Sox9 Is Crucial for Mesenchymal Stem Cells to Enhance Cutaneous Wound Healing

Photobiomodulation Facilitates Rat Cutaneous Wound Healing by Promoting Epidermal Stem Cells and Hair Follicle Stem Cells Proliferation

BACKGROUND

Cutaneous wound healing represents a common fundamental phenomenon requiring the participation of cells of distinct types and a major concern for the public. Evidence has confirmed that photobiomodulation (PBM) using near-infrared (NIR) can promote wound healing, but the  cells involved and the precise molecular mechanisms remain elusive.

METHODS

Full-thickness skin defects with a diameter of 1.0 cm were made on the back of rats and randomly divided into the control group, 10 J, 15 J, and 30 J groups. The wound healing rate at days 4, 8, and 12 postoperatively was measured. HE and Masson staining was conducted to reveal the histological characteristics. Immunofluorescence staining was performed to label the epidermal stem cells (ESCs) and hair follicle stem cells (HFSCs). Western blot was performed to detect the expressions of proteins associated with ESCs and HFSCs. Cutaneous wound tissues were collected for RNA sequencing. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes analysis was performed, and the hub genes were identified using CytoHubba and validated by qRT-PCR.

RESULTS

PBM can promote reepithelialization, extracellular matrix deposition, and wound healing, increase the number of KRT14+/PCNA+ ESCs and KRT15+/PCNA+ HFSCs, and upregulate the protein expression of P63, Krt14, and PCNA. Three hundred and sixty-six differentially expressed genes (DEGs) and 7 hub genes including Sox9, Krt5, Epcam, Cdh1, Cdh3, Dsp, and Pkp3 were identified. These DEGs are enriched in skin development, cell junction, and cadherin binding involved in cell-cell adhesion etc., while these hub genes are related to skin derived stem cells and cell adhesion.

CONCLUSION

PBM accelerates wound healing by enhancing reepithelialization through promoting ESCs and HFSCs proliferation and elevating the expression of genes associated with stem cells and cell adhesion. This may provide a valuable alternative strategy to promote wound healing and reepithelialization by modulating the proliferation of skin derived stem cells and regulating genes related to cell adhesion.

SOX family transcription factors as therapeutic targets in wound healing: A comprehensive review

The SOX family plays a vital role in determining the fate of cells and has garnered attention in the fields of cancer research and regenerative medicine. It also shows promise in the study of wound healing, as it actively participates in the healing processes of various tissues such as skin, fractures, tendons, and the cornea. However, our understanding of the mechanisms behind the SOX family's involvement in wound healing is limited compared to its role in cancer. Gaining insight into its role, distribution, interaction with other factors, and modifications in traumatized tissues could provide valuable new knowledge about wound healing. Based on current research, SOX2, SOX7, and SOX9 are the most promising members of the SOX family for future interventions in wound healing. SOX2 and SOX9 promote the renewal of cells, while SOX7 enhances the microvascular environment. The SOX family holds significant potential for advancing wound healing research. This article provides a comprehensive review of the latest research advancements and therapeutic tools related to the SOX family in wound healing, as well as the potential benefits and challenges of targeting the SOX family for wound treatment.

EGR1 Promotes Ovarian Hyperstimulation Syndrome Through Upregulation of SOX9 Expression

Angiogenesis is strongly associated with ovarian hyperstimulation syndrome (OHSS) progression. Early growth response protein 1 (EGR1) plays an important role in angiogenesis. This study aimed to investigate the function and mechanism of EGR1 involved in OHSS progression. RNA-sequencing was used to identify differentially expressed genes. In vitro OHSS cell model was induced by treating KGN cells with human chorionic gonadotropin (hCG). In vivo OHSS model was established in mice. The expression levels of EGR1, SOX1, and VEGF were determined by Quantitative Real-Time polymerase chain reaction (qRT-PCR), Western blot, immunofluorescence staining, and immunochemistry assay. The content of VEGF in the culture medium of human granulosa-like tumor cell line (KGN) cells was accessed by the ELISA assay. The regulatory effect of EGR1 on SRY-box transcription factor 9 (SOX9) was addressed by luciferase reporter assay and chromatin immunoprecipitation. The ERG1 and SOX9 levels were significantly upregulated in granulosa cells from OHSS patients and there was a positive association between EGR1 and SOX9 expression. In the ovarian tissues of OHSS mice, the levels of EGR1 and SOX9 were also remarkedly increased. Treatment with hCG elevated the levels of vascular endothelial growth factor (VEGF), EGR1, and SOX9 in KGN cells. Silencing of EGR1 reversed the promoting effect of hCG on VEGF and SOX9 expression in KGN cells. EGR1 transcriptionally regulated SOX9 expression through binding to its promoter. In addition, administration of dopamine decreased hCG-induced VEGF in KGN cells and ameliorated the progression of OHSS in mice, which were companied with decreased EGR1 and SOX9 expression. EGR1 has a promoting effect on OHSS progression and dopamine protects against OHSS through suppression of EGR1/SOX9 cascade. Our findings may provide new targets for the treatment of OHSS.

Bioactive Small Molecule Enhances Skin Burn Wound Healing and Hair Follicle Regeneration by Activating PI3K/AKT Signaling Pathway: A Preclinical Evaluation in Animal Model

Rational: A bioactive small molecule of precision medicine involves targeted therapies. Shikonin, a herbal extract, is an active small molecule that is traditionally used in wound healing for its anti-tumor and anti-inflammatory properties. Therefore, the present study aims to evaluate the anti-inflammatory role of shikonin in skin burn wound healing and hair follicle regeneration and to identify molecular signaling pathways that promote the regeneration. Method: A secondary skin burn model of mice was established by conventional method. The burn wound was externally treated with shikonin ointment and excipient treated mice were used as controls. Skin samples were taken on the day 3 and 7 after drug treatment and the dosage was unified in the experiments. The wound healing process was observed by histopathological and immunofluorescence (IF) staining. The proliferation of hair follicle cells in wound skin was tracked by 5-Ethynyl-2'-deoxyuridne (EdU) staining. The inflammatory factors at the wound healing site were quantified by polymerase chain reaction (qPCR). The PI3K/Akt, P65, Ki67 signaling proteins and Bax/BCL2 apoptosis proteins were studied by western blot analysis. The functionality of PI3K/Akt signaling pathway was tested using LY294002, an inhibitor of PI3K. Result: Shikonin treated mice group exhibited better and faster skin burn wound healing in comparison with the controls. The proliferation of new skin cells and hair follicle regeneration in the wound site of the shikonin treated group was more active. The recruitment of macrophages in shikonin treated group was inhibited inturn decreased the expression of inflammatory factors. However, LY294002 inhibited the shikonin-mediated PI3K/Akt signaling pathway and affected the wound healing process. Conclusion: In conclusion, this study strengthens the hypothesis that bioactive small molecule, shikonin, inhibits inflammation, promotes wound healing and has a significant protective effect on the deep hair follicles against burn skin injury by activating the PI3K/Akt signaling pathway.