Hair follicle growth is cyclical, and hair cycle dysfunction can lead to hair follicle-related disorders, including alopecia and hirsutism. The objective was to investigate the influence and underlying mechanism of Krüppel-like factor 4 (KLF4) overexpression on hair follicle growth and development in C57BL/6 mice. To provide a theoretical basis for the biological functions of KLF4 gene in hair follicle development and hair follicle cycle, mice were assigned to three groups: experimental, overexpressing KLF4 (Ad-KLF4); control, expressing green fluorescent protein (Ad-NC); and blank, no treatment. Fur was removed from the dorsal surface, and the mice were intradermally injected with 25 μL 1 × 10¹⁰ PFU/mL adenovirus vector (Ad-KLF4 or Ad-NC) at three points. Samples were collected for molecular biological and histological analysis. It was found that mRNA and protein levels of Wnt pathway-associated factors β-catenin, LEF1, hair follicle cell proliferation-related factor Ki67, and hair follicle inner caledrin marker AE15 were all significantly greater in the Ad-NC and blank groups than in Ad-KLF4 mice (P < 0.01). These findings were confirmed by immunohistochemical analysis. Hair growth was monitored photographically for 14 days, showing an absence of growth in the injected region of the KLF4-overexpressing mice in contrast to non-overexpressing areas where hair growth was normal. HE staining showed that hair follicles in the blank and Ad-NC mice were normal, while those in the KLF4-overexpressing areas remained in telogen or early anagen with spherical dermal papillae situated at the edge of the dermis and subcutaneous tissue without an inner heel sheath. In conclusion, it was found that KLF4 downregulated key Wnt/β-catenin-associated factors during follicular regeneration in mice, reducing both follicular development and growth.

毛囊的生长是周期性的，毛发周期功能障碍会导致毛囊相关疾病，包括脱发和多毛症。目的是探讨 Krüppel 样因子 4 (KLF4) 过表达对 C57BL/6 小鼠毛囊生长发育的影响及其潜在机制。为了为KLF4基因在毛囊发育和毛囊周期中的生物学功能提供理论依据，将小鼠分为三组：实验组、过表达KLF4组（Ad-KLF4）；对照，表达绿色荧光蛋白（Ad-NC）；和空白，没有治疗。去除背面毛皮，在3个点皮内注射25μL 1×10 ¹⁰ PFU/mL腺病毒载体（Ad-KLF4或Ad-NC）。收集样品用于分子生物学和组织学分析。结果发现，Ad-NC组和空白组中Wnt通路相关因子β-catenin、LEF1、毛囊细胞增殖相关因子Ki67和毛囊内caledrin标记物AE15的mRNA和蛋白水平均显着高于对照组。 Ad-KLF4 小鼠（P  < 0.01）。这些发现通过免疫组织化学分析得到证实。对毛发生长进行了 14 天的摄影监测，结果显示 KLF4 过表达小鼠的注射区域没有生长，而非过表达区域的毛发生长正常。HE染色显示空白小鼠和Ad-NC小鼠的毛囊正常，而KLF4过表达区域的毛囊仍处于休止期或毛发生长初期早期，真皮边缘和皮下组织呈球形真皮乳头，无内跟鞘。总之，我们发现 KLF4 下调小鼠卵泡再生过程中关键的 Wnt/β-catenin 相关因子，从而降低卵泡的发育和生长。