Erythroid differentiation regulator 1 promotes wound healing by inducing the production of C‑C motif chemokine ligand 2 via the activation of MAP kinases in vitro and in vivo

CD146-dependent macrophage infiltration promotes epidural fibrosis via the Erdr1/ERK/CCR2 pathway

Low back pain due to epidural fibrosis is a major complication after spine surgery. Macrophages infiltrate the wound area post laminectomy, but the role of macrophages in epidural fibrosis remains largely elusive. In a mouse model of laminectomy, macrophage depletion decreased epidural fibrosis. CD146, an adhesion molecule involved in cell migration, is expressed by macrophages. CD146-defective macrophages exhibited impaired migration, which was mediated by reduced expression of CCR2 and suppression of the MAPK/ERK signaling pathway. CD146-defective macrophages suppress the MAPK/ERK signaling pathway by increasing Erdr1. In vivo, CD146 deficiency decreased macrophage infiltration and reduced extracellular matrix deposition in wound tissues. Moreover, the anti-CD146 antibody AA98 suppressed macrophage infiltration and epidural fibrosis. Taken together, these findings demonstrated that CD146 deficiency alleviates epidural fibrosis by decreasing the migration of macrophages via the Erdr1/ERK/CCR2 pathway. Blocking CD146 and macrophage infiltration may help alleviate epidural fibrosis.

Optimizing a five-factor cocktail to prepare reparative macrophages for wound healing

The treatment of non-healing wounds, such as diabetic ulcers, remains a critical clinical challenge. Recent breakthroughs in cell therapy have shown great promise, with one primary focus on preparing cells with comprehensive reparative functions and foreseeable safety. In our previous study, we recapitulated the pro-regenerative and immunosuppressive functions of tumor-associated macrophages (TAMs) in non-tumor-derived macrophages, endowing the latter with characteristics for promoting diabetic wound healing - termed TAMs-educated macrophages (TAMEMs). To eliminate the use of tumor-derived sources and devise a more controllable method to prepare TAMEM-like cells, in this study, we identify a cocktail comprising five recombinant proteins as an essential condition to induce non-polarized macrophages (termed TAMEMs5) into therapeutic cells with pro-healing functions. The screened five factors are osteopontin (OPN), macrophage inflammatory protein (MIP)-2, chemokine (C-C motif) ligand 8 (CCL8), vascular endothelial growth factor (VEGF)-B, and macrophage colony-stimulating factor (M-CSF). We demonstrate the rationale for screening these factors and the phenotype of TAMEMs5 prepared from murine bone marrow-derived macrophages, which exhibit angiogenic and immunomodulatory effects in vitro. Then, we induce primary human monocytes from periphery blood into TAMEMs5, which show pro-healing effects in a human primary cell-based ex vivo model (T-SkinTM). Our study demonstrates a simple, effective, and controllable approach to induce primary macrophages to possess repairing activities, which may provide insights for developing cell-based therapeutics for non-healing wounds clinically.

Epigenetic modification: A novel insight into diabetic wound healing

Wound healing is an intricate and fine regulatory process. In diabetic patients, advanced glycation end products (AGEs), excessive reactive oxygen species (ROS), biofilm formation, persistent inflammation, and angiogenesis regression contribute to delayed wound healing. Epigenetics, the fast-moving science in the 21st century, has been up to date and associated with diabetic wound repair. In this review, we go over the functions of epigenetics in diabetic wound repair in retrospect, covering transcriptional and posttranscriptional regulation. Among these, we found that histone modification is widely involved in inflammation and angiogenesis by affecting macrophages and endothelial cells. DNA methylation is involved in factors regulation in wound repair but also affects the differentiation phenotype of cells in hyperglycemia. In addition, noncodingRNA regulation and RNA modification in diabetic wound repair were also generalized. The future prospects for epigenetic applications are discussed in the end. In conclusion, the study suggests that epigenetics is an integral regulatory mechanism in diabetic wound healing.

Human fetal dermal fibroblast-myeloid cell diversity is characterized by dominance of pro-healing Annexin1-FPR1 signaling

Fetal skin achieves scarless wound repair. Dermal fibroblasts play a central role in extracellular matrix deposition and scarring outcomes. Both fetal and gingival wound repair share minimal scarring outcomes. We tested the hypothesis that compared to adult skin fibroblasts, human fetal skin fibroblast diversity is unique and partly overlaps with gingival skin fibroblasts. Human fetal skin (FS, n = 3), gingiva (HGG, n = 13), and mature skin (MS, n = 13) were compared at single-cell resolution. Dermal fibroblasts, the most abundant cluster, were examined to establish a connectome with other skin cells. Annexin1-FPR1 signaling pathway was dominant in both FS as well as HGG fibroblasts and related myeloid cells while scanty in MS fibroblasts. Myeloid-specific FPR1-ORF delivered in murine wound edge using tissue nanotransfection (TNT) technology significantly enhanced the quality of healing. Pseudotime analyses identified the co-existence of an HGG fibroblast subset with FPR1high myeloid cells of fetal origin indicating common underlying biological processes.

Roles of MicroRNA-21 in Skin Wound Healing: A Comprehensive Review

MicroRNA-21 (miR-21), one of the early mammalian miRNAs identified, has been detected to be upregulated in multiple biological processes. Increasing evidence has demonstrated the potential values of miR-21 in cutaneous damage and skin wound healing, but lack of a review article to summarize the current evidence on this issue. Based on this review, relevant studies demonstrated that miR-21 played an essential role in wound healing by constituting a complex network with its targeted genes (i.e., PTEN, RECK. SPRY1/2, NF-κB, and TIMP3) and the cascaded signaling pathways (i.e., MAPK/ERK, PI3K/Akt, Wnt/β-catenin/MMP-7, and TGF-β/Smad7-Smad2/3). The treatment effectiveness developed by miR-21 might be associated with the promotion of the fibroblast differentiation, the improvement of angiogenesis, anti-inflammatory, enhancement of the collagen synthesis, and the re-epithelialization of the wound. Currently, miRNA nanocarrier systems have been developed, supporting the feasibility clinical feasibility of such miR-21-based therapy. After further investigations, miR-21 may serve as a potential therapeutic target for wound healing.

HSP47 contributes to angiogenesis by induction of CCL2 in bladder cancer

Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone and is involved in tumor progression by promoting angiogenesis. However, the regulatory network of HSP47 in angiogenesis remains elusive. In this study, we report a novel mechanism of HSP47-induced angiogenesis in bladder cancer (BC). We find that HSP47 is abnormally overexpressed in BC and is correlated with poor prognosis. HSP47 down-regulation suppresses angiogenesis in BC cells. Mechanistically, activation of the ERK pathway and induction of C-C Motif Chemokine Ligand 2 (CCL2) are responsible for HSP47-induced angiogenesis. The correlation between HSP47 with CCL2 and angiogenesis is further confirmed in BC clinical samples. Taken together, our findings suggest that HSP47 contributes to BC angiogenesis by induction of CCL2 and provide a potential anti-angiogenesis target for BC therapy.