Autologous Tissue Repair and Total Face Restoration.

Importance: Total face restoration remains a challenge in modern reconstructive surgery. After 17 years of experiments and preliminary clinical studies, a new concept of face prefabrication was developed for face restoration with autologous tissue. Objective: To evaluate the long-term results of face restoration with autologous tissue and report a finalized and standardized approach of face prefabrication. Design, Setting, and Participants: In this single-center long-term retrospective study, 32 patients who underwent total face restoration between 2005 and 2022 were reviewed. These patients underwent total facial reconstruction, which included flap prefabrication, 3-dimensional printing, tissue expansion, and flap transfer with aid of indocyanine green angiography (IGA). The flap first undergoes prefabrication by transferring vascularized fascia under the skin of the selected chest. A tissue expander is then placed under the fascia to create a large, thin, reliable skin flap after expansion. Once completed, the flap is transferred to the face during the second stage of the reconstruction. Intraoperative IGA is performed to guide the design of subsequent openings for facial fissures. Data were analyzed from July to September 2023. Main Outcomes and Measures: Flap healing, reconstructive outcome, and patient recovery were assessed during follow-up. Three questionnaires, including the 36-Item Short Form Health Survey (SF-36), Aesthetic and Functional Status Score of Facial Soft-Tissue Deformities/Defects, and the EuroQoL Health-Related Quality of Life (EQ-5D-5L), were used to evaluate the quality of life and satisfaction with facial aesthetic and functional status. Results: Of 24 included patients, 14 (58%) were male, and the mean (range) age was 32.9 (8-62) years. The mean (range) follow-up was 5.6 (2-12) years. All patients reported a significant improvement in quality of life (SF-36), especially in mean (SD) social functioning (preoperative score, 53.65 [34.51]; postoperative score, 80.73 [19.10]) and emotional stability (preoperative score, 56.67 [25.55]; postoperative score, 71.17 [18.51]). A total of 22 patients (92%) went back to work. Mean (SD) facial aesthetic status (preoperative score, 4.96 [3.26]; postoperative score, 11.52 [3.49]; P < .001) and functional status (preoperative score, 11.09 [3.51]; postoperative score, 15.78 [3.26]; P < .001) also improved. In addition, there was a significant increase in overall satisfaction and self-reported health status (preoperative score, 8.13 [1.52]; postoperative score, 3.58 [2.31]). Conclusions and Relevance: In this study, 5-year follow-up results suggested that this innovative approach to total face restoration offered a safe and valid option for indicated patients, with acceptable reconstructive and cosmetic outcomes.

New progress in roles of TGF-ß signaling crosstalks in cellular functions, immunity and diseases.

The family of secreted dimeric proteins known as the Transforming Growth Factor-ß (TGF-ß) family plays a critical role in facilitating intercellular communication within multicellular animals. A recent symposium on TGF-ß Biology - Signaling, Development, and Diseases, held on December 19-21, 2023, in Hangzhou, China, showcased some latest advances in our understanding TGF-ß biology and also served as an important forum for scientific collaboration and exchange of ideas. More than twenty presentations and discussions at the symposium delved into the intricate mechanisms of TGF-ß superfamily signaling pathways, their roles in normal development and immunity, and the pathological conditions associated with pathway dysregulation.

Targeting the nuclear long noncoding transcript LSP1P5 abrogates extracellular matrix deposition by trans-upregulating CEBPA in keloids.

Keloids are characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix (ECM) and are a major global health care burden among cutaneous diseases. However, the function of long noncoding RNA (lncRNA)-mediated ECM remodeling during the pathogenesis of keloids is still unclear. Herein, we identified a long noncoding transcript, namely, lymphocyte-specific protein 1 pseudogene 5 (LSP1P5), that modulates ECM component deposition in keloids. First, high-throughput transcriptome analysis showed that LSP1P5 was selectively upregulated in keloids and correlated with more severe disease in a clinical keloid cohort. Therapeutically, the attenuation of LSP1P5 significantly decreased the expression of ECM markers (COL1, COL3, and FN1) both in vitro and in vivo. Intriguingly, an antifibrotic gene, CCAAT enhancer binding protein alpha (CEBPA), is a functional downstream candidate of LSP1P5. Mechanistically, LSP1P5 represses CEBPA expression by hijacking Suppressor of Zeste 12 to the promoter of CEBPA, thereby enhancing the polycomb repressive complex 2-mediated H3K27me3 and changing the chromosomal opening status of CEBPA. Taken together, these findings indicate that targeting LSP1P5 abrogates fibrosis in keloids through epigenetic regulation of CEBPA, revealing a novel antifibrotic therapeutic strategy that bridges our current understanding of lncRNA regulation, histone modification and ECM remodeling in keloids.

ALKBH5-mediated m6A demethylation fuels cutaneous wound re-epithelialization by enhancing PELI2 mRNA stability.

BACKGROUND: Impaired wound re-epithelialization contributes to cutaneous barrier reconstruction dysfunction. Recently, N6-methyladenosine (m6A) RNA modification has been shown to participate in the determination of RNA fate, and its aberration triggers the pathogenesis of numerous diseases. Howbeit, the function of m6A in wound re-epithelialization remains enigmatic. METHODS: Alkbh5‒/‒ mouse was constructed to study the rate of wound re-epithelialization after ALKBH5 ablation. Integrated high-throughput analysis combining methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq was used to identify the downstream target of ALKBH5. In vitro and in vivo rescue experiments were conducted to verify the role of the downstream target on the functional phenotype of ALKBH5-deficient cells or animals. Furthermore, the interacting reader protein and regulatory mechanisms were determined through RIP-qPCR, RNA pull-down, and RNA stability assays. RESULTS: ALKBH5 was specifically upregulated in the wound edge epidermis. Ablation of ALKBH5 suppressed keratinocyte migration and resulted in delayed wound re-epithelialization in Alkbh5‒/‒ mouse. Integrated high-throughput analysis revealed that PELI2, an E3 ubiquitin protein ligase, serves as the downstream target of ALKBH5. Concordantly, exogenous PELI2 supplementation partially rescued keratinocyte migration and accelerated re-epithelialization in ALKBH5-deficient cells, both in vitro and in vivo. In terms of its mechanism, ALKBH5 promoted PELI2 expression by removing the m6A modification from PELI2 mRNA and enhancing its stability in a YTHDF2-dependent manner. CONCLUSIONS: This study identifies ALKBH5 as an endogenous accelerator of wound re-epithelialization, thereby benefiting the development of a reprogrammed m6A targeted therapy for refractory wounds.

Intraoperative Indocyanine Green Angiography Facilitates Flap Fenestration and Facial Organ Fabrication in Total Facial Restoration.

BACKGROUND: As effective measures to visualize flap vasculature and perfusion were unavailable, flap fenestration and facial organ fabrication could not be performed safely, preventing the transition from 2-D coverage to the restoration of the 3-D structure of facial organs. This study aims to evaluate the efficacy of indocyanine green angiography (ICGA) in guiding flap fenestration and facial organ fabrication in total facial restoration. METHODS: Ten patients with total facial scarring following burn injury were enrolled in the study. They were treated with pre-expanded, prefabricated monoblock flaps for total face restoration. The opening of nostrils, oral and palpebral orifices, together with organ fabrication, were conducted under the guidance of intraoperative ICGA via hemodynamic evaluation of flap perfusion. Postoperative follow-up parameters include vascular crisis, infection, flap necrosis and patients' aesthetic and functional recovery. RESULTS: The opening of facial organ orifices was performed at the stage of flap transfer in nine patients. To avoid damaging the major nourishing vessels, the left palpebral orifice was opened eight days after the flap transfer in one patient, as observed by ICGA. Based on ICGA evaluation, the decision to perform additional vascular anastomosis before flap fenestration was made in six patients. Hemodynamic analysis of flap perfusion following fenestration revealed no significant change. Follow-up showed satisfactory aesthetic recovery and well-restored 3-D structures of facial organs. CONCLUSION: This pilot study demonstrates how intraoperative ICGA can enhance the safety of flap fenestration, thereby transforming full facial restoration from the 2-D to the 3-D realm by facilitating facial organ fabrication.

The application of augmented reality in plastic surgery training and education: A narrative review.

Continuing problems with fewer training opportunities and a greater awareness of patient safety have led to a constant search for an alternative technique to bridge the existing theory-practice gap in plastic surgery training and education. The current COVID-19 epidemic has aggravated the situation, making it urgent to implement breakthrough technological initiatives currently underway to improve surgical education. The cutting edge of technological development, augmented reality (AR), has already been applied in numerous facets of plastic surgery training, and it is capable of realizing the aims of education and training in this field. In this article, we will take a look at some of the most important ways that AR is now being used in plastic surgery education and training, as well as offer an exciting glimpse into the potential future of this field thanks to technological advancements.

Imatinib blocks tyrosine phosphorylation of Smad4 and restores TGF-ß growth-suppressive signaling in BCR-ABL1-positive leukemia.

Loss of TGF-ß-mediated growth suppression is a major contributor to the development of cancers, best exemplified by loss-of-function mutations in genes encoding components of the TGF-ß signaling pathway in colorectal and pancreatic cancers. Alternatively, gain-of-function oncogene mutations can also disrupt antiproliferative TGF-ß signaling. However, the molecular mechanisms underlying oncogene-induced modulation of TGF-ß signaling have not been extensively investigated. Here, we show that the oncogenic BCR-ABL1 of chronic myelogenous leukemia (CML) and the cellular ABL1 tyrosine kinases phosphorylate and inactivate Smad4 to block antiproliferative TGF-ß signaling. Mechanistically, phosphorylation of Smad4 at Tyr195, Tyr301, and Tyr322 in the linker region interferes with its binding to the transcription co-activator p300/CBP, thereby blocking the ability of Smad4 to activate the expression of cyclin-dependent kinase (CDK) inhibitors and induce cell cycle arrest. In contrast, the inhibition of BCR-ABL1 kinase with Imatinib prevented Smad4 tyrosine phosphorylation and re-sensitized CML cells to TGF-ß-induced antiproliferative and pro-apoptotic responses. Furthermore, expression of phosphorylation-site-mutated Y195F/Y301F/Y322F mutant of Smad4 in Smad4-null CML cells enhanced antiproliferative responses to TGF-ß, whereas the phosphorylation-mimicking Y195E/Y301E/Y322E mutant interfered with TGF-ß signaling and enhanced the in vivo growth of CML cells. These findings demonstrate the direct role of BCR-ABL1 tyrosine kinase in suppressing TGF-ß signaling in CML and explain how Imatinib-targeted therapy restored beneficial TGF-ß anti-growth responses.

Young fibroblast-derived exosomal microRNA-125b transfers beneficial effects on aged cutaneous wound healing.

Aged skin wounds heal poorly, resulting in medical, economic, and social burdens posed by nonhealing wounds. Age-related defects in repair are associated with reduced myofibroblasts and dysfunctional extracellular matrix (ECM) deposition. Bidirectional cell-cell communication involving exosome-borne cargo such as micro RNAs (miRs) has emerged as a critical mechanism for wound healing and aged tissue regeneration. Here we report that at the wound edge, aged fibroblasts display reduced migration and differentiation into myofibroblasts, with impaired ECM deposition, when compared with young tissue. Proper activation of fibroblasts to myofibroblasts may alleviate age-related defects in wound healing. Herein, an exosome-guided cell technique was performed to induce effective wound healing. Supplementing wounds with exosomes isolated from young mouse wound-edge fibroblasts (exosomesYoung) significantly improved the abundance of myofibroblasts and wound healing in aged mice and caused fibroblasts to migrate and transition to myofibroblasts in vitro. To determine the underlying mechanism, we found that exosomal transfer of miR-125b to fibroblasts inhibited sirtuin 7 (Sirt7), thus accelerating myofibroblast differentiation and wound healing in aged mice. Notably, after epidermal inhibition of miR-125b or overexpression of Sirt7 in fibroblasts, migration and myofibroblast transition were perturbed. Our findings thus reveal that miR-125b is transferred through exosomes from young fibroblasts to old fibroblasts contributes to promoting fibroblast migration and transition to counteract aging, suggesting a potential avenue for anti-aging interventions in wound healing.

CD39+ Fibroblasts Enhance Myofibroblast Activation by Promoting IL-11 Secretion in Hypertrophic Scars.

Fibroblasts (Fbs) are critical to hypertrophic scar (HTS) formation and were recently shown to be highly heterogeneous. However, Fb heterogeneity in HTSs has not been fully elucidated. In this study, we observed an increased fraction of CD39+ Fbs in HTS after screening four Fb subtypes (CD26+, CD36+, FAP+, and CD39+). CD39+ Fbs, enriched in the upper dermis, were positively correlated with scar severity. The transcriptional analysis of CD39+ and CD39- Fbs sorted from HTS revealed that IL-11 was more highly expressed in CD39+ Fbs. We then showed that IL-11 was upregulated in HTSs and that its expression was induced by TGFß1 in vitro. TGFß1 also stimulated the expression of CD39 at the transcriptional and protein levels, mediating the maintenance of the CD39+ phenotype. Furthermore, IL-11 facilitated myofibroblast activation and extracellular matrix production in both CD39+ and CD39- Fbs. Interestingly, CD39+ Fbs secreted more IL-11 on TGFß1 treatment and were less responsive to IL-11 than CD39- Fbs. Notably, a CD39 inhibitor effectively reduced stretch-induced scar formation and attenuated bleomycin-induced skin fibrosis, suggesting an antiscarring approach by targeting CD39+ Fbs.

Reconstruction of Large Cervicofacial Defects With Expanded Island Superficial Temporal Artery Flaps and an 810-nm Diode Laser Hair Removal Technique.

BACKGROUND: Extensive cervicofacial reconstruction is challenging for plastic surgeons. Because of the location of the adjacent scalp flap nourished by the superficial temporal artery (STA), it can be a candidate for cervicofacial reconstruction. OBJECTIVES: This article aims to report a combined treatment of an expanded island STA flap and an 810-nm diode laser hair removal technique for extensive cervicofacial defects. METHODS: Between January 2015 and December 2018, 10 patients with lower face and neck scar contraction were reconstructed with a bilateral or unilateral expanded STA island flap and an 810-nm diode laser for hair removal in this retrospective study. Hair removal via the 810-nm laser was started when the injected volume reached the volume of the expander, with a fluence of 35 to 40 J/cm2 and a 1 to 2 Hz repetition rate. Before second-stage surgery, the hair reduction rate was assessed. Twelve months after surgery, the degree of epilation efficacy according to the satisfaction scale and Global Aesthetic Improvement Scale was evaluated. RESULTS: This study included 2 single-pedicle flaps and 8 double-pedicle flaps. The average size of the implanted expanders was 600 mL. The average injected volume was 1405 mL. Before second surgery, there was a 67.4% hair reduction rate. Twelve months after surgery, the results of Global Aesthetic Improvement Scale were very good (3), good (6), average (1), and poor (0). CONCLUSIONS: The expanded island STA flap and 810-nm diode laser technique may be a novel treatment option for severe face and neck aesthetic reconstruction.

Protein tyrosine phosphatase PTPN2 regulates TGF-ß signaling through Smad4 dephosphorylation.

Transforming Growth Factor beta (TGF-ß) is a multifunctional cytokine that regulates cell proliferation, differentiation, and apoptosis. Dysregulation of the TGF-ß signaling is one of the major mechanisms underlying tumor progression. We have previously reported that anaplastic lymphoma kinase (ALK) phosphorylates Smad4 at Tyr95, which compromises the DNA-binding ability of Smad4 and thus renders ALK-positive cancer cells resistant to TGF-ß tumor-suppressive action. In this study, we demonstrated that tyrosine phosphatase PTPN2 positively regulated TGF-ß signaling through dephosphorylating Smad4 at the Tyr95 site. Both in vitro and cell-based assays revealed that PTPN2 bound to and dephosphorylated Smad4, thereby preserving the DNA-binding ability of Smad4. Furthermore, overexpression of PTPN2 restored TGF-ß transcriptional and growth inhibitory responses in ALK-positive cancer cells. Consistently, Spermidine, an activator of PTPN2, also promoted TGF-ß-induced gene expression, apoptosis, and anti-proliferation effect. Taken together, we revealed that PTPN2 functioned as a tumor suppressor to antagonize the inhibitory effect of tyrosine phosphorylation of Smad4 and to ensure the proper TGF-ß growth inhibitory signaling in cancer cells.

Imaging for thinned perforator flap harvest: current status and future perspectives.

With advances in anatomical knowledge and technology, increased interest has been directed towards reconstruction with enhanced aesthetic and functional outcomes. A myriad of thinned perforator flap harvest approaches have been developed for this purpose; however, concerns about jeopardizing their vascularity remain. To ensure optimum reconstructive outcome without hampering the flap's microcirculation, it is important to make good use of the existing advanced imaging modalities that can provide clear visualization of perforator branches, particularly in the adipose layer, and an accurate assessment of flap perfusion. Therefore, this review will highlight the imaging modalities that have been utilized for harvesting a thinned perforator flap from these two perspectives, along with future insights into creating both functionally and aesthetically satisfying, yet simultaneously safe, thinned perforator flaps for the best reconstructive outcomes for patients.

HSPA13 facilitates NF-κB-mediated transcription and attenuates cell death responses in TNFα signaling.

RIP1 has emerged as a master regulator in TNFα signaling that controls two distinct cellular fates: cell survival versus programmed cell death. Because the default response of most cells to TNFα is NF-κB­mediated inflammation and survival, a specific mechanism must exist to control the divergence of signaling outcome. Here, we identify HSPA13 as a transcription-independent checkpoint to modulate the role of RIP1 in TNFα signaling. Through specific binding to TNFR1 and RIP1, HSPA13 enhances TNFα-induced recruitment of RIP1 to TNFR1, and consequently promotes downstream NF-κB transcriptional responses. Meanwhile, HSPA13 attenuates the participation of RIP1 in cytosolic complex II and prevents cells from programmed death. Loss of HSPA13 shifts the transition of RIP1 from complex I to complex II and promotes both apoptosis and necroptosis. Thus, our study provides compelling evidence for the cellular protective function of HSPA13 in fine-tuning TNFα responses.

Identification and functional analysis of a three-miRNA ceRNA network in hypertrophic scars.

BACKGROUND: Hypertrophic scar (HTS) is a fibrotic disorder of skins and may have repercussions on the appearance as well as functions of patients. Recent studies related have shown that competitive endogenous RNA (ceRNA) networks centering around miRNAs may play an influential role in HTS formation. This study aimed to construct and validate a three-miRNA (miR-422a, miR-2116-3p, and miR-3187-3p) ceRNA network, and explore its potential functions. METHODS: Quantitative real­time PCR (qRT­PCR) was used to compare expression levels of miRNAs, lncRNAs, and genes between HTS and normal skin. Target lncRNAs and genes of each miRNA were predicted using starBase as well as TargetScan database to construct a distinct ceRNA network; overlapping target lncRNAs and genes of the three miRNAs were utilized to develop a three-miRNA ceRNA network. For every network, protein-protein interaction (PPI) network analysis was performed to identify its hub genes. For each network and its hub genes, Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to explore their possible functions. RESULTS: MiR-422a, miR-2116-3p, and miR-3187-3p were all downregulated in HTS tissues and fibroblasts. MiR-422a-based ceRNA network consisted of 101 lncRNAs with 133 genes; miR-2116-3p-centered ceRNA network comprised 85 lncRNAs and 978 genes; miR-3187-3p-derived ceRNA network encompassed 84 lncRNAs as well as 1128 genes. The three-miRNA ceRNA network included 2 lncRNAs with 9 genes, where MAPK1, FOSL2, ABI2, KPNA6, CBL, lncRNA-KCNQ1OT1, and lncRNA-EBLN3P were upregulated. According to GO and KEGG analysis, these networks were consistently related to ubiquitination. Three ubiquitination-related genes (CBL, SMURF2, and USP4) were upregulated and negatively correlated with the expression levels of the three miRNAs in HTS tissues. CONCLUSIONS: This study identified a three-miRNA ceRNA network, which might take part in HTS formation and correlate with ubiquitination.

Targeting Dermal Fibroblast Subtypes in Antifibrotic Therapy: Surface Marker as a Cellular Identity or a Functional Entity?

Fibroblasts are the chief effector cells in fibrotic diseases and have been discovered to be highly heterogeneous. Recently, fibroblast heterogeneity in human skin has been studied extensively and several surface markers for dermal fibroblast subtypes have been identified, holding promise for future antifibrotic therapies. However, it has yet to be confirmed whether surface markers should be looked upon as merely lineage landmarks or as functional entities of fibroblast subtypes, which may further complicate the interpretation of cellular function of these fibroblast subtypes. This review aims to provide an update on current evidence on fibroblast surface markers in fibrotic disorders of skin as well as of other organ systems. Specifically, studies where surface markers were treated as lineage markers and manipulated as functional membrane proteins are both evaluated in parallel, hoping to reveal the underlying mechanism behind the pathogenesis of tissue fibrosis contributed by various fibroblast subtypes from multiple angles, shedding lights on future translational researches.

AMBRA1 Promotes TGFß Signaling via Nonproteolytic Polyubiquitylation of Smad4.

Transforming growth factor ß (TGFß) is prometastatic in advanced cancers and its biological activities are mainly mediated by the Smad family of proteins. Smad4 is the central signal transducer and transcription factor in the TGFß pathway, yet the underlying mechanisms that govern transcriptional activities of Smad4 are not fully understood. Here, we show that AMBRA1, a member of the DDB1 and CUL4-associated factor (DCAF) family of proteins, serves as the substrate receptor for Smad4 in the CUL4-RING (CRL4) ubiquitin ligase complex. The CRL4-AMBRA1 ubiquitin ligase mediates nonproteolytic polyubiquitylation of Smad4 to enhance its transcriptional functions. Consequently, AMBRA1 potentiated TGFß signaling and critically promoted TGFß-induced epithelial-to-mesenchymal transition, migration, and invasion of breast cancer cells. Mouse models of breast cancer demonstrated that AMBRA1 promotes metastasis. Collectively, these results show that CRL4-AMBRA1 facilitates TGFß-driven metastasis by increasing Smad4 polyubiquitylation, suggesting AMBRA1 may serve as a new therapeutic target in metastatic breast cancer. SIGNIFICANCE: This study identifies AMBRA1 as a novel regulator of TGFß signaling and breast cancer metastasis, supporting further exploration of AMBRA1 as a target for cancer therapy.

Inhibition of CUB and sushi multiple domains 1 (CSMD1) expression by miRNA-190a-3p enhances hypertrophic scar-derived fibroblast migration in vitro.

BACKGROUND: Hypertrophic scar (HTS) is a fibroproliferative skin disorder characterized by excessive cell proliferation, migration, and extracellular matrix (ECM) deposition. The CUB and Sushi multiple domains 1 (CSMD1) has previously been identified as the key regulatory gene of hypertrophic scar by a large sample GWAS study. However, further research has not yet been conducted to verify this finding in other HTS patients and to determine the underlying mechanism. RESULTS: In this study, we verified that CSMD1 was downregulated in both HTS tissue and HTS-derived fibroblasts. The knockdown of CSMD1 resulted in enhanced migration and fibronectin1 (FN1) secretion in fibroblasts in vitro. In addition, the upstream and downstream regulatory mechanisms of CSMD1 were also investigated through microRNA (miRNA) databases screening and RNA-sequencing (RNA-seq) respectively. The screening of four common microRNA (miRNA) databases suggested that miR-190a-3p binds to the CSMD1 and may regulate its expression. We confirmed that miR-190a-3p directly targeted the CSMD1-3'-UTR using luciferase reporter assays. Furthermore, the overexpression of miR-190a-3p showed promotion of migratory activity and FN1 secretion in fibroblasts, resembling the effect of CSMD1 knockdown; whereas the knockdown of miR-190a-3p exerted the opposite effect. Finally, transcriptomic analysis showed activation of Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway in the CSMD1 knockdown fibroblasts. CONCLUSIONS: This study has validated the conclusions of the previous GWAS study conducted in Chinese population. In vitro experiments have provided further evidence on the function of CSMD1 in the development of HTS, and have also revealed the underlying upstream and downstream regulating mechanisms. Additionally, the JAK/STAT signaling pathway identified using RNA-seq might provide a potential treatment approach, especially for HTS.