A New Option to Preserve Esthetics in Perioral Defect Reconstruction With Normal Anatomical Structures: Bipedicled Preexpanded Forehead Flap With Random Skin Flap Extension.

Plastic surgeons charged with reconstructing extensive perioral defects face dual challenges of functional restoration and esthetic considerations. While forehead flaps are commonly used to reconstruct perioral defects, in cases involving partial upper lip defects where normal anatomical structures are preserved, traditional forehead flaps may compromise esthetics. This study aimed to address this issue by employing bipedicled preexpanded forehead flaps based on the frontal branches of the superficial temporal artery (hereafter, "STA-bfb-based preexpanded forehead flap") with random flap extensions to repair perioral defects. Between April 2004 and July 2020, 7 patients (5 males and 2 females; 6 had post-burn facial scars involving the entire lower lip and part of the upper lip, and 1 presented with noma sequelae) underwent perioral defect reconstruction using this approach. Tissue expanders were placed in the forehead donor area, and an STA-bfb-based preexpanded forehead flap with random flap extensions was used to repair the perioral defect. The flap pedicle was divided into 3 weeks. All flaps remained viable with no perfusion-related complications. At follow-up 12 to 96 months later, the color and texture of the flaps demonstrated excellent compatibility with the surrounding skin, suggesting that the use of an STA-bfb-based preexpanded forehead flap with random skin flap extensions is a reliable method for repairing perioral defects. The authors' results have implications for plastic surgeons seeking a solution for challenging perioral defect reconstructions, balancing the need for esthetic outcomes with functional restoration.

Structural basis of human full-length kindlin-3 homotrimer in an auto-inhibited state.

Kindlin-1, -2, and -3 directly bind integrin ß cytoplasmic tails to regulate integrin activation and signaling. Despite their functional significance and links to several diseases, structural information on full-length kindlin proteins remains unknown. Here, we report the crystal structure of human full-length kindlin-3, which reveals a novel homotrimer state. Unlike kindlin-3 monomer, which is the major population in insect and mammalian cell expression systems, kindlin-3 trimer does not bind integrin ß cytoplasmic tail as the integrin-binding pocket in the F3 subdomain of 1 protomer is occluded by the pleckstrin homology (PH) domain of another protomer, suggesting that kindlin-3 is auto-inhibited upon trimer formation. This is also supported by functional assays in which kindlin-3 knockout K562 erythroleukemia cells reconstituted with the mutant kindlin-3 containing trimer-disrupting mutations exhibited an increase in integrin-mediated adhesion and spreading on fibronectin compared with those reconstituted with wild-type kindlin-3. Taken together, our findings reveal a novel mechanism of kindlin auto-inhibition that involves its homotrimer formation.

Successful Reconstruction of Complex Sacrococcygeal Defects Using Chimeric Perforator Propeller Flap.

BACKGROUND: Complex soft tissue defects, which result from the surgical resection of sacral tumors, manifest as a combination of skin defects, dead space, infection, and prosthesis exposure. Because the traditional musculocutaneous flap lacks flexibility because of the close connection between the skin flap and the muscle component, the musculocutaneous flap is not suitable for reconstructing complex soft tissue defects where the dead space and skin defects are located at different sites. Furthermore, the perforator flap is also not appropriate for reconstructing complex defects because it lacks the muscular component. We considered the possibility of using the chimeric perforator propeller flap for reconstructing complex sacrococcygeal defects. METHODS: This study included 7 patients who underwent, between July 2007 and July 2021, the reconstruction of complex soft tissue defects of the sacrococcygeal region using a chimeric perforator propeller flap. RESULTS: Among the included cases, the etiologies were chordoma (n = 3), sacral tumor (n = 3), and squamous cell carcinoma (n = 1). In all the cases, vacuum-assisted closure therapy was used to treat wound infections before surgery. The average sizes of the skin and muscle flaps were 195.8 cm 2 (range, 100-350 cm 2 ) and 83.6 cm 2 (range, 60-140 cm 2 ), respectively. The superior gluteal artery was the source artery for the chimeric perforator propeller flap. The donor sites were primarily closed in all cases. One patient had delayed wound healing, and the secondary wound healed using conservative dressing changes. The other 6 flaps had no complications. The average follow-up time was 5.3 months (range, 1-9 months). Muscle weakness and compromised ambulation in the affected lower extremities were not observed in any of the patients. Furthermore, all 7 patients had no tumor recurrence, prosthesis exposure, and infection events in the sacrococcygeal region. CONCLUSIONS: The chimeric perforator propeller flap may be an option for reconstructing complex soft tissue defects in the sacrococcygeal region.

Changes in the Transcriptome-Associated Co-Expression Profile of Embryonic External Ear Development After the BMP5 Gene Mutation.

This study aimed to perform an association analysis of the full transcriptome in Bmp5 short-ear mice during the development of the external ear in mouse embryos using advanced sequencing techniques. To understand the changes in gene regulation and expression of BMP5 gene mutations involved in the external ear embryonic development of mice, external ear tissues of mouse embryos developed to E15.5 and E17.5 were obtained using a BMP5 short-ear mouse model. The association analysis of the full transcriptome mainly involved the analysis of lncRNA and mRNA associations, the analysis of lncRNA and miRNA associations, the analysis of miRNA and mRNA associations, the analysis of circRNA and mRNA associations and circRNA, miRNA, and mRNA associations. The results showed that regulation of the full transcriptome is associated with external ear development in BMP5 short-ear mouse embryos, and some key regulatory changes in full transcriptome after BMP5 gene point mutation are different. This study will provide a new clue to investigate the mechanism underlying the regulation of mouse external ear development by the full transcriptome.

Changes in Transcriptome-Associated Co-Expression Profile of Embryonic External Ear Development After Prkra Gene Mutation.

The aim was to understand the changes in gene expression during the mouse external ear embryonic development in the full transcriptomes of mice with a point mutation in the Prkra gene, the outer ear tissues of mouse embryos were developed to embryonic day (E)15.5 and E17.5, and a Prkra Little-ear mouse model was obtained. The purpose of this study was to perform a whole transcriptome association analysis of the Prkra Little-ear mouse model during external ear embryonic development using advanced sequencing techniques. The association analysis of the full transcriptome mainly included lncRNA and mRNA association analysis, lncRNA and miRNA association analysis, miRNA and mRNA association analysis, circRNA and mRNA association analysis, circRNA, miRNA, and mRNA association analysis, and lncRNA, miRNA, and mRNA association analysis. The results of the correlation analysis showed that in the Prkra Little-ear mouse embryo development of the external ear was regulated by whole transcriptome and that these changes were different in wild-type mice. This study provides a new concept for elucidating the mechanism of the regulation of mouse external ear development.

Point Mutation in Prkra Alters miRNA Expression During Embryonic External Ear Development.

Microtia is a congenital malformation of the external ear that can lead to conductive hearing impairment. In this study, we investigated the role of the Prkra gene in external ear development. We used advanced sequencing techniques to evaluate the differential expression of microRNAs (miRNAs) involved in external ear development in mouse embryos after point mutation in the Prkra gene. The Prkra Little ear mouse model was used to obtain mouse embryos at the E15.5 and E17.5 developmental stages, and changes in miRNA expression profiles were detected. Gene ontology and Kyoto Encyclopedia of Genes and Genomes functional annotations were performed on differentially expressed miRNAs, and existing and new miRNAs were studied. miRNAs were observed to be involved in multiple signaling pathways during the E15.5 and E17.5 developmental stages. The results show a correlation between miRNA regulation and external ear development in Prkra Little ear mice, and differences were detected in key regulatory miRNAs owing to point mutations in the Prkra gene. This study provides new insights into the biological mechanisms through which miRNAs regulate external ear development in mouse embryos. Changes in the mouse miRNA expression profiles can also provide insights into the pathogenesis of human congenital microtia at the level of miRNA regulation.

Prkra Mutation Alters Long Noncoding RNA Expression During Embryonic External Ear Development.

Point mutations in the Prkra gene result in abnormalities in mouse external ear development; however, the regulatory mechanisms underlying this phenotype are unclear. This study evaluated long noncoding RNA (lncRNA) expression profiles in the outer ear tissues of embryos at E15.5 and E17.5 from the Prkra little ear mouse model using transcriptome sequencing. Differentially expressed lncRNAs between the experimental and control groups were identified and evaluated by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses. The results revealed various lncRNAs that contribute to the external ear development in Prkra mutant mice, some of which were involved in multiple developmental signaling pathways. There were expression changes in some key regulatory lncRNAs after point mutations in the Prkra gene, some of which were involved in multiple developmental signaling pathways, such as the Hippo, MAPK, and ErbB signaling pathways. These results provide insight into the regulatory mechanism underlying external ear embryonic development and reveal candidate lncRNAs.

Bmp5 Mutation Alters mRNA Expression During External Ear Development.

To understand changes in gene regulation and mRNA expression in external ear development, we used a bone morphogenetic protein 5 (BMP5) short-ear mouse model. External ear tissues at E15.5 and E17.5 were collected, and mRNA expression profiles were analyzed. Upregulated and downregulated mRNA expression was identified using find_circ and CIRI2 software. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed using the differentially expressed mRNAs. Alterations in related signal pathways were identified from the upregulated and downregulated mRNA transcripts. The results showed a correlation between the mRNA expression during external ear development in BMP5 short-ear mice, including key regulatory mRNA changes after point mutations of the Bmp5 gene. This study provides evidence for the mechanism underlying mRNA regulation during external ear development. Changes in mRNA expression profiles also provide clues for future studies regarding the regulatory mechanisms underlying external ear development.

Prkra Mutation Alters mRNA Expression During Embryonic External Ear Development.

To understand the changes in mRNA expression during the embryonic development of the external mouse ear after the point mutation of the Prkra gene, Prkra short ear mouse model was used to study the development of the embryonic external ear. The tissues of the embryonic external ear were obtained when mouse embryos developed to E15.5 and E17.5. The changes in the mRNA expression profile were detected and analyzed. Find_circ and CIRI2 softwares were used to identify the upregulated and down-regulated expression of mRNA in the experimental and control groups. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional annotations were conducted on the differentially expressed mRNA, and the related signal pathways were analyzed after the upregulation and down-regulation of mRNA expression. This study aimed to understand the regulation of mRNA expression in Prkra short-ear mice during the external ear development in embryos. The results showed a correlation between abnormally expressed mRNA and signal pathways and the regulation of the development of the external ear of Prkra short-ear mice, and there were differences in some key regulatory mRNA changes after the Prkra gene point mutation. This study will provide a new clue for the mechanism of mRNA regulating the development of the external mouse ear. The change in mRNA expression profile can also provide clues for studying the biological regulation mechanism of external ear embryonic development.

Effect of Mechanical Tension on the Long-Chain Noncoding RNA Expression Profile of Human Skin Regeneration.

This study investigates the potential gene regulation of long-chain noncoding RNAs (lncRNAs) during skin regeneration by analyzing the changes in the lncRNA expression profile during skin regeneration under mechanical tension. Through the effect of mechanical tension on human skin tissue, the authors observed that after the accelerated differentiation and proliferation of skin epidermal cells, the lncRNA expression profile was compared with that of normal epidermal cells, and differential expression of lncRNA in skin tissue was found. Fifty-three lncRNAs were differentially expressed between the experimental and control groups, and compared with the control group, 22 lncRNAs were upregulated and 31 lncRNAs were downregulated in the experimental group. In addition, through the annotation of the functions of gene ontology and kyoto encyclopedia of genes and genomes, it was further clarified that the main signaling pathway of lncRNAs in the process of skin tissue expansion is involved in the regulation of skin tissue regeneration, and the regulatory network of lncRNAs and microRNAs was established. The results of this study will provide a theoretical basis for the mechanism of lncRNA regulation of skin regeneration, and changes in the lncRNA expression profile can also provide clues for the study of the biological regulation mechanism of skin regeneration.

Changes in the Long Noncoding RNA Expression Profile in the Development of the Embryonic External Ear After BMP5 Gene Mutation.

To understand the role of long noncoding RNA (lncRNA) gene regulation and changes in expression in mouse external ear embryonic development, a BMP5 short ear mouse model was used to measure changes in the lncRNA expression in the outer ear tissues of mouse embryos developed to E15.5 and E17.5 using high-throughput sequencing. The changes in lncRNA expression were identified using find_circ and CIRI2 software, and functional analyses were performed using gene ontology and the Kyoto encyclopedia of genes and genomes annotations of differentially expressed lncRNAs. The results show a correlation between the regulation of lncRNA and some key regulatory lncRNA changes after point mutations in BMP5 . This study provides new insights into the mechanism, by which lncRNAs regulate the development of the mouse's external ear. The change in lncRNA expression profiles can also provide clues for the study of the regulatory mechanisms of external ear embryonic development.

Comparison of Microfat, Nanofat, and Extracellular Matrix/Stromal Vascular Fraction Gel for Skin Rejuvenation: Basic Animal Research.

BACKGROUND: Although stromal vascular fraction (SVF) cells and adipose-derived stem cells have well-defined antiaging effects on skin, certain disadvantages have limited their clinical application. OBJECTIVES: The aim of this study was to evaluate the effects of microfat, nanofat, and SVF-gel in improving ultraviolet (UV)-induced photoaged skin injury in nude mice. METHODS: After successfully establishing a photoaging model by UVA and UVB irradiation in nude mice, the back of each mouse was divided into 2 regions and randomly injected under the dermis with 0.5 mL of microfat, nanofat, SVF-gel, and phosphate-buffered saline. Inflammatory infiltration, dermis thickness, hydroxyproline content, Type I/Type III collagen ratio, elastic fiber morphology, skin cell proliferation, and adipocyte viability were measured. The overall structure of the skin was also observed by scanning electron microscopy. RESULTS: In the microfat group, the grafts survived well, with intact structure and viable adipocytes and little infiltration of inflammatory cells. Microfat promoted skin cell proliferation, collagen content increased, the ratio of Type I and III collagen reversed, and new oxytalan fibers formed, which to some extent improved the photoaging skin. In the nanofat and SVF-gel groups, a large amount of inflammatory cell infiltration and foam cell deposition in the grafts and dermis led to fibrosis and proliferation of skin tissue. Although the skin thickness and collagen content were also increased, these factors did not improve the photoaging skin. CONCLUSIONS: Microfat survives well, and improves photoaged skin injury in nude mice by promoting skin tissue regeneration and supplementing the capacity of subcutaneous adipose tissue.

Intramuscular Fat Graft Results in Lower Retention but Similar Quality Compared with Subcutaneous Counterpart.

ABSTRACT: The adipose tissue has been injected into both subcutaneous and intramuscular planes for volume augmentation. However, the differences in their outcomes have yet to be fully elucidated. To investigate the differences of intramuscular and subcutaneous graft outcome, adipose tissue was harvested from the inguinal fat pad of mice and then placed into the quadriceps femoris or the subcutaneous plane, respectively. At 8 weeks, the graft outcome was evaluated by gross weight assessment, hema-toxylin and eosin staining, and CD31 staining. The authors found out that though the intramuscular graft had lower weight retention than the subcutaneous graft, the histologic quality and vascularity were similar between the intramuscular and subcutaneous graft. To summarize, the muscle is a feasible plane for fat grafting clinically. While performing intramuscular fat grafting, moderate overcorrec-tion may be necessary to achieve satisfactory results.

Bmp5 Mutation Alters miRNA Expression During Embryonic External Ear Development.

ABSTRACT: To understand the changes in gene regulation and expression of MicroRNA (miRNA) involved in external mouseear embryonic development after point mutation of the Bmp5 gene, the outer ear tissues of developed E15.5 and E17.5 mouse embryos were obtained using a Bmp5 short ear mouse model, and the changes in miRNA expression profiles were detected. Changes in miRNA expression in the experimental and control groups were identified during Bmp5 short ear mouse embryo development at E15.5 and E17.5. GO and Kyoto Encyclopedia of Genes and Genomes functional annotations were performed on differentially expressed miRNAs. Multiple signal pathways related to miRNA expression were enhanced during the development of E15.5 and E17.5 embryos of Bmp5 short-ear mice. Based on the basic characteristics of miRNAs, this study aimed to determine the differential expression of miRNAs in Bmp5 short-ear mice during the development of external ear embryos using advanced sequencing techniques. The results showed differences in some key regulatory miRNA changes after point mutations in the Bmp5 gene. This study provides new insights into the mechanism by which miRNAs regulate the development of the external mouse ear. Changes in miRNA expression profiles can also provide clues for studying the biological regulatory mechanism of external ear embryonic development.

Prkra Mutation Alters circRNA Expression During Embryonic External Ear Development.

ABSTRACT: The changes in circRNA expression profile in the mouse external ear tissue during embryonic development to E15.5 and E17.5 can provide clues for the study of the regulation of external ear embryonic development. To understand the changes in gene regulation and expression of circRNA involved in mouse external ear embryonic development, a Prkra Little ear mouse model was used, and the changes in circRNA expression profiles were detected using next-generation sequencing. The changes in the expression of circRNA in the experimental group compared with those in the control group were identified using the find_circ and CiRi2 software, and the differentially expressed circRNAs were annotated via Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. The results show that the development of mouse external ear embryos is regulated by circRNA expression.

Orchestrated actin nucleation by the Candida albicans polarisome complex enables filamentous growth.

Candida albicans is a dimorphic fungus that converts from a yeast form to a hyphae form during infection. This switch requires the formation of actin cable to coordinate polarized cell growth. It's known that nucleation of this cable requires a multiprotein complex localized at the tip called the polarisome, but the mechanisms underpinning this process were unclear. Here, we found that C. albicans Aip5, a homolog of polarisome component ScAip5 in Saccharomyces cerevisiae that nucleates actin polymerization and synergizes with the formin ScBni1, regulates actin assembly and hyphae growth synergistically with other polarisome proteins Bni1, Bud6, and Spa2. The C terminus of Aip5 binds directly to G-actin, Bni1, and the C-terminal of Bud6, which form the core of the nucleation complex to polymerize F-actin. Based on insights from structural biology and molecular dynamic simulations, we propose a possible complex conformation of the actin nucleation core, which provides cooperative positioning and supports the synergistic actin nucleation activity of a tri-protein complex Bni1-Bud6-Aip5. Together with known interactions of Bni1 with Bud6 and Aip5 in S. cerevisiae, our findings unravel molecular mechanisms of C. albicans by which the tri-protein complex coordinates the actin nucleation in actin cable assembly and hyphal growth, which is likely a conserved mechanism in different filamentous fungi and yeast.

A novel model to predict mental distress among medical graduate students in China.

BACKGROUND: Poor mental health was reported among medical graduate students in some studies. Identification of risk factors for predicting the mental health is capable of reducing psychological distress among medical graduate students. Therefore, the aim of the study was to identify potential risk factors relating to mental health and further create a novel prediction model to calculate the risk of mental distress among medical graduate students. METHODS: This study collected and analyzed 1079 medical graduate students via an online questionnaire. Included participants were randomly classified into a training group and a validation group. A model was developed in the training group and validation of the model was performed in the validation group. The predictive performance of the model was assessed using the discrimination and calibration. RESULTS: One thousand and fifteen participants were enrolled and then randomly divided into the training group (n = 508) and the validation group (n = 507). The prevalence of severe mental distress was 14.96% in the training group, and 16.77% in the validation group. The model was developed using the six variables, including the year of study, type of student, daily research time, monthly income, scientific learning style, and feeling of time stress. The area under the receiver operating characteristic curve (AUROC) and calibration slope for the model were 0.70 and 0.90 (95% CI: 0.65 ~ 1.15) in the training group, respectively, and 0.66 and 0.80 (95% CI, 0.51 ~ 1.09) in the validation group, respectively. CONCLUSIONS: The study identified six risk factors for predicting anxiety and depression and successfully created a prediction model. The model may be a useful tool that can identify the mental status among medical graduate students. TRIAL REGISTRATION: No. ChiCTR2000039574 , prospectively registered on 1 November 2020.

Blood Impairs Viability of Fat Grafts and Adipose Stem Cells: Importance of Washing in Fat Processing.

BACKGROUND: Fat processing plays a pivotal role in graft survival. Each component of the blood in lipoaspirate affects fat survival in different ways, but the mechanisms are not clear. OBJECTIVES: The aim of this study was to investigate, by various experimental methods, the effect of blood on the viability of fat grafts and adipose stem cells (ASCs). METHODS: Blood and fat samples were obtained from 6 female patients undergoing aesthetic liposuction. For the in vivo experiment, we compared fat mixed with normal saline or various ratios of blood in nude mice. The samples were explanted at 2 and 8 weeks to evaluate the gross volume retention and histologic and immunohistochemical characteristics. For in vitro experiments, ASCs were pretreated with hemoglobin at different concentrations and for different times. We then assessed the proliferation, migration, adipogenesis, and reactive oxygen species production of ASCs. RESULTS: Blood in the graft led to a decrease in graft viability, as evaluated by general observation and histologic and immunohistochemical morphology in vivo. In vitro experiments showed inhibited proliferation, migration, and adipogenesis, and increased reactive oxygen species production in ACSs, after hemoglobin treatment, suggesting impaired ASC viability. CONCLUSIONS: This study suggests that blood impairs the viability of fat grafts and ASCs and provides evidence that washing to remove blood is important in fat processing.

Comparison of Microfat, Nanofat, and Extracellular Matrix/Stromal Vascular Fraction Gel for Skin Rejuvenation: Basic Research and Clinical Applications.

BACKGROUND: Over the past 2 decades, fat grafting has been extensively applied in the field of tissue regeneration. OBJECTIVES: The aim of this study was to investigate the therapeutic potential of microfat, nanofat, and extracellular matrix/stromal vascular fraction gel (SVF-gel) in skin rejuvenation. METHODS: Microfat was harvested by a cannula with multiple 0.8-mm smooth side holes and processed with a fat stirrer to remove fibers. Nanofat and SVF-gel were prepared according to previously reported methods, and their structure and viability were evaluated. Then, SVF cells from the 3 types of samples were isolated and characterized, and the cell viability was compared. RESULTS: The microstructure of the 3 samples showed distinct differences. The microfat group showed a diameter of 100 to 120.0 µm under the microscope and presented a botryoid shape under calcein acetoxymethyl (calcein-AM)/propidium iodide staining. Scanning electron microscopy analysis showed that the microfat maintained an integral histologic structure. In the nanofat group, no viable adipocytes and no normal histologic structure were observed, but high levels of free lipids were noted. The SVF-gel group showed uniform dispersion of cells with different sizes and parts of the adipose histologic structure. Cell count and culture revealed that the number of viable SVF cells decreased distinctly in the nanofat group compared with the microfat group. In contrast, the number of viable SVF cells in the SVF-gel group increased moderately. Clinical applications with microfat showed marked improvements in skin wrinkles. CONCLUSIONS: Microfat can preserve the integrity of the histologic structure and presents the advantages of subcutaneous volumetric restoration and improvement of skin quality in skin rejuvenation compared with the nanofat and SVF-gel.

Protective effect of Agrimonia pilosa polysaccharides on dexamethasone-treated MC3T3-E1 cells via Wnt/ß-Catenin pathway.

A water-soluble polysaccharide (APP-AW) was isolated from Agrimonia pilosa and prepared to three sulphated derivatives (S1, S2 and S3). The results showed that pre-treatment with APP-AW, S1, S2 and S3 each at the concentration of 50 µg/mL for 48 hours was able to prevent cytotoxicity induced by 1 µmol/L dexamethasone (Dex) in MC3T3-E1 cells via inhibition of apoptosis, which is in line with the findings in flow cytometry analysis. Meanwhile, the decreased ALP activity, collagen content, mineralization, BMP2, Runx2, OSX and OCN protein expression in DEX-treated MC3T3-E1 cells were reversed by the addition of APP-AW, S1, S2 and S3. Moreover, APP-AW, S1, S2 and S3 rescued DEX-induced increase of Bax, cytochrome c and caspase-3 and decrease of Bcl-2, Wnt3, ß-catenin and c-Myc protein expression in MC3T3-E1 cells. Our findings suggest that pre-treatment with APP-AW, S1, S2 and S3 could significantly protect MC3T3-E1 cells against Dex-induced cell injury via inhibiting apoptosis and activating Wnt/ß-Catenin signalling pathway, thus application of these polysaccharides may be a promising alternative strategy for steroid-induced avascular necrosis of the femoral head (SANFH) therapy.