MATERIALS AND METHODS: An electronic search of 3 databases (Medline, CENTRAL, Scopus) was performed to identify randomized control trials evaluating the efficacy of RAU interventions published until December 2022. A network meta-analysis (NMA) was conducted on 4 outcomes: reduction in pain, duration of ulceration, the diameter of ulceration, and area of ulceration. The interventions are then arranged using the surface area under cumulative ranking (SUCRA).
RESULTS: A total of 38 trials involving 2773 patients were included were included in quantitative synthesis by NMA. Our analysis showed that Diode laser [MD, -4.865 ± 1.951 (95%CI = (-8.690, -1.041)] was the most effective in reducing the pain score followed by Amlexanox [MD, -2.673 ± 1.075 (95%CI = -4.779, -0.566)]. Iralvex performed the best in reducing the duration of ulceration [MD, -6.481 ± 1.841 (95%CI = -10.090, -2.872)]. Diode laser, acacia nilotica with licorice formulation, and amlexanox were the most effective interventions for reduction of ulcer diameter. Majority of the trials reported absence of any adverse effects and those reported were mild.
CONCLUSION: Our NMA has identified several interventions to be more effective than a placebo. Laser therapy may be an option for promoting pain management, however, most have only been tested in 1 or 2 trials. Further studies with rigorous methodology on larger samples are recommended to strengthen the current evidence.
AIM: To investigate the regulation of rs10889677 and the role of buparlisib in the PI3K signaling pathway in CAC pathogenesis.
METHODS: Genomic DNA from 32 colonic samples, including CAC (n = 7), UC (n = 10) and CRC (n = 15), was sequenced for the rs10889677 mutation. The mutant and wildtype fragments were amplified and cloned in the pmirGLO vector. The luciferase activity of cloned vectors was assessed after transfection into the HT29 cell line. CAC mice were induced by a mixture of a single azoxymethane injection and three cycles of dextran sulphate sodium, then buparlisib was administered after 14 d. The excised colon was subjected to immunohistochemistry for Ki67 and Cleaved-caspase-3 markers and quantitative real-time polymerase chain reaction analysis for Pdk1 and Sgk2.
RESULTS: Luciferase activity decreased by 2.07-fold in the rs10889677 mutant, confirming the hypothesis that the variant disrupted miRNA binding sites, which led to an increase in IL23R expression and the activation of the PI3K signaling pathway. Furthermore, CAC-induced mice had a significantly higher disease activity index (P < 0.05). Buparlisib treatment significantly decreased mean weight loss in CAC-induced mice (P < 0.05), reduced the percentage of proliferating cells by 5%, and increased the number of apoptotic cells. The treatment also caused a downward trend of Pdk1 expression and significantly decreased Sgk2 expression.
CONCLUSION: Our findings suggested that the rs10889677 variant as a critical initiator of the PI3K signaling pathway, and buparlisib had the ability to prevent PI3K-non-AKT activation in the pathophysiology of CAC.
METHODS AND RESULTS: Selective agonists of PKA and EPAC synergistically inhibited Egr1 expression, which was essential for VSMC proliferation. Forskolin, adenosine, A2B receptor agonist BAY60-6583 and Cicaprost also inhibited Egr1 expression in VSMC but not in endothelial cells. Inhibition of Egr1 by cAMP was independent of cAMP response element binding protein (CREB) activity but dependent on inhibition of serum response element (SRE) activity. SRF binding to the Egr1 promoter was not modulated by cAMP stimulation. However, Egr1 expression was dependent on the SRF co-factors Elk1 and 4 but independent of MAL. Inhibition of SRE-dependent Egr1 expression was due to synergistic inhibition of Rac1 activity by PKA and EPAC, resulting in rapid cytoskeleton remodelling and nuclear export of ERK1/2. This was associated with de-phosphorylation of the SRF co-factor Elk1.
CONCLUSION: cAMP inhibits VSMC proliferation by rapidly inhibiting Egr1 expression. This occurs, at least in part, via inhibition of Rac1 activity leading to rapid actin-cytoskeleton remodelling, nuclear export of ERK1/2, impaired Elk1-phosphorylation and inhibition of SRE activity. This identifies one of the earliest mechanisms underlying the anti-mitogenic effects of cAMP in VSMC but not in endothelial cells, making it an attractive target for selective inhibition of VSMC proliferation.