Combination of chemically modified SDF-1α mRNA and small skin improves wound healing in diabetic rats with full-thickness skin defects.

OBJECTIVES: Diabetes mellitus is associated with refractory wound healing, yet current therapies are insufficient to accelerate the process of healing. Recent studies have indicated chemically modified mRNA (modRNA) as a promising therapeutic intervention. The present study aimed to explore the efficacy of small skin engineered to express modified mRNAs encoding the stromal cell-derived factor-1α (SDF-1α) facilitating wound healing in a full-thickness skin defect rat model. This study, devised therapeutic strategies for diabetic wounds by pre-treating small skin with SDF-1α modRNA. MATERIALS AND METHODS: The in vitro transfection efficiency was evaluated using fluorescence microscopy and the content of SDF-1α in the medium was determined using ELISA after the transfection of SDF-1α into the small skin. To evaluate the effect of SDF-1α modRNA and transplantation of the small skin cells on wound healing, an in vivo full-thickness skin defect rat model was assessed. RESULTS: The results revealed that a modRNA carrying SDF-1α provided potent wound healing in the small skin lesions reducing reduced scar thickness and greater angiogenesis (CD31) in the subcutaneous layer. The SDF-1α cytokines were significantly secreted by the small skin after transfection in vitro. CONCLUSIONS: This study demonstrated the benefits of employing small skin combined with SDF-1α modRNA in enhancing wound healing in diabetic rats having full-thickness skin defects.

Opsonized nanoparticles target and regulate macrophage polarization for osteoarthritis therapy: A trapping strategy.

Osteoarthritis (OA) is a chronic disease caused by joint inflammation. Its occurrence and development depend on a continuous inflammation environment. The activated M1 macrophages play a critical role in the inflammatory response of OA. Regulating the pro-inflammatory M1 to anti-inflammatory M2 macrophages in the OA articular cavity could be a rational strategy for OA treatment. It has been acknowledged that activated macrophages could proactively capture opsonized nanoparticles in the bloodstream and then accumulate into the reticuloendothelial system (RES) organs. Based on this fact, a trapping strategy is proposed, which transforms a normal nanoparticle into an opsonized attractant to target and regulate macrophage polarization. In this study, the opsonized nanoparticle (IgG/Bb@BRPL) had several key features, including an immunoglobulin IgG (the opsonized layer), an anti-inflammatory agent berberine (Bb), and an oxidative stress-responsive bilirubin grafted polylysine biomaterial (BR-PLL) for drug loading (the inner nanocore). In vitro studies confirmed that IgG/Bb@BRPL prefer to be phagocytosed by M1 macrophage, not M0. And the internalized IgG/Bb@BRPL effectively promoted macrophage polarization toward the M2 phenotype and protected nearby chondrocytes. In vivo studies suggested that IgG/Bb@BRPL significantly enhanced therapeutic outcomes by suppressing inflammation and promoting cartilage repair while not prolonging the retention period compared to non-opsonized counterparts. This proof-of-concept study provided a novel opsonization trapping strategy for OA drug delivery and treatment.

Chemically Modified SDF-1α mRNA Promotes Random Flap Survival by Activating the SDF-1α/CXCR4 Axis in Rats.

Random skin flaps are frequently applied in plastic and reconstructive surgery for patients suffering from soft tissue defects caused by congenital deformities, trauma and tumor resection. However, ischemia and necrosis in distal parts of random skin flaps remains a common challenge that limits the clinical application of this procedure. Recently, chemically modified mRNA (modRNA) was found to have great therapeutic potential. Here, we explored the potential of fibroblasts engineered to express modified mRNAs encoding the stromal cell-derived factor-1α (SDF-1α) to improve vascularization and survival of therapeutic random skin flaps. Our study showed that fibroblasts pre-treated with SDF-1α modRNA have the potential to salvage ischemic skin flaps. Through a detailed analysis, we revealed that a fibroblast SDF-1α modRNA combinatorial treatment dramatically reduced tissue necrosis and significantly promoted neovascularization in random skin flaps compared to that in the control and vehicle groups. Moreover, SDF-1α modRNA transcription in fibroblasts promoted activation of the SDF-1α/CXCR4 pathway, with concomitant inactivation of the MEK/ERK, PI3K/AKT, and JAK2/STAT3 signaling pathways, indicating a possible correlation with cell proliferation and migration. Therefore, fibroblast-mediated SDF-1α modRNA expression represents a promising strategy for random skin flap regeneration.

Scutellarin Attenuates the IL-1ß-Induced Inflammation in Mouse Chondrocytes and Prevents Osteoarthritic Progression.

Osteoarthritis (OA) is a chronic degenerative disease wherein the articular cartilage exhibits inflammation and degradation. Scutellarin (SCU) is a flavonoid glycoside with a range of pharmacological activities, as shown in previous studies demonstrating its anti-inflammatory activity. How SCU impacts the progression of OA, however, has not been explored to date. Herein, we assessed the impact of SCU on murine chondrocytes in an OA model system. In in vitro assays, we measured chondrocyte expression of key OA-associated factors such as matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) via qRT-PCR and Western blotting, the expression of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were detected by qRT-PCR. Our results showed that the downregulation of MMP-13, ADAMTS-5, COX-2, and iNOS expression by SCU and the overproduction of IL-6, TNF-α, and PGE2 induced by IL-1ß were all inhibited by SCU in a concentration-dependent manner. Moreover, SCU was able to reverse aggrecan and collagen II degradation and nuclear factor-κB (NF-κB) and nuclear factor erythroid-derived 2-like 2 (Nrf2) signaling pathway activation both in vivo and in vitro. We further used a destabilization of the medial meniscus (DMM) murine model of OA to explore the therapeutic benefits of SCU in vivo. Together, our findings suggest SCU to be a potentially valuable therapeutic agent useful for treating OA.

The Protective Effect of Magnolol in Osteoarthritis: In vitro and in vivo Studies.

Osteoarthritis (OA), defined as a long-term progressive joint disease, is characterized by cartilage impairment and erosion. In recent decades, magnolol, as a type of lignin extracted from Magnolia officinalis, has been proved to play a potent anti-inflammatory role in various diseases. The current research sought to examine the latent mechanism of magnolol and its protective role in alleviating the progress of OA in vivo as well as in vitro experimentations. In vitro, the over-production of Nitric oxide (NO), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6), induced by interleukin-1 beta (IL-1ß), were all inhibited notably by magnolol in a concentration-dependent manner. Moreover, magnolol could also downregulate the expression of metalloproteinase 13 (MMP13) and thrombospondin motifs 5 (ADAMTS5). All these changes ultimately led to the deterioration of the extracellular matrix (ECM) induced by IL-1ß. Mechanistically, magnolol suppressed the activation of PI3K/Akt/NF-κB pathway. Furthermore, a powerful binding capacity between magnolol and PI3K was also revealed in our molecular docking research. In addition, magnolol-induced protective effects in OA development were also detected in a mouse model. In summary, this research suggested that magnolol possessed a new therapeutic potential for the development of OA.

Peiminine inhibits the IL-1ß induced inflammatory response in mouse articular chondrocytes and ameliorates murine osteoarthritis.

Osteoarthritis (OA) is a common arthrosis characterized by degeneration and inflammation of articular cartilage. In recent decades, peiminine (Pm) has been identified as one of the active ingredients of Fritillaria plants. According to reports, Pm has a potent anti-inflammatory effect in various diseases. However, the effectiveness of Pm as an anti-inflammatory in OA has not previously been reported. This research aims to evaluate the anti-inflammatory effect of Pm on interleukin (IL)-1ß-induced mice chondrocytes and its chondroprotective effect in a mouse OA model with surgical destabilization of the medial meniscus. IL-1ß-induced expression of nitric oxide (NO), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) were all inhibited significantly by Pm pretreatment in vitro. In addition, Pm also inhibited the expression of thrombospondin motifs 5 (ADAMTS-5) and matrix metalloproteinase-13 (MMP-13), which are responsible for the degradation of the extracellular matrix (ECM). Additionally, the degradation of aggrecan and collagen II was reversed by Pm. Furthermore, Pm inhibited Akt phosphorylation and the nuclear transfer of nuclear factor-κB (NF-κB) and activated Nrf2/HO-1 signaling pathways both in vitro and in vivo. These findings suggested that Pm alleviated inflammatory effects in the IL-1ß-induced chondrocytes. Therefore, Pm might be a potential therapeutic agent for OA.

Hypoxia preconditioning promotes bone marrow mesenchymal stem cells survival by inducing HIF-1α in injured neuronal cells derived exosomes culture system.

Bone marrow derived stem cells (BMSCs) transplantation are viewed as a promising therapeutic candidate for spinal cord injury (SCI). However, the inflammatory microenvironment in the spinal cord following SCI limits the survival and efficacy of transplanted BMSCs. In this study, we investigate whether injured neuronal cells derived exosomes would influence the survival of transplanted BMSCs after SCI. In order to mimic the microenvironment in SCI that the neuronal cells or transplanted BMSCs suffer in vivo, PC12 cells conditioned medium and PC12 cell's exosomes collected from H2O2-treated PC12 cell's culture medium were cultured with BMSCs under oxidative stress in vitro. PC12 cells conditioned medium and PC12 cell's exosomes significantly accelerated the apoptosis of BMSCs induced by H2O2. Moreover, the cleaved caspase-3, cytochrome (Cyt) C, lactate dehydrogenase (LDH) releases, and apoptotic percentage were increased, and the ratio of Bcl-2/Bax and cell viability were decreased. Inhibition of exosome secretion via Rab27a small interfering RNA prevented BMSCs apoptosis in vitro. In addition, hypoxia-preconditioned promoted the survival of BMSCs under oxidative stress both in vivo after SCI and in vitro. Our results also indicate that HIF-1α plays a central role in the survival of BMSCs in hypoxia pretreatment under oxidative stress conditions. siRNA-HIF-1α increased apoptosis of BMSCs; in contrast, HIF-1α inducer FG-4592 attenuated apoptosis of BMSCs. Taken together, we found that the injured PC12 cells derived exosomes accelerate BMSCs apoptosis after SCI and in vitro, hypoxia pretreatment or activating expression of HIF-1α to be important in the survival of BMSCs after transplantation, which provides a foundation for application of BMSCs in therapeutic potential for SCI.