ABSTRACT
The blood supply in the retina ensures photoreceptor function and maintains regular vision. Leber's hereditary optic neuropathy (LHON), caused by the mitochondrial DNA mutations that deteriorate complex I activity, is characterized by progressive vision loss. Although some reports indicated retinal vasculature abnormalities as one of the comorbidities in LHON, the paracrine influence of LHON-affected retinal ganglion cells (RGCs) on vascular endothelial cell physiology remains unclear. To address this, we established an in vitro model of mitochondrial complex I deficiency using induced pluripotent stem cell-derived RGCs (iPSC-RGCs) treated with a mitochondrial complex I inhibitor rotenone (Rot) to recapitulate LHON pathologies. The secretomes from Rot-treated iPSC-RGCs (Rot-iPSC-RGCs) were collected, and their treatment effect on human umbilical vein endothelial cells (HUVECs) was studied. Rot induced LHON-like characteristics in iPSC-RGCs, including decreased mitochondrial complex I activity and membrane potential, and increased mitochondrial reactive oxygen species (ROS) and apoptosis, leading to mitochondrial dysfunction. When HUVECs were exposed to conditioned media (CM) from Rot-iPSC-RGCs, the angiogenesis of HUVECs was suppressed compared to those treated with CM from control iPSC-RGCs (Ctrl-iPSC-RGCs). Angiogenesis-related proteins were altered in the secretomes from Rot-iPSC-RGC-derived CM, particularly angiopoietin, MMP-9, uPA, collagen XVIII, and VEGF were reduced. Notably, GeneMANIA analysis indicated that VEGFA emerged as the pivotal angiogenesis-related protein among the identified proteins secreted by health iPSC-RGCs but reduced in the secretomes from Rot-iPSC-RGCs. Quantitative real-time PCR and western blots confirmed the reduction of VEGFA at both transcription and translation levels, respectively. Our study reveals that Rot-iPSC-RGCs establish a microenvironment to diminish the angiogenic potential of vascular cells nearby, shedding light on the paracrine regulation of LHON-affected RGCs on retinal vasculature.
ABSTRACT
BACKGROUND: The long-term outcome on patients with chronic thromboembolic pulmonary hypertension (CTEPH) has not been ideal after standard medical treatment. However, good outcome for patients with CTEPH after interventions such as pulmonary endarterectomy (PEA) and balloon pulmonary angioplasty (BPA) has been reported recently. The aim of this study was to evaluate the impact of PEA or BPA on long-term outcomes for CTEPH patients in Han-Chinese population. METHODS: This was a multicenter, prospective case-control study. Patients with CTEPH were enrolled between January, 2018 and March, 2020. They were divided into two groups, including intervention (PEA or BPA) and conservative groups. The followed-up period was 26 months after treatment. The endpoints were all-cause mortality and CTEPH mortality. RESULTS: A total of 129 patients were enrolled and assigned to receive PEA/BPA (N = 73), or conservative therapy (N = 56). Overall, the 26-month survival rate of all-cause mortality was significantly higher in intervention group compared to that in conservative group (95.89% vs 80.36%; log-rank p = 0.0164). The similar trend was observed in the 26-month survival rate of CTEPH mortality (97.26% vs 85.71%; log-rank p = 0.0355). Regarding Cox proportional-hazard regression analysis, the hazard ratios (HRs) on patients with CTEPH receiving intervention in the outcome of all-cause mortality and CTEPH mortality were statistically significant (HR = 0.07 and p = 0.0141 in all-cause mortality; HR = 0.11 and p = 0.0461 in CTEPH mortality). CONCLUSION: This multicenter prospective case-control study demonstrated that intervention such as PEA and BPA increased the long-term survival rate for patient with CTEPH significantly. Intervention was an independent factor in long-term outcome for patients with CTEPH, including all-cause mortality and CTEPH mortality.