Transplantable stem cell nanobridge scaffolds for accelerating articular cartilage regeneration.

Microfracture technique for treating articular cartilage defects usually has poor clinical outcomes due to critical heterogeneity and extremely limited in quality. To improve the effects of current surgical technique (i.e., microfracture technique), we propose the transplantable stem cell nanobridge scaffold, acting as a protective bridge between host tissue and defected cartilage as well as microfracture-derived cells. Nanobridge scaffolds have a sophisticated nanoaligned structure with freestanding and flexible shapes for imposing direct structural guidance to cells including transplanted stem cells and host cells, and it can induce not only chondrocyte migration but also stem cell differentiation, maturation, and growth factor secretion. The transplantable stem cell nanobridge scaffold is capable of reconstructing the defected cartilage with homogeneous architecture and highly enhanced adhesive stress similar with native cartilage tissue by the synergistic effects of stem cells-based chondro-induction and nanotopography-based chondro-conduction. Our findings demonstrate a significant advancement in the traditional treatment technique by using a nanoengineered tool for achieving successful cartilage regeneration.

Anti-inflammatory effects of mesenchymal stem cell-conditioned media inhibited macrophages activation in vitro.

The immunomodulatory effects of mesenchymal stem cells (MSCs) on macrophages have been reported, however, the underlying mechanism remains unknown. Therefore, this study aimed to investigate the anti-inflammatory effects of MSCs on lipopolysaccharide (LPS)-stimulated macrophages and the subsequent downregulation of their inflammatory mediators. Macrophages were treated with conditioned media from MSCs, without a subsequent change of MSCs responding to the inflammation state. This study also evaluated whether the interleukin (IL) 4 stimulation of MSCs can improve their anti-inflammatory effects. Results demonstrated that the MSC-conditioned medium (MSC-CM) stimulated with IL4 significantly inhibited inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression of LPS-activated macrophages. MSC-CM treatment inhibited the mRNA transcription of the cytokines IL1ß and IL6, the chemokines C-C motif ligand (CCL) 2, CCL3, CCL4, and CCL5, and the chemokine receptors CCR2 and CCR5, in LPS-stimulated macrophages. As revealed through western blot and immunofluorescence analyses, the phosphorylation of p38, JNK, and ERK MAPKs, as well as phosphorylation of NF-κB in stimulated macrophages, were also inhibited by the MSC-CM. Further, more potent anti-inflammatory effects were observed with the IL4-stimulated cells, compared with those observed with the non-stimulated cells. The MSC-CM demonstrated a potent anti-inflammatory effect on LPS-activated macrophages, while the IL4 stimulation improved this effect. These findings indicate that MSCs could exert anti-inflammatory effects on macrophages, and may be considered as a therapeutic agent in inflammation treatment.

Human adipose-derived mesenchymal stem cell-based medical microrobot system for knee cartilage regeneration in vivo.

Targeted cell delivery by a magnetically actuated microrobot with a porous structure is a promising technique to enhance the low targeting efficiency of mesenchymal stem cell (MSC) in tissue regeneration. However, the relevant research performed to date is only in its proof-of-concept stage. To use the microrobot in a clinical stage, biocompatibility and biodegradation materials should be considered in the microrobot, and its efficacy needs to be verified using an in vivo model. In this study, we propose a human adipose-derived MSC-based medical microrobot system for knee cartilage regeneration and present an in vivo trial to verify the efficacy of the microrobot using the cartilage defect model. The microrobot system consists of a microrobot body capable of supporting MSCs, an electromagnetic actuation system for three-dimensional targeting of the microrobot, and a magnet for fixation of the microrobot to the damaged cartilage. Each component was designed and fabricated considering the accessibility of the patient and medical staff, as well as clinical safety. The efficacy of the microrobot system was then assessed in the cartilage defect model of rabbit knee with the aim to obtain clinical trial approval.

Anti-neuroinflammatory effects of galangin in LPS-stimulated BV-2 microglia through regulation of IL-1ß production and the NF-κB signaling pathways.

Neuroinflammation resulting from microglial activation is involved in the pathogenesis of neurodegenerative diseases, including Parkinson's diseases. Microglial activation plays an important role in neuroinflammation and contributes to several neurological disorders. Hence, inhibition of both microglial activation and the generation of pro-inflammatory cytokines may lead to an effective treatment for neurodegenerative diseases. In the present study, the anti-neuroinflammatory effects of galangin were investigated in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Galangin significantly decreased the generation of nitric oxide, interleukin-1ß, and inducible nitric oxide synthase in LPS-stimulated BV-2 microglial cells. In addition, galangin inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase 1/2. Furthermore, it was observed that activation of both IκB-α and nuclear factor kappa B (NF-κB) was significantly increased following LPS stimulation, and this effect was suppressed by galangin treatment. In conclusion, galangin displayed an anti-neuroinflammatory activity in LPS-stimulated BV-2 microglial cells. Galangin inhibited LPS-induced neuroinflammation via the MAPK and NF-κB signaling pathways and might act as a natural therapeutic agent for the treatment of various neuroinflammatory conditions.

Anti-Neuroinflammatory Effects of Vanillin Through the Regulation of Inflammatory Factors and NF-κB Signaling in LPS-Stimulated Microglia.

Microglia, resident macrophages of the central nervous system (CNS), is responsible for immune responses and homeostasis of the CNS. Microglia plays a complex role in neuroinflammation, which has been implicated in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Therefore, therapeutic agents that suppress the microglia-mediated inflammatory response could potentially be used in the prevention or treatment of neurodegenerative diseases. Vanillin, a primary component of vanilla bean extract, has anti-inflammatory, anticancer, and antitumor properties. However, the effects of vanillin on the anti-neuroinflammatory responses of microglial cells are still poorly understood. In this study, we investigated the mechanism by which vanillin induces anti-neuroinflammatory responses in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. We found that vanillin significantly decreased the production of nitric oxide and pro-inflammatory cytokines, including interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Vanillin also reduced the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), as well as the mRNA expression levels of IL-1ß, TNF-α, and IL-6. Moreover, vanillin inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB. Collectively, these results suggest that vanillin has anti-neuroinflammatory properties and may act as a natural therapeutic agent for neuroinflammatory diseases.

Pseudane-VII Regulates LPS-Induced Neuroinflammation in Brain Microglia Cells through the Inhibition of iNOS Expression.

We previously isolated pseudane-VII from the secondary metabolites of Pseudoalteromonas sp. M2 in marine water, and demonstrated its anti-inflammatory efficacy on macrophages. However, the molecular mechanism by which pseudane-VII suppresses neuroinflammation has not yet been elucidated in brain microglia. Microglia is activated by immunological stimulation or brain injury. Activated microglia secrete proinflammatory mediators which damage neurons. Neuroinflammation appears to be associated with certain neurological diseases, including Parkinson's disease and Alzheimer's disease. Natural compounds that suppress microglial inflammatory responses could potentially be used to prevent neurodegenerative diseases or slow their progression. In the present study, we found that pseudane-VII suppresses neuroinflammation in lipopolysaccaride (LPS)-stimulated BV-2 microglial cells and brain. Pseudane-VII was shown to inhibit the LPS-stimulated NO, ROS production and the expression of iNOS and COX-2. To identify the signaling pathway targeted by pseudane-VII, we used western blot analysis to assess the LPS-induced phosphorylation state of p38, ERK1/2, JNK1/2, and nuclear factor-kappaB (NF-κB). We found that pseudane-VII attenuated LPS-induced phosphorylation of MAPK and NF-κB. Moreover, administration of pseudane-VII in mice significantly reduced LPS-induced iNOS expression and microglia activation in brain. Taken together, our findings suggest that pseudane-VII may represent a potential novel target for treatment for neurodegenerative diseases.

Anti-inflammatory effects of trans-cinnamaldehyde on lipopolysaccharide-stimulated macrophage activation via MAPKs pathway regulation.

OBJECTIVES: Inflammation is a primary response of the innate immune system against various infections. Macrophages are a type of immune cell that have a critical role in the inflammation. Recent studies reported that various natural compounds could regulate immune responses such as inflammation. Trans-cinnamaldehyde (TCA) is a natural compound from cinnamon, especially abundant in cinnamon bark. Previous studies reported that TCA has anti-biofilm, anti-microbial, and anti-cancer activities. However, the anti-inflammatory effects and the mechanism of TCA on macrophages are still unknown. MATERIALS AND METHODS: Raw 264.7 murine macrophage cells were used in this study. Major assays were MTT, Griess assay, Western blot, enzyme-linked immunosorbent assay (ELISA) and reverse transcription (RT)-PCR analysis. RESULTS: In this study, we investigated the anti-inflammatory effects of TCA on the RAW 264.7 murine macrophage cell line. TCA significantly decreased lipopolysaccharide (LPS)-induced nitric oxide (NO) production in a dose-dependent manner. Moreover, TCA treatment significantly reduced mRNA expression and protein expression of inducible NO synthase (iNOS) in LPS-stimulated macrophages in a dose-dependent manner. TCA treatment also diminished the mRNA expression level and secretion of IL-1ß, IL-6 and TNF-α in LPS-activated macrophages. TCA elicited the anti-inflammatory effects by inhibiting ERK, JNK and p38 MPAKs phosphorylation in the cells. DISCUSSION AND CONCLUSION: TCA elicits the anti-inflammatory effects on LPS-stimulated macrophage activation via suppression of MAPKs phosphorylation, and pro-inflammatory gene expression. Therefore, this study provides important information regarding the use of TCA as a candidate therapeutic agent against inflammation.

Pseudane-VII Isolated from Pseudoalteromonas sp. M2 Ameliorates LPS-Induced Inflammatory Response In Vitro and In Vivo.

The ocean is a rich resource of flora, fauna, food, and biological products. We found a wild-type bacterial strain, Pseudoalteromonas sp. M2, from marine water and isolated various secondary metabolites. Pseudane-VII is a compound isolated from the Pseudoalteromonas sp. M2 metabolite that possesses anti-melanogenic activity. Inflammation is a response of the innate immune system to microbial infections. Macrophages have a critical role in fighting microbial infections and inflammation. Recent studies reported that various compounds derived from natural products can regulate immune responses including inflammation. However, the anti-inflammatory effects and mechanism of pseudane-VII in macrophages are still unknown. In this study, we investigated the anti-inflammatory effects of pseudane-VII. In present study, lipopolysaccharide (LPS)-induced nitric oxide (NO) production was significantly decreased by pseudane-VII treatment at 6 µM. Moreover, pseudane-VII treatment dose-dependently reduced mRNA levels of pro-inflammatory cytokines including inos, cox-2, il-1ß, tnf-α, and il-6 in LPS-stimulated macrophages. Pseudane-VII also diminished iNOS protein levels and IL-1ß secretion. In addition, Pseudane-VII elicited anti-inflammatory effects by inhibiting ERK, JNK, p38, and nuclear factor (NF)-κB-p65 phosphorylation. Consistently, pseudane-VII was also shown to inhibit the LPS-stimulated release of IL-1ß and expression of iNOS in mice. These results suggest that pseudane-VII exerted anti-inflammatory effects on LPS-stimulated macrophage activation via inhibition of ERK, JNK, p38 MAPK phosphorylation, and pro-inflammatory gene expression. These findings may provide new approaches in the effort to develop anti-inflammatory therapeutics.