Cardiac fibrosis is characterized by an elevated amount of extracellular matrix (ECM) within the heart. However, the persistence of cardiac fibrosis ultimately diminishes contractility and precipitates cardiac dysfunction. Circular RNAs (circRNAs) are emerging as important regulators of cardiac fibrosis. Here, we elucidate the functional role of a specific circular RNA CELF1 in cardiac fibrosis and delineate a novel feedback loop mechanism. Functionally, circ-CELF1 was involved in enhancing fibrosis-related markers' expression and promoting the proliferation of cardiac fibroblasts (CFs), thereby exacerbating cardiac fibrosis. Mechanistically, circ-CELF1 reduced the ubiquitination-degradation rate of BRPF3, leading to an elevation of BRPF3 protein levels. Additionally, BRPF3 acted as a modular scaffold for the recruitment of histone acetyltransferase KAT7 to facilitate the induction of H3K14 acetylation within the promoters of the Celf1 gene. Thus, the transcription of Celf1 was dramatically activated, thereby inhibiting the subsequent response of their downstream target gene Smad7 expression to promote cardiac fibrosis. Moreover, Celf1 further promoted Celf1 pre-mRNA transcription and back-splicing, thereby establishing a feedback loop for circ-CELF1 production. Consequently, a novel feedback loop involving CELF1/circ-CELF1/BRPF3/KAT7 was established, suggesting that circ-CELF1 may serve as a potential novel therapeutic target for cardiac fibrosis.

Objective: To compare the efficacy and safety of combining diosmin with Jiuhua hemorrhoid suppository versus diosmin alone for the treatment of hemorrhoid hemorrhage. Methods: The Jiuhua hemorrhoid suppository study was conducted in 10 medical centers across China from April 1, 2019 to June 30, 2020. Patients with hemorrhoid bleeding were randomized in a ratio of 1 : 1 to either receive Jiuhua hemorrhoid suppository and diosmin tablets (the study group) or diosmin tablets alone (the control group). The suppository was used once a day after defecation or at bedtime after rinsing the anus with warm water. Diosmin tablets were administered only once a day (0.9 g). The primary endpoint of the study was the assessment of hemorrhoid bleeding relief 7 ± 2 days after treatment, classified as “very effective” “effective” and “ineffective”. The secondary endpoint included the evaluation of pain alleviation using the visual analogue scale (VAS, with scores ranging from 0 to 10) and edema (with scores ranging from 0 to 3). The safety of the two treatment regimens was evaluated 14 ± 2 days after drug administration. Results: The full analysis set (FAS) comprised 107 participants in the study group and 111 in the control group, while the per-protocol set (PPS) included 106 participants in the study group and 111 in the control group. In terms of hemorrhoid bleeding, the proportion of very effective and effective cases in the study group were significantly higher than that in the control group [106 (99.06%) vs. 91 (81.98%), P < 0.0001] in the FAS, and the PPS results [105 (99.06%) vs. 91 (81.98%), P < 0.0001] were comparable to the FAS results. The pain VAS scores at day 7 after treatment were comparable between the two groups (0.80 ± 1.17 vs. 0.80 ± 1.20, P = 0.2177). The majority of the participants in both groups had an edema score of 0 at day 7 after treatment [96 (89.72%) vs. 99 (91.67%), P = 0.370 5]. Adverse events (AEs) occurred in 9 patients (8.4%) in the study group and 3 patients (2.7%) in the control group. In addition, 5 AEs in the study group and 1 AE in the control group were possibly in association with the study drug. Conclusion Compared with the administration of diosmin oral tablets alone, the addition of Jiuhua hemorrhoid suppository to the tablets demonstrates enhanced efficacy in addressing hemorrhoid bleeding, with satisfactory patient adherence and acceptable safety.