Effects of different transforming growth factor beta (TGF-β) isomers on wound closure of bone cell monolayers

Mathematical investigation of normal and abnormal wound healing dynamics: local and non-local models

The movement of cells during (normal and abnormal) wound healing is the result of biomechanical interactions that combine cell responses with growth factors as well as cell-cell and cell-matrix interactions (adhesion and remodelling). It is known that cells can communicate and interact locally and non-locally with other cells inside the tissues through mechanical forces that act locally and at a distance, as well as through long non-conventional cell protrusions. In this study, we consider a non-local partial differential equation model for the interactions between fibroblasts, macrophages and the extracellular matrix (ECM) via a growth factor (TGF-$ \beta $) in the context of wound healing. For the non-local interactions, we consider two types of kernels (i.e., a Gaussian kernel and a cone-shaped kernel), two types of cell-ECM adhesion functions (i.e., adhesion only to higher-density ECM vs. adhesion to higher-/lower-density ECM) and two types of cell proliferation terms (i.e., with and without decay due to overcrowding). We investigate numerically the dynamics of this non-local model, as well as the dynamics of the localised versions of this model (i.e., those obtained when the cell perception radius decreases to 0). The results suggest the following: (ⅰ) local models explain normal wound healing and non-local models could also explain abnormal wound healing (although the results are parameter-dependent); (ⅱ) the models can explain two types of wound healing, i.e., by primary intention, when the wound margins come together from the side, and by secondary intention when the wound heals from the bottom up.

Review on Additives in Hydrogels for 3D Bioprinting of Regenerative Medicine: From Mechanism to Methodology

The regeneration of biological tissues in medicine is challenging, and 3D bioprinting offers an innovative way to create functional multicellular tissues. One common way in bioprinting is bioink, which is one type of the cell-loaded hydrogel. For clinical application, however, the bioprinting still suffers from satisfactory performance, e.g., in vascularization, effective antibacterial, immunomodulation, and regulation of collagen deposition. Many studies incorporated different bioactive materials into the 3D-printed scaffolds to optimize the bioprinting. Here, we reviewed a variety of additives added to the 3D bioprinting hydrogel. The underlying mechanisms and methodology for biological regeneration are important and will provide a useful basis for future research.

Ubiquitin-Specific Protease 15 Maintains Transforming Growth Factor-β Pathway Activity by Deubiquitinating Transforming Growth Factor-β Receptor I during Wound Healing

Wound healing is a process of cutaneous barrier reconstruction that occurs after skin injury and involves diverse cytokines and cell types. Similar to several deubiquitinating enzymes, ubiquitin-specific protease 15 (USP15) can remove ubiquitin chains from specific proteins to rescue them from degradation. However, the regulatory role of USP15 in wound healing remains unclear. We investigated the dynamic function of USP15 in wound healing. First, in USP15 knockout mice, we observed a significant delay in wound closure. In addition, inhibition of cell proliferation and migration was observed in USP15-silenced human dermal fibroblasts. Through RNA sequencing, it was revealed that the transforming growth factor-β (TGF-β) pathway was suppressed after USP15 knockdown. Furthermore, coimmunoprecipitation demonstrated that USP15 could interact with TGF-β receptor I and promote its deubiquitination, thereby maintaining TGF-β signaling pathway activity by enhancing TGF-β receptor I stability. These observations shed light on the function and mechanisms of USP15-mediated modulation of the TGF-β signaling pathway during wound healing, thus providing a novel potential target for the treatment of refractory wounds.

GP73 promotes invasion and metastasis of bladder cancer by regulating the epithelial-mesenchymal transition through the TGF-β1/Smad2 signalling pathway

This study investigated the effects of Golgi membrane protein 73 (GP73) on the epithelial-mesenchymal transition (EMT) and on bladder cancer cell invasion and metastasis through the TGF-β1/Smad2 signalling pathway. Paired bladder cancer and adjacent tissue samples (102) and normal bladder tissue samples (106) were obtained. Bladder cancer cell lines (T24, 5637, RT4, 253J and J82) were selected and assigned to blank, negative control (NC), TGF-β, thrombospondin-1 (TSP-1), TGF-β1+ TSP-1, GP73-siRNA-1, GP73-siRNA-2, GP73-siRNA-1+ TSP-1, GP73-siRNA-1+ pcDNA-GP73, WT1-siRNA and WT1-siRNA + GP73-siRNA-1 groups. Expressions of GP73, TGF-β1, Smad2, p-Smad2, E-cadherin and vimentin were detected using RT-qPCR and Western blotting. Cell proliferation, migration and invasion were determined using MTT assay, scratch testing and Transwell assay, respectively. Compared with the blank and NC groups, levels of GP73, TGF-β1, Smad2, p-Smad2, N-cadherin and vimentin decreased, and levels of WT1 and E-cadherin increased in the GP73-siRNA-1 and GP73-siRNA-2 groups, while the opposite results were observed in the WT1 siRNA, TGF-β, TSP-1 and TGF-β + TSP-1 groups. Cell proliferation, migration and invasion notably decreased in the GP73-siRNA-1 and GP73-siRNA-2 groups in comparison with the blank and NC groups, while in the WT1 siRNA, TGF-β, TSP-1 and TGF-β + TSP-1 groups, cell migration, invasion and proliferation showed the reduction after the EMT. These results suggest that GP73 promotes bladder cancer invasion and metastasis by inducing the EMT through down-regulating WT1 levels and activating the TGF-β1/Smad2 signalling pathway.

Overexpression of immunosuppressive cytokines is associated with poorer clinical stage of oral squamous cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the expression of IL-10 and TGF-β2 in oral squamous cell carcinoma (OSCC) and its relationship with prognostic clinical and microscopic parameters.

DESIGN

Immunohistochemistry was used to assess the expression of IL-10 and TGF-β2 in OSCC samples from 43 patients who had undergone surgical excision and neck dissection. Metastatic lymph nodes were included in the study (n=23). Samples of healthy oral mucosa (n=20) were used as controls. The sections were evaluated using a semi-quantitative method in conjunction with staining intensity.

RESULTS

Our findings showed that the expression of IL-10 and TGF-β2 by neoplastic and stromal cells was high in most of the OSCC samples (>70% of samples), especially when compared to the controls (≅10% of samples) (P<0.05). OSCC neoplastic cells in cervical lymph nodes were also positive for IL-10 and TGF-β2. An association between high expression of IL-10 by neoplastic cells and advanced clinical stage (T3-T4) was verified (P=0.02). Although not statistically significant, the expression of TGF-β2 was also augmented in advanced stage tumours.

CONCLUSIONS

These data suggest that the ability of OSCC neoplastic cells to secrete immunosuppressive cytokines could contribute to clinical progression by maintaining a microenvironment conducive to evasion and tumour proliferation.