Target Cell Migration Research Articles

Bone marrow mesenchymal stem cells overexpressing stromal cell- derived factor 1 aid in bone formation in osteoporotic mice

BackgroundOsteoporosis is characterized by low systemic bone mineral content and destruction of bone microarchitecture. Promoting bone regeneration and reversing its loss by infusion of exogenous bone marrow mesenchymal stem cells (BMSCs) is a potentially effective treatment for osteoporosis. However, their limited migration to target organs reduces the therapeutic effect of the cells. Stromal cell-derived factor 1 (SDF1) is a chemokine that induces targeted cell migration through the SDF1/CXCR4 (C-X-C chemokine receptor 4) axis and can induce migration of exogenous mesenchymal stem cells to sites of high SDF1 concentration. There are no studies on BMSCs overexpressing SDF1 (SDF1-BMSCs) in osteoporotic mice in vivo. We aimed to investigate if the increased SDF1 concentration facilitated cell migration to the bone.MethodsWe used lentivirus to construct BMSCs overexpressing SDF1 or knocking down CXCR4. We verified the proliferation ability of the cells in vitro using Cell Counting Kit-8 (CCK8) and 5-Bromodeoxyuridinc (BrdU), the migration ability of the cells using Transwell, and the osteogenic and lipogenic ability of the cells using osteogenic and lipogenic induction solutions. In in vivo experiments, we induced osteoporosis in 72 female mice by ovariectomy and injected different groups of cells via the tail vein. Femoral tissue samples were collected for a fixed time, and the osteogenic and homing abilities of the cells were verified by MicroCT and tissue section staining.ResultsWe successfully demonstrated that high expression of SDF1 promoted cell proliferation and migration in vitro, without affecting their cell differentiation ability. In an ovariectomized mouse model, SDF1-BMSCs were more likely to be home to the femur than the BMSCs, had a better pro-osteogenic ability, and had higher expression of Wnt-1. Blocking the SDF1/CXCR4 axis reduced the homing of exogenous mesenchymal stem cells (MSCs) to the femur and their osteogenic capacity.ConclusionsSDF1-BMSCs can further promote bone formation by increasing the number of cells homing to the femur in osteoporotic mice. Our study shows that stem cells can promote their proliferation and home to the femur via the SDF1/CXCR4 axis and further help bone formation via Wnt-1 signaling.

Targeting Cell Migration to Prevent Graft-Versus-Host Disease: A New Strategy

Targeting Cell Migration to Prevent Graft-Versus-Host Disease: A New Strategy

Direct visualization of emergent metastatic features within an ex vivo model of the tumor microenvironment.

Metabolic conditions such as hypoxia, nutrient starvation, and media acidification, together with interactions with stromal cells are critical drivers of metastasis. Since these conditions arise deep within tumor tissues with poor access to the bloodstream, the observation of nascent metastases in vivo is exceedingly challenging. On the other hand, conventional cell culture studies cannot capture the complex nature of metastatic processes. We thus designed and implemented an ex vivo model of the tumor microenvironment to study the emergence of metastatic features in tumor cells in their native 3-dimensional (3D) context. In this system, named 3MIC, tumor cells spontaneously create ischemic-like conditions, and it allows the direct visualization of tumor-stroma interactions with high spatial and temporal resolution. We studied how 3D tumor spheroids evolve in the 3MIC when cultured under different metabolic environments and in the presence or absence of stromal cells. Consistent with previous experimental and clinical data, we show that ischemic environments increase cell migration and invasion. Importantly, the 3MIC allowed us to directly observe the emergence of these pro-metastatic features with single-cell resolution allowing us to track how changes in tumor motility were modulated by macrophages and endothelial cells. With these tools, we determined that the acidification of the extracellular media was more important than hypoxia in the induction of pro-metastatic tumor features. We also illustrate how the 3MIC can be used to test the effects of anti-metastatic drugs on cells experiencing different metabolic conditions. Overall, the 3MIC allows us to directly observe the emergence of metastatic tumor features in a physiologically relevant model of the tumor microenvironment. This simple and cost-effective system can dissect the complexity of the tumor microenvironment to test perturbations that may prevent tumors from becoming metastatic.

Carotid artery transplantation of brain endothelial cells enhances neuroprotection and neurorepair in ischaemic stroke rats.

Brain microvascular endothelial cells (BMECs), an important component of the neurovascular unit, can promote angiogenesis and synaptic formation in ischaemic mice after brain parenchyma transplantation. Since the therapeutic efficacy of cell-based therapies depends on the extent of transplanted cell residence in the target tissue and cell migration ability, the delivery route has become a hot research topic. In this study, we investigated the effects of carotid artery transplantation of BMECs on neuronal injury, neurorepair, and neurological dysfunction in rats after cerebral ischaemic attack. Purified passage 1 endothelial cells (P1-BMECs) were prepared from mouse brain tissue. Adult rats were subjected to transient middle cerebral artery occlusion (MCAO) for 30 min. Then, the rats were treated with 5 × 105 P1-BMECs through carotid artery infusion or tail vein injection. We observed that carotid artery transplantation of BMECs produced more potent neuroprotective effects than caudal injection in MCAO rats, including reducing infarct size and alleviating neurological deficits in behavioural tests. Carotid artery-transplanted BMECs displayed a wider distribution in the ischaemic rat brain. Immunostaining for endothelial progenitor cells and the mature endothelial cell markers CD34 and RECA-1 showed that carotid artery transplantation of BMECs significantly increased angiogenesis. Carotid artery transplantation of BMECs significantly increased the number of surviving neurons, decreased the cerebral infarction volume, and alleviated neurological deficits. In addition, we found that carotid artery transplantation of BMECs significantly enhanced ischaemia-induced hippocampal neurogenesis, as measured by doublecortin (DCX) and Ki67 double staining within 2 weeks after ischaemic injury. We conclude that carotid artery transplantation of BMECs can promote cerebral angiogenesis, neurogenesis, and neurological function recovery in adult rats after ischaemic stroke. Our results suggest that carotid injection of BMECs may be a promising new approach for treating acute brain injuries.

NETosis-Inspired Cell Surface-Constrained Framework Nucleic Acids Traps (FNATs) for Cascaded Extracellular Recognition and Cellular Behavior Modulation.

Upon pathogenic stimulation, activated neutrophils release nuclear DNA into the extracellular environment, forming web-like DNA structures known as neutrophil extracellular traps (NETs), which capture and kill bacteria, fungi, and cancer cells. This phenomenon is commonly referred to as NETosis. Inspired by this, we introduce a cell surface-constrained web-like framework nucleic acids traps (FNATs) with programmable extracellular recognition capability and cellular behavior modulation. This approach facilitates dynamic key chemical signaling molecule recognition such as adenosine triphosphate (ATP), which is elevated in the extracellular microenvironment, and triggers FNA self-assembly. This, in turn, leads to in situ tightly interwoven FNAs formation on the cell surface, thereby inhibiting target cell migration. Furthermore, it activates a photosensitizer-capturing switch, chlorin e6 (Ce6), and induces cell self-destruction. This cascade platform provides new potential tools for visualizing dynamic extracellular activities and manipulating cellular behaviors using programmable in situ self-assembling DNA molecular devices.

NETosis‐Inspired Cell Surface‐Constrained Framework Nucleic Acids Traps (FNATs) for Cascaded Extracellular Recognition and Cellular Behavior Modulation

AbstractUpon pathogenic stimulation, activated neutrophils release nuclear DNA into the extracellular environment, forming web‐like DNA structures known as neutrophil extracellular traps (NETs), which capture and kill bacteria, fungi, and cancer cells. This phenomenon is commonly referred to as NETosis. Inspired by this, we introduce a cell surface‐constrained web‐like framework nucleic acids traps (FNATs) with programmable extracellular recognition capability and cellular behavior modulation. This approach facilitates dynamic key chemical signaling molecule recognition such as adenosine triphosphate (ATP), which is elevated in the extracellular microenvironment, and triggers FNA self‐assembly. This, in turn, leads to in situ tightly interwoven FNAs formation on the cell surface, thereby inhibiting target cell migration. Furthermore, it activates a photosensitizer‐capturing switch, chlorin e6 (Ce6), and induces cell self‐destruction. This cascade platform provides new potential tools for visualizing dynamic extracellular activities and manipulating cellular behaviors using programmable in situ self‐assembling DNA molecular devices.

Traditional Plant-Derived Compounds Inhibit Cell Migration and Induce Novel Cytoskeletal Effects in Glioblastoma Cells.

Glioblastomas (GBMs) are aggressive and invasive cancers of the brain, associated with high rates of tumour recurrence and poor patient outcomes despite initial treatment. Targeting cell migration is therefore of interest in highly invasive cancers such as GBMs, to prevent tumour dissemination and regrowth. One current aim of GBM research focuses on assessing the anti-migratory properties of novel or repurposed inhibitors, including plant-based drugs which display anti-cancer properties. We investigated the potential anti-migratory activity of plant-based products with known cytotoxic effects in cancers, using a range of two-dimensional (2D) and three-dimensional (3D) migration and invasion assays as well as immunofluorescence microscopy to determine the specific anti-migratory and phenotypic effects of three plant-derived compounds, Turmeric, Indigo and Magnolia bark, on established glioma cell lines. Migrastatic activity was observed in all three drugs, with Turmeric exerting the most inhibitory effect on GBM cell migration into scratches and from the spheroid edge at all the timepoints investigated (p < 0.001). We also observed novel cytoskeletal phenotypes affecting actin and the focal adhesion dynamics. As our in vitro results determined that Turmeric, Indigo and Magnolia are promising migrastatic drugs, we suggest additional experimentation at the whole organism level to further validate these novel findings.

Enhancing bone tissue engineering using iron nanoparticles and magnetic fields: A focus on cytomechanics and angiogenesis in the chicken egg chorioallantoic membrane model.

To evaluate the potential of iron nanoparticles (FeNPs) in conjunction with magnetic fields (MFs) to enhance osteoblast cytomechanics, promote cell homing, bone development activity, and antibacterial capabilities, and to assess their in vivo angiogenic viability using the chicken egg chorioallantoic membrane (CAM) model. Experimental study conducted in a laboratory setting to investigate the effects of FeNPs and MFs on osteoblast cells and angiogenesis using a custom titanium (Ti) substrate coated with FeNPs. A custom titanium (Ti) was coated with FeNPs. Evaluations were conducted to analyze the antibacterial properties, cell adhesion, durability, physical characteristics, and nanoparticle absorption associated with FeNPs. Cell physical characteristics were assessed using protein markers, and microscopy, CAM model, was used to quantify blood vessel formation and morphology to assess the FeNP-coated Ti's angiogenic potential. This in vivo study provided critical insights into tissue response and regenerative properties for biomedical applications. Statistical analysis was performed using appropriate tests to compare experimental groups and controls. Significance was determined at P < 0.05. FeNPs and MFs notably improved osteoblast cell mechanical properties facilitated the growth and formation of new blood vessels and bone tissue and promoted cell migration to targeted sites. In the group treated with FeNPs and exposed to MFs, there was a significant increase in vessel percentage area (76.03%) compared to control groups (58.11%), along with enhanced mineralization and robust antibacterial effects (P < 0.05). The study highlights the promising potential of FeNPs in fostering the growth of new blood vessels, promoting the formation of bone tissue, and facilitating targeted cell migration. These findings underscore the importance of further investigating the mechanical traits of FeNPs, as they could significantly advance the development of effective bone tissue engineering techniques, ultimately enhancing clinical outcomes in the field.

Glioblastoma Cells Use an Integrin- and CD44-Mediated Motor-Clutch Mode of Migration in Brain Tissue.

Glioblastoma (GBM) is an aggressive malignant brain tumor with 2year survival rates of 6.7% (Stupp et al. in J Clin Oncol Off J Am Soc Clin Oncol 25:4127-4136, 2007; Mohammed et al. in Rep Pract Oncol Radiother 27:1026-1036, 2002). One key characteristic of the disease is the ability of glioblastoma cells to migrate rapidly and spread throughout healthy brain tissue (Lefranc et al. in J Clin Oncol Off J Am Soc Clin Oncol 23:2411-2422, 2005; Hoelzinger et al. in J Natl Cancer Inst 21:1583-1593, 2007). To develop treatments that effectively target cell migration, it is important to understand the fundamental mechanism driving cell migration in brain tissue. Several models of cell migration have been proposed, including the motor-clutch, bleb-based motility, and osmotic engine models. Here we utilized confocal imaging to measure traction dynamics and migration speeds of glioblastoma cells in mouse organotypic brain slices to identify the mode of cell migration. We found that nearly all cell-vasculature interactions reflected pulling, rather than pushing, on vasculature at the cell leading edge, a finding consistent with a motor-clutch mode of migration, and inconsistent with an osmotic engine model or confined bleb-based migration. Reducing myosin motor activity, a key component in the motor-clutch model, was found to decrease migration speed at high doses for all cell types including U251 and 6 low-passage patient-derived xenograft lines (3 proneural and 3 mesenchymal subtypes). Variable responses were found at low doses, consistent with a motor-clutch mode of migration which predicts a biphasic relationship between migration speed and motor-to-clutch ratio. Targeting of molecular clutches including integrins and CD44 slowed migration of U251 cells. Overall we find that glioblastoma cell migration is most consistent with a motor-clutch mechanism to migrate through brain tissue ex vivo, and that both integrins and CD44, as well as myosin motors, play an important role in constituting the adhesive clutch. The online version contains supplementary material available at 10.1007/s12195-024-00799-x.

THE KYNURENINE PATHWAY AND ITS ROLE IN GLIOBLASTOMA CELL MIGRATION

Abstract AIMS The kynurenine (Kyn) pathway plays an important role in the pathogenesis of many cancers including glioblastomas (GBMs). The enzymes, indoleamine-2,3-dioxygenase (IDO1) and tryptophan-2,3-dioxygenase (TDO2), regulate the first and rate-limiting step resulting in the formation of N-formyl-kynurenine, which is then readily converted into Kyn by kynurenine formaldehyde. Cancers expressing the IDO1 and TDO2 enzymes can produce immunosuppressive tryptophan metabolites that compromise the host immune system leading to poor patient prognosis. The inhibitors TD12, TD18 and TD34 were recently developed due to the lack of TDO2 and IDO1/TDO2 inhibitors, of which TD34 can block both IDO1 and TDO2 activity. Here, we investigated the ability of these novel inhibitors to also target cell migration in GBM as part of our ongoing research interest in this area. METHOD Two established brain tumour cell lines, U87 and U251 and one patient-derived cell line, E55, were used to determine IC50 values and anti-migratory concentrations by MTT for application in 2D and 3D migration/invasion assays. RESULTS Cell migration in all cell lines was significantly reduced in the presence of the TD12, TD18 and TD34 inhibitors. E55 appeared to be 100-fold more sensitive to drug activity; immunofluorescence analysis indicates changes in the actin cytoskeleton and cell adhesion CONCLUSIONS Initial results suggest that TDO2 and the IDO1 enzymes play also a role in cell migration in GBM and provide further evidence for the involvement of the Kyn pathway in the pathology of GBMs. This also supports the application of inhibitors targeting TDO2 and IDO1 as novel complementary treatment options in GBM.

GLIOBLASTOMA CELL INVASION IS TARGETABLE BY COMBINATION TREATMENT WITH MIGRASTATIC INHIBITORS

Abstract AIMS One of the hallmarks of cancer is cell migration and invasion, a striking feature of glioblastoma (GBM). The highly migratory potential of tumour cells enables recurrence of GBM tumours leading to poor survival and patient death. We recently characterised a panel of migrastatic inhibitors and reported on the ability of glioma cells to overcome drug activity by employing a mesenchymal to amoeboid migratory switch. Here we demonstrate that targeting different signalling pathways involved in cell migration induces synergistic drug activity of single inhibitors. METHOD The previously described inhibitors CCG-1423 and Rhosin Hydrochloride were used singly or in combination to target cell migration in established glioma cell lines. Characterisation of drug activity was achieved by 2D and 3D migration and invasion assays and cytoskeletal and morphological changes were assessed by immunofluorescence assays. RESULTS When used in single applications, the inhibitors did not have a significant effect on cell migration in 2D and 3D. However, combination treatments led to significantly reduced migration in both 2D and 3D with notable effects on the cytoskeleton as evidenced by changes in focal adhesion dynamics and in actin localisation. Cellular features also changed in response to combination treatment as noted by increase in cell size and adhesion to neighbouring cells. CONCLUSIONS The observed effects are in keeping with targeting two distinct signalling pathways driving cells to either adopt amoeboid or mesenchymal cell migration/invasion mechanisms. We propose that a ‘cocktail’ of migrastatic inhibitors should be included in future experimental designs for consideration as novel, complementary treatment strategies in GBM.

Let-7i: A key player and a promising biomarker in diseases.

MicroRNAs (miRNAs) are endogenous non-coding single-stranded small RNAs that regulate gene expression by recognizing homologous sequences and interfering with transcriptional, translational or epigenetic processes. MiRNAs are involved in a variety of disease processes, and regulate the physiological and pathological status of diseases by modulating target cell activity, migration, invasion, apoptosis, autophagy and other processes. Among them, let-7i is highly expressed in various systems, which participates in the process of tumors, cardiovascular and cerebrovascular diseases, fibrotic diseases, inflammatory diseases, neurodegenerative diseases and other diseases, and plays a positive or negative regulatory role in these diseases through different signal pathways and key molecules. Moreover, it can be used as an early diagnosis and prognostic marker for a variety of diseases and become a potential therapeutic target. As a biomarker, let-7i is frequently tested in combination with other miRNAs to diagnose multiple diseases and evaluate the clinical treatment or prognosis.

MiR-210-3p enriched extracellular vesicles from hypoxic neuroblastoma cells stimulate migration and invasion of target cells

BackgroundTumor hypoxia stimulates release of extracellular vesicles (EVs) that facilitate short- and long-range intercellular communication and metastatization. Albeit hypoxia and EVs release are known features of Neuroblastoma (NB), a metastasis-prone childhood malignancy of the sympathetic nervous system, whether hypoxic EVs can facilitate NB dissemination is unclear.MethodsHere we isolated and characterized EVs from normoxic and hypoxic NB cell culture supernatants and performed microRNA (miRNA) cargo analysis to identify key mediators of EVs biological effects. We then validated if EVs promote pro-metastatic features both in vitro and in an in vivo zebrafish model.ResultsEVs from NB cells cultured at different oxygen tensions did not differ for type and abundance of surface markers nor for biophysical properties. However, EVs derived from hypoxic NB cells (hEVs) were more potent than their normoxic counterpart in inducing NB cells migration and colony formation. miR-210-3p was the most abundant miRNA in the cargo of hEVs; mechanistically, overexpression of miR-210-3p in normoxic EVs conferred them pro-metastatic features, whereas miR-210-3p silencing suppressed the metastatic ability of hypoxic EVs both in vitro and in vivo.ConclusionOur data identify a role for hypoxic EVs and their miR-210-3p cargo enrichment in the cellular and microenvironmental changes favoring NB dissemination.

Estrogenic Modulation of Ionic Channels, Pumps and Exchangers in Airway Smooth Muscle.

To preserve ionic homeostasis (primarily Ca2+, K+, Na+, and Cl-), in the airway smooth muscle (ASM) numerous transporters (channels, exchangers, and pumps) regulate the influx and efflux of these ions. Many of intracellular processes depend on continuous ionic permeation, including exocytosis, contraction, metabolism, transcription, fecundation, proliferation, and apoptosis. These mechanisms are precisely regulated, for instance, through hormonal activity. The lipophilic nature of steroidal hormones allows their free transit into the cell where, in most cases, they occupy their cognate receptor to generate genomic actions. In the sense, estrogens can stimulate development, proliferation, migration, and survival of target cells, including in lung physiology. Non-genomic actions on the other hand do not imply estrogen's intracellular receptor occupation, nor do they initiate transcription and are mostly immediate to the stimulus. Among estrogen's non genomic responses regulation of calcium homeostasis and contraction and relaxation processes play paramount roles in ASM. On the other hand, disruption of calcium homeostasis has been closely associated with some ASM pathological mechanism. Thus, this paper intends to summarize the effects of estrogen on ionic handling proteins in ASM. The considerable diversity, range and power of estrogens regulates ionic homeostasis through genomic and non-genomic mechanisms.

Abstract P6-14-18: Effect of 3q oncogene SEC62 on migration and proliferation of triple-negative breast cancer cells

Abstract Background Chromosome 3q26 amplifications represent a frequent alteration in various cancer entities including breast cancer. SEC62 – a 3q26 encoded gene – was identified as a potential onco- and tumor-driver gene for the pathogenesis of breast cancer. Although the precise physiological function of the respective protein Sec62 is not completely understood, Sec62 seems to induce an increased stress tolerance, enhanced cell migration and invasive potential in SEC62 overexpressing cells. SEC62 overexpressing breast cancer patients have been shown to have a higher rate of lymph node metastasis and poorer overall prognosis. Hence, we aimed to further evaluate the effect of Sec62 for triple-negative breast cancer by targeting cell migration and proliferation of triple-negative cell lines altered in their SEC62 expression. Objectives The aim of this study was to investigate the role of Sec62 for triple-negative breast cancer in cell culture using functional analyzes comparing cell migration and cell proliferation in triple-negative cell lines using the effects of siRNA-mediated Sec62 depletion in vitro. Material&amp; Methods In this study, three SEC62 gene silencing experiments each with two different siRNAs directed against the SEC62 mRNA were carried out in comparison to a control siRNA in combination with cell proliferation and cell migration tests plus Western blots for the triple-negative breast cancer cell line CAL120 in order to determine the suspected causal relationship between SEC62- overexpression and an increased cell migration and thus an enhanced invasion potential of the cancer cells. The cell proliferation was examined in real time in the 96 well xCELLigence system and the cell migration using Fluoroblock without matrigel using fluorescence microscopy. Results In cell migration assays, the median migrated cell number in the control siRNA group was 263 (241-279), the cell number in the groups of the two siRNAs directed against the Sec62 mRNA was 72 (70-149) and 178 (96-276) (p &amp;lt; 0.01). In cell proliferation assays, the median cell index in the control siRNA group was 7.5 (7.4-7.6), while it was 7.4 (7.3-7 .5) and 7.6 (7.5-7.7) (p=0.37). In the first analyzes of the medians of the three gene silencing experiments of the cell line CAL120, the expected negative effect of the SEC62-siRNA on cell migration is confirmed, while, as expected, the effect on cell proliferation remains unchanged with decreasing Sec62 content. Conclusion In this in vitro study using cell migration and cell proliferation assays we found a correlation between SEC62 overexpression and increased cell migration. This implies a potential association between Sec62 and an increased tumor cell invasion in triple-negative breast cancer. Citation Format: Julia SM Zimmermann, Annika Cullmann, Askin Kaya, Merle Doerk, Maximilian Linxweiler, Marc P Radosa, Sven Lang, Martin Jung, Erich F Solomayer, Julia C Radosa. Effect of 3q oncogene SEC62 on migration and proliferation of triple-negative breast cancer cells [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-18.

Effect of CTP-mediated PTEN on 5637 bladder cancer cells and the underlying molecular mechanism.

The aim of the present study was to explore the effect of cytoplasmic transduction peptide (CTP)-phosphatase and tensin homolog (PTEN) on the proliferation, cell cycle, apoptosis, migration and invasion of bladder cancer cells and the underlying molecular mechanism. A eukaryotic expression vector, pTT5-CTP-PTEN, was constructed. The constructed vector was transfected into HEK 293-6E cells to express a fusion protein, CTP-PTEN. The fusion protein was purified. 5637 bladder cancer cells were cocultured with purified CTP-PTEN fusion protein. Target gene expression, protein expression, cell proliferation, cell cycle, apoptosis, cell invasion and cell migration were examined by reverse transcription polymerase chain reaction (RT-PCR), western blot, MTT assay, flow cytometry, Transwell assay, and cell scratch assay, respectively. Both PTEN and CTP-PTEN fusion protein inhibited the proliferation, cell cycle, invasion and migration of bladder cancer cells and promoted the apoptosis of bladder cancer cells. The effect of CTP-PTEN was more significant. The fused expression of CTP and PTEN significantly increased the penetrability of the tumor suppressor gene PTEN into cancer cells. The CTP-PTEN fusion protein exhibited a significant carcinostatic effect on 5637 bladder cancer cells.

Pulsed Electromagnetic Field Therapy and Direct Current Electric Field Modulation Promote the Migration of Fibroblast-like Synoviocytes to Accelerate Cartilage Repair In Vitro.

Articular cartilage injuries are a common source of joint pain and dysfunction. As articular cartilage is avascular, it exhibits a poor intrinsic healing capacity for self-repair. Clinically, osteochondral grafts are used to surgically restore the articular surface following injury. A significant challenge remains with the repair properties at the graft-host tissue interface as proper integration is critical toward restoring normal load distribution across the joint. A key to addressing poor tissue integration may involve optimizing mobilization of fibroblast-like synoviocytes (FLS) that exhibit chondrogenic potential and are derived from the adjacent synovium, the specialized connective tissue membrane that envelops the diarthrodial joint. Synovium-derived cells have been directly implicated in the native repair response of articular cartilage. Electrotherapeutics hold potential as low-cost, low-risk, non-invasive adjunctive therapies for promoting cartilage healing via cell-mediated repair. Pulsed electromagnetic fields (PEMFs) and applied direct current (DC) electric fields (EFs) via galvanotaxis are two potential therapeutic strategies to promote cartilage repair by stimulating the migration of FLS within a wound or defect site. PEMF chambers were calibrated to recapitulate clinical standards (1.5 ± 0.2 mT, 75 Hz, 1.3 ms duration). PEMF stimulation promoted bovine FLS migration using a 2D in vitro scratch assay to assess the rate of wound closure following cruciform injury. Galvanotaxis DC EF stimulation assisted FLS migration within a collagen hydrogel matrix in order to promote cartilage repair. A novel tissue-scale bioreactor capable of applying DC EFs in sterile culture conditions to 3D constructs was designed in order to track the increased recruitment of synovial repair cells via galvanotaxis from intact bovine synovium explants to the site of a cartilage wound injury. PEMF stimulation further modulated FLS migration into the bovine cartilage defect region. Biochemical composition, histological analysis, and gene expression revealed elevated GAG and collagen levels following PEMF treatment, indicative of its pro-anabolic effect. Together, PEMF and galvanotaxis DC EF modulation are electrotherapeutic strategies with complementary repair properties. Both procedures may enable direct migration or selective homing of target cells to defect sites, thus augmenting natural repair processes for improving cartilage repair and healing.

A sequentially triggered DNA nanocapsule for targeted drug delivery based on pH-responsive i-motif and tumor cell-specific aptamer.

Targeted drug delivery with minor off-target effects is urgently needed for precise cancer treatments. Here, a sequentially triggered strategy based on double targeting elements is designed to meet this purpose. By using an acidic pH-responsive i-motif DNA and a tumor cell-specific aptamer as targeting elements, a smart dual-targeted DNA nanocapsule (ZBI5-DOX) was constructed. ZBI5-DOX can be firstly triggered by acidic pH, and then bind to target cells via aptamer recognition and thus targeted release of the carried DOX chemotherapeutics. With this smart DNA nanocapsule, the carried DOX could be precisely delivered to target SMMC-7721 tumor cells in acidic conditions. After drug treatments, selective cytotoxicity of the DNA nanocapsule was successfully achieved. Meanwhile, the DNA nanocapsule had a specific inhibition effect on target cell migration and invasion. Therefore, this sequentially triggered strategy may provide deep insight into the next generation of targeted drug delivery.

S-Adenosylmethionine Inhibits Colorectal Cancer Cell Migration through Mirna-Mediated Targeting of Notch Signaling Pathway.

Metastasis is a leading cause of mortality and poor prognosis in colorectal cancer (CRC). Thus, the identification of new compounds targeting cell migration represents a major clinical challenge. Recent findings evidenced a central role for dysregulated Notch in CRC and a correlation between Notch overexpression and tumor metastasis. MicroRNAs (miRNAs) have been reported to cross-talk with Notch for its regulation. Therefore, restoring underexpressed miRNAs targeting Notch could represent an encouraging therapeutic approach against CRC. In this context, S-adenosyl-L-methionine (AdoMet), the universal biological methyl donor, being able to modulate the expression of oncogenic miRNAs could act as a potential antimetastatic agent. Here, we showed that AdoMet upregulated the onco-suppressor miRNAs-34a/-34c/-449a and inhibited HCT-116 and Caco-2 CRC cell migration. This effect was associated with reduced expression of migration-/EMT-related protein markers. We also found that, in colorectal and triple-negative breast cancer cells, AdoMet inhibited the expression of Notch gene, which, by luciferase assay, resulted the direct target of miRNAs-34a/-34c/-449a. Gain- and loss-of-function experiments with miRNAs mimics and inhibitors demonstrated that AdoMet exerted its inhibitory effects by upregulating miRNAs-34a/-34c/-449a. Overall, these data highlighted AdoMet as a novel Notch inhibitor and suggested that the antimetastatic effects of AdoMet involve the miRNA-mediated targeting of Notch signaling pathway.

Treatment of Acute Wounds With Recombinant Human-Like Collagen and Recombinant Human-Like Fibronectin in C57BL/6 Mice Individually or in Combination.

Wound repair is accomplished by the interaction between the cells involved in the repair and the extracellular matrix (ECM). Collagen is the main component of ECM, which is involved in transduction of signal, transportation of growth factors and cytokines. Fibronectin (FN) is also an important ECM, which participates in the initiation of fibroblast cell (FC) and promotes adhesion, migration, proliferation and differentiation of target cells. Compared with natural protein, the recombinant protein prepared by artificial method has the advantages of poor immunogenicity, wide range of sources, low cost and high activity. In this study, we used recombinant human-like collagen (RHC) and recombinant human-like fibronectin (rhFN) to treat acute wounds in C57BL/6 mice individually or in combination, and explored their effects on wound healing. Our study confirmed that these two recombinant proteins could effectively promote the proliferation, migration and adhesion of FCs. Meanwhile, it could positively regulate the healing speed and quality of acute wounds, re-epithelialization, collagen deposition, inflammation and angiogenesis. Moreover, we proved that the combination of the two was better than the treatment alone. Consequently, it has a good prospect as a new tissue material in the field of skin repair.