Mutation analysis of the Gadd45 gene at exon 4 in atypical fibroxanthoma

<p>Abstract</p> <p>Background</p> <p>Atypical fibroxanthoma (AFX) histologically mimics high-grade sarcoma in the skin, although it follows a benign clinical course. AFX occurs in the sun-exposed skin and for this reason, an association with ultraviolet light has long been suspected. Bax and Gadd45 are p53 effector proteins. Bax is a programmed cell death protein and belongs to the Bcl-2 family. Gadd45 is a multifunctional DNA damage-inducible gene associated with the process of DNA damage.</p> <p>Methods</p> <p>Immunohistochemical expression of Bax was analyzed in 7 cases of AFX, and in 7 cases of benign fibrous histiocytoma (BFH) used as a comparison. The expression pattern of Bax was compared to previously reported p53 and Gadd45 expressions in a correspondent series. Mutation of the Gadd45 gene at exon 4 was also analyzed in AFX.</p> <p>Results</p> <p>AFX and BFH showed immunoreactivities respectively for Bax (3/7, 0/7), Gadd45 (4/7, 1/7) and p53 (2/7, 0/7). There was no exact correlation between p53 expression and Bax or Gadd45 expression. However, the pattern of expression between Bax and Gadd45 was also the same, with the exception of one case. No mutation of the Gadd45 gene at exon 4 was observed in a series of 6 AFX cases where DNA was available (0/6).</p> <p>Conclusion</p> <p>These results suggest a possible association between Bax and Gadd45 in AFX, and may refute any possibility of dysfunction of Gadd45 in terms of gene mutation, at least at exon 4 of the Gadd45 gene.</p

Pro-angiogenic scaffold-free Bio three-dimensional conduit developed from human induced pluripotent stem cell-derived mesenchymal stem cells promotes peripheral nerve regeneration

Although autologous nerve grafting is widely accepted as the gold standard treatment for segmental nerve defects, harvesting autologous nerves is highly invasive and leads to functional loss of the ablated part. In response, artificial nerve conduits made of artificial materials have been reported, but the efficacy of the nerve regeneration still needs improvement. The purpose of this study is to investigate the efficacy and mechanism of the Bio three-dimensional (3D) conduit composed of xeno-free human induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs). The 5-mm nerve gap of the sciatic nerve in immunodeficient rats was bridged with the Bio 3D conduit or silicone tube. Functional and histological recovery were assessed at 8 weeks after surgery. The regenerated nerve in the Bio 3D group was significantly superior to that in the silicone group based on morphology, kinematics, electrophysiology, and wet muscle weight. Gene expression analyses demonstrated neurotrophic and angiogenic factors. Macroscopic observation revealed neovascularization both inside and on the surface of the Bio 3D conduit. Upon their subcutaneous implantation, iMSCs could induce angiogenesis. The Bio 3D conduit fabricated from iMSCs are an effective strategy for nerve regeneration in animal model. This technology will be useful in future clinical situations

The efficacy of a scaffold-free Bio 3D conduit developed from human fibroblasts on peripheral nerve regeneration in a rat sciatic nerve model

バイオ3Dプリンターを用いた末梢神経損傷に対する神経再生技術の開発. 京都大学プレスリリース. 2017-02-27.バイオ3Dプリンタを用いた神経再生技術の開発に成功 --末梢神経損傷に対する三次元神経導管の医師主導治験を開始--. 京都大学プレスリリース. 2021-01-15.Background: Although autologous nerve grafting is the gold standard treatment of peripheral nerve injuries, several alternative methods have been developed, including nerve conduits that use supportive cells. However, the seeding efficacy and viability of supportive cells injected in nerve grafts remain unclear. Here, we focused on a novel completely biological, tissue-engineered, scaffold-free conduit. Methods: We developed six scaffold-free conduits from human normal dermal fibroblasts using a Bio 3D Printer. Twelve adult male rats with immune deficiency underwent mid-thigh-level transection of the right sciatic nerve. The resulting 5-mm nerve gap was bridged using 8-mm Bio 3D conduits (Bio 3D group, n = 6) and silicone tube (silicone group, n = 6). Several assessments were conducted to examine nerve regeneration eight weeks post-surgery. Results: Kinematic analysis revealed that the toe angle to the metatarsal bone at the final segment of the swing phase was significantly higher in the Bio 3D group than the silicone group (-35.78 ± 10.68 versus -62.48 ± 6.15, respectively; p < 0.01). Electrophysiological studies revealed significantly higher compound muscle action potential in the Bio 3D group than the silicone group (53.60 ± 26.36% versus 2.93 ± 1.84%; p < 0.01). Histological and morphological studies revealed neural cell expression in all regions of the regenerated nerves and the presence of many well-myelinated axons in the Bio 3D group. The wet muscle weight of the tibialis anterior muscle was significantly higher in the Bio 3D group than the silicone group (0.544 ± 0.063 versus 0.396 ± 0.031, respectively; p < 0.01). Conclusions: We confirmed that scaffold-free Bio 3D conduits composed entirely of fibroblast cells promote nerve regeneration in a rat sciatic nerve model

Long-Term Outcome of Sciatic Nerve Regeneration Using Bio3D Conduit Fabricated from Human Fibroblasts in a Rat Sciatic Nerve Model

Previously, we developed a Bio3D conduit fabricated from human fibroblasts and reported a significantly better outcome compared with artificial nerve conduit in the treatment of rat sciatic nerve defect. The purpose of this study is to investigate the long-term safety and nerve regeneration of Bio3D conduit compared with treatments using artificial nerve conduit and autologous nerve transplantation. We used 15 immunodeficient rats and randomly divided them into three groups treated with Bio3D ( n = 5) conduit, silicon tube ( n = 5), and autologous nerve transplantation ( n = 5). We developed Bio3D conduits composed of human fibroblasts and bridged the 5 mm nerve gap created in the rat sciatic nerve. The same procedures were performed to bridge the 5 mm gap with a silicon tube. In the autologous nerve group, we removed the 5 mm sciatic nerve segment and transplanted it. We evaluated the nerve regeneration 24 weeks after surgery. Toe dragging was significantly better in the Bio3D group (0.20 ± 0.28) than in the silicon group (0.6 ± 0.24). The wet muscle weight ratios of the tibial anterior muscle of the Bio3D group (79.85% ± 5.47%) and the autologous nerve group (81.74% ± 2.83%) were significantly higher than that of the silicon group (66.99% ± 3.51%). The number of myelinated axons and mean myelinated axon diameter was significantly higher in the Bio3D group (14708 ± 302 and 5.52 ± 0.44 μm) and the autologous nerve group (14927 ± 5089 and 6.04 ± 0.85 μm) than the silicon group (7429 ± 1465 and 4.36 ± 0.21 μm). No tumors were observed in any of the rats in the Bio3D group at 24 weeks after surgery. The Bio3D group showed significantly better nerve regeneration and there was no significant difference between the Bio3D group and the nerve autograft group in all endpoints

The Efficacy of a Scaffold-free Bio 3D Conduit Developed from Autologous Dermal Fibroblasts on Peripheral Nerve Regeneration in a Canine Ulnar Nerve Injury Model: A Preclinical Proof-of-Concept Study

Autologous nerve grafting is widely accepted as the gold standard treatment for segmental nerve defects. To overcome the inevitable disadvantages of the original method, alternative methods such as the tubulization technique have been developed. Several studies have investigated the characteristics of an ideal nerve conduit in terms of supportive cells, scaffolds, growth factors, and vascularity. Previously, we confirmed that biological scaffold-free conduits fabricated from human dermal fibroblasts promote nerve regeneration in a rat sciatic nerve injury model. The purpose of this study is to evaluate the feasibility of biological scaffold-free conduits composed of autologous dermal fibroblasts using a large-animal model. Six male beagle dogs were used in this study. Eight weeks before surgery, dermal fibroblasts were harvested from their groin skin and grown in culture. Bio 3D conduits were assembled from proliferating dermal fibroblasts using a Bio 3D printer. The ulnar nerve in each dog’s forelimb was exposed under general anesthesia and sharply cut to create a 5 mm interstump gap, which was bridged by the prepared 8 mm Bio 3D conduit. Ten weeks after surgery, nerve regeneration was investigated. Electrophysiological studies detected compound muscle action potentials (CMAPs) of the hypothenar muscles and motor nerve conduction velocity (MNCV) in all animals. Macroscopic observation showed regenerated ulnar nerves. Low-level hypothenar muscle atrophy was confirmed. Immunohistochemical, histological, and morphometric studies confirmed the existence of many myelinated axons through the Bio 3D conduit. No severe adverse event was reported. Hypothenar muscles were re-innervated by regenerated nerve fibers through the Bio 3D conduit. The scaffold-free Bio 3D conduit fabricated from autologous dermal fibroblasts is effective for nerve regeneration in a canine ulnar nerve injury model. This technology was feasible as a treatment for peripheral nerve injury and segmental nerve defects in a preclinical setting

Peripheral nerve regeneration following scaffold-free conduit transplant of autologous dermal fibroblasts: a non-randomised safety and feasibility trial

Abstract Background The use of Bio 3D nerve conduits is a promising approach for peripheral nerve reconstruction. This study aimed to assess their safety in three patients with peripheral nerve defects in their hands. Methods We describe a single institution, non-blinded, non-randomised control trial conducted at Kyoto University Hospital. Eligibility criteria included severed peripheral nerve injuries or a defect in the region distal to the wrist joint not caused by a congenital anomaly; a defect with a length of ≤20 mm in a nerve with a diameter ≤2 mm; failed results of sensory functional tests; ability to register in the protocol within 6 months from the day of injury; refusal of artificial nerve or autologous nerve transplantation; age 20–60 years; and willingness to participate and provide informed written consent. Six weeks before transplantation, skin was harvested, dermal fibroblasts were isolated and expanded, and Bio 3D nerve conduits were created using a Bio 3D printer. Bio 3D nerve conduits were transplanted into the patients’ nerve defects. The safety of Bio 3D nerve conduits in patients with a peripheral nerve injury in the distal part of the wrist joint were assessed over a 48-week period after transplantation. Results No adverse events related to the use of Bio 3D nerve conduits were observed in any patient, and all three patients completed the trial. Conclusions Bio 3D nerve conduits were successfully used for clinical nerve reconstruction without adverse events and are a possible treatment option for peripheral nerve injuries

Immunohistochemistry of the mid portion of the regenerated nerve eight weeks after surgery in both groups.

<p>A-C: Longitudinal sections in the Bio 3D group. D-F: Longitudinal sections in the silicone group. G-I: Transverse sections in the Bio 3D group. J-L: Transverse sections in the silicone group. A-F: scale bar = 100 μm. G-L: scale bar = 500 μm.</p