Lingwei Bu’s research while affiliated with Southern Medical University and other places

Skin aging has been associated with the onset of various skin issues, and recent studies have identified an increase in Cdc42 activity in naturally aging mice. While previous literature has suggested that CASIN, a specific inhibitor of Cdc42 activity, may possess anti‐aging properties, its specific effects on the epidermis and dermis, as well as the underlying mechanisms in naturally aging mice, remain unclear. Our study revealed that CASIN demonstrated the ability to increase epidermal and dermal thickness, enhance dermal‐epidermal junction, and stimulate collagen and elastic fiber synthesis in 9‐, 15‐, and 24‐month‐old C57BL/6 mice in vivo. Moreover, CASIN was found to enhance the proliferation, differentiation, and colony formation and restore the cytoskeletal morphology of primary keratinocytes in naturally aging skin in vitro. Furthermore, the anti‐aging properties of CASIN on primary fibroblasts in aging mice were mediated by the ribosomal protein RPL4 using proteomic sequencing, influencing collagen synthesis and cytoskeletal morphology both in vitro and in vivo. Meanwhile, both subcutaneous injection and topical application exhibited anti‐aging effects for a duration of 21 days. Additionally, CASIN exhibited anti‐inflammatory properties, while reduced expression of RPL4 was associated with increased inflammation in the skin of naturally aging mice. Taken together, our results unveil a novel function of RPL4 in skin aging, providing a foundational basis for future investigations into ribosomal proteins. And CASIN shows promise as a potential anti‐aging agent for naturally aging mouse skin, suggesting potential applications in the field.

Background Current animal models of sensitive skin do not adequately reflect the objective symptoms or physiological manifestations observed in human sensitive skin. Objective To construct and validate a sensitive skin model in mice. Methods Tape stripping (TS) was used to induce partial mechanical disruption of the lipid film and stratum corneum. Subsequently, propylene glycol (PG) was applied to disrupt the lipid structure in the skin barrier, and capsaicin (CS) activate transient receptor potential vanilloid 1 (TRPV1) receptors of keratinocytes to simulate the formation of sensitive skin. Evident itching and tingling sensations, scaly skin, vasodilation, local congestion, increased transepidermal water loss (TEWL), elevated TRPV1 expression, and inflammatory symptoms were subsequently evaluated. Results TS combined with PG and CS application resulted in skin flakes; skin barrier disruption; vascular dilation; increased itching, stinging, and inflammation; TRPV1 upregulation in the epidermis; and a significant increase in lactic acid‐induced itching and stinging. Conclusion Using a combination of TS and PG, and CS application, a mouse model of sensitive skin was successfully established involving various skin phenotypes and physiological manifestations, including skin flakes, vasodilation, increased blood flow and TEWL, itching and stinging sensations, inflammation, and elevated TRPV1 expression.

This study aimed to design a novel mouse model of chronic photoaging. We used three different species of mice (C57BL/6J, ICR, and KM) to create a chronic photoaging model of the skin. The irradiation time was gradually increased for 40 consecutive days. The skins of the mice were removed on day 41 and subjected to staining to observe them for morphological changes. Immunohistochemistry was used to detect tumor necrosis factor-α (TNF-α) and p53 expression; superoxide dismutase (SOD) and malondialdehyde (MDA) were measured as well. Compared with C57BL/J mice, which showed hyperpigmentation, the irradiated skin of ICR and KM mice showed more obvious skin thickening and photoaging changes of the collagen and elastic fibers. KM mice had higher levels of inflammation, oxidative stress, and senescent cells. Compared with the 5-month-old KM mice, the photoaging changes of the 9-month-old KM mice were more pronounced, the SOD values were lower, and the MDA values were higher. In summary, KM mice have higher levels of abnormal elastic fibers, inflammation, cellular senescence, and oxidative stress than ICR mice, and are more suitable for studies related to chronic skin photoaging. C57BL/6J mice were found to be suitable for studies related to skin pigmentation due to photoaging.

Background In our previous study, activin B in combination with ADSCs enhances skin wound healing. However, the underlying molecular mechanisms are not well studied. Cdc42 is recognized to play a critical role in the regulation of stem cells. Methods Pull-down assay was performed to investigate the activity of Cdc42. The dominant-negative mutant of Cdc42 (Cdc42N17) was used to explore the role of Cdc42 in activin B-induced ADSCs migration, proliferation, and secretion in vitro. Cdc42N17-transfected ADSCs were injected into a full-thickness excisional wound model to explore their efficiency in wound healing in vivo. The wound healing efficacy was evaluated by the wound closure rates and histological examination. The neovascularization and wound contraction were detected by immunohistochemistry staining of CD31 and α-SMA. Finally, the underlying mechanisms were explored by RNA sequencing. Results Cdc42N17 inhibited ADSCs migration, proliferation, and secretion induced by activin B. Furthermore, Cdc42N17-transfected ADSCs inhibited the wound closure rate and suppressed the expression of CD31 and α-SMA induced by activin B in vivo. The RNA sequencing showed that the differentially expressed genes in Cdc42N17-transfected ADSCs versus ADSCs were associated with cell migration, proliferation, and adhesion. Further study revealed that the Cdc42-Erk-Srf pathway was required for activin B-induced proliferation in ADSCs. Conclusions Our study indicates that Cdc42 plays a crucial role in ADSCs-mediated skin wound healing induced by activin B. Graphical Abstract