Methylation Pattern Mediated by m6A Regulator and Tumor Microenvironment Invasion in Lung Adenocarcinoma

Background. Recent research has established the existence of epigenetic modulation of the immune response. The possible involvement of RNA-n6-methyladenosine (m6A) alteration in tumor microenvironment (TME) cell invasion, on the other hand, is unknown. Methods. Based on 23 m6A regulators, we examined the alteration patterns of m6A in 629 LUAD tissues and comprehensively connected these modification patterns with TME cell invasion characteristics. The m6A score was calculated, and the m6A modification pattern of a single tumor was quantified using principal component analysis. Then, we further verified the expression of m6A related enzymes and the role hub gene (NOL10) closely related to survival in lung cancer cell lines. Results. Three separate m6A alteration modes have been discovered. TME cell invasion characteristics in the three modes were very similar to the three immunological phenotypes of tumors: immunological rejection, immunological inflammation, and immunological desert. We show that assessing the m6A modification pattern in a single tumor may help predict tumor inflammatory stage, subtype, TME interstitial activity, and prognosis. TME phenotypic inflammation is indicated by a high m6A score, which is characterized by elevated mutation load and immunological activation. The low m6A subtype showed matrix activation and ineffective immune infiltration, indicating that the TME phenotype of noninflammation and immunological rejection had a poor survival probability. Increased neoantigen burden was also linked to a high m6A score. Patients with a higher m6A score saw substantial therapeutic and clinical improvements. And reducing hub gene NOL10 expression substantially inhibited lung cancer cell growth and migration. Conclusions. This research shows that m6A alteration is critical in the creation of TME variety and complexity. The analysis of a single tumor’s m6A alteration pattern will aid in improving our knowledge of TME invasion features and guiding more effective immunotherapy tactics.

Strategies for large bone defect reconstruction after trauma, infections or tumour excision: a comprehensive review of the literature

Large bone defects resulting from musculoskeletal tumours, infections, or trauma are often unable to heal spontaneously. The challenge for surgeons is to avoid amputation, and provide the best functional outcomes. Allograft, vascularized fibular or iliac graft, hybrid graft, extracorporeal devitalized autograft, distraction osteogenesis, induced-membrane technique, and segmental prostheses are the most common surgical strategies to manage large bone defects. Given its optimal osteogenesis, osteoinduction, osteoconduction, and histocompatibility properties, along with the lower the risk of immunological rejection, autologous graft represents the most common used strategy for reconstruction of bone defects. However, the choice of the best surgical technique is still debated, and no consensus has been reached. The present study investigated the current reconstructive strategies for large bone defect after trauma, infections, or tumour excision, discussed advantages and disadvantages of each technique, debated available techniques and materials, and evaluated complications and new perspectives.

Microstructured Hyaluronic Acid Hydrogel for Tooth Germ Bioengineering

Tooth loss has been found to adversely affect not just masticatory and speech functions, but also psychological health and quality of life. Currently, teeth replacement options include dentures, bridges, and implants. However, these artificial replacement options remain inferior to biological replacements due to their reduced efficiency, the need for replacements, and the risk of immunological rejection. To this end, there has been a heightened interest in the bioengineering of teeth in recent years. While there have been reports of successfully regenerated teeth, controlling the size and shape of bioengineered teeth remains a challenge. In this study, methacrylated hyaluronic acid (MeHA) was synthesized and microstructured in a hydrogel microwell array using soft lithography. The resulting MeHA hydrogel microwell scaffold resembles the shape of a naturally developing human tooth germ. To facilitate the epithelial–mesenchymal interactions, human adult low calcium high temperature (HaCaT) cells were seeded on the surface of the hydrogels and dental pulp stem cells (DPSCs) were encapsulated inside the hydrogels. It was found that hydrogel scaffolds were able to preserve the viability of both types of cells and they appeared to favor signaling between epithelial and mesenchymal cells, which is necessary in the promotion of cell proliferation. As such, the hydrogel scaffolds offer a promising system for the bioengineering of human tooth germs in vitro.

Bone Marrow-derived Mesenchymal Stem Cells Reverse Hepatic Fibrosis, Improved Vascularity, and Attenuate the Apoptosis in Carbon Tetrachloride-induced Hepatic Fibrosis Experimental Rats

Background: Liver fibrosis is a sequel of different chronic inflammatory diseases. The most effective treatment for end-stage liver fibrosis is liver transplantation; but the shortage of donor organs, immunological rejection, surgical complications, and high medical costs limit the transplantation. That’s why we are in argent need to develop new strategies in treatment. Objectives: to evaluate the role of MSCs in regenerating liver cells and reverse hepatic fibrosis. Materials and Methods: 30 Animals were randomly divided into three groups (10 animals each): group 1: a negative control; group 2: induced liver fibrosis (pathological control).; group 3: induced liver fibrosis that received undifferentiated BM MSCs (3×106 cells/ml intraperitoneally/single dose); The extent of fibrosis, vascularization, and inflammation and hepatic cell apoptosis were evaluated together with assessment of liver functions. Results: The MSCs treated group showed significant improvement of liver functions, and attenuation of fibrosis histopathologicaly and down regulate the expression of TGF ß versus the induced fibrosis group. inflammatory marker(TNF,IL-6) were down regulated and vascularity was restored in MSCs treated group compared to CCL4 induced fibrosis rats. Conclusion: MSCs provide promising therapeutic agents in treatment of liver fibrosis.

iBTA-Induced Biotube® Blood Vessels: 2020 Update

Blood access is a lifeline for dialysis patients. However, serious problems such as stenosis or obstruction of access blood vessels, which are life-threatening conditions in daily clinical practice, still remain. One of the most promising candidates for solving these problems may be Biotube blood vessels. More than 20 years have passed since the development of in-body tissue architecture (iBTA), a technology for preparing tissues for autologous implantation in patients. The tissues obtained by iBTA do not elicit immunological rejection, which is one of the ultimate goals of regenerative medical engineering; however, their practical applications were quite challenging. The seemingly unorthodox iBTA concepts that do not follow the current pre-established medical system may not be readily accepted in general medicine. In contrast, there are many diseases that cannot be adequately addressed even with the latest and most advanced medical technology. However, iBTA may be able to save patients with serious diseases. It is natural that the development of high-risk medical devices that do not fit the corporate logic would be avoided. In order to actively treat such largely unattached diseases, we started Biotube Co., Ltd. with an aim to contribute to society. Biotubes induced by iBTA are collagenous tubular tissues prepared in the patient’s body for autologous implantation. The application of Biotubes as tissues for vascular implantation has been studied for many years. Biotubes may have excellent potential as small-diameter artificial blood vessels, one of the most difficult to clinically achieve. Their possibility is currently being confirmed in preclinical tests. Biotubes may save hundreds of thousands of patients worldwide annually from amputation. In addition, we aim to eliminate the recuring access vascular problems in millions of dialysis patients. This study provides an update on the current development status and future possibilities of Biotubes and their preparation molds, Biotube Makers.

Incorporation of an Allogenic Cortical Bone Graft Following Arthrodesis of the First Metatarsophalangeal Joint in a Patient with Hallux Rigidus

Hallux rigidus is degenerative arthritis of the first metatarsophalangeal joint characterized by pain and stiffness in the joint with limitation of motion and functional impairment. Recently, bone grafts have been introduced in orthopedic procedures, namely osteosynthesis and arthrodesis. Allografts can induce bone formation, provide support for vascular and bone ingrowth and have a low risk of immunological rejection. A 52-year-old female patient with hallux rigidus underwent arthrodesis of the first metatarsophalangeal joint using Shark Screw® made of allogenic cortical bone. Corrective surgery was performed after 10 weeks, and a 5 × 3 mm large part of the Shark Screw® with the surrounding patient’s bone was removed. A histological evaluation revealed a vascularized graft with the newly formed compact lamellar bone fitting exactly to the cortical graft. The bone surface was lined by plump osteoblasts with osteoid production, and osteocytes were present in the lacunae. The arthrodesis of the first metatarsophalangeal joint using an allogenic cortical bone graft results in fast, primary bone healing without immunological rejection. This case suggests that the cortical allograft is a good and safe treatment option with an excellent graft incorporation into the host bone. However, as the literature evaluating the histology of different bone grafts is scarce, further high-level evidence studies with adequate sample sizes are needed to confirm our findings.

Use of Post-transplant Cyclophosphamide Treatment to Build a Tolerance Platform to Prevent Liquid and Solid Organ Allograft Rejection

Corneal transplantation (CT) is the most frequent type of solid organ transplant (SOT) performed worldwide. Unfortunately, immunological rejection is the primary cause of graft failure for CT and therefore advances in immune regulation to induce tolerance remains an unmet medical need. Recently, our work and others in pre-clinical studies found that cyclophosphamide (Cy) administered after (“post-transplant,” PTCy) hematopoietic stem cell transplantation (HSCT), i.e., liquid transplants is effective for graft vs. host disease prophylaxis and enhances overall survival. Importantly, within the past 10 years, PTCy has been widely adopted for clinical HSCT and the results at many centers have been extremely encouraging. The present studies found that Cy can be effectively employed to prolong the survival of SOT, specifically mouse corneal allografts. The results demonstrated that the timing of PTCy administration is critical for these CT and distinct from the kinetics employed following allogeneic HSCT. PTCy was observed to interfere with neovascularization, a process critically associated with immune rejection of corneal tissue that ensues following the loss of ocular “immune privilege.” PTCy has the potential to delete or directly suppress allo-reactive T cells and treatment here was shown to diminish T cell rejection responses. These PTCy doses were observed to spare significant levels of CD4+ FoxP3+ (Tregs) which were found to be functional and could readily receive stimulating signals leading to their in vivo expansion via TNFRSF25 and CD25 agonists. In total, we posit future studies can take advantage of Cy based platforms to generate combinatorial strategies for long-term tolerance induction.

Artemisinin Attenuates Transplant Rejection by Inhibiting Multiple Lymphocytes and Prolongs Cardiac Allograft Survival

Immunological rejection is an important factor resulting in allograft dysfunction, and more valid therapeutic methods need to be explored to improve allograft outcomes. Many researches have indicated that artemisinin and its derivative exhibits immunosuppressive functions, apart from serving as a traditional anti-malarial drug. In this assay, we further explored the therapeutic effects of artemisinin for transplant rejection in a rat cardiac transplantation model. We found that it markedly attenuated allograft rejection and histological injury and significantly prolonged the survival of allograft. Upon further exploring the mechanism, we demonstrated that artemisinin not only attenuated T cell-mediated rejection (TCMR) by reducing effector T cell infiltration and inflammatory cytokine secretion and increasing regulatory T cell infiltration and immunoregulatory cytokine levels, but also attenuated antibody-mediated rejection (ABMR) through inhibition of B cells activation and antibody production. Furthermore, artemisinin also reduced macrophage infiltration in allografts, which was determined to be important for TCMR and ABMR. Moreover, we demonstrated that artemisinin significantly inhibited the function of pure T cells, B cells, and macrophages in vitro. All in all, this study provide evidence that artemisinin significantly attenuates TCMR and ABMR by targeting multiple effectors. Therefore, this agent might have potential for use in clinical settings to protect against transplant rejection.

Molecular Pathways Modulated by Mesenchymal Stromal Cells and Their Extracellular Vesicles in Experimental Models of Liver Fibrosis

End-stage liver fibrosis is common to all chronic liver diseases. Since liver transplantation has several limitations, including lack of donors, immunological rejection, and high medical costs, therapeutic alternatives are needed. The administration of mesenchymal stromal cells (MSCs) has been proven effective in tissue regeneration after damage. However, the risk of uncontrolled side effects, such as cellular rejection and tumorigenesis, should be taken into consideration. A safer alternative to MSC transplantation is represented by the MSC secretome, which retains the same beneficial effect of the cell of origin, without showing any considerable side effect. The paracrine effect of MSCs is mainly carried out by secreted particles in the nanometer range, known as extracellular vesicles (EVs) that play a fundamental role in intercellular communication. In this review, we discuss the current literature on MSCs and MSC-EVs, focusing on their potential therapeutic action in liver fibrosis and on their molecular content (proteins and RNA), which contributes in reverting fibrosis and prompting tissue regeneration.

Ten-year outcomes of microkeratome-assisted lamellar keratoplasty for keratoconus

Background/AimsTo report the 10-year outcomes of modified microkeratome-assisted lamellar keratoplasty (LK) for keratoconus.MethodsIn this single-centre interventional case series, 151 consecutive eyes with keratoconus underwent modified microkeratome-assisted LK. Eyes with scars extending beyond the posterior half of the corneal stroma and preoperative thinnest-point pachymetry value of less than 300 μm were excluded. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunological rejection, ectasia recurrence and graft failure rates.ResultsBaseline BSCVA (0.89±0.31 logarithm of the minimum angle of resolution (logMAR)) significantly improved to 0.10±0.12 logMAR at year 3 (p<0.001), and remained stable up to 10 years. At 10 years, 94% of eyes saw ≥20/40, 61% saw ≥20/25 and 24% saw ≥20/20 Snellen BSCVA. At final follow-up, RA exceeding 4.5 dioptres was observed in 5 cases (4%). Endothelial cell loss was 25±17% at 1 year with an annual decline of 2% over 10 years. The 10-year cumulative risk for immunological rejection and graft failure was 8.5%, and 2.4%, respectively. No case developed recurrent ectasia at 10 years.ConclusionModified microkeratome-assisted LK results in stable visual and refractive outcomes with low rates of immunological rejection and graft failure in the absence of recurrence of ectasia for at least 10 years.