RESUMO
BACKGROUND: Peripheral nerve injury (PNI) is commonly observed in clinical practice, yet the underlying mechanisms remain unclear. This study investigated the correlation between the expression of a Ras-related protein Rab32 and pyroptosis in rats following PNI, and potential mechanisms have been explored by which Rab32 may influence Schwann cells pyroptosis and ultimately peripheral nerve regeneration (PNR) through the regulation of Reactive oxygen species (ROS) levels. METHODS: The authors investigated the induction of Schwann cell pyroptosis and the elevated expression of Rab32 in a rat model of PNI. In vitro experiments revealed an upregulation of Rab32 during Schwann cell pyroptosis. Furthermore, the effect of Rab32 on the level of ROS in mitochondria in pyroptosis model has also been studied. Finally, the effects of knocking down the Rab32 gene on PNR were assessed, morphology, sensory and motor functions of sciatic nerves, electrophysiology and immunohistochemical analysis were conducted to assess the therapeutic efficacy. RESULTS: Silencing Rab32 attenuated PNI-induced Schwann cell pyroptosis and promoted peripheral nerve regeneration. Furthermore, our findings demonstrated that Rab32 induces significant oxidative stress by damaging the mitochondria of Schwann cells in the pyroptosis model in vitro. CONCLUSION: Rab32 exacerbated Schwann cell pyroptosis in PNI model, leading to delayed peripheral nerve regeneration. Rab32 can be a potential target for future therapeutic strategy in the treatment of peripheral nerve injuries.
Assuntos
Traumatismos dos Nervos Periféricos , Ratos , Animais , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/terapia , Espécies Reativas de Oxigênio/metabolismo , Piroptose , Ratos Sprague-Dawley , Proliferação de Células , Células de Schwann/metabolismo , Nervo Isquiático/lesões , Nervo Isquiático/metabolismo , Regeneração Nervosa/fisiologiaRESUMO
Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to abnormal oxidative stress and high levels of reactive oxygen species (ROS), a condition detrimental for bone formation, making the OP-related bone healing a significant clinical challenge. As the osteogenic differentiation ability of bone marrow mesenchymal stem cells (BMSCs) is closely related to bone regeneration; currently, this study assessed the effects of Picein on BMSCs in vitro and bone regeneration in osteoporotic bone defect in vivo. Cell viability was determined by CCK-8 assay. The production of (ROS), malonaldehyde, superoxide dismutase activities, and glutathione was evaluated by using commercially available kits, and a flow cytometry analysis was adopted to detect macrophage polarization. Osteogenic capacity of BMSCs was evaluated by alkaline phosphatase (ALP) activity, ALP staining, and Alizarin red S staining. The expression of osteogenic-related proteins (OPN, Runx-2, OCN) and osteogenic-related genes (ALP, BMP-4, COL-1, and Osterix) were evaluated by Western blotting and real-time PCR (RT-PCR). In addition, proliferation, migration ability, and angiogenic capacity of human umbilical vein endothelial cells (HUVECs) were evaluated by EdU staining, scratch test, transwell assay, and tube formation assay, respectively. Angiogenic-related genes (VEGF, vWF, CD31) were also evaluated by RT-PCR. Results showed that Picein alleviated erastin-induced oxidative stress, enhanced osteogenic differentiation capacity of BMSCs, angiogenesis of HUVECs, and protects cells against ferroptosis through Nrf2/HO-1/GPX4 axis. Moreover, Picein regulate immune microenvironment by promoting the polarization of M2 macrophages in vitro. In addition, Picein also reduce the inflammation levels and promotes bone regeneration in osteoporotic bone defect in OP rat models in vivo. Altogether, these results suggested that Picein can promote bone regeneration and alleviate oxidative stress via Nrf2/HO-1/GPX4 pathway, offering Picein as a novel antioxidant agent for treating osteoporotic bone defect.
Assuntos
Regeneração Óssea , Ferroptose , Heme Oxigenase-1 , Fator 2 Relacionado a NF-E2 , Osteoporose , Estresse Oxidativo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Osteoporose/tratamento farmacológico , Ferroptose/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Regeneração Óssea/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ratos Sprague-Dawley , Ratos , Humanos , Feminino , Transdução de Sinais/efeitos dos fármacosRESUMO
Large segmental bone defects are commonly operated with autologous bone grafting, which has limited bone sources and poses additional surgical risks. In this study, we fabricated poly(lactide-co-glycolic acid) (PLGA)/ß-tricalcium phosphate (ß-TCP) composite membranes by electrostatic spinning and further promoted osteogenesis by regulating the release of ß-TCP in the hope of replacing autologous bone grafts in the clinical practice. The addition of ß-TCP improved the mechanical strength of PLGA by 2.55 times. Moreover, ß-TCP could accelerate the degradation of PLGA and neutralize the negative effects of acidification of the microenvironment caused by PLGA degradation. In vitro experiments revealed that PLGA/TCP10 membranes are biocompatible and the released ß-TCP can modulate the activity of osteoblasts by enhancing the calcium ions concentration in the damaged area and regulating the pH of the local microenvironment. Simultaneously, an increase in ß-TCP can moderate the lactate content of the local microenvironment, synergistically enhancing osteogenesis by promoting the tube-forming effect of human umbilical vein endothelial cells. Therefore, it is potential to utilize PLGA/TCP bioactive membranes to modulate the microenvironment at the site of bone defects to promote bone regeneration.
RESUMO
Currently, sonodynamic therapy (SDT) has limited therapeutic outcomes and immune responses, highlighting the urgent need for enhanced strategies that can stimulate robust and long-lasting antitumor effects. Microcystis, a notorious microalga, reveals the possibility of mediating SDT owing to the presence of gas vesicles (GVs) and phycocyanin (PC). Herein, a nontoxic strain of Microcystis elabens (labeled Me) is developed as a novel agent for SDT because it generates O2 under red light (RL) illumination, while GVs and PC act as cavitation nuclei and sonosensitizers, respectively. Moreover, algal debris is released after ultrasound (US) irradiation, which primes the Toll-like receptor pathway to initiate a cascade of immune responses. This sono-immune strategy inhibits CT26 colon tumor growth largely by promoting dendritic cell (DC) maturation and cytotoxic T-cell activation. After combination with the immune checkpoint blockade (ICB), the therapeutic outcome is further amplified, accompanied by satisfactory abscopal and immune memory effects; the similar potency is proven in the "cold" 4T1 triple-negative breast tumor. In addition, Me exhibits good biosafety without significant acute or chronic toxicity. Briefly, this study turns waste into wealth by introducing sono-immunotherapy based on Microcystis that achieved encouraging therapeutic effects on cancer, which is expected to be translated into the clinic.
Assuntos
Microcystis , Animais , Camundongos , Linhagem Celular Tumoral , Terapia por Ultrassom/métodos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Humanos , Ficocianina/química , Ficocianina/farmacologia , Imunoterapia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Neoplasias do Colo/terapia , Neoplasias do Colo/imunologiaRESUMO
Peripheral nerve injury (PNI) remains a challenging area in regenerative medicine. Nerve guide conduit (NGC) transplantation is a common treatment for PNI, but the prognosis of NGC treatment is unsatisfactory due to 1) neuromechanical unmatching and 2) the intra-conduit inflammatory microenvironment (IME) resulting from Schwann cell pyroptosis and inflammatory-polarized macrophages. A neuromechanically matched NGC composed of regenerated silk fibroin (RSF) loaded with poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (P:P) and dimethyl fumarate (DMF) are designed, which exhibits a matched elastic modulus (25.1 ± 3.5 MPa) for the peripheral nerve and the highest 80% elongation at break, better than most protein-based conduits. Moreover, the NGC can gradually regulate the intra-conduit IME by releasing DMF and monitoring sciatic nerve movements via piezoresistive sensing. The combination of NGC and electrical stimulation modulates the IME to support PNI regeneration by synergistically inhibiting Schwann cell pyroptosis and reducing inflammatory factor release, shifting macrophage polarization from the inflammatory M1 phenotype to the tissue regenerative M2 phenotype and resulting in functional recovery of neurons. In a rat sciatic nerve crush model, NGC promoted remyelination and functional and structural regeneration. Generally, the DMF/RSF/P:P conduit provides a new potential therapeutic approach to promote nerve repair in future clinical treatments.
Assuntos
Fibroínas , Regeneração Nervosa , Traumatismos dos Nervos Periféricos , Animais , Regeneração Nervosa/efeitos dos fármacos , Regeneração Nervosa/fisiologia , Ratos , Traumatismos dos Nervos Periféricos/terapia , Fibroínas/química , Fibroínas/farmacologia , Modelos Animais de Doenças , Ratos Sprague-Dawley , Células de Schwann/metabolismo , Regeneração Tecidual Guiada/métodos , Inflamação , Alicerces Teciduais/química , Nervo Isquiático/lesõesRESUMO
Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to the imbalance between osteogenesis and osteoclastogenesis, making osteoporotic bone defects healing a significant clinical challenge. Calcium phosphate cement (CPC) is a promising bone substitute material due to its good osteoinductive activity, however, the drawbacks such as fragility, slow degradation rate and incapability to control bone loss restrict its application in osteoporotic bone defects treatment. Currently, we developed the PLGA electrospun nanofiber sheets to carry alendronate (ALN) and magnesium oxide nanoparticle (nMgO) into CPC, therefore, to obtain a high-strength bone cement (C/AM-PL/C). The C/AM-PL/C bone cement had high mechanical strength, anti-washout ability, good injection performance and drug sustained release capacity. More importantly, the C/AM-PL/C cement promoted the osteogenic differentiation of bone marrow mesenchymal stem cells and neovascularization via the release of Mg2+ (from nMgO) and Ca2+ (during the degradation of CPC), and inhibited osteoclastogenesis via the release of ALN in vitro. Moreover, the injection of C/AM-PL/C cement significantly improved bone healing in an OP model with femur condyle defects in vivo. Altogether, the injectable C/AM-PL/C cement could facilitate osteoporotic bone regeneration, demonstrating its capacity as a promising candidate for treatment of osteoporotic bone defects.
RESUMO
The treatment of osteoporotic bone defect remains a big clinical challenge because osteoporosis (OP) is associated with oxidative stress and high levels of reactive oxygen species (ROS), a condition detrimental for bone formation. Anti-oxidative nanomaterials such as selenium nanoparticles (SeNPs) have positive effect on osteogenesis owing to their pleiotropic pharmacological activity which can exert anti-oxidative stress functions to prevent bone loss and facilitate bone regeneration in OP. In the current study a strategy of one-pot method by introducing Poly (lactic acid-carbonate) (PDT) and ß-Tricalcium Phosphate (ß-TCP) with SeNPs, is developed to prepare an injectable, anti-collapse, shape-adaptive and adhesive bone graft substitute material (PDT-TCP-SE). The PDT-TCP-SE bone graft substitute exhibits sufficient adhesion in biological microenvironments and osteoinductive activity, angiogenic effect and anti-inflammatory as well as anti-oxidative effect in vitro and in vivo. Moreover, the PDT-TCP-SE can protect BMSCs from erastin-induced ferroptosis through the Sirt1/Nrf2/GPX4 antioxidant pathway, which, in together, demonstrated the bone graft substitute material as an emerging biomaterial with potential clinical application for the future treatment of osteoporotic bone defect. STATEMENT OF SIGNIFICANCE: Injectable, anti-collapse, adhesive, plastic and bioactive bone graft substitute was successfully synthesized. Incorporation of SeNPs with PDT into ß-TCP regenerated new bone in-situ by moderating oxidative stress in osteoporotic bone defects area. The PDT-TCP-SE bone graft substitute reduced high ROS levels in osteoporotic bone defect microenvironment. The bone graft substitute could also moderate oxidative stress and inhibit ferroptosis via Sirt1/Nrf2/GPX4 pathway in vitro. Moreover, the PDT-TCP-SE bone graft substitute could alleviate the inflammatory environment and promote bone regeneration in osteoporotic bone defect in vivo. This biomaterial has the advantages of simple synthesis, biocompatibility, anti-collapse, injectable, and regulation of oxidative stress level, which has potential application value in bone tissue engineering.