RESUMO
OBJECTIVES: Chronic limb-threatening ischemia (CLTI) is mostly caused by arteriosclerosis, but is sometimes due to connective tissue disease. However, there is a limited knowledge of clinical outcomes of patients with CLTI with connective tissue disease. The objective of the study was to assess outcomes after distal bypass in these patients using global vascular guidelines. MATERIAL AND METHODS: Data from distal bypasses performed for CLTI at a single center from 2014 to 2023 were evaluated retrospectively. Clinical outcomes after distal bypass were compared for patients with CLTI with arteriosclerosis (AS group) and those with connective tissue disease (CD group). The primary endpoints were limb salvage and wound healing. RESULTS: Of the 282 distal bypasses performed for 222 patients with CLTI, 22 were conducted for 21 patients with connective tissue disease (CD group). The connective tissue disease was progressive systemic scleroderma (n = 11 patients), pemphigoid diseases (n = 2), polyarteritis nodosa (n = 2), rheumatoid arthritis (n = 2), and others (n = 4). Compared with the AS group, the CD group included more females (P = .007) and had greater oral steroid use (P < .001) and a higher Global Limb Anatomical Staging System (GLASS) inframalleolar (IM) modifier P2 (P < .001). The mean follow-up period of the whole cohort was 27 ± 22 months with no significant difference between the groups (P = .25), and 22 limbs required major amputation during this period. The 2-year limb salvage rate was significantly lower in the CD group compared to the AS group (75% vs 94%, P = .020). Wound healing was achieved in 220 (78%) limbs, and the 12-month wound healing rate was significantly lower in the CD group (52% vs 86%, P = .006). CONCLUSION: The low 2-year limb salvage and 12-month wound healing rates in patients with CLTI with connective tissue disease indicate that distal bypass may be challenging in these patients.
RESUMO
Renal function declines with aging and is pathologically characterized by chronic inflammation and fibrosis. Renal senescence is induced not only by aging but also by various stimuli, including ischemia reperfusion injury. Recently, the accumulation of p16INK4a-positive cells in the kidney has been considered a molecular feature of renal senescence, with the p16INK4a gene reportedly regulated by mixed-lineage leukemia 1 (MLL1)/WD-40 repeat protein 5 (WDR5)-mediated histone 3 lysine 4 trimethylation (H3K4me3). Here, we determined whether inhibition of MLL1/WDR5 activity attenuates renal senescence, inflammation, and fibrosis in mice with ischemia reperfusion injury and in cultured rat renal fibroblasts. MM-102 or OICR-9429, both MLL1/WDR5 protein-protein interaction inhibitors, and small interfering RNA (siRNA) for MLL1 or WDR5 suppressed the expression of p16INK4a in mice with ischemia reperfusion injury, accompanied by downregulation of H3K4me3 expression. MM-102 attenuated renal fibrosis and inflammation in the kidney of mice with ischemia reperfusion injury. Moreover, in vitro study showed that transforming growth factor-ß1 induced the expression of MLL1, WDR5, H3K4me3, and p16INK4a. Finally, chromatin immunoprecipitation identified the p16INK4a promoter at an H3K4me3 site in renal fibroblasts. Thus, our findings show that H3K4me3 inhibition ameliorates ischemia reperfusion-induced renal senescence along with fibrosis and inflammation.