research Initiative This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Mineralocorticoid receptor antagonism improves corneal integrity in a rat model of limbal stem cell deficiency.

A fixed dose combination (FDC) product is the resulting product of a combination of more than one active pharmaceutical ingredients from different classes combined into a single dosage form. A total of 3 batches of amlodipine (ADB) and spironolactone (SPRN) have been formulated employing various excipients at different concentrations. Pre-compression studies such as angle of repose, bulk and tapped density, and post- compression evaluation such as: weight variation, hardness, friability. In-vitro release study were similarly evaluated using standard procedures. All the evaluation parameters such as weight variation, hardness, friability and in-vitro release study were within the official acceptable limits. The release of ADB was 58 % (2 % binder), 55.58 % (4 % binder) and 55.78 % (6 % binder) after 10 min and gradually increased to 100 % drug release before 30 min of study; while release of SPRN was 48.64 % (2 % binder), 52.83 % (4 % binder) and 33.32 % (6 % binder) after initial 10 min and achieved 100 % release after 20 min of study. The FDC formulation of ADB/SPRN into an oral solid dosage form (tablet) was successful. The results of the physicochemical properties evaluated show a promising novel formulation for possible fixed dose combination of these molecules in the management of hypertension.

Background/Objectives: Spironolactone (SP) has been used off-label in pediatrics since its approval, but its use is challenged by limited pharmacokinetic (PK) data in adults and especially in children. Methods: Physiologically based pharmacokinetic (PBPK) models for SP and its active metabolites, canrenone (CAN) and 7α thio-methyl spironolactone (TMS), in adults were developed. These models aim to enhance understanding of SP's PK and provide a basis for predicting PK and optimizing SP dosing in infants and neonates. Given SP's complex metabolism, we assumed complete conversion to CAN and TMS by CES1 enzymes, fitting CES1-mediated metabolism to the parent-metabolite model using PK data. We incorporated ontogeny for CES1 and CYP3A4 and other age-related physiological changes into the model to anticipate PK in the pediatric population. Results: The PBPK models for SP, CAN, and TMS accurately captured the observed PK data in healthy adults across various dosing regimens, including the impact of food on drug exposure. The pediatric PBPK model was evaluated using PK data from infants and neonates. Simulations indicate that 2.5 mg/kg in 6-month to 2-year infants and 2 mg/kg in 1-6-months infants matched the total unbound systemic exposure equivalent to the standard recommended daily maintenance dose of 100 mg in adults for treating edema. Conclusions: The developed PBPK model provides valuable insights for dosing decisions and optimizing therapeutic outcomes, especially in populations where clinical studies are challenging.

Background/Objectives: Spironolactone (SP), an aldosterone inhibitor widely used to treat androgen-dependent disorders such as acne, hirsutism, and alopecia, has demonstrated therapeutic potential in both oral and topical formulations. However, SP's low solubility and poor bioavailability in conventional formulations have driven the development of novel nanocarriers to enhance its efficacy. This review systematically examines recent advancements in SP-loaded nanocarriers, including lipid nanoparticles (LNPs), vesicular nanoparticles (VNPs), polymeric nanoparticles (PNPs), and nanofibers (NFs). Methods: A search strategy was developed, and the relevant literature was systematically searched using databases such as Scopus, PubMed, and Google Scholar. The review process, including screening, inclusion, and exclusion criteria, adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: A comprehensive analysis of 13 eligible research articles, corresponding to 15 studies, highlights key aspects such as encapsulation efficiency, stability, particle size, and in vitro and in vivo efficacy. Six studies focused on lipid nanoparticles (LNPs), including solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), which were found to improve SP's bioavailability and skin permeation. Another six studies investigated vesicular nanoparticles (VNPs), such as ethosomes and niosomes, demonstrating superior skin targeting and penetration capabilities. Two studies on polymeric nanoparticles (PNPs) showed effectiveness in delivering SP to hair follicles for the treatment of alopecia and acne. Additionally, one study on SP-loaded nanofibers indicated significant potential for topical rosacea therapy. Conclusions: SP-loaded nanocarrier systems represent promising advancements in targeted topical therapy. However, further clinical studies are required to optimize their safety, efficacy, and delivery mechanisms.

Obstructive sleep apnea (OSA), is characterized by intermittent hypoxia (IH), and is associated with increased cardiovascular mortality that may not be reduced by standard therapies. Inappropriate activation of the renin-angiotensin-aldosterone system occurs in IH, and mineralocorticoid receptor (MR) blockade has been shown to improve vascular outcomes in cardiovascular disease. Thus, we hypothesized that MR inhibition prevents coronary and renal vascular dysfunction in mice exposed to chronic IH. Human and mouse coronary vascular cells and male C57BL/6J mice were exposed to IH or room air (RA) for 12 hours/day for 3 days (in vitro) and 6 weeks with or without treatments with spironolactone (SPL) or hydrochlorothiazide (HTZ). In vitro studies demonstrated that IH increased MR gene expression in human and mouse coronary artery endothelial and smooth muscle cells. Exposure to IH in mice increased blood pressure, reduced coronary flow velocity reserve (CFVR), attenuated endothelium-dependent dilation, and enhanced vasoconstrictor responsiveness in coronary, but not renal arteries. Importantly, SPL treatment prevented altered coronary vascular function independent of blood pressure as normalization of BP with HTZ did not improve CFVR or coronary vasomotor function. These data demonstrate that chronic IH, which mimics the hypoxia-reoxygenation cycles of moderate-to-severe OSA, increases coronary vascular MR expression in vitro. It also selectively promotes coronary vascular dysfunction in mice. Importantly, this dysfunction is sensitive to MR antagonism by SPL, independent of blood pressure. These findings suggest that MR blockade could serve as an adjuvant therapy to improve long-term cardiovascular outcomes in patients with OSA.

Abstract Objective to evaluate different effects on blood pressure (BP) control in two treatment options spironolactone (SPIR) versus eplerenone (EPL) as an add-on therapy in resistant hypertensive (RAH) patients. Design and methods: We studied 208 patients with true RAH confirmed by the office and ambulatory BP monitoring (ABPM) despite the use of 3 antihypertensive medications including a calcium channel blocker, a blocker of the renin-angiotensin system, and a thiazide diuretic with maximally tolerated doses for at least 3 months. Patients were randomized into 2 groups throughout 12 weeks of once-daily treatment with SPIR (25–50 mg) or EPL (25-50 mg) in addition to their baseline triple-combination and then rotated with drugs. BP was measured in the office and by ABPM. Changes in laboratory tests were also studied. The predictive values of plasma aldosterone, active renin concentration (ARC), aldosterone-renin ratio (ARR), and serum potassium were analyzed to determine the antihypertensive response. Results There were no significant differences in the reduction of average office BP, average systolic 24-h, daytime, and nighttime BP by SPIR and EPL. SPIR reduced average diastolic 24-h BP by 7.3 mm Hg, diastolic daytime BP by 7.2 mm Hg, and diastolic nighttime BP by 7.5 mm Hg compared with a reduction of 5.6 mm Hg (P = 0.01), 5.6 mm Hg (P = 0.03) and 4.2 mm Hg (P = 0.0001) with EPL, respectively. Overall, 40.7 % RAH patients achieved targets of clinical BP and 24-h ABPM levels on SPIR and 33.3 % on EPL (Р = 0.002). After 12 weeks of treatment mean plasma potassium concentrations increased by 7.1 (P = 0.0001) on SPIR and by 5.0 % (Р = 0.0001) on EPL, but eGFR did not significantly change on the two drugs. Plasma aldosterone (β = 0.498, Р = 0.02) and ARC (β= -0.374, Р = 0.04) were predictors of the BP-lowering effect of SPIR and plasma aldosterone (β = 0.453, Р = 0.04) was a predictor of reduction BP for EPL in multivariate modeling. Breast pain or tenderness, changes in sex drive, and irregular menstrual cycles or spotting were more often by SPIR than by EPL (5.2 % vs 1.9 %, respectively, P = 0.04). Conclusions The greater antihypertensive effect of SPIR is related to aldosterone status, ARS level in resistant hypertension. EPL may be recommended for RAH patients who have high serum potassium levels that cannot tolerate spironolactone and for people with systolic resistant hypertension.

Abstract Deferring in-hospital initiation of guideline-recommended medications in HFrEF has a few chances they will be initiated ambulatory, especially in the case of coexisting HFrEF and chronic kidney disease (CKD). The aim was to investigate the safety of in-hospital initiation of SGLT2i with MRA therapy for patients hospitalized for HFrEF and CKD 3. Methods 88 patients with HFrEF (on top of standard therapy ACE-I/ARB, B-blockers) and CKD (baseline eGFR between 30 and 60 ml/min) were included in the study. The potassium (K), creatinine (C), uric acid (UA) levels were estimated at baseline and week 12. After biochemical evaluation, patients started on spironolactone (SP) treatment with a median dose of 20 mg daily (titrated) and dapagliflozin (D) with a dose of 10 mg daily (D+SP). Blood pressure (BP), K, and renal function (RF) were checked at weeks 1 (in-hospital), 2, 4, 6, 8, 12 (ambulatory), and more frequently as necessary. Results After the start of therapy D+SP mean eGFR decreased significantly at week 1 from 51.14±9.18 to 46.26±7.91 ml/min/1.73m2 (P<.0001) and at week 2 to 44.18±6.51 ml/min/1.73m2 (-2.08±1.2; P<.001). At week 4 mean eGFR decreased to 42.73±6.86 ml/min/1.73m2 (-1.45±1.1; P<.05). So, a significant decrease in eGFR was observed only during the first month with no significant decrease at 6 and 12 weeks after the start of therapy. Six patients (8%) experienced a significant decline in RF resulting in temporary withdrawal of SP. At week 2 mean K level increased significantly from 4.56±0.63 to 5.07±0.57 mmol/L (P<.001). At weeks 4, 6, 8 K levels remain stable. At week 12 mean K level decreased significantly compared with week 2 (to 4.92±0.57 mmol/L, P<.05). The incidences of severe hyperkalemia (HK) (K+≥6.0mmol/L) were in three patients < 2 %, and moderate HK (K 5.5–5.9 mmol/L) occurred in ten patients (11 %). Patients who experienced inpatient hyperkalemia had a significantly lower eGFR than patients without episodes of HK (38.70 vs. 55.21 mL/min/1.73 m2; P<.0001). Episodes of HK were predicted by baseline K≥5.0 mmol/L and eGFR≤40 ml/min/1.73m2. Additionally, there was a significant improvement in blood UA (-1,53±0.49 mg/dL, P<.01). By multivariate analysis older age, diabetes, low diastolic BP (<60 mm Hg), eGFR≤40 ml/min/1.73m2 at baseline were associated with decreased RF (0.378, P<.01; 0.632, P<.001; 0.771, P<.0001; 0.397, P<.01; respectively), whereas episodes of HK were predicted by baseline K≥5.0 mmol/L and eGFR≤40 ml/min/1.73m2 (0.785, P<.0001; 0.542, P<.001; respectively). Conclusion Initiation of SGLT2i with MRA in patients hospitalized for HFrEF and CKD 3 was mainly safe although it caused an early drop in eGFR. Importantly, a fall in eGFR was observed during the first month. Concern about the reduction in eGFR should be in older diabetic patients with eGFR≤40 and low diastolic blood pressure. Although hyperkalemia was common, the occurrence of it was predicted by baseline potassium level and eGFR.

In several countries, recent research has shown an increase in the prevalence of adult female acne (AFA), defined as the acne that appears in women aged over 25. This disease brings some particularities and challenges, such as a greater impact on quality of life (QoL) and chronicity. A negative impact on QoL has been observed, as well as anxiety, depression, anger, low self-esteem, and feelings of embarrassment and frustration. To quantify AFA's impact on QoL and the influence of two dermatological treatments. A prospective study including 40 women, aging from 25 to 44 years old, with mild-to-moderate acne was conducted. Participants underwent clinical, laboratory, and photographic evaluations. They were randomized into two treatment groups: group 1 - azelaic acid (AZA) 15% gel twice daily; group 2 - spironolactone (SPIRO) 100 mg/day and treated for 6 months. At baseline and at the end of treatments, a specific QoL questionnaire for acne, already translated and validated for Brazilian Portuguese (Acne-QoL-BR), was applied. It contains 19 questions allotted in four domains. Each item within a domain is scored from 0 to 6. The total score ranges from 0 to 114 and domains are distributed as follows: 0-30 (self-perception), 0-30 (role-emotional), 0-24 (role-social), 0-30 (acne-symptoms). Higher scores reflect better QoL. The mean age was 32.7 (SD: 5.42); 85% presented persistent acne. After treatment regardless of group, there was a significant improvement in total score and all domains' scores of acne QoL-BR (p < 0.001), with no difference between groups, despite one treatment being topical and the other systemic (p=0.918). Acne-QoL-BR is a useful tool for quantifying the impact of acne and should be used as an efficacy parameter in clinical trials.

Multivariate approaches for assessing dissolution behaviour of spironolactone. Dissolution-driven determination of polymorphic purity limits

The electrospinning process is an effective technique for creating micro- and nanofibers from synthetic and natural polymers, with significant potential for biomedical applications and drug delivery systems due to their high drug-loading capacity, large surface area, and tunable release times. Poly(L-lactic acid) (PLLA) stands out for its excellent thermo-mechanical properties, biodegradability, and bioabsorbability. Electrospun PLLA nanofibrous structures have been extensively investigated as wound dressings, sutures, drug delivery carriers, and tissue engineering scaffolds. This study aims to create and characterize electrospun PLLA membranes loaded with spironolactone (SP), mimicking active compounds of Ganoderma lucidum (GL), to develop a biodegradable patch for topical wound-healing applications. GL, a medicinal mushroom, enhances dermal wound healing with its bioactive compounds, such as polysaccharides and ganoderic acids. Focusing on GL extracts-obtained through green extraction methods-and innovative drug delivery, we created new fibers for wound-healing potential applications. To integrate complex mixtures of bioactive compounds into the fibers, we developed a prototype using a single pure substance representing the extract mixture. This painstaking work presents the results of the fabricating, wetting, moisture properties, material resilience, and full characterization of the product, providing a robust rationale for the fabrication of fibers imbued with more complex extracts.

Spironolactone (SPL) is an effective treatment for women acne, but other effects on skin biophysical properties remain to be investigated. The aim of the current study was to explore the effects of oral SPL used to treat women acne on skin biophysical properties, including hydration, transepidermal water loss (TEWL), skin surface lipid (SSL) levels, mechanical properties, color, pH, and pore size. Twenty-five Thai women with acne treated with oral SPL were followed for 6 months. Skin hydration, TEWL, SSL levels, mechanical properties, color, pH, and pore size of the forehead, chest, and inner arm were evaluated at baseline and 2, 4, and 6 months after treatment with oral SPL. Facial and upper back pore size were also assessed. Clinical outcomes were changes in these skin biophysical properties at each visit compared with baseline. Skin hydration, TEWL, SSL levels, color, pH, and pore size remained stable throughout the study. Facial skin parameters at 6 months demonstrated the following changes: hydration levels, 7.60 (95% confidence interval [CI], -59.74 to 74.94); TEWL, -2.36 (95% CI, -5.77 to 1.06); L* value, 0.51 (95% CI, -0.70 to 1.72); individual typology angle, 1.65 (95% CI -2.27 to 5.57); pH, 0.01 (95% CI -0.43 to 0.46); pore size, -0.24 (95% CI, -1.21 to 0.73); and SSL levels, 7.60 (95% CI -59.74 to 74.94). Improvement of facial mechanical properties was observed. R0 (indicating skin tightness) and R1 (indicating elasticity) showed significant decreases (-0.076 [95% CI, -0.141 to -0.010] and -0.016 [95% CI, -0.033 to -0.001]). R3 and R4 (representing tiring effects) were also improved (-0.091 [95% CI, -0.158 to -0.025] and -0.022 [95% CI, -0.044 to -0.001]). Parameters in the truncal and inner arm areas remained stable, except for skin elasticity and tiring effects, which exhibited a similar trend of improvement as the facial area. The changes were notable as early as 4 months. Oral SPL used for acne did not impair the skin barrier. Moreover, the skin mechanical properties were improved at 4 to 6 months.

Abstract Background: Previous studies demonstrated that nucleotide excision repair (NER) plays a critical role in cisplatin-based chemotherapy response in muscle-invasive bladder cancer (MIBC), and that spironolactone (SP) is a potent NER inhibitor. We sought to investigate the role of SP in enhancing the response to mitomycin chemotherapy in non-muscle invasive bladder cancer (NMIBC). Materials and Methods: KU1919 cells (NER proficient) were used for chemotherapy response to mitomycin. Cell viability was examined using CellTiter-Glo. IC50 concentrations were calculated using a four-parameter sigmoidal model and plots generated by GraphPad Prism 9. Drug combination indexes (CI) of chemotherapy and SP were calculated using Chou-Talalay method. Cell cycle and apoptosis analysis were measured by assay and Annexin V apoptosis detection kit. DNA damage response and apoptosis signaling were examined by Western blot of gamma-H2AX, cleaved Caspase-3, and cleaved PARP. Results: Combinations of mitomycin and SP (2 μM: 40 μM, CI = 0.09) resulted in strong synergies in KU1919 cells. Mitomycin combined with SP led to more cells with a sub-G1 phase DNA content (9.43% vs. 4.69%, P &amp;lt; 0.01) and apoptosis (55.85% vs. 13.11% P &amp;lt; 0.01) than treatment with mitomycin alone. Western blot analyses showed that the addition of SP to mitomycin treatment induced increased protein expression of DNA damage response genes (gamma-H2AX) and activation of apoptosis (cleaved Caspase-3 and cleaved PARP). Conclusion: Targeting the NER pathway with SP in NMIBC enhances mitomycin-induced DNA damage signaling and subsequent cell apoptosis. These findings offer proof of concept and rationale for combining NER inhibitors with intravesical chemotherapy in NMIBC. Citation Format: Dongbo Xu, Li Wang, Kyle Wieczorekl, Zhiyu Tian, Qiang Li. Targeting nucleotide excision repair in non-muscle invasive bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B021.