Dept. of Stomatology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Stomatological Hospital, Zhengzhou 450052, China.
Dept. of Stomatology, Xuzhou Central Hospital, Xuzhou 221009, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2021 Jun 1;39(3):274-278. doi: 10.7518/hxkq.2021.03.005.
The effect of Vps4b gene mutation on the expressions of cytokeratin 14 (CK14) and proliferating cell nuclear antigen (PCNA) in the Hertwig's epithelial root sheath (HERS) is investigated.
The bilateral mandibular tissues of mouse on postnatal days 5, 9, 11, 15, and 19 were removed. The mandibular first molar tissue sections were obtained after paraffin embedding. The CK14 and PCNA expressions in the epithelial root sheath of the normal mouse and Vps4b knockout mouse were compared through immunohistochemistry.
On postnatal day 5, the normal mouse began to form HERS and had a strong positive PCNA expression in the HERS cells; on postnatal day 9, the HERS structure was continuous, and PCNA was positive in the HERS cells; on postnatal day 11, a small portion of HERS began to break, and PCNA was weakly positive in the HERS cells; on postnatal day 15, HERS continued to fracture; PCNA was weakly and positively expressed in the HERS cells on the root surface; on postnatal day 19, the tooth root reached normal physiological length, and PCNA was positively expressed in the HERS cells of the terminal part. Similar to the normal mouse, the gene knockout mouse also formed a HERS structure on postnatal day 5. However, HERS began to break on postnatal day 9. On postnatal day 19, only a few fragments of HERS were found on the root surface, and the root development was immature. Moreover, the expression intensity of PCNA in the gene knockout mouse was decreased.
The Vps4b gene mutation may change the CK14 and PCNA expressions, leading to abnormal root development.
研究 Vps4b 基因突变对 Hertwig 上皮根鞘（HERS）中细胞角蛋白 14（CK14）和增殖细胞核抗原（PCNA）表达的影响。
取新生后 5、9、11、15 和 19 天的小鼠双侧下颌组织，石蜡包埋后获取下颌第一磨牙组织切片，采用免疫组织化学方法比较正常小鼠和 Vps4b 基因敲除小鼠上皮根鞘中 CK14 和 PCNA 的表达。
新生后 5 天，正常小鼠开始形成 HERS，HERS 细胞中 PCNA 呈强阳性表达；新生后 9 天，HERS 结构连续，HERS 细胞中 PCNA 阳性；新生后 11 天，部分 HERS 开始断裂，HERS 细胞中 PCNA 弱阳性；新生后 15 天，HERS 继续断裂，根表面 HERS 细胞中 PCNA 弱阳性表达；新生后 19 天，牙根达到正常生理长度，HERS 细胞终末部分呈 PCNA 阳性表达。与正常小鼠相似，基因敲除小鼠在新生后 5 天也形成了 HERS 结构，但在新生后 9 天 HERS 开始断裂。新生后 19 天，根表面仅发现少量 HERS 碎片，牙根发育不成熟，且基因敲除小鼠中 PCNA 的表达强度降低。
Vps4b 基因突变可能改变 CK14 和 PCNA 的表达，导致牙根发育异常。
