Skin expansion is a widely utilized clinical technique for skin regeneration stimulated by mechanical stretch, yet the inadequate regenerative efficiency of skin remains a significant challenge. While metabolic reprogramming is a known adaptive response to mechanical stress, the specific metabolic alterations in the skin and their functional consequences in skin regeneration are unclear. Using a rat scalp expansion model combined with LC-MS/MS metabolomic analysis, we identified a significant upregulation of prostaglandin F2α (PGF2α) and activation of the arachidonic acid pathway in expanded skin. In addition, mechanical stretch was found to stimulate PGF2α secretion from human dermal fibroblasts, which then potently inhibited fibroblast proliferation and migration. Mechanistically, PGF2α acts through FP receptor activation, triggering mitochondrial damage, oxidative stress, and autophagic flux. Rescue experiments revealed that reactive oxygen species (ROS) served as the primary cytotoxic agent underlying the functional impairment, whereas autophagy functioned as a compensatory survival pathway. Collectively, these findings identify PGF2α as a key mechanotransduction mediator that signals through the FP receptor to dysregulate fibroblast function, with the net outcome determined by the balance between its induction of damaging ROS and a protective autophagic response. Targeting the PGF2α/FP receptor axis may therefore represent a promising therapeutic strategy to promote skin regeneration during skin expansion.

Background Tissue expansion is a clinically established technique for addressing severe soft tissue defects and organ deformities. However, its advancement is limited by suboptimal efficiency and related complications. Elucidating the molecular and cellular mechanisms of skin regeneration during tissue expansion is therefore critical for enhancing therapeutic efficacy and minimizing adverse events. Angiotensin-converting enzyme 2 (ACE2) plays pivotal roles in tissue remodeling and regeneration. Our prior work identified ACE2 as mechanosensitive gene activated by mechanical stretch. Nevertheless, its regulatory mechanisms in epidermal regeneration during tissue expansion remain unclear. Methods HaCaT cells were treated with the ACE2 inhibitor MLN-4760, siRNA, and overexpression plasmids. Cell proliferation and migration were assessed by EdU assay and wound healing assay respectively. Transcriptomic sequencing was conducted to identify the differentially expressed genes (DEGs) after ACE2 knockdown in keratinocytes, which highlighted tenascin-C (TNC) as a critical DEG associated with epidermal regeneration. TNC silencing in HaCaT cells was analyzed via EdU and wound healing assays. In vivo, MLN-4760 was topically applied to the expanded rat skin, with epidermal regeneration assessed by H&E and PCNA immunofluorescence staining, while western blotting was used to evaluate the expression of proteins involved in TNC/PI3K/AKT/mTOR pathway. Results Both pharmacological inhibition and genetic knockdown of ACE2 enhanced the proliferation and migration of HaCaT cells, whereas ACE2 overexpression suppressed these activities. Mechanistically, ACE2 modulated cell behaviors and function through the TNC. In vivo, topical MLN-4760 application in a rat skin expansion model increased epidermal thickness, promoted keratinocyte proliferation, upregulated TNC expression, and activated PI3K/AKT/mTOR signaling in expanded skin. Conclusions ACE2 negatively regulates epidermal regeneration during tissue expansion by suppressing TNC expression and the PI3K/AKT/mTOR pathway.

ABSTRACT Background Tissue expansion is a widely employed technique in reconstructive surgery aimed at addressing considerable skin defects. Nevertheless, matters like inadequate expansion capability and the potential for skin breakage due to the fragility of the expanded tissue present notable hurdles in enhancing skin regeneration during this process. Angiotensin‐converting enzyme 2 (ACE2) is recognized for its essential role in facilitating tissue renewal and regeneration. However, its precise impact on skin renewal during tissue expansion remains underexplored. This study seeks to elucidate ACE2's contribution to skin regeneration, specifically examining its role in collagen synthesis. Methods This study evaluated the expression and distribution of ACE2 in expanded skin using samples derived from both rats and human patients. Additionally, we investigated ACE2 expression in stretched keratinocytes in vitro. ACE2 knockout keratinocytes were transfected with small interfering RNA (siRNA) and cocultured with fibroblasts to observe fibroblast proliferation and migration. MLN‐4760 was utilized to inhibit the ACE2 enzymatic activity. Additionally, we analyzed parameters such as the size of expanded skin, dermal thickness, and the levels of collagen I (COL I), collagen III (COL III), and transforming growth factor β (TGF‐β) to elucidate the role of ACE2 in the context of expanded skin. Results The thinning of the expanded dermis was linked with elevated ACE2 expression. Enzymatic activity and ACE2 expression were both increased by mechanical stress. Additionally, ACE2 utilized Ang II to activate the migration and proliferation of human dermal fibroblasts. In vivo, the ACE2 inhibitor MLN‐4760 promoted skin regeneration and reduced dermal thinning by elevating COL I, COL III, and TGF‐β during expansion. Conclusions This finding suggest that mechanical stretch increases ACE2 expression, which in turn promotes the regeneration of expanded skin. The basis for using ACE2 in clinical settings to increase tissue expansion efficacy is provided by this work.

BACKGROUND:Head and neck burns frequently result in severe functional impairments and significant aesthetic deformities due to extensive soft tissue defects and contractures. Reconstructing these complex defects effectively remains challenging, necessitating strategies that optimize both functional outcomes and aesthetic satisfaction. This study aimed to evaluate the clinical efficacy and safety of pre-expanded internal mammary artery perforator (IMAP) and transverse cervical artery perforator (TCAP) flaps for reconstructing cervicofacial deformities resulting from deep burns. METHODS:A retrospective review was conducted on 36 patients (14 males, 22 females; mean age 24 years, range 8-45) treated between January 2020 and December 2023 using 42 pre-expanded anterior chest flaps. Patients were classified into 2 anatomically distinct groups based on the location of their cervicofacial deformities. Type I deformities primarily involved the mandibular region (chin and lower cheek), for which pre-expanded IMAP flaps were utilized. Type II deformities involved the cervical region (neck and supraclavicular area), reconstructed using pre-expanded TCAP flaps. This classification guided flap selection to optimize tissue matching and functional restoration. All cases involved a 2-stage approach comprising soft-tissue expansion followed by scar excision and contracture release. Outcomes assessed at 6 months postoperatively included flap survival, functional recovery (neck mobility), aesthetic results, and patient satisfaction. RESULTS:Flap survival was 100%, with no congestion or necrosis reported. Two patients experienced minor infections during the expansion phase, managed successfully with antibiotics. All donor sites were closed primarily without grafting. Postoperative assessments revealed that neck mobility improved significantly, with all patients achieving neck extension exceeding 110° and no residual functional limitations. Aesthetic outcomes were rated as good by 83.3% of patients and acceptable by 16.7%. No donor-site complications or dissatisfaction were reported. CONCLUSION:Pre-expanded IMAP and TCAP flaps provide reliable vascularity and optimal functional and aesthetic outcomes in cervicofacial reconstruction after deep burn injuries. This structured classification and treatment algorithm allows tailored reconstructive strategies based on defect location and vascular anatomy, promoting enhanced clinical outcomes. Further multicenter studies are warranted to validate these findings and refine standardized protocols.

The question mark ear is a rare external auricular deformity characterized by the cleft between the helix and earlobe. There is also limited guidance on the management of these deformities. A noteworthy aspect of the question mark ear is the broadening of the upper auricle, yet this feature can be easily overlooked. The hybrid technique, consisting of antihelix reformation, scapha reduction, and helical rim flap advancement, was proposed to correct the deformity and restore the natural appearance of the auricle. Auricular measurements, including the length and width of the auricle, the lateral circumference of the helix rim from the superior apex to the inferior apex, and the height of the cleft, were performed preoperatively and postoperatively. Fourteen patients with question mark ear deformities were treated, 11 unilaterally and 3 bilaterally. The patient's ages ranged from 5 to 23 years old and 14.3 years on average. Follow-up ranged from 4 to 24 months and 10 months on average. Preoperative measurements indicated that the auricular width of the question mark ear was greater than that of the contralateral side, while postoperative measurements showed no significant difference in auricular width compared to the contralateral side. In addition, auricular measurements demonstrated a notable enhancement in the overall auricular configuration and cleft repair. The hybrid technique was applicable to correct question mark deformities with good results. The vertical mattress suture technique could reform the natural appearance of the antihelix. Scapha reduction and helical rim flap advancement were effective in correcting the cleft between the helix and earlobe.

OBJECTIVE:This clinical study described the application of the preexpanded paramedian frontal flap in the repair of midfacial congenital melanocytic nevus to summarize the aesthetic effects of this facial repair. METHODS:The authors analyzed data from 15 patients (8 males and 7 females) who underwent median facial pigmented nevus repair with a preexpanded parafrontal median flap. The operation was divided into 3 stages as follows: tissue expander implantation under the prefrontal area, the flap with pedicled transfer after nevus removal after 2 to 3 months of expansion, and the vascular pedicle cut as a delayed operation 3 weeks later and then the flap pedicle was severed. Also, the residual pigment nevus was repaired, and the flap pedicle was restored to the forehead. During the follow-up, the necessary flap thinning and hair removal were performed. Demographic information, site and area of nevus, operative procedure, and complications were recorded. RESULTS:The complications of expander implantation contained hematoma (n = 1) and incision dehiscence (n = 2), but they had no effects on the overall repair after symptomatic treatment. All transferred flaps had good blood supply. Six patients were treated with flap thinning, and 13 cases of distal flaps were treated with laser hair removal. The color, texture, and thickness of the repaired flap were consistent with the facial recipient area with an unobvious surgical scar, no contractures on the middle facial organs and tissues, and no obvious eyebrow displacement. CONCLUSION:Preexpanded paramedian frontal flap could be an effective way to repair a large area of midfacial pigmented nevus.

BACKGROUND:Mechanical stretch is utilized in the process of tissue expansion to promote skin regeneration, which is crucial for wound healing and organ reconstruction purposes. Enlarged dermal area is one of the significant histological characteristics of the expanded skin. However, the underlying biological processes and molecular pathways associated with dermal regeneration triggered by mechanical stretch are still not well understood. METHODS:Twelve male Sprague-Dawley (SD) rats were divided into the expansion group and sham group randomly. Upon creating a rat scalp expansion model, the dermis was isolated from the full-thickness skin in both experimental groups for RNA sequencing. This process led to the identification of differentially expressed genes (DEGs). Subsequently, we conducted Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA) to identify the essential biological processes associated with dermal regeneration induced by mechanical stretch, leveraging data from the DEGs. A network of protein-protein interactions (PPI) was built to detect the critical modules and central genes. The expression levels of these hub genes were evaluated using quantitative real-time polymerase chain reaction (qPCR). RESULTS:Increased expanded skin area and dermal thinning which represent the typical changes of expanded skin were observed in the expansion group. A total of 782 DEGs were identified in the expansion group relative to the sham group. The DEGs were associated with several biological processes, including the organization of the extracellular matrix, the enhancement of macrophage activation, and the promotion of angiogenesis, among others. Cell components encompassing Toll-like receptor 2-Toll-like receptor 6 protein complex, interstitial matrix, extracellular matrix (ECM), and collagen trimer were discovered. Molecular function categories including integrin binding, insulin-like growth factor binding, and fatty acid elongase activity were involved. The KEGG pathway analysis demonstrated the significant enrichment of pathways including the PI3K-Akt signaling pathway, fatty acid metabolism, and extracellular matrix-receptor interactions. GSEA results displayed that mechanical stretch correlated with the regulation of cell activation processes, cytokine-mediated signaling pathways, and immune system processes. PPI network resulted in the identification of 598 nodes along with a total of 5,304 interaction pairs between proteins. And ten hub genes containing Ccl2, Cxcl10, Fasn, Itgad, Cd163, Mmp9, Cd36, Tlr2, Igf1, and Wnt2 were identified by bioinformatics analysis and validated by qPCR. CONCLUSIONS:This in vivo study for the first time revealed the DEGs related to mechanical stretch stimulated dermal regeneration and identified the involved pathways and hub genes correlated with macrophage recruitment and polarization, fibroblast proliferation and ECM production and angiogenesis, which may benefit further studies aimed at developing therapeutic strategies for facilitating expanded skin regeneration.

BACKGROUND:Treating extensive benign tumors of the head and face presents a longstanding challenge, necessitating efficacy at the lesion site, and postoperative esthetic considerations for the donor area. OBJECTIVE:This study aims to explore the clinical outcomes of pre-expanded local flap reconstruction for extensive benign tumors of the head and face post resection. METHOD:From March 2018 to March 2023, a total of 18 patients with extensive benign tumors of the head and face were admitted, including 13 cases of nevus, 2 cases of hemangioma, 2 cases of neurofibroma, and 1 case of verruca. Based on the location and size of the lesions, suitable local areas were selected for tissue expansion, and expanders were implanted for regular saline injections over 8 to 16 weeks. After reaching the desired expansion, resection of the head and facial tumors and local flap reconstruction were performed. Postoperatively, data on patients' information, tumor types, tumor area, expansion volume, postexpander complications, vascular condition after flap transfer, and donor site condition were collected. RESULT:In this series of 18 patients, benign tumors of the head and face were completely repaired through 1 to 2 stages of tissue expansion surgeries. Postimplantation complications included hematoma in 1 case and infections in 2 cases, with one instance of expander infection leading to surgical failure. However, all other patients achieved adequate expansion, successful flap survival post-transfer, and experienced no other complications. Follow-up over 6 to 24 months showed no recurrence at the lesion sites, with flaps maintaining consistent color, texture, and thickness matching surrounding skin tissue. In addition, donor site healing was excellent, with no obvious surgical scars. CONCLUSIONS:Pre-expanded local flap reconstruction is an ideal method for repairing extensive benign tumors of the head and face postresection.

BackgroundHead and neck burns frequently result in severe functional impairments and significant aesthetic deformities due to extensive soft tissue defects and contractures. Reconstructing these complex defects effectively remains challenging, necessitating strategies that optimize both functional outcomes and aesthetic satisfaction. This study aimed to evaluate the clinical efficacy and safety of pre-expanded internal mammary artery perforator (IMAP) and transverse cervical artery perforator (TCAP) flaps for reconstructing cervicofacial deformities resulting from deep burns.MethodsA retrospective review was conducted on 36 patients (14 males, 22 females; mean age 24 years, range 8-45) treated between January 2020 and December 2023 using 42 pre-expanded anterior chest flaps. Patients were classified into 2 anatomically distinct groups based on the location of their cervicofacial deformities. Type I deformities primarily involved the mandibular region (chin and lower cheek), for which pre-expanded IMAP flaps were utilized. Type II deformities involved the cervical region (neck and supraclavicular area), reconstructed using pre-expanded TCAP flaps. This classification guided flap selection to optimize tissue matching and functional restoration. All cases involved a 2-stage approach comprising soft-tissue expansion followed by scar excision and contracture release. Outcomes assessed at 6 months postoperatively included flap survival, functional recovery (neck mobility), aesthetic results, and patient satisfaction.ResultsFlap survival was 100%, with no congestion or necrosis reported. Two patients experienced minor infections during the expansion phase, managed successfully with antibiotics. All donor sites were closed primarily without grafting. Postoperative assessments revealed that neck mobility improved significantly, with all patients achieving neck extension exceeding 110 degrees and no residual functional limitations. Aesthetic outcomes were rated as good by 83.3% of patients and acceptable by 16.7%. No donor-site complications or dissatisfaction were reported.ConclusionPre-expanded IMAP and TCAP flaps provide reliable vascularity and optimal functional and aesthetic outcomes in cervicofacial reconstruction after deep burn injuries. This structured classification and treatment algorithm allows tailored reconstructive strategies based on defect location and vascular anatomy, promoting enhanced clinical outcomes. Further multicenter studies are warranted to validate these findings and refine standardized protocols.

Haematoma is an early complication of tissue expander placement and can lead to infection, capsule contracture, and various complications, hindering successful reconstruction. However, no scientific models can accurately predict the risk of haematoma following tissue expansion. Therefore, this study aimed to develop and validate a prediction model for haematoma following tissue expander placement. The medical records of patients who underwent expander placement between 2001 and 2021 were obtained from the clinical database of the Department of Plastic Surgery at the Xijing Hospital. A total of 4,579 consecutive patients with 7,080 expanders and 179 expanded pocket haematomas were analysed. Multivariate logistic regression analysis identified adult age (P = 0.006), male sex (P < 0.001), scar reconstruction (P = 0.019), perioperative hypertension (P < 0.001), face and neck location (P = 0.002), and activated partial thromboplastin time above the normal range (P < 0.001) as risk factors for haematoma. Therefore, these were included in the prediction model, and a nomogram was constructed. The discrimination of the nomogram was robust (area under the curve: 0.78; 95% confidence interval: 0.72–0.83). Further, the prediction model had a strong fit (Hosmer–Lemeshow test, P=0.066) and maintained similar discrimination after considering performance optimism (bootstrapped area under the curve: 0.79; 95% confidence interval: 0.73–0.84). This clinical prediction model was created using a generalisable dataset and can be utilised to obtain valid haematoma predictions after expander placement, assisting surgeons in implementing preventive measures or interventions to reduce the occurrence of haematoma.

Skin soft tissue expansion is the process of obtaining excess skin mixed with skin development, wound healing, and mechanical stretching. Previous studies have reported that tissue expansion significantly induces epidermal proliferation throughout the skin. However, the mechanisms underlying epidermal regeneration during skin soft tissue expansion are yet to be clarified. Hair follicle stem cells (HFSCs) have been recognized as a promising approach for epidermal regeneration. This study examines HFSC-related epidermal regeneration mechanisms under expanded condition and proposes a potential method for its cellular and molecular regulation.

Haematoma is an early complication of tissue expander placement and can lead to infection, capsule contracture and various complications, hindering successful reconstruction. However, no scientific models can accurately predict the risk of haematoma following tissue expansion. Therefore, this study aimed to develop and validate a prediction model for haematoma following tissue expander placement. The medical records of patients who underwent expander placement between 2001 and 2021 were obtained from the clinical database of the Department of Plastic Surgery at the Xijing Hospital. A total of 4579 consecutive patients with 7080 expanders and 179 expanded pocket haematomas were analysed. Multivariate logistic regression analysis identified adult age (P = 0.006), male sex (P < 0.001), scar reconstruction (P = 0.019), perioperative hypertension (P < 0.001), face and neck location (P = 0.002) and activated partial thromboplastin time above the normal range (P < 0.001) as risk factors for haematoma. Therefore, these were included in the prediction model, and a nomogram was constructed. The discrimination of the nomogram was robust (area under the curve: 0.78; 95% confidence interval: 0.72-0.83). Further, the prediction model had a strong fit (Hosmer-Lemeshow test, P = 0.066) and maintained similar discrimination after considering performance optimism (bootstrapped area under the curve: 0.79; 95% confidence interval: 0.73-0.84). This clinical prediction model was created using a generalisable dataset and can be utilised to obtain valid haematoma predictions after expander placement, assisting surgeons in implementing preventive measures or interventions to reduce the occurrence of haematoma.

Following facial reconstruction with a scalp flap, unwanted hair is a common esthetic problem. Reports on the safety, effectiveness, and differences in laser hair removal before, during, and after tissue expansion are lacking. The authors aimed to assess the efficacy of 800-nm diode laser hair removal before, during, and after flap expansion. A total of 366 patients who underwent long-pulse 800-nm diode laser hair removal from the scalp flap were included in this study. The patients were divided into 3 groups based on the timing of laser hair removal: nonexpansion, expander, and expanded. Participants received 1 to 8 treatment sessions at intervals of 25 to 30 days. To assess the effectiveness and differences in the treatment of each group, 2 independent observers compared the photographs and measured the reduction in the terminal hair count after treatment. The hair reduction rate was significantly higher with fewer treatment sessions when laser hair removal was performed during tissue expansion compared with after surgery or before surgery. Two cases of blisters were reported in the expanded group, all of which healed after aspiration and dressing changes. No severe adverse events were reported. Hair removal during or after scalp flap expansion is safe and effective when using an 800-nm diode laser. The depilation process during tissue expansion should be extremely accurate and well-designed. Depilation of the scalp before surgery is not recommended because of its low efficiency and long treatment duration.

Background Tissue expansion, a technique in which skin regeneration is induced by mechanical stretch stimuli, is commonly used for tissue repair and reconstruction. In this study, we aimed to monitor the autophagy levels of expanded skin after the application of expansion stimuli and explore the effect of autophagy modulation on skin regeneration.Methods A rat scalp expansion model was established to provide a stable expanded skin response to mechanical stretch. Autophagy levels at different time points (6, 12, 24, 48 and 72 h after the last expansion) were detected via western blotting. The effect of autophagy regulation on skin regeneration during tissue expansion was evaluated via skin expansion efficiency assessment, western blotting, immunofluorescence staining, TUNEL staining and laser Doppler blood flow imaging.Results The autophagic flux reached its highest level 48 h after tissue expansion. Activating autophagy by rapamycin increased the area of expanded skin as well as the thicknesses of epidermis and dermis. Furthermore, activating autophagy accelerated skin regeneration during tissue expansion by enhancing the proliferation of cells and the number of epidermal basal and hair follicle stem cells, reducing apoptosis, improving angiogenesis, and promoting collagen synthesis and growth factor secretion. Conversely, the regenerative effects were reversed when autophagy was blocked.Conclusions Autophagy modulation may be a promising therapeutic strategy for improving the efficiency of tissue expansion and preventing the incidence of the complication of skin necrosis.

Botulinum toxin A (BTX-A) can enhance the efficacy of fat grafting. However, most studies conducted animal experiments, lacked objective clinical data, or were non-randomized controlled trials. Thus, objective evaluation of the clinical effectiveness of BTX-A is still elusive. A randomized, self-controlled trial (2020–2022) on 16 patients who underwent bilateral autogenous fat breast augmentation was performed with each patient receiving autologous fat graft and BTX-A on one side and fat graft and equal volume of saline on the other side. All patients were followed. The effects of BTX-A were evaluated objectively by comparing the remaining bilateral fat graft volumes obtained through digital three-dimensional reconstruction. The improvement of each breast appearance and complication were assessed by the physician and patients who were blinded to the treatment. The outcome of fat breast augmentation was evident for both sides at follow-up with no evidence of fat embolism, vascular/nervous injury, infection, and prolonged bruising. The analysis of the three-dimensional reconstruction data and assessments from both physicians and patients showed significant differences in the fat graft retention volume between the BTX-A side and the control side. No significant difference was found in the incidence of complications between the two sides. Autogenous fat breast augmentation is safe and effective. This study shows that BTX-A can significantly improve the retention rate of fat transplantation, but cannot reduce complications. Trial registration This study was registered prior to patient enrollment (ClinicalTrials.gov identifier:ChiCTR2100054878). This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

BACKGROUND:Public awareness of monkeypox is critical in the fight against this infectious disease. However, at present a survey of the Chinese population on monkeypox is lacking. This study was conducted to compensate for the lack of knowledge and identify a vaccination intention assessment for monkeypox in China.METHODS:The questionnaire comprised 20 items with the following three aspects: basic information, knowledge, and willingness to vaccinate or pay. For this study, 521 valid respondents were recruited. Utilizing logistic regression, the researchers identified the factors related with knowledge and vaccination intentions.RESULTS:The average total score for knowledge of monkeypox was 5.6 (score range 0-10), and 309 (59.3%) participants were categorized as having greater knowledge based on a total score of 6. Most participants (76.4%) were willing to accept a monkeypox vaccination. The average acceptable cost of the monkeypox vaccine was CNY261.2. Factors such as level of education, and working within the healthcare profession were related to monkeypox knowledge. An increased knowledge of monkeypox was related to a higher willingness to vaccinate. Participants who were willing to pay more for vaccines included those with high incomes, who suffered from chronic diseases, and healthcare workers.CONCLUSIONS:The Chinese population had relatively high knowledge of monkeypox and demonstrated a willingness to receive the vaccine.

OPINION article Front. Surg., 06 January 2023Sec. Reconstructive and Plastic Surgery Volume 9 - 2022 | https://doi.org/10.3389/fsurg.2022.1029065

Background:Despite the application of tissue expansion in the reconstruction of significant tissue defects, complications with expanded random-pattern skin flaps remain a major challenge. Insufficient angiogenesis is one of the keys factors in flap ischemia and dysfunction. Macrophages play a key role in promoting tissue angiogenesis, but their effects on expanded flap angiogenesis and the survival of the transferred skin flap are still unknown.Methods:A rat scalp expansion model was established to evaluate the dynamic changes of macrophages in expanded skin. Clodronate liposomes (Clo-lipo) were injected into the expanded scalps to deplete the macrophages, and the expanded scalp flaps with macrophage depletion were orthotopically transferred. The remaining expanded rat scalp flaps were treated with either a macrophage-colony stimulating factor (M-CSF) alone or M-CSF in combination with Clo-lipo and transferred. The number of macrophages, blood perfusion, microvascular densities (MVDs), flap survival, histological changes, and gene expression related to macrophage polarization and angiogenesis were determined with immunofluorescence (IF) staining, full-field laser perfusion imager, hematoxylin and eosin (HE) staining, and quantitative real-time polymerase chain reaction.Results:The number of pan-macrophages significantly increased in the expanded scalp on days 14 and 21 after expander placement. The depletion rate after treatment with Clo-lipo was 29.06%, and the number of macrophages was significantly reduced in the group that underwent Clo-lipo treatment on day 14 before flap transfer (P<0.05). Macrophage depletion resulted in decreased blood perfusion, reduced MVDs, lower expression of factors, and poor survival rate. The recruitment of macrophages with a M-CSF led to higher blood perfusion, increased MVDs, greater expression of angiogenic factors, and better flap survival after flap transfer.Conclusions:Alternatively activated macrophages in the expanded flap could significantly promote angiogenesis, improve blood perfusion, and ultimately increase the flap survival rate. Modulating alternatively activated macrophages may provide a key therapeutic strategy to promote expanded skin flap survival. Our study has provided a basis for clinically improving random-pattern skin flap survival.

TRPV3 is a non-selective cation channel that is highly expressed in keratinocytes in the skin. Traditionally, keratinocytes-expressed TRPV3 is involved in multiple physiological and pathological functions of the skin, such as itching, heat pain, and hair development. Although the underlying mechanisms by which TRPV3 functions in vivo remain obscure, recent research studies suggest that several cytokines and EGFR signaling pathways may be involved. However, there have also been other studies with opposite results that question the role of TRPV3 in heat pain. In addition, an increasing number of studies have suggested a novel role of TRPV3 in promoting skin regeneration, indicating that TRPV3 may become a new potential target for regulating skin regeneration. This paper not only reviews the role of keratinocytes-expressed TRPV3 in the physiological and pathological processes of itching, heat pain, hair development, and skin regeneration, but also reviews the relationship between TRPV3 gene mutations and skin diseases such as atopic dermatitis (AD) and Olmsted syndrome (OS). This review will lay a foundation for further developing our understanding of the mechanisms by which TRPV3 is involved in itching, heat pain, and hair development, as well as the treatments for TRPV3-related skin diseases.