Inflammation and cutaneous nervous system involvement in hypertrophic scarring

Are symptoms in pathologic scars related to nerve function or density? A scoping review

BACKGROUND

Hypertrophic scars and keloids are forms of pathologic scarring that can give rise to pain and pruritus. The link between nerve function and nerve density and the symptoms in pathologic scars (PS) remains unclear.

OBJECTIVE

We aim to assess current knowledge on nerve function and nerve density in PS, and to explore a possible association between alterations in sensibility/nerve density and pathologic scar symptoms.

METHODS

A scoping review was conducted. After performing a systematic search using PubMed, Embase and Web-of-Science, relevant papers were selected and analyzed by 2 reviewers. Data was charted in tables in combination with a narrative summary of main findings.

RESULTS

Nineteen studies were included. Overall, functional sensibility in PS seems disturbed, with a higher frequency of allodynia and altered thermosensory thresholds, suggesting involvement of small fiber neuropathy. Nerve fiber density varied with the investigated skin layer and the used staining techniques, which implied limitations to compare findings from different studies. However, evidence suggests involvement of neuropeptides in the pathologic scar formation and symptomatology.

CONCLUSIONS

Wide heterogeneity between studies exists. Therefore, no firm conclusions can be formulated. However, evidence suggests involvement of the cutaneous nervous system by neurogenic inflammation in the pathophysiology of pathologic scars and their symptoms.

LEP and LEPR are possibly a double-edged sword for wound healing

Wound healing is a complex and error-prone process. Wound healing in adults often leads to the formation of scars, a type of fibrotic tissue that lacks skin appendages. Hypertrophic scars and keloids can also form when the wound-healing process goes wrong. Leptin (Lep) and leptin receptors (LepRs) have recently been shown to affect multiple stages of wound healing. This effect, however, is paradoxical for scarless wound healing. On the one hand, Lep exerts pro-inflammatory and profibrotic effects; on the other hand, Lep can regulate hair follicle growth. This paper summarises the role of Lep and LepRs on cells in different stages of wound healing, briefly introduces the process of wound healing and Lep and LepRs, and examines the possibility of promoting scarless wound healing through spatiotemporal, systemic, and local regulation of Lep levels and the binding of Lep and LepRs.

Research status and hot topics of the effects of skin innervation on wound healing from 1959 to 2022: A bibliometric analysis

Background

Skin innervation plays an important role in wound healing by either direct contact with or indirect secretions that impact skin cells. Many studies in this field have been published; however, there is a lack of bibliometric analyses focusing on the effect of skin innervation on skin wound healing. In this study, we aimed to analyse the research trends, status, and hotspots in this field.

Methods

Reviews and articles published in English were extracted from the Web of Science Core Collection (WoSCC) database based on subject term searches. Microsoft Office Excel, VOSviewer, and CiteSpace were used to analyse publication date, country or region, institution, author, and author keywords.

Results

A total of 368 papers published between 1959 and 2022 were included in the analysis. Although there was a pulsation during this period, there was an overall upward trend in studies related to the effect of skin innervation on wound healing. The United States, particularly the University of Washington, and Gibran, Nicole S. from the University of Washington, was the most active in this field. Wound Repair and Regeneration published the most relevant literature, and “Calcitonin gene-related peptide: physiology and pathophysiology” had the highest total number of citations. “Diabetic foot ulcer,” “epidermal stem cells,” “mesenchymal stem cells,” and “mast cells” are current and potential future research hotspots.

Conclusion

This bibliometric analysis will inform the overall trends in research related to the effect of skin innervation on wound healing, summarise relevant research hotspots, and guide future work.

Traditional Chinese medicine for hypertrophic scars—A review of the therapeutic methods and potential effects

Hypertrophic scar (HS) is a typical pathological response during skin injury, which can lead to pain, itching, and contracture in patients and even affect their physical and mental health. The complexity of the wound healing process leads to the formation of HS affected by many factors. Several treatments are available for HS, whereas some have more adverse reactions and can even cause new injuries with exacerbated scarring. Traditional Chinese Medicine (TCM) has a rich source, and most botanical drugs have few side effects, providing new ideas and methods for treating HS. This paper reviews the formation process of HS, the therapeutic strategy for HS, the research progress of TCM with its relevant mechanisms in the treatment of HS, and the related new drug delivery system of TCM, aiming to provide ideas for further research of botanical compounds in the treatment of HS, to promote the discovery of more efficient botanical candidates for the clinical treatment of HS, to accelerate the development of the new drug delivery system and the final clinical application, and at the same time, to promote the research on the anti-HS mechanism of multiherbal preparations (Fufang), to continuously improve the quality control and safety and effectiveness of anti-HS botanical drugs in clinical application.

Insight into the role of DPP-4 in fibrotic wound healing

Wound healing is a complex and long-term process consisting of hemostasis, inflammation, proliferation, and maturation/remodeling. These four stages overlap and influence each other; they affect wound healing in different ways, and if they do not function perfectly, they may cause scarring, proliferative scarring and keloid formation. A therapeutic target affecting wound healing in multiple ways will help the healing process proceed more effectively. DPP-4/CD26 is a multifunctional dimorphic glycoprotein widely distributed on the surface of a variety of cells, including fibroblasts and keratin-forming cells. It has been found to affect periwound inflammation, re-epithelialization, extracellular matrix secretion and skin fibrosis and is a potential target for promoting wound healing and inhibiting scar formation. After presenting a brief introduction of the wound healing process and DPP-4/CD26, this paper summarizes the effects of DPP-4/CD26 on cells involved in different stages of wound healing and discusses the feasibility of DPP-4/CD26 as a multifunctional target for the treatment of wound healing and inhibition of scar formation.

Therapeutic Strategies by Regulating Interleukin Family to Suppress Inflammation in Hypertrophic Scar and Keloid

Hypertrophic scar (HS) and keloid are fibroproliferative disorders (FPDs) of the skin due to aberrant wound healing, which cause disfigured appearance, discomfort, dysfunction, psychological stress, and patient frustration. The unclear pathogenesis behind HS and keloid is partially responsible for the clinical treatment stagnancy. However, there are now increasing evidences suggesting that inflammation is the initiator of HS and keloid formation. Interleukins are known to participate in inflammatory and immune responses, and play a critical role in wound healing and scar formation. In this review, we summarize the function of related interleukins, and focus on their potentials as the therapeutic target for the treatment of HS and keloid.

Autopsy and postnatal follow-up of prenatally diagnosed ventricular outpouchings

OBJECTIVES

Prenatal ventricular outpouchings (VOs), which include congenital ventricular aneurysms (CAs) and congenital ventricular diverticula (CD), are very rare. We describe the features and outcomes of prenatal VOs diagnosed over a 4-year period.

METHODS

Retrospective cohort study of cases of prenatal diagnoses of CAs and CD at our center between June 2014 and January 2018. The prenatal and postnatal echocardiogram data were reviewed, and telephone follow-up was conducted of liveborn cases.

RESULTS

A total of 25 VOs were identified. Two were lost to follow-up, 15 chose termination of pregnancy, and eight resulted in livebirths. Only two cases underwent autopsy: Histopathology showed that the CA wall was substituted by collagen fibers. At follow-up, none of the eight liveborn babies experienced adverse events, and three VOs near the tricuspid annulus almost disappeared, though one was extremely large.

CONCLUSIONS

In our center, all liveborn babies with VO had good prognoses. We hypothesize that VOs located near the right ventricular annulus may be caused by prenatally unbalanced pressure, given their decrease in size after birth when the right heart pressure declines.

The Effect of Wenxin Keli on the mRNA Expression Profile of Rabbits with Myocardial Infarction

Aims. The molecular mechanisms of Chinese traditional medicine Wenxin Keli (WXKL) were unknown. This study was aimed at exploring the effects of WXKL on the gene expression profile and pathological alteration of rabbits with myocardial infarction. Methods. Twenty male adult rabbits were randomly divided into 4 groups: sham, model, WXKL, and captopril groups. Model, WXKL, and captopril groups underwent the ligation of the left anterior descending coronary artery while sham group went through an identical procedure without ligation. WXKL (817 mg/kg/d), captopril (8 mg/kg/d), and distilled water (to model and sham groups) were administered orally to each group. After 4 weeks, the rabbits were examined with echocardiography and the hearts were taken for expression chip and pathological staining (H&E, Masson, and Tunel) studies. Results. The data revealed that WXKL downregulated genes associated with inflammation (CX3CR1, MRC1, and FPR1), apoptosis (CTSC and TTC5), and neurohumoral system (ACE and EDN1) and upregulated angiogenesis promoting genes such as RSPO3. Moreover, the results also showed that WXKL improved cardiac function and prevented histopathological injury and apoptosis. Conclusion. The present study demonstrated that WXKL might play an important role in inhibiting inflammation, renin-angiotensin system, and apoptosis. It might be a promising Chinese medicine in the treatment of patients with myocardial infarction.