Cooperation of TGF-β and FGF signalling pathways in skin development

Effects of no-ozone cold plasma and mouse mesenchymal stem cell treatments on wound healing in a mouse skin model

Skin wounds heal faster during stem cell differentiation. Cold plasma reportedly enhances cell proliferation and differentiation and enhances the efficacy of stem cell therapy. However, the exact mechanism of action involved remains unknown. Therefore, this study aimed to evaluate the effect of a combination therapy involving the transplantation of mouse mesenchymal stem cells (mMSCs) into mice with wounds followed by their activation using no-ozone cold plasma (NCP). Balb/c mMSCs were transplanted into BALB/c mice and treated with NCP for 5 min. The animals were divided into four groups based on treatments received: no treatment (Wound), mMSCs only (mMSC), NCP only (NCP), and both mMSC and NCP (mMSC + NCP). NCP treatment was administered six times over two weeks, and tissue samples were prepared by sacrificing the mice in the 1st and 2nd weeks. The wound healing efficacy was assessed using morphological, histological, and molecular approaches including wound healing length measurements, hematoxylin and eosin staining, Masson trichrome staining, immunofluorescence staining, immunohistochemistry, and real-time polymerase chain reaction. The wound healing effect was better in the mMSC + NCP group than that in the groups treated with either. Tracking the injected mMSCs in mice also revealed that the mMSC + NCP group had a greater survival rate. Furthermore, upon wound healing, the mMSC + NCP group exhibited elevated levels of growth factors, like platelet-derived growth factor, transforming growth factor-beta, and vascular endothelial growth factor. These results suggest that NCP stimulated transplanted mMSCs, resulting in faster wound healing. Therefore, further studies are warranted in preclinical and clinical studies to confirm this effect.

4-aminopyridine attenuates inflammation and apoptosis and increases angiogenesis to promote skin regeneration following a burn injury

Severe thermal skin burns are complicated by inflammation and apoptosis, which delays wound healing and contributes to significant morbidity. Diverse treatments demonstrate limited success with mitigating these processes to accelerate healing. Agents that alter cell behavior to improve healing would alter treatment paradigms. We repurposed 4-aminopyridine (4-AP), a drug approved by the US FDA for multiple sclerosis, to treat severe burns. We found that 4-AP, in the early stages of burn healing, significantly reduced the expression of pro-inflammatory cytokines IL1β and TNFα while increasing the expression of anti-inflammatory markers CD206, ARG-1, and IL10. 4-AP attenuated apoptosis, with decreases in apoptotic markers BAX, caspase-9, and caspase-3 and increases in anti-apoptotic markers BCL2 and BCL-XL. Furthermore, 4-AP promoted angiogenesis through increases in the expression of CD31, VEGF, and eNOS. Together, these likely contributed to accelerated burn wound closure, as demonstrated in increased keratinocyte proliferation (K14) and differentiation (K10) markers. In the later stages of burn healing, 4-AP increased TGFβ and FGF levels, which are known to mark the transformation of fibroblasts to myofibroblasts. This was further demonstrated by an increased expression of α-SMA and vimentin, as well as higher levels of collagen I and III, MMP 3, and 9 in animals treated with 4-AP. Our findings support the idea that 4-AP may have a novel, clinically relevant therapeutic use in promoting burn wound healing.

Beyond skin deep: Revealing the essence of iPS cell-generated skin organoids in regeneration

Various methods have been used for in vivo and in vitro skin regeneration, including stem cell therapy, tissue engineering, 3D printing, and platelet-rich plasma (PRP) injection therapy. However, these approaches are rooted in the existing knowledge of skin structures, which overlook the normal physiological processes of skin development and fall short of replicating the skin's regenerative processes outside the body. This comprehensive review primarily focuses on skin organoids derived from human pluripotent stem cells, which have the capacity to regenerate human skin tissue by restoring the embryonic skin structure, thus offering a novel avenue for producing in vitro skin substitutes. Furthermore, they contribute to the repair of damaged skin lesions in patients with systemic sclerosis or severe burns. Particular emphasis will be placed on the origins, generations, and applications of skin organoids, especially in dermatology, and the challenges that must be addressed before clinical implementation.

Signalling interaction between β-catenin and other signalling molecules during osteoarthritis development

Osteoarthritis (OA) is the most prevalent disorder of synovial joint affecting multiple joints. In the past decade, we have witnessed conceptual switch of OA pathogenesis from a 'wear and tear' disease to a disease affecting entire joint. Extensive studies have been conducted to understand the underlying mechanisms of OA using genetic mouse models and ex vivo joint tissues derived from individuals with OA. These studies revealed that multiple signalling pathways are involved in OA development, including the canonical Wnt/β-catenin signalling and its interaction with other signalling pathways, such as transforming growth factor β (TGF-β), bone morphogenic protein (BMP), Indian Hedgehog (Ihh), nuclear factor κB (NF-κB), fibroblast growth factor (FGF), and Notch. The identification of signalling interaction and underlying mechanisms are currently underway and the specific molecule(s) and key signalling pathway(s) playing a decisive role in OA development need to be evaluated. This review will focus on recent progresses in understanding of the critical role of Wnt/β-catenin signalling in OA pathogenesis and interaction of β-catenin with other pathways, such as TGF-β, BMP, Notch, Ihh, NF-κB, and FGF. Understanding of these novel insights into the interaction of β-catenin with other pathways and its integration into a complex gene regulatory network during OA development will help us identify the key signalling pathway of OA pathogenesis leading to the discovery of novel therapeutic strategies for OA intervention.

A novel SNP in NKX1-2 gene is associated with carcass traits in Dezhou donkey

BACKGROUND

At present, donkey meat in the market shows an imbalance between supply and demand, and there is an urgent need to cultivate a meat-type Dezhou donkey breed. On the one hand, it can improve the imbalance in the market, and on the other hand, it can promote the rapid development of the donkey industry. This study aimed to reveal significant genetic variation in the NK1 homeobox 2 gene (NKX1-2) of Dezhou donkeys and investigate the association between genotype and body size in Dezhou donkeys.

RESULTS

In this study, a SNP (g.54704925 A > G) was identified at the exon4 by high-depth resequencing of the Dezhou donkey NKX1-2 gene. The AA genotype is the dominant genotype. The g.54704925 A > G site was significantly associated with body length, thoracic girth, and hide weight (P < 0.05), while it was highly significantly associated with body height and carcass weight (P < 0.01) in Dezhou donkeys.

CONCLUSION

Overall, the results of this study showed that the NKX1-2 gene could be a candidate gene for breeding meat-type Dezhou donkeys, and the g.54704925 A > G locus could be used as a marker locus for selection and breeding.