M2 macrophages play an important role in tissue repair and regeneration. They have also been found to modulate β-cell replication in mouse models of pancreatic injury and disease. We previously reported that β-cell replication is strongly increased in a subgroup of human organ donors characterized by prolonged duration of stay in an intensive care unit (ICU) and increased number of leukocytes in the pancreatic tissue. In the present study we investigated the relationship between duration of stay in the ICU, M2 macrophages, vascularization, and pancreatic cell replication. Pancreatic organs from 50 donors without diabetes with different durations of stay in the ICU were analyzed by immunostaining and digital image analysis. The number of CD68+CD206+ M2 macrophages increased three- to sixfold from ≥6 days’ duration of stay in the ICU onwards. This was accompanied by a threefold increased vascular density and a four- to ninefold increase in pancreatic cells positive for the replication marker Ki67. A strong correlation was observed between the number of M2 macrophages and β-cell replication. These results show that a prolonged duration of stay in the ICU is associated with an increased M2 macrophage number, increased vascular density, and an overall increase in replication of all pancreatic cell types. Our data show evidence of marked levels of tissue repair in the human donor pancreas.

中文翻译：

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长期重症监护后，人类供体胰腺组织修复的证据。

M2巨噬细胞在组织修复和再生中起重要作用。还发现它们在胰腺损伤和疾病的小鼠模型中调节 β 细胞复制。我们之前曾报道，在一个以重症监护病房 (ICU) 住院时间延长和胰腺组织中白细胞数量增加为特征的人体器官供体亚组中，β 细胞复制强烈增加。在本研究中，我们调查了 ICU 停留时间、M2 巨噬细胞、血管化和胰腺细胞复制之间的关系。通过免疫染色和数字图像分析对来自 50 名在 ICU 停留时间不同的无糖尿病供体的胰腺器官进行了分析。CD68+CD206+M2 巨噬细胞的数量从 ICU 停留时间≥6 天开始增加了三到六倍。这伴随着血管密度增加了三倍，复制标记 Ki67 阳性的胰腺细胞增加了四到九倍。在 M2 巨噬细胞的数量和 β 细胞复制之间观察到很强的相关性。这些结果表明，在 ICU 停留时间延长与 M2 巨噬细胞数量增加、血管密度增加以及所有胰腺细胞类型复制的总体增加有关。我们的数据显示了人类供体胰腺组织修复水平显着的证据。这些结果表明，在 ICU 停留时间延长与 M2 巨噬细胞数量增加、血管密度增加以及所有胰腺细胞类型复制的总体增加有关。我们的数据显示了人类供体胰腺组织修复水平显着的证据。这些结果表明，在 ICU 停留时间延长与 M2 巨噬细胞数量增加、血管密度增加以及所有胰腺细胞类型复制的总体增加有关。我们的数据显示了人类供体胰腺组织修复水平显着的证据。