Neuropeptide Substance P Enhances Skin Wound Healing In Vitro and In Vivo under Hypoxia

Andrographolide represses HIF-1α and VEGFA expression, thus inhibiting hypoxia-induced proliferation, oxidative stress, and inflammatory cytokine secretion in human keratinocytes

Epidermal hypoxia, hyperproliferation of keratinocytes, and inflammation in skin lesions are relevant to the pathogenesis of inflammatory skin diseases, including psoriasis. Andrographolide (Andro) is a natural labdane diterpene with diverse biofunctions. Andro has been reported to alleviate psoriasis in mice. However, the exact mechanisms need further study. Our results demonstrated that Andro inhibited hypoxia-induced proliferation of human keratinocytes. Andro also protected the keratinocytes from hypoxia-induced oxidative stress and inflammatory response. Furthermore, we found that Andro suppressed the expression of HIF-1α and VEGFA expression in hypoxia-exposed keratinocytes. Overexpression of either HIF-1α or VEGFA attenuated the inhibitory effects of Andro on hypoxia-induced proliferation, oxidative stress, and inflammatory cytokine secretion. In summary, our results demonstrated that Andro protected keratinocytes from hypoxia-induced proliferation, oxidative stress, and inflammatory cytokine secretion by suppressing HIF-1α and VEGFA expression. Our findings provide an unreported insight into the potential use of Andro as an effective agent for the treatment of inflammatory skin diseases such as psoriasis in the future.

A calcitonin gene-related peptide co-crosslinked hydrogel promotes diabetic wound healing by regulating M2 macrophage polarization and angiogenesis

Delayed diabetic wound (DBW) healing is a severe complication of diabetes, characterized notably by peripheral sensory neuropathy. The underlying mechanism of sensory nerves and DBW remain unclear. Here, we demonstrate the role of calcitonin gene-related peptide (CGRP) in regulating epithelialization and angiogenesis in DBW. Subsequently, we design and synthesis a gelatin methacryloyl (GelMA-CGRP) hydrogel that slowly releases CGRP, and evaluated its effect on promoting DBW healing. The results show that CGRP is abnormally downregulated in DBW, and CGRP ablation further delays DBW healing. This is due to the reduced M2 polarization and decreased angiogenesis in the absence of CGRP, whereas local application of GelMA-CGRP accelerates DBW healing. Mechanistic studies indicate that CGRP promotes M2 macrophage polarization by inhibiting the p53 signaling pathway and enhances endothelial cell function, thereby accelerating DBW healing. These findings suggest that CGRP could provide a novel therapeutic approach for diabetic wound treatment. STATEMENT OF SIGNIFICANCE: Current methods for treating diabetic wounds have many limitations. Compared to conventional dressings, hydrogels combined with drugs or biological factors to promote diabetic wound healing have become an important research direction in recent years. This study reveals the key role of CGRP in the pathogenesis of diabetic wounds. The research found that CGRP promotes M2 macrophage polarization and angiogenesis by inhibiting the p53 signaling pathway, thereby promoting diabetic wound healing. We further utilized the carrier properties of GelMA hydrogel to develop a GelMA-CGRP hydrogel material that slowly delivers CGRP and effectively treats diabetic wounds. This material demonstrates strong biocompatibility and antimicrobial properties, offering a novel approach for the treatment of diabetic wounds.

Efficacy and mechanisms of concentrated growth factor on facial nerve rehabilitation in a rabbit model

Accelerated rehabilitation following facial nerve injury presents unique clinical challenges. This study evaluates the therapeutic effects of concentrated growth factor (CGF) on facial nerve recovery in a rabbit model and on RSC96 Schwann cells. Characterization of the CGF membrane (CGFM) revealed a three-dimensional fibrin network with embedded platelets, and representative growth factors, including TGF-β1, PDGF-BB, IGF-1, bFGF, and VEGF, were detected. In vivo, the Crush + CGFM group exhibited enhanced axon and myelin regeneration, increased Schwann cell proliferation, and improved facial nerve function compared to the Crush group. In vitro, CGF treatment significantly promoted the proliferation and migration of RSC96 cells and facilitated axon elongation in NG108-15 cells compared to controls. Mechanistically, CGF treatment led to a significant increase in PDGFRβ phosphorylation. Inhibition of this pathway with SU16f decreased Schwann cell activity and hindered overall nerve rehabilitation. These results underscore CGF's potential to accelerate nerve repair by promoting axon and myelin regeneration and enhancing Schwann cell biological activity, with the PDGFRβ pathway playing a crucial regulatory role. This study highlights CGF as a promising therapeutic strategy for improving facial nerve rehabilitation.

NK1 receptor mediates cerebral cellular and extracellular morphological changes during the LPS-induced febrile response

Fever elicited by bacterial lypopolyssacharide (LPS) is mediated by pro-inflammatory cytokines, which activate central mediators and regulate the hypothalamic temperature setpoint. This response is often accompanied by morphological changes involving the extracellular matrix, neurons and glial cells, with significant health impacts. The NK1 receptor is involved in the febrile response induced by LPS but its effects over the extracellular matrix in the context of neuroinflammation remain unknown. The present work aims to clarify the extracellular changes associated with NK1 signaling in LPS-induced fever. Male Wistar rats were exposed to LPS intraperitoneally. Experimental groups were pre-treated intracerebroventricularly with the NK1 selective inhibitor SR140333B or saline. Histological changes involving the brain extracellular matrix were evaluated using hematoxylin and eosin, Mason's trichrome, picrosirius, alcian blue, periodic acid Schiff's stains. The expression of matrix metalloproteinase 9 (MMP9) was studied using confocal microscopy. Fever was accompanied by edema, perivascular lymphoplamacytic and neutrophylic infiltration, spongiosis and MMP9 overexpression. SR140333B significantly reduced LPS-induced fever (p < 0.0001), MMP9 overexpression (p < 0.01) and associated histological changes. These results contribute to characterize cerebral extracellular matrix changes associated with LPS-induced fever. Overall, the present work supports a role for NK1 receptor in these neuroinflammatory changes, involving MMP9 overexpression, edema and leukocytic infiltration.

IGF-1 inhibits inflammation and accelerates angiogenesis via Ras/PI3K/IKK/NF-κB signaling pathways to promote wound healing

Exogenous insulin-like growth factor-1 (IGF-1) has been reported to promote wound healing through regulation of vascular endothelial cells (VECs). Despite the existing studies of IGF-1 on VEC and its role in angiogenesis, the mechanisms regarding anti-inflammatory and angiogenetic effects of IGF-1 remain unclear. In this study, we investigated the wound-healing process and the related signaling pathway of IGF-1 using an inflammation model induced by IFN-γ. The results demonstrated that IGF-1 can increase cell proliferation, suppress inflammation in VECs, and promote angiogenesis. In vivo studies further confirmed that IGF-1 can reduce inflammation, enhance vascular regeneration, and improve re-epithelialization and collagen deposition in acute wounds. Importantly, the Ras/PI3K/IKK/NF-κB signaling pathways was identified as the mechanisms through which IGF-1 exerts its anti-inflammatory and pro-angiogenic effects. These findings contribute to the understanding of IGF-1's role in wound healing and may have implications for the development of new wound treatment approaches.

[Role of neodymium laser in surgery: stimulation of postoperative surgical wounds healing. Results of clinical studies]

OBJECTIVE

To prove the effectiveness of the low-intensity laser radiation application in the treatment of wounds of different origin.

MATERIAL AND METHODS

The clinical study involved 110 persons, divided into 55 subjects in both the study and control groups. The patients of the study group were exposed to the long-wave short-pulse neodymium laser immediately and within 35 days after interventions with a skin incision using it, in a way that wound treated with laser received low-level laser therapy. The control group patients' wounds were treated with standard methods by the means of topical drugs corresponding to the clinical manifestations of the wound process in each particular case. The study was carried out in the hospital of the department of maxillofacial and plastic surgery of the dental complex of the «Russian University of Medicine» from 2019 to 2022, and further conservative treatment was conducted in the department of dermatology and cosmetology of the University Hospital of the Medical Graduate School (Institute) of the RSSU. All wounds were classified into three groups for the convenience of systematization and formation of a generalized treatment protocol for postoperative surgical wounds.

RESULTS

The objectivity and optimality of the chosen by us actions were confirmed in the conducted work. The formed scars were visually assessed on the POSAS scale at the end of the treatment by patients and 4 independent doctors, as well as each scar was visually assessed by four independent doctors and patients. At the end of the study we formed and proposed an algorithm for the treatment of surgical wounds of various origins. The parameters of the Aerolase Neo Light Pod neodymium laser for the treatment of patients with different types of skin wounds were clinically determined. Experimentally proven properties of the Aerolase Neo Light Pod neodymium laser on accelerating the healing process of surgical wounds through photobiomodulation mechanism support their regeneration with the formation of negligible normotrophic scars, as well as reduce the length of patients' treatment in surgical hospitals, as compared to patients receiving standard external drugs.

Neuropeptide substance P: A promising regulator of wound healing in diabetic foot ulcers

In the past, neuropeptide substance P (SP) was predominantly recognized as a neuroinflammatory factor, while its potent healing activity was overlooked. This paper aims to review the regulatory characteristics of neuropeptide SP in both normal and diabetic wound healing. SP actively in the regulation of wound healing-related cells directly and indirectly, exhibiting robust inflammatory properties, promoting cell proliferation and migration and restoring the activity and paracrine ability of skin cells under diabetic conditions. Furthermore, SP not only regulates healing-related cells but also orchestrates the immune environment, thereby presenting unique and promising application prospects in wound intervention. As new SP-based preparations are being explored, SP-related drugs are poised to become an effective therapeutic intervention for diabetic foot ulcers (DFU).

4-Aminopyridine Induces Nerve Growth Factor to Improve Skin Wound Healing and Tissue Regeneration

The discovery of ways to enhance skin wound healing is of great importance due to the frequency of skin lesions. We discovered that 4-aminopyridine (4-AP), a potassium channel blocker approved by the FDA for improving walking ability in multiple sclerosis, greatly enhances skin wound healing. Benefits included faster wound closure, restoration of normal-appearing skin architecture, and reinnervation. Hair follicle neogenesis within the healed wounds was increased, both histologically and by analysis of K15 and K17 expression. 4-AP increased levels of vimentin (fibroblasts) and alpha-smooth muscle actin (α-SMA, collagen-producing myofibroblasts) in the healed dermis. 4-AP also increased neuronal regeneration with increased numbers of axons and S100⁺ Schwann cells (SCs), and increased expression of SRY-Box Transcription Factor 10 (SOX10). Treatment also increased levels of transforming growth factor-β (TGF-β), substance P, and nerve growth factor (NGF), important promoters of wound healing. In vitro studies demonstrated that 4-AP induced nerve growth factor and enhanced proliferation and migration of human keratinocytes. Thus, 4-AP enhanced many of the key attributes of successful wound healing and offers a promising new approach to enhance skin wound healing and tissue regeneration.

Substance P, A Promising Therapeutic Target in Musculoskeletal Disorders

A large number of studies have focused on the role of substance P (SP) and the neurokinin-1 receptor (NK1R) in the pathogenesis of a variety of medical conditions. This review provides an overview of the role of the SP-NK1R pathway in the pathogenesis of musculoskeletal disorders and the evidence for its role as a therapeutic target for these disorders, which are major public health problems in most countries. To summarize, the brief involvement of SP may affect tendon healing in an acute injury setting. SP combined with an adequate conjugate can be a regenerative therapeutic option in osteoarthritis. The NK1R antagonist is a promising agent for tendinopathy, rheumatoid arthritis, and osteoarthritis. Research on the SP-NK1R pathway will be helpful for developing novel drugs for osteoporosis.

The Regenerative Potential of Substance P

Wound healing is a highly coordinated process which leads to the repair and regeneration of damaged tissue. Still, numerous diseases such as diabetes, venous insufficiencies or autoimmune diseases could disturb proper wound healing and lead to chronic and non-healing wounds, which are still a great challenge for medicine. For many years, research has been carried out on finding new therapeutics which improve the healing of chronic wounds. One of the most extensively studied active substances that has been widely tested in the treatment of different types of wounds was Substance P (SP). SP is one of the main neuropeptides released by nervous fibers in responses to injury. This review provides a thorough overview of the application of SP in different types of wound models and assesses its efficacy in wound healing.

The Modulatory Influence of Plant-Derived Compounds on Human Keratinocyte Function

The plant kingdom is a rich source of secondary metabolites with numerous properties, including the potential to modify keratinocyte biology. Keratinocytes are important epithelial cells that play a protective role against various chemical, physical and biological stimuli, and participate in reactive oxygen scavenging and inflammation and wound healing processes. The epidermal cell response may be modulated by phytochemicals via changes in signal transduction pathways. Plant extracts and single secondary compounds can possess a high antioxidant capacity and may suppress reactive oxygen species release, inhibit pro-apoptotic proteins and apoptosis and activate antioxidant enzymes in keratinocytes. Moreover, selected plant extracts and single compounds also exhibit anti-inflammatory properties and exposure may result in limited production of adhesion molecules, pro-inflammatory cytokines and chemokines in keratinocytes. In addition, plant extracts and single compounds may promote keratinocyte motility and proliferation via the regulation of growth factor production and enhance wound healing. While such plant compounds may modulate keratinocyte functions, further in vitro and in vivo studies are needed on their mechanisms of action, and more specific toxicity and clinical studies are needed to ensure their effectiveness and safety for use on human skin.