Abdelmagid Samir M, Barbe Mary F, Safadi Fayez F
Department of Anatomy and Neurobiology, Northeast Ohio Medical University (NEOMED) School of Medicine, Rootstown, OH 44272, USA.
Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
Life Sci. 2015 Feb 15;123:25-34. doi: 10.1016/j.lfs.2014.11.011. Epub 2014 Dec 13.
Chronic inflammation in aging is characterized by increased inflammatory cytokines, bone loss, decreased adaptation, and defective tissue repair in response to injury. Aging leads to inherent changes in mesenchymal stem cell (MSC) differentiation, resulting in impaired osteoblastogenesis. Also, the pro-inflammatory cytokines increase with aging, leading to enhanced myelopoiesis and osteoclastogenesis. Bone marrow macrophages (BMMs) play pivotal roles in osteoblast differentiation, the maintenance of hematopoietic stem cells (HSCs), and subsequent bone repair. However, during aging, little is known about the role of macrophages in the differentiation and function of MSC and HSC. Aged mammals have higher circulating pro-inflammatory cytokines than young adults, supporting the hypothesis of increased inflammation with aging. This review will aid in the understanding of the potential role(s) of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages in differentiation and function of osteoblasts and osteoclasts in relation to aging.
衰老过程中的慢性炎症表现为炎症细胞因子增加、骨质流失、适应性下降以及损伤后组织修复缺陷。衰老导致间充质干细胞（MSC）分化发生内在变化，从而损害成骨细胞生成。此外，促炎细胞因子随衰老而增加，导致骨髓生成和破骨细胞生成增强。骨髓巨噬细胞（BMM）在成骨细胞分化、造血干细胞（HSC）维持及后续骨修复中起关键作用。然而，在衰老过程中，巨噬细胞在MSC和HSC分化及功能中的作用尚不清楚。老年哺乳动物循环中的促炎细胞因子高于年轻成年动物，这支持了衰老过程中炎症增加的假说。本综述将有助于理解促炎（M1）和抗炎（M2）巨噬细胞在与衰老相关的成骨细胞和破骨细胞分化及功能中的潜在作用。
