RESUMO
Vascular and nervous systems, two major networks in mammalian bodies, show a high degree of anatomical parallelism and functional crosstalk. During development, neurons guide and attract blood vessels, and consequently this parallelism is established. Here, we identified a noncanonical neurovascular interaction in eye development and disease. VEGFR2, a critical endothelial receptor for VEGF, was more abundantly expressed in retinal neurons than in endothelial cells, including endothelial tip cells. Genetic deletion of VEGFR2 in neurons caused misdirected angiogenesis toward neurons, resulting in abnormally increased vascular density around neurons. Further genetic experiments revealed that this misdirected angiogenesis was attributable to an excessive amount of VEGF protein around neurons caused by insufficient engulfment of VEGF by VEGFR2-deficient neurons. Moreover, absence of neuronal VEGFR2 caused misdirected regenerative angiogenesis in ischemic retinopathy. Thus, this study revealed neurovascular crosstalk and unprecedented cellular regulation of VEGF: retinal neurons titrate VEGF to limit neuronal vascularization. PAPERFLICK:
Assuntos
Neovascularização Fisiológica , Neurônios/metabolismo , Retina/crescimento & desenvolvimento , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Endocitose , Técnicas de Introdução de Genes , Camundongos , Camundongos Knockout , Neurogênese , Retina/metabolismo , Retina/patologia , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
BACKGROUND: Identification of the proper lymphatics is important for successful lymphaticovenular anastomosis (LVA) for lymphedema; however, visualization of lymphatic vessels is challenging. Photoacoustic lymphangiography (PAL) can help visualize lymphatics more clearly than other modalities. Therefore, we investigated the usefulness of PAL and determined whether the clear and three-dimensional image of PAL affects LVA outcomes. METHODS: We recruited 22 female patients with lower extremity lymphedema. The operative time, number of incisions, number of anastomoses, lymphatic vessel detection rate (number of functional lymphatics identified during the operation/number of incisions), and limb volume changes preoperatively and 3 months postoperatively were compared retrospectively. The patients were divided according to whether PAL was performed or not, and results were compared between those undergoing PAL (PAL group; n = 10) and those who did not (near-infrared fluorescence [NIRF] group, n = 12). RESULTS: The mean age of the patients was 55.9 ± 15.1 years in the PAL group and 50.7 ± 14.9 years in the NIRF group. One patient in the PAL group and three in the NIRF group had primary lymphedema. Eighteen patients (PAL group, nine; and NIRF group, nine) had secondary lymphedema. Based on preoperative evaluation using the International Society of Lymphology (ISL) classification, eight patients were determined to be in stage 2 and two patients in late stage 2 in the PAL group. In contrast, in the NIRF group, one patient was determined to be in stage 0, three patients each in stage 1 and stage 2, and five patients in late stage 2. Lymphatic vessel detection rates were 93% (42 LVAs and 45 incisions) and 83% (50 LVAs and 60 incisions) in the groups with and without PAL, respectively (p = 0.42). Limb volume change was evaluated in five limbs of four patients and in seven limbs of five patients in the PAL and NIRF groups as 336.6 ± 203.6 mL (5.90% ± 3.27%) and 52.9 ± 260.7 mL (0.71% ± 4.27%), respectively. The PAL group showed a significant volume reduction. (p = .038). CONCLUSIONS: Detection of functional lymphatic vessels on PAL is useful for treating LVA.
Assuntos
Vasos Linfáticos , Linfedema , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Verde de Indocianina , Linfografia/métodos , Projetos Piloto , Estudos Retrospectivos , Linfedema/diagnóstico por imagem , Linfedema/cirurgia , Vasos Linfáticos/diagnóstico por imagem , Vasos Linfáticos/cirurgia , Anastomose Cirúrgica/métodos , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/cirurgiaRESUMO
Adult mammalian wounds leave visible scars, whereas skin wounds in developing mouse fetuses are scarless until a certain point in development when complete regeneration occurs, including the structure of the dermis and skin appendages. Analysis of the molecular mechanisms at this transition will provide clues for achieving scarless wound healing. The fibroblast growth factor (FGF) family is a key regulator of inflammation and fibrosis during wound healing. We aimed to determine the expression and role of FGF family members in fetal wound healing. ICR mouse fetuses were surgically wounded at embryonic day 13 (E13), E15, and E17. Expression of FGF family members and FGF receptor (FGFR) in tissue samples from these fetuses was evaluated using in situ hybridization and reverse transcription-quantitative polymerase chain reaction. Fgfr1 was downregulated in E15 and E17 wounds, and its ligand Fgf7 was upregulated in E13 and downregulated in E15 and E17. Recombinant FGF7 administration in E15 wounds suppressed fibrosis and promoted epithelialization at the wound site. Therefore, the expression level of Fgf7 may correlate with scar formation in late mouse embryos, and external administration of FGF7 may represent a therapeutic option to suppress fibrosis and reduce scarring.
Assuntos
Fator 7 de Crescimento de Fibroblastos/metabolismo , Cicatrização , Animais , Cicatriz/patologia , Feto/metabolismo , Fibrose , Mamíferos , Camundongos , Camundongos Endogâmicos ICR , Pele/metabolismoRESUMO
Mast cells and inflammatory cells are abundant in keloid and hypertrophic scar tissues. Even if the cause of physical injury is similar, such as piercing or scratching with hands, clinical findings show differences in the size of keloids in the same area. Hence, we performed histological studies on giant keloids larger than the earlobe, and other smaller keloids. We also examined the risk factors associated with the formation of giant lesions. No statistically significant differences in the association of the risk factors were observed. However, histological observations clearly showed a high number of degranulated or active mast cells with a trend towards a greater number of degranulated mast cells in the giant keloid tissues. Collagen production also tended to increase. Two patients with giant keloids were severely obese, suggesting that the persistent inflammatory state of obesity may also be involved in the growth of keloid lesions.
Assuntos
Cicatriz Hipertrófica , Otopatias , Queloide , Cicatriz Hipertrófica/patologia , Colágeno , Otopatias/patologia , Fibroblastos/patologia , Humanos , Queloide/patologia , Mastócitos/patologiaRESUMO
BACKGROUND: Lymphatic vessels are difficult to identify using existing modalities as because of their small diameter and the transparency of the lymph fluid flowing through them. METHODS: Here, we introduce photoacoustic lymphangiography (PAL), a new modality widely used for lymphedema treatment, to observe limb lymphatic vessels. The photoacoustic imaging system used in this study can simultaneously visualize lymphatic vessels and veins with a high resolution (0.2 mm) and can also observe their three-dimensional relationship with each other. RESULTS: High-resolution images of the lymphatic vessels, detailed structure of the dermal back flow, and the three-dimensional positional relationship between the lymphatic vessels and veins were observed by PAL. CONCLUSION: The clear image provided by PAL could have a major application in pre- and postoperative use during lymphaticovenular anastomosis for lymphedema treatment.
Assuntos
Vasos Linfáticos , Linfedema , Técnicas Fotoacústicas , Anastomose Cirúrgica/efeitos adversos , Humanos , Vasos Linfáticos/diagnóstico por imagem , Vasos Linfáticos/cirurgia , Linfedema/diagnóstico por imagem , Linfedema/etiologia , Linfedema/cirurgia , Linfografia/métodos , Técnicas Fotoacústicas/efeitos adversos , Técnicas Fotoacústicas/métodosRESUMO
Vascular endothelial growth factor (VEGF) is a potent mitogen critical for angiogenesis and organogenesis. Deletion or inhibition of VEGF during development not only profoundly suppresses vascular outgrowth, but significantly affects the development and function of various organs. In the brain, VEGF is thought to not only promote vascular growth, but also directly act on neurons as a neurotrophic factor by activating VEGF receptors. In the present study, we demonstrated that deletion of VEGF using hGfap-Cre line, which recombines genes specifically in cortical and hippocampal neurons, severely impaired brain organization and vascularization of these regions. The mutant mice had motor deficits, with lethality around the time of weaning. Multiple reporter lines indicated that VEGF was highly expressed in neurons, but that its cognate receptors, VEGFR1 and 2 were exclusive to endothelial cells in the brain. In accordance, mice lacking neuronal VEGFR1 and VEGFR2 did not exhibit neuronal deformities or lethality. Taken together, our data suggest that neuron-derived VEGF contributes to cortical and hippocampal development likely through angiogenesis independently of direct neurotrophic effects mediated by VEGFR1 and 2.
Assuntos
Hipocampo/crescimento & desenvolvimento , Neurônios/metabolismo , Lobo Parietal/crescimento & desenvolvimento , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Alelos , Animais , Células Endoteliais/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Neovascularização Fisiológica/genética , Reação em Cadeia da Polimerase , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
Nicotinamide adenine dinucleotide (NAD) is an essential coenzyme that mediates various redox reactions. Particularly, mitochondrial NAD plays a critical role in energy production pathways, including the tricarboxylic acid (TCA) cycle, fatty acid oxidation, and oxidative phosphorylation. NAD also serves as a substrate for ADP-ribosylation and deacetylation by poly(ADP-ribose) polymerases (PARPs) and sirtuins, respectively. Thus, NAD regulates energy metabolism, DNA damage repair, gene expression, and stress response. Numerous studies have demonstrated the involvement of NAD metabolism in neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and retinal degenerative diseases. Mitochondrial dysfunction is considered crucial pathogenesis for neurodegenerative diseases such as AD and PD. Maintaining appropriate NAD levels is important for mitochondrial function. Indeed, decreased NAD levels are observed in AD and PD, and supplementation of NAD precursors ameliorates disease phenotypes by activating mitochondrial functions. NAD metabolism also plays an important role in axonal degeneration, a characteristic feature of peripheral neuropathy and neurodegenerative diseases. In addition, dysregulated NAD metabolism is implicated in retinal degenerative diseases such as glaucoma and Leber congenital amaurosis, and NAD metabolism is considered a therapeutic target for these diseases. In this review, we summarize the involvement of NAD metabolism in axon degeneration and various neurodegenerative diseases and discuss perspectives of nutritional intervention using NAD precursors.
Assuntos
NAD/metabolismo , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/terapia , Animais , Humanos , Mitocôndrias/metabolismo , NAD/uso terapêuticoRESUMO
The placental labyrinth is the interface for gas and nutrient exchange between the embryo and the mother; hence its proper development is essential for embryogenesis. However, the molecular mechanism underlying development of the placental labyrinth, particularly in terms of its endothelial organization, is not well understood. Here, we determined that fibronectin leucine-rich transmembrane protein 2 (FLRT2), a repulsive ligand of the UNC5 receptor family for neurons, is unexpectedly expressed in endothelial cells specifically in the placental labyrinth. Mice lacking FLRT2 in endothelial cells exhibited embryonic lethality at mid-gestation, with systemic congestion and hypoxia. Although they lacked apparent deformities in the embryonic vasculature and heart, the placental labyrinths of these embryos exhibited aberrant alignment of endothelial cells, which disturbed the feto-maternal circulation. Interestingly, this vascular deformity was related to endothelial repulsion through binding to the UNC5B receptor. Our results suggest that the proper organization of the placental labyrinth depends on coordinated inter-endothelial repulsion, which prevents uncontrolled layering of the endothelium.
Assuntos
Glicoproteínas de Membrana/metabolismo , Organogênese , Placenta/embriologia , Placenta/metabolismo , Transdução de Sinais , Animais , Sobrevivência Celular , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Células Endoteliais/metabolismo , Feminino , Deleção de Genes , Hipóxia/patologia , Glicoproteínas de Membrana/deficiência , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica , Receptores de Netrina , Placenta/irrigação sanguínea , Placenta/citologia , Gravidez , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/metabolismoRESUMO
Nicotinamide adenine dinucleotide (NAD) is an important coenzyme that participates in various energy metabolism pathways, including glycolysis, ß-oxidation, and oxidative phosphorylation. Besides, it is a required cofactor for post-translational modifications such as ADP-ribosylation and deacetylation by poly (ADP-ribose) polymerases (PARPs) and sirtuins, respectively. Thus, NAD regulates energy metabolism, DNA damage repair, gene expression, and stress response through these enzymes. Numerous studies have shown that NAD levels decrease with aging and under disturbed nutrient conditions, such as obesity. Additionally, a decline in NAD levels is closely related to the development of various metabolic disorders, including diabetes and fatty liver disease. In addition, many studies have revealed that administration of NAD precursors, such as nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), efficiently increase NAD levels in various tissues and prevent such metabolic diseases. These NAD precursors are contained in natural foods, such as cow milk, vegetables, and meats. Therefore, altered NAD metabolism can be a practical target for nutritional intervention. Recently, several human clinical trials using NAD precursors have been conducted to investigate the safety, pharmacokinetics, and efficacy against metabolic disorders such as glucose intolerance. In this review, we summarize current knowledge on the implications of NAD metabolism in metabolic diseases and discuss the outcomes of recent human clinical trials.
Assuntos
Dieta , Doenças Metabólicas/fisiopatologia , NAD/metabolismo , Humanos , Doenças Metabólicas/metabolismoRESUMO
Serine is a nonessential amino acid and plays an important role in cellular metabolism. In mammalian serine biosynthesis, 3-phosphoglycerate dehydrogenase (PHGDH) is considered a rate-limiting enzyme and is required for normal development. Although the biological functions of PHGHD in the nervous system have been intensively studied, its function in adipose tissue is unknown. In this study, we found that PHGDH is abundantly expressed in mature adipocytes of white adipose tissue. We generated an adipocyte-specific PHGDH knockout mouse (PHGDH FKO) and used it to investigate the role of serine biosynthesis in adipose tissues. Although PHGDH FKO mice had no apparent defects in adipose tissue development, these mice ameliorated glucose intolerance upon diet-induced obesity. Additionally, we found that the serine levels increase drastically in the adipose tissues of obese wild type mice, whereas no significant rise was observed in PHGDH FKO mice. Furthermore, wild type mice fed a serine-deficient diet also exhibited better glucose tolerance. These results suggest that PHGDH-mediated serine biosynthesis has important roles in adipose tissue glucose metabolism and could be a therapeutic target for diabetes in humans.
Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Intolerância à Glucose/genética , Fosfoglicerato Desidrogenase/genética , Adipócitos/citologia , Animais , Peso Corporal , Dieta , Feminino , Deleção de Genes , Glucose/metabolismo , Intolerância à Glucose/metabolismo , Teste de Tolerância a Glucose , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Fosfoglicerato Desidrogenase/metabolismo , Serina/químicaRESUMO
Nicotinamide adenine dinucleotide (NAD) is a major co-factor that mediates multiple biological processes including redox reaction and gene expression. Recently, NAD metabolism has received considerable attention because administration of NAD precursors exhibited beneficial effects against aging-related metabolic disorders in animals. Although numerous studies have reported that NAD levels decline with aging in multiple animal tissues, the pathway and kinetics of NAD metabolism in aged organs are not completely understood. To determine the NAD metabolism upon aging, we developed targeted metabolomics based on an LC/MS/MS system. Our method is simple and applicable to crude biological samples, including culture cells and animal tissues. Unlike a conventional enzymatic cycling assay, our approach can determine NAD and NADH (reduced form of NAD) by performing a single sample preparation. Further, we validated our method using biological samples and investigated the alteration of the NAD metabolome during aging. Consistent with previous reports, the NAD levels in the liver and skeletal muscle decreased with aging. Further, we detected a significant increase in nicotinamide mononucleotide and nicotinamide riboside in the kidney upon aging. The LC/MS/MS-based NAD metabolomics that we have developed is extensively applicable to biomedical studies, and the results will present innovative ideas for the aging studies, especially for that of NAD metabolism.
Assuntos
Cromatografia Líquida/métodos , Metaboloma/fisiologia , Metabolômica/métodos , NAD/análise , NAD/metabolismo , Espectrometria de Massas em Tandem/métodos , Envelhecimento , Animais , Rim/metabolismo , Modelos Lineares , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculos/metabolismo , Especificidade de Órgãos , Reprodutibilidade dos TestesRESUMO
Healthcare providers treating wounds have difficulties assessing the prognosis of patients with critical limb ischemia who had been discharged after complete healing of major amputation wounds. The word "major" in "major amputation" gives the impression of "being more severe" than "minor amputation." Therefore, even if wounds are healed after major amputation, they imagine that prognosis after major amputation would be poorer than that after minor amputation. We investigated the prognosis of diabetic nephropathy patients 2 years after amputations. Those patients underwent dialysis as well as amputation following percutaneous transluminal angioplasty for their foot wounds. They were ambulatory prior to these surgeries. Among 56 cases of minor amputation, 45 were males and 11 were females, and mortality was 41.1%. The mortality of cases with and without a coronary intervention history was 53.1% and 25.0%, respectively (p = 0.034). Among 10 cases of major amputation, 9 were males and 1 was female, and mortality was 60%. The mortality of cases with and without a coronary intervention history was 75.0% and 0%, respectively. Although we predicted poor prognosis in cases with major amputation, there was no significant difference in mortality 2 years after amputations (p = 0.267). Thus far poor prognosis has been reported for major amputation. It might be due to inclusion of the following patients: patients with wounds proximal to ankle joints, patients with extensive gangrene spreading to the lower legs, patients with septicemia from wound infection and who died around the time of operation, and patients with malnutrition. The results of our present study showed that the outcomes at 2 years postoperatively were similar between patients with major amputations and those with minor amputations, if surgical wounds were able to heal. We should not estimate the prognosis by the level of amputation, rather we should consider the effect of coronary intervention history on prognosis.
Assuntos
Amputação Cirúrgica/métodos , Isquemia/cirurgia , Extremidade Inferior/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Isquemia/diagnóstico , Isquemia/mortalidade , Japão/epidemiologia , Extremidade Inferior/cirurgia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Índice de Gravidade de Doença , Taxa de Sobrevida/tendências , CicatrizaçãoRESUMO
A 31-year-old nulligravid woman with a 3 year history of infertility visited our hospital. After consultation and a transvaginal ultrasound and MR imaging, her uterine anomaly was identified as complete septate uterus: class V (a) by the American Fertility Society (AFS). She had a doubled uterine cervix and a vaginal septum. Hysteroscopic metroplasty was performed with the aid of a laparoscopy. Both tubal patencies were confirmed with indigocarmine in a laparoscopic image. Laparoscopic electronic cautery was also done on the left ovarian endometrioma (stage 1 endometriosis; the revised American Society for Reproductive Medicine (rASRM) classification 4 point minimal). We distrained an intrauterine device in the uterine cavity and removed it after two cycles of menstruation. The patient subsequently became pregnant during her third menstrual cycle and the current progress of her pregnancy is favorable.
Assuntos
Histeroscopia/métodos , Laparoscopia/métodos , Procedimentos Cirúrgicos Urogenitais/métodos , Útero/anormalidades , Útero/cirurgia , Adulto , Eletrocoagulação , Endometriose/cirurgia , Feminino , Humanos , Doenças Ovarianas/cirurgia , Gravidez , Resultado do Tratamento , Vagina/anormalidades , Vagina/cirurgiaRESUMO
The BM microenvironment is required for the maintenance, proliferation, and mobilization of hematopoietic stem and progenitor cells (HSPCs), both during steady-state conditions and hematopoietic recovery after myeloablation. The ECM meshwork has long been recognized as a major anatomical component of the BM microenvironment; however, the molecular signatures and functions of the ECM to support HSPCs are poorly understood. Of the many ECM proteins, the expression of tenascin-C (TN-C) was found to be dramatically up-regulated during hematopoietic recovery after myeloablation. The TN-C gene was predominantly expressed in stromal cells and endothelial cells, known as BM niche cells, supporting the function of HSPCs. Mice lacking TN-C (TN-C(-/-)) mice showed normal steady-state hematopoiesis; however, they failed to reconstitute hematopoiesis after BM ablation and showed high lethality. The capacity to support transplanted wild-type hematopoietic cells to regenerate hematopoiesis was reduced in TN-C(-/-) recipient mice. In vitro culture on a TN-C substratum promoted the proliferation of HSPCs in an integrin α9-dependent manner and up-regulated the expression of the cyclins (cyclinD1 and cyclinE1) and down-regulated the expression of the cyclin-dependent kinase inhibitors (p57(Kip2), p21(Cip1), p16(Ink4a)). These results identify TN-C as a critical component of the BM microenvironment that is required for hematopoietic regeneration.
Assuntos
Células da Medula Óssea/citologia , Medula Óssea/metabolismo , Hematopoese , Células-Tronco Hematopoéticas/citologia , Tenascina/metabolismo , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/efeitos da radiação , Células da Medula Óssea/metabolismo , Transplante de Medula Óssea , Proliferação de Células , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Deleção de Genes , Células-Tronco Hematopoéticas/metabolismo , Cadeias alfa de Integrinas/genética , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , Células Estromais/citologia , Células Estromais/metabolismo , Tenascina/análise , Tenascina/genética , Regulação para Cima , Irradiação Corporal TotalRESUMO
Unlike adult mammalian wounds, early embryonic mouse skin wounds completely regenerate and heal without scars. Analysis of the underlying molecular mechanism will provide insights into scarless wound healing. Twist2 is an important regulator of hair follicle formation and biological patterning; however, it is unclear whether it plays a role in skin or skin appendage regeneration. Here, we aimed to elucidate Twist2 expression and its role in fetal wound healing. ICR mouse fetuses were surgically wounded on embryonic day 13 (E13), E15, and E17, and Twist2 expression in tissue samples from these fetuses was evaluated via in situ hybridization, immunohistochemistry, and reverse transcription-quantitative polymerase chain reaction. Twist2 expression was upregulated in the dermis of E13 wound margins but downregulated in E15 and E17 wounds. Twist2 knockdown on E13 left visible marks at the wound site, inhibited regeneration, and resulted in defective follicle formation. Twist2-knockdown dermal fibroblasts lacked the ability to undifferentiate. Furthermore, Twist2 hetero knockout mice (Twist + /-) formed visible scars, even on E13, when all skin structures should regenerate. Thus, Twist2 expression correlated with skin texture formation and hair follicle defects in late mouse embryos. These findings may help develop a therapeutic strategy to reduce scarring and promote hair follicle regeneration.
Assuntos
Folículo Piloso , Regeneração , Pele , Proteína 2 Relacionada a Twist , Cicatrização , Animais , Camundongos , Feto/metabolismo , Fibroblastos/metabolismo , Folículo Piloso/metabolismo , Camundongos Endogâmicos ICR , Camundongos Knockout , Regeneração/genética , Proteínas Repressoras , Pele/metabolismo , Proteína 1 Relacionada a Twist , Proteína 2 Relacionada a Twist/metabolismo , Proteína 2 Relacionada a Twist/genética , Cicatrização/genética , Cicatrização/fisiologiaRESUMO
Wounds that occur in adults form scars due to fibrosis, whereas those in embryos regenerate. If wound healing in embryos is mimicked in adults, scarring can be reduced. We found that mouse fetuses could regenerate tissues up to embryonic day (E) 13, but visible scars remained thereafter. This regeneration pattern requires actin cable formation at the epithelial wound margin via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK). Here, we investigated whether the AMPK-activating effect of salicylate, an anti-inflammatory drug, promotes regenerative wound healing. Salicylate administration resulted in actin cable formation and complete wound regeneration in E14 fetuses, in which scarring should have normally occurred, and promoted contraction of the panniculus carnosus muscle, resulting in complete wound regeneration. In vitro, salicylate further induced actin remodeling in mouse epidermal keratinocytes in a manner dependent on cell and substrate target-specific AMPK activation and subsequent regulation of Rac1 signaling. Furthermore, salicylate promoted epithelialization, enhanced panniculus carnosus muscle contraction, and inhibited scar formation in adult mice. Administration of salicylates to wounds immediately after injury may be a novel method for preventing scarring by promoting a wound healing pattern similar to that of embryonic wounds.
Assuntos
Proteínas Quinases Ativadas por AMP , Actinas , Cicatrização , Animais , Proteínas Quinases Ativadas por AMP/metabolismo , Cicatrização/efeitos dos fármacos , Camundongos , Actinas/metabolismo , Salicilatos/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Contração Muscular/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Cicatriz/metabolismo , Cicatriz/patologia , Ativação Enzimática/efeitos dos fármacosRESUMO
This study investigated the three-dimensional (3D) cellular interactions and tunneling nanotubes (TNTs) during fetal mouse skin regeneration on embryonic days 13 (E13) and 15 (E15). We aimed to understand spatial relationships among cell types involved in skin regeneration and assess the potential role of TNTs. Full-thickness skin incisions were performed in E13 and E15 embryos. Wound sites were collected, embedded in epoxy resin, processed for 3D reconstruction (1 µm thickness sections), and subjected to whole-mount immunostaining. We conducted in vitro co-culture experiments with fetal macrophages and fibroblasts to observe TNT formation. To assess the effect of TNTs on skin regeneration, an inhibiting agent (cytochalasin B) was administered to amniotic fluid. Results revealed that E13 epidermal keratinocytes interacted with dermal fibroblasts and macrophages, facilitating skin regrowth. TNT structures were observed at the E13-cell wound sites, among macrophages, and between macrophages and fibroblasts, confirmed through in vitro co-culture experiments. In vitro and utero cytochalasin B administration hindered those formation and inefficient skin texture regeneration at E13 wound sites. This emphasizes the necessity of 3D cellular interactions between epidermal and dermal cells during skin regeneration in mouse embryos at E13. The prevalence of TNT structures indicated their involvement in achieving complete skin texture restoration.
Assuntos
Técnicas de Cocultura , Fibroblastos , Nanotubos , Regeneração , Pele , Animais , Camundongos , Regeneração/fisiologia , Pele/metabolismo , Nanotubos/química , Queratinócitos/citologia , Queratinócitos/fisiologia , Macrófagos/metabolismo , Feto , Feminino , Cicatrização/efeitos dos fármacos , Cicatrização/fisiologia , Comunicação Celular , Citocalasina B/farmacologiaRESUMO
Unlike adults, early developing fetuses can completely regenerate tissue, and replicating this could lead to the development of treatments to reduce scarring. Mice epidermal structures, including wound healing patterns, are regenerated until embryonic day (E) 13, leaving visible scars thereafter. These patterns require actin cable formation at the epithelial wound margin through AMP-activated protein kinase (AMPK) activation. We aimed to investigate whether the administration of compound 13 (C13), a recently discovered AMPK activator, to the wound could reproduce this actin remodeling and skin regeneration pattern through its AMPK activating effect. The C13 administration resulted in partial formations of actin cables, which would normally result in scarring, and scar reduction during the healing of full-layer skin defects that occurred in E14 and E15 fetuses. Furthermore, C13 was found to cause AMPK activation in these embryonic mouse epidermal cells. Along with AMPK activation, Rac1 signaling, which is involved in leaflet pseudopodia formation and cell migration, was suppressed in C13-treated wounds, indicating that C13 inhibits epidermal cell migration. This suggests that actin may be mobilized by C13 for cable formation. Administration of C13 to wounds may achieve wound healing similar to regenerative wound healing patterns and may be a potential candidate for new treatments to heal scars.
RESUMO
Mammalian skin, including human and mouse skin, does not regenerate completely after injury; it is repaired, leaving a scar. However, it is known that skin wounds up to a certain stage of embryonic development can regenerate. The mechanism behind the transition from regeneration to scar formation is not fully understood. Panniculus carnosus muscle (PCM) is present beneath the dermal fat layer and is a very important tissue for wound contraction. In rodents, PCM is present throughout the body. In humans, on the other hand, it disappears and becomes a shallow fascia on the trunk. Fetal cutaneous wounds, including PCM made until embryonic day 13 (E13), regenerate completely, but not beyond E14. We visualized the previously uncharacterized development of PCM in the fetus and investigated the temporal and spatial changes in PCM at different developmental stages, ranging from full regeneration to non-regeneration. Furthermore, we report that E13 epidermal closure occurs through actin cables, which are bundles of actomyosin formed at wound margins. The wound healing process of PCM suggests that actin cables may also be associated with PCM. Our findings reveal that PCM regenerates through a similar mechanism.
RESUMO
OBJECTIVE: To improve skin appearance at the donor site of a split-thickness skin graft, part of the harvested skin was minced and grafted back onto the site in a process we named "recruited minced skin grafting." MATERIALS AND METHODS: Thirteen Japanese patients who needed split-thickness skin grafts were treated with recruited minced skin grafting. Five patients were used as controls, in whom donor sites were treated with the traditional method. Part of the split-thickness skin was minced using two surgical blades (number 24) to an approximate particle size of less than 0.5 mm. Minced skin was spread and transplanted onto the donor site and covered with polyurethane foam. Twelve months after the operation, donor sites were scored for hypopigmentation, hyperpigmentation, redness, and disruption of skin texture. Gross appearance was evaluated according to total score. RESULTS: Donor sites treated with recruited minced skin grafts had significantly better appearance than those of controls. Donor sites that had more than 5% of the total area treated tended to have better results. CONCLUSION: Recruited minced skin grafting is a good method of improving the appearance of the donor site.