Facial nerve paralysis interferes with mimetic muscle function. To reconstruct natural facial movement, free muscle flaps are transplanted as new muscles. However, it is difficult to maintain resting ...tonus. A dual innervation technique in which other nerves such as the hypoglossal nerve or contralateral facial nerve are added is often applied. Using 10-week-old rats (n = 10), the masseteric and hypoglossal nerves were cut, and the distal stump of the masseteric nerve and the proximal stump of the hypoglossal nerve were then sutured (suture group). In the other group, the masseteric nerve was cut and cauterized (cut group). Immunohistochemistry and microarray were performed on the extracted masseter muscle. The immunohistochemistry results suggested that the muscles in the suture group obtained oxidative characteristics. The microarray showed the genes involved in mitochondrial function, including Perm1. In summary, our data support the validity of the dualinnervation technique for facial paralysis treatment.
Abstract
Up to a certain developmental stage, a fetus can completely regenerate wounds in the skin. To clarify the mechanism of fetal skin regeneration, identifying when the skin switches from ...fetal-type wound regeneration to adult-type wound repair is necessary. We hypothesized that this switch occurs at several time points and that complete skin regeneration requires epidermal–dermal interactions and the formation of actin cables. We compared normal skin and wound morphology at each developmental stage. We examined two parameters: epidermal texture and dermal structure. We found that the three-dimensional structure of the skin was completely regenerated in full-thickness skin incisions made before embryonic day (E) 13. However, the skin texture did not regenerate in wounds made after E14. We also found that the dermal structure regenerates up to E16, but wounds created after E17 heal as scars with dermal fibrosis. By controlling the activity of AMP-activated protein kinase and altering actin cable formation, we could regulate scar formation in utero. These findings may contribute to therapies that allow complete skin regeneration without scarring.
Cellular senescence is characterized by cell cycle arrest and the senescence-associated secretory phenotype (SASP) and can be triggered by a variety of stimuli, including deoxyribonucleic acid ...(DNA) damage, oxidative stress, and telomere exhaustion. Cellular senescence is associated with skin aging, and identification of specific markers of senescent cells is essential for development of targeted therapies. Cathepsin F (CTSF) has been implicated in dermatitis and various cancers and participates in cell immortalization through its association with Bcl family proteins. It is a candidate therapeutic target to specifically label and eliminate human skin fibroblasts and keratinocytes immortalized by aging and achieve skin rejuvenation. In this study, we investigated whether CTSF is associated with senescence in human fibroblasts and keratinocytes. In senescence models, created using replicative aging, ionizing radiation exposure, and the anticancer drug doxorubicin, various senescence markers were observed, such as senescence-associated β-galactosidase (SA-β-gal) activity, increased SASP gene expression, and decreased uptake of the proliferation marker BrdU. Furthermore, CTSF expression was elevated at the gene and protein levels. In addition, CTSF-positive cells were abundant in aged human epidermis and in some parts of the dermis. In the population of senescent cells with arrested division, the number of CTSF-positive cells was significantly higher than that in the proliferating cell population. These results suggest that CTSF is a candidate for therapeutic modalities targeting aging fibroblasts and keratinocytes.
Skin senescence is characterized by a decrease in extracellular matrix and the accumulation of senescent fibroblasts in the dermis, and their secretion of humoral factors. Ependymin-related protein 1 ...(EPDR1) is involved in abnormal fibroblast metabolism and collagen deposition, however, its relation to skin aging is unclear. We investigated whether and how EPDR1 is involved in age-related dermal deterioration. When young dermal fibroblasts and senescent cells were co-cultured in a semipermeable membrane separation system, the young fibroblasts showed decreased gene expression of collagen type I α1 chain (
) and elastin, and increased expression of matrix metalloproteinase (
)
and
. Senescence marker expression and EPDR1 production were increased in the culture medium of senescent cells. Treatment of young fibroblasts with recombinant EPDR1, enhanced matrix-related gene expression and suppressed
expression, whereas
knockdown had the opposite effects. EPDR1 gene and protein expression were increased in aged skin, compared to young skin. These results suggest that senescent cells affect nearby fibroblasts, in part through EPDR1 secretion, and exert negative effects on matrix production in the dermis. These results may lead to the discovery of potential candidate targets in the development of skin anti-aging therapies.
Limited data exist with regard to the outcome of the Nuss procedure for pectus excavatum repair in adults. Here, we analysed changes in lung capacity and thoracic morphology based on computed ...tomography (CT) imaging in adults with pectus excavatum before surgery, during bar insertion and after bar removal. Patients who underwent the Nuss procedure for pectus excavatum after the age of 20 were included in this study. Chest CT scans of the included participants were taken before the Nuss procedure, immediately before removal of the pectus bar and 6 months after removal of the pectus bar. Lung capacity and thoracic morphology measurements were made from the CT scans. Six patients aged 24–43 years were included in this study. After the Nuss procedure, lung capacity was decreased in all patients. Although the pectus bar was removed, lung capacity had not significantly increased and was almost the same volume as before the Nuss procedure. After the Nuss procedure, the funnel chest shape had improved in all cases, patients’ thoracic spine had also moved forward as the thorax moved forward and patients’ stoop had improved.
Despite a lack of change in lung capacity, surgical modification should be considered to reduce stress on the thoracic spine and in turn, reduce pain in patients with pectus excavatum. However, further long-term observation seems necessary.
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.
An artificial sphincter implanted in the bulbous urethra to treat severe postprostatectomy urinary incontinence is effective, but embedding-associated complications can occur. We assessed the ...feasibility, efficacy, and safety of urethral graciloplasty cross-innervated by the pudendal nerve. A simulation surgery on three male fresh cadavers was performed. Both ends of the gracilis muscle were isolated only on its vascular pedicle with proximal end of the obturator nerve severed and transferred to the perineum. We examined whether the gracilis muscle could be wrapped around the bulbous urethra and whether the obturator nerve was long enough to suture with the pudendal nerve. In addition, surgery was performed on a 71-year-old male patient with severe urinary incontinence. The postoperative 12-month outcomes were assessed using a 24-hour pad test and urodynamic study. In all cadaveric simulations, the gracilis muscles could be wrapped around the bulbous urethra in a γ-loop configuration. The length of the obturator nerve was sufficient for neurorrhaphy with the pudendal nerve. In the clinical case, the postoperative course was uneventful. The mean maximum urethral closure pressure and functional profile length increased from 40.7 to 70 cm H
O and from 40.1 to 45.3 mm, respectively. Although urinary incontinence was not completely cured, the patient was able to maintain urinary continence at night. Urethral graciloplasty cross-innervated by the pudendal nerve is effective in raising the urethral pressure and reducing urinary incontinence.
Heterochronic parabiosis is used to study the systemic effects of aging and involves surgically connecting two animals of different ages such that they have common blood circulation. Although this ...technique has been prevalent for a long time, there is no scientific consensus on the age of the animals that should be used. We hypothesized that the younger the animal, the greater would be its rejuvenating effect. Hence, to test this hypothesis, we created parabiosis of 67-week-old mice with younger mice of different ages (4-week-old and 8-week-old). We evaluated the changes in appearance and the expression IL-1A, IL-6, and Cdkn2a (p16) in the liver, kidney, brain, and skin. These cytokines belong to the senescence-associated secretory phenotype (SASP) factors, and are indicators of aging. Although we did not find any significant changes in the appearance of the mice, we found statistically significant differences in some SASP factors between the liver of the 4-week-old and 8-week-old pairs. However, overall, compared to the 8-week-old mice, the 4-week-old does not exert a significantly higher rejuvenation effect on the older mice. Hence, we concluded that the rejuvenation of older mice during heterochronic parabiosis might not be affected by the exact age of the younger mice.
Peroxisome proliferator‐activated receptor γ (PPARγ) is a member of the nuclear receptor superfamily known for its anti‐inflammatory and macrophage differentiation effects, as well as its ability to ...promote fat cell differentiation and reduce insulin resistance. Pioglitazone (Pio) is a PPARγ agonist used clinically as an anti‐diabetic agent for improving insulin sensitivity in patients with diabetes. The objective of this study was to develop a drug delivery system (DDS) for the local release of Pio to promote wound healing. Pio of low aqueous solubility was water‐solubilized by micelles formed from gelatin grafted with L‐lactic acid oligomers, and incorporated into a biodegradable gelatin hydrogel. An 8‐mm punch biopsy tool was used to prepare two skin wounds on either side of the midline of 8‐week‐old mice. Wounds were treated by the hydrogels with (Pio‐hydrogel group) or without (control group) Pio, and the wound area were observed 1, 4, 7, and 14 days after treatment. In addition, a protein assay and immunohistological stain were performed to determine the effects of the Pio‐hydrogel on inflammation and macrophage differentiation. The Pio‐hydrogels promote wound healing. Moreover, Western blotting analysis demonstrated that treatment with Pio‐hydrogels resulted in decreased levels of the cytokines MIP‐2 and TGF‐β, and increased levels of glucose‐regulating adiponectin. It is concluded that Pio‐incorporated hydrogels promote the proliferation and remodeling phases of wound healing, and may prove to be effective as wound dressings.
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