Kazama Junichiro James, Yamamoto Suguru, Narita Ichiei, Kurihara Satoshi
Division of Blood Purification Therapy, Niigata University Medical and Dental Hospital, Niigata, Japan.
Ther Apher Dial. 2011 Jun;15 Suppl 1:9-13. doi: 10.1111/j.1744-9987.2011.00919.x.
The morphological appearance of an osteoblast largely alters with its differentiation and maturation, along with the change of cell function. We quantitatively observed the osteoblast morphology and compared it with bone metabolism. Biopsied iliac bone samples obtained from 77 dialysis patients (14 mild change, 37 osteitis fibrosa, 2 osteomalacia, 8 mixed, and 16 adynamic bone) were included in the study. Osteoblast appearances were classified into three groups: (i) type II and III osteoblasts, namely, active osteoblasts characterized by cuboidal or columnar shapes with or without a nuclear clear zone; (ii) type IV osteoblasts, lining osteoblasts characterized by extremely thin cytoplasm; and (iii) type V osteoblasts, apoptotic osteoblasts characterized by nuclear chromatin concentration. The results were quantitatively expressed as the length of bone surface covered by each type of osteoblasts. The type II and III osteoblasts were predominant in osteitis fibrosa, mixed, and mild change. The type IV osteoblasts were overwhelmingly predominant in adynamic bone. The type V osteoblasts appeared most frequently in osteitis fibrosa, followed by mixed and mild change. Both absolute and relative lengths of bone surface covered by the type V osteoblasts were significantly higher in the high-turnover bone group (osteitis fibrosa and mixed) than the low-turnover bone group (adynamic bone and osteomalacia). The type V osteoblasts were slightly correlated with serum intact parathyroid hormone levels. In conclusion, a high bone-turnover condition seems to be associated with the promotion of osteoblastic apoptosis in dialysis patients. This finding may explain the fact that osteopenia develops faster in CKD patients with high turnover of bone.
成骨细胞的形态外观会随着其分化和成熟以及细胞功能的变化而发生很大改变。我们定量观察了成骨细胞形态，并将其与骨代谢进行了比较。本研究纳入了从77例透析患者获取的髂骨活检样本（14例轻度改变、37例纤维性骨炎、2例骨软化症、8例混合型和16例骨动力缺乏症）。成骨细胞外观分为三组：（i）II型和III型成骨细胞，即活跃的成骨细胞，其特征为立方体形或柱状形，有或无核透明区；（ii）IV型成骨细胞，即衬里成骨细胞，其特征为细胞质极薄；（iii）V型成骨细胞，即凋亡成骨细胞，其特征为核染色质浓缩。结果以每种类型成骨细胞覆盖的骨表面长度进行定量表示。II型和III型成骨细胞在纤维性骨炎、混合型和轻度改变中占主导。IV型成骨细胞在骨动力缺乏症中绝对占主导。V型成骨细胞最常出现在纤维性骨炎中，其次是混合型和轻度改变。高转换骨组（纤维性骨炎和混合型）中V型成骨细胞覆盖的骨表面绝对长度和相对长度均显著高于低转换骨组（骨动力缺乏症和骨软化症）。V型成骨细胞与血清完整甲状旁腺激素水平呈轻度相关。总之，高骨转换状态似乎与透析患者成骨细胞凋亡的促进有关。这一发现可能解释了骨转换率高的慢性肾脏病患者骨量减少发展更快这一事实。
