Wrublewsky Selina, Glas Julia, Carlein Christopher, Nalbach Lisa, Hoffmann Markus Daniel Alexander, Pack Mandy, Vilas-Boas Eloisa Aparecida, Ribot Nathan, Kappl Reinhard, Menger Michael D, Laschke Matthias W, Ampofo Emmanuel, Roma Leticia Prates
Institute for Clinical and Experimental Surgery, Saarland University, 66421, Homburg, Germany.
Department of Biophysics, Center for Human and Molecular Biology (ZHMB), Saarland University, 66421, Homburg, Germany.
Redox Biol. 2022 Sep;55:102419. doi: 10.1016/j.redox.2022.102419. Epub 2022 Jul 31.
Islet transplantation is a promising treatment strategy for type 1 diabetes mellitus (T1DM) patients. However, oxidative stress-induced graft failure due to an insufficient revascularization is a major problem of this therapeutic approach. NADPH oxidase (NOX)2 is an important producer of reactive oxygen species (ROS) and several studies have already reported that this enzyme plays a crucial role in the endocrine function and viability of β-cells. Therefore, we hypothesized that targeting islet NOX2 improves the outcome of islet transplantation. To test this, we analyzed the cellular composition and viability of isolated wild-type (WT) and Nox2 islets by immunohistochemistry as well as different viability assays. Ex vivo, the effect of Nox2 deficiency on superoxide production, endocrine function and anti-oxidant protein expression was studied under hypoxic conditions. In vivo, we transplanted WT and Nox2 islets into mouse dorsal skinfold chambers and under the kidney capsule of diabetic mice to assess their revascularization and endocrine function, respectively. We found that the loss of NOX2 does not affect the cellular composition and viability of isolated islets. However, decreased superoxide production, higher glucose-stimulated insulin secretion as well as expression of nuclear factor erythroid 2-related factor (Nrf)2, heme oxygenase (HO)-1 and superoxide dismutase 1 (SOD1) was detected in hypoxic Nox2 islets when compared to WT islets. Moreover, we detected an early revascularization, a higher take rate and restoration of normoglycemia in diabetic mice transplanted with Nox2 islets. These findings indicate that the suppression of NOX2 activity represents a promising therapeutic strategy to improve engraftment and function of isolated islets.
胰岛移植是1型糖尿病（T1DM）患者一种很有前景的治疗策略。然而，由于血管再生不足导致的氧化应激诱导的移植物失败是这种治疗方法的一个主要问题。NADPH氧化酶（NOX）2是活性氧（ROS）的重要产生者，多项研究已经报道该酶在β细胞的内分泌功能和活力中起关键作用。因此，我们推测靶向胰岛NOX2可改善胰岛移植的结果。为了验证这一点，我们通过免疫组织化学以及不同的活力测定法分析了分离的野生型（WT）和Nox2胰岛的细胞组成和活力。在体外，研究了Nox2缺陷在缺氧条件下对超氧化物产生、内分泌功能和抗氧化蛋白表达的影响。在体内，我们将WT和Nox2胰岛分别移植到小鼠背部皮褶腔和糖尿病小鼠的肾被膜下，以评估它们的血管再生和内分泌功能。我们发现NOX2的缺失不影响分离胰岛的细胞组成和活力。然而，与WT胰岛相比，在缺氧的Nox2胰岛中检测到超氧化物产生减少、葡萄糖刺激的胰岛素分泌增加以及核因子红细胞2相关因子（Nrf）2、血红素加氧酶（HO）-1和超氧化物歧化酶1（SOD1）的表达增加。此外，我们在移植了Nox2胰岛的糖尿病小鼠中检测到早期血管再生、更高的植入率和血糖正常化的恢复。这些发现表明，抑制NOX2活性是改善分离胰岛植入和功能的一种有前景的治疗策略。
