Induced pluripotent stem cell-derived extracellular vesicles enriched with miR-126 induce proangiogenic properties and promote repair of ischemic tissue.

Emerging evidence suggests that stem cell-derived extracellular vesicles (EVs) may induce pro-regenerative effects in ischemic tissues by delivering bioactive molecules, including microRNAs. Recent studies have also shown pro-regenerative benefits of EVs derived from induced pluripotent stem (iPS) cells. However, the underlying mechanisms of EV benefits and the role of their transferred regulatory molecules remain incompletely understood. Accordingly, we investigated the effects of human iPS-derived EVs (iPS-EVs) enriched in proangiogenic miR-126 (iPS-miR-126-EVs) on functional properties of human endothelial cells (ECs) in vitro. We also examined the outcomes following EV injection in a murine model of limb ischemia in vivo. EVs were isolated from conditioned media from cultures of unmodified and genetically modified human iPS cells overexpressing miR-126. The iPS-miR-126-EVs were enriched in miR-126 when compared with control iPS-EVs and effectively transferred miR-126 along with other miRNAs to recipient ECs improving their functional properties essential for ischemic tissue repair, including proliferation, metabolic activity, cell survival, migration, and angiogenic potential. Injection of iPS-miR-126-EVs in vivo in a murine model of acute limb ischemia promoted angiogenesis, increased perfusion, and enhanced functional recovery. These observations corresponded with elevated expression of genes for several proangiogenic factors in ischemic tissues following iPS-miR-126-EV transplantation. These results indicate that innate pro-regenerative properties of iPS-EVs may be further enhanced by altering their molecular composition via controlled genetic modifications. Such iPS-EVs overexpressing selected microRNAs, including miR-126, may represent a novel acellular tool for therapy of ischemic tissues in vivo.

The dynamics of the electrotactic reaction of mouse 3T3 fibroblasts.

The molecular mechanisms behind electrotaxis remain largely unknown, with no identified primary direct current electric field (dcEF) sensor. Two leading hypotheses propose mechanisms involving the redistribution of charged components in the cell membrane (driven by electrophoresis or electroosmosis) and the asymmetric activation of ion channels. To investigate these mechanisms, we studied the dynamics of electrotactic behaviour of mouse 3T3 fibroblasts. We observed that 3T3 fibroblasts exhibit cathodal migration within just 1 min when exposed to physiological dcEF. This rapid response suggests the involvement of ion channels in the cell membrane. Our large-scale screening method identified several ion channel genes as potential key players, including the inwardly rectifying potassium channel Kir4.2. Blocking the Kir channel family with Ba2+ or silencing the Kcnj15 gene, encoding Kir4.2, significantly reduced the directional migration of 3T3 cells. Additionally, the levels of the intracellular regulators of Kir channels, spermine (SPM) and spermidine (SPD), had a significant impact on cell directionality. Interestingly, inhibiting Kir4.2 resulted in the temporary cessation of electrotaxis for approximately 1-2 h before its return. This observation suggests a two-phase mechanism for the electrotaxis of mouse 3T3 fibroblasts, where ion channel activation triggers the initial rapid response to dcEF, and the subsequent redistribution of membrane receptors sustains long-term directional movement. In summary, our study unveils the involvement of Kir channels and proposes a biphasic mechanism to explain the electrotactic behaviour of mouse 3T3 fibroblasts, shedding light on the molecular underpinnings of electrotaxis.

Hypoxia enhances anti-fibrotic properties of extracellular vesicles derived from hiPSCs via the miR302b-3p/TGFß/SMAD2 axis.

BACKGROUND: Cardiac fibrosis is one of the top killers among fibrotic diseases and continues to be a global unaddressed health problem. The lack of effective treatment combined with the considerable socioeconomic burden highlights the urgent need for innovative therapeutic options. Here, we evaluated the anti-fibrotic properties of extracellular vesicles (EVs) derived from human induced pluripotent stem cells (hiPSCs) that were cultured under various oxygen concentrations. METHODS: EVs were isolated from three hiPSC lines cultured under normoxia (21% O2; EV-N) or reduced oxygen concentration (hypoxia): 3% O2 (EV-H3) or 5% O2 (EV-H5). The anti-fibrotic activity of EVs was tested in an in vitro model of cardiac fibrosis, followed by a detailed investigation of the underlying molecular mechanisms. Sequencing of EV miRNAs combined with bioinformatics analysis was conducted and a selected miRNA was validated using a miRNA mimic and inhibitor. Finally, EVs were tested in a mouse model of angiotensin II-induced cardiac fibrosis. RESULTS: We provide evidence that an oxygen concentration of 5% enhances the anti-fibrotic effects of hiPS-EVs. These EVs were more effective in reducing pro-fibrotic markers in activated human cardiac fibroblasts, when compared to EV-N or EV-H3. We show that EV-H5 act through the canonical TGFß/SMAD pathway, primarily via miR-302b-3p, which is the most abundant miRNA in EV-H5. Our results show that EV-H5 not only target transcripts of several profibrotic genes, including SMAD2 and TGFBR2, but also reduce the stiffness of activated fibroblasts. In a mouse model of heart fibrosis, EV-H5 outperformed EV-N in suppressing the inflammatory response in the host and by attenuating collagen deposition and reducing pro-fibrotic markers in cardiac tissue. CONCLUSIONS: In this work, we provide evidence of superior anti-fibrotic properties of EV-H5 over EV-N or EV-H3. Our study uncovers that fine regulation of oxygen concentration in the cellular environment may enhance the anti-fibrotic effects of hiPS-EVs, which has great potential to be applied for heart regeneration.

Anti-inflammatory, Anti-fibrotic and Pro-cardiomyogenic Effects of Genetically Engineered Extracellular Vesicles Enriched in miR-1 and miR-199a on Human Cardiac Fibroblasts.

RATIONALE: Emerging evidence indicates that stem cell (SC)- derived extracellular vesicles (EVs) carrying bioactive miRNAs are able to repair damaged or infarcted myocardium and ameliorate adverse remodeling. Fibroblasts represent a major cell population responsible for scar formation in the damaged heart. However, the effects of EVs on cardiac fibroblast (CFs) biology and function has not been investigated. OBJECTIVE: To analyze the biological impact of stem cell-derived EVs (SC-EVs) enriched in miR-1 and miR-199a on CFs and to elucidate the underlying molecular mechanisms. METHODS AND RESULTS: Genetically engineered human induced pluripotent stem cells (hiPS) and umbilical cord-derived mesenchymal stem cells (UC-MSCs) expressing miR-1 or miR-199a were used to produce miR-EVs. Cells and EVs were thoughtfully analyzed for miRNA expression using RT-qPCR method. Both hiPS-miRs-EVs and UC-MSC-miRs-EVs effectively transferred miRNAs to recipient CFs, however, hiPS-miRs-EVs triggered cardiomyogenic gene expression in CFs more efficiently than UC-MSC-miRs-EVs. Importantly, hiPS-miR-1-EVs exhibited cytoprotective effects on CFs by reducing apoptosis, decreasing levels of pro-inflammatory cytokines (CCL2, IL-1ß, IL-8) and downregulating the expression of a pro-fibrotic gene - α-smooth muscle actin (α-SMA). Notably, we identified a novel role of miR-199a-3p delivered by hiPS-EVs to CFs, in triggering the expression of cardiomyogenic genes (NKX2.5, TNTC, MEF2C) and ion channels involved in cardiomyocyte contractility (HCN2, SCN5A, KCNJ2, KCND3). By targeting SERPINE2, miR-199a-3p may reduce pro-fibrotic properties of CFs, whereas miR-199a-5p targeted BCAM and TSPAN6, which may be implicated in downregulation of inflammation. CONCLUSIONS: hiPS-EVs carrying miR-1 and miR-199a attenuate apoptosis and pro-fibrotic and pro-inflammatory activities of CFs, and increase cardiomyogenic gene expression. These finding serve as rationale for targeting fibroblasts with novel EV-based miRNA therapies to improve heart repair after myocardial injury.

Bronchial Fibroblasts from Asthmatic Patients Display Impaired Responsiveness to Direct Current Electric Fields (dcEFs).

Accumulating evidence suggests that an important role is played by electric signals in modifying cell behaviour during developmental, regenerative and pathological processes. However, their role in asthma has not yet been addressed. Bronchial fibroblasts have recently been identified having important roles in asthma development. Therefore, we adapted an experimental approach based on the lineages of human bronchial fibroblasts (HBF) derived from non-asthmatic (NA) donors and asthmatic (AS) patients to elucidate whether their reactivity to direct current electric fields (dcEF) could participate in the asthmatic process. The efficient responsiveness of NA HBF to an electric field in the range of 2-4 V/cm was illustrated based on the perpendicular orientation of long axes of the cells to the field lines and their directional movement towards the anode. These responses were related to the activity of TGF-ß signalling, as the electrotaxis and re-orientation of NA HBF polarity was impaired by the inhibitors of canonical and non-canonical TGF-ß-dependent pathways. A similar tendency towards perpendicular cell-dcEF orientation was observed for AS HBF. However, their motility remained insensitive to the electric field applied at 2-4 V/cm. Collectively, these observations demonstrate the sensitivity of NA HBF to dcEF, as well as the inter-relations between this parameter and the canonical and non-canonical TGF-ß pathways, and the differences between the electrotactic responses of NA and AS HBF point to the possible role of their dcEFs in desensitisation in the asthmatic process. This process may impair the physiologic behaviour of AS HBF functions, including cell motility, ECM deposition, and contractility, thus promoting bronchial wall remodelling, which is a characteristic of bronchial asthma.

PPARδ Agonist GW501516 Suppresses the TGF-ß-Induced Profibrotic Response of Human Bronchial Fibroblasts from Asthmatic Patients.

The airway wall remodeling observed in asthma is associated with subepithelial fibrosis and enhanced activation of human bronchial fibroblasts (HBFs) in the fibroblast to myofibroblast transition (FMT), induced mainly by transforming growth factor-ß (TGF-ß). The relationships between asthma severity, obesity, and hyperlipidemia suggest the involvement of peroxisome proliferator-activated receptors (PPARs) in the remodeling of asthmatic bronchi. In this study, we investigated the effect of PPARδ ligands (GW501516 as an agonist, and GSK0660 as an antagonist) on the FMT potential of HBFs derived from asthmatic patients cultured in vitro. This report shows, for the first time, the inhibitory effect of a PPARδ agonist on the number of myofibroblasts and the expression of myofibroblast-related markers-α-smooth muscle actin, collagen 1, tenascin C, and connexin 43-in asthma-related TGF-ß-treated HBF populations. We suggest that actin cytoskeleton reorganization and Smad2 transcriptional activity altered by GW501516 lead to the attenuation of the FMT in HBF populations derived from asthmatics. In conclusion, our data demonstrate that a PPARδ agonist stimulates antifibrotic effects in an in vitro model of bronchial subepithelial fibrosis. This suggests its potential role in the development of a possible novel therapeutic approach for the treatment of subepithelial fibrosis during asthma.

Long-Term Fenofibrate Treatment Stimulates the Phenotypic Microevolution of Prostate Cancer Cells In Vitro.

Fenofibrate is a widely used anti-hyperlipidemic agonist of peroxisome proliferator-activated receptor alpha (PPARα). As a metabolic blocker, fenofibrate interferes with cancer promotion/progression via its misbalancing effects on cellular metabolism. However, the consequences of its long-term application for patients with diagnosed drug-resistant cancers are unknown. We addressed this point by tracing the phenotypic microevolution of naïve and drug-resistant prostate cancer PC3_DCX20 cells that underwent a long-term exposition to 10 µM and 50 µM fenofibrate. Their resistance to fenofibrate, metabolic profile and invasive phenotype were estimated in the control conditions and under fenofibrate-induced stress. Apparently, drug efflux systems are not effective against the cytostatic FF action. However, wtPC3 and PC3_DCX20 cells that survived the long-term 50 µM fenofibrate treatment gave rise to lineages that displayed an increased proliferation rate, lower motility in the control conditions and enhanced fenofibrate resistance. Attenuated fenofibrate bioavailability modified the pattern of PC3 microevolution, as illustrated by phenotypic differences between wtPC3/PC3_DCX20 lineages propagated in the presence of 50 µM and 10 µM fenofibrate. Collectively, our observations indicate that fenofibrate acts as a selective factor that affects prostate cancer microevolution. We also pinpoint potential consequences of long-term exposition of prostate cancer patients to metabolic blockers.

Acquired drug resistance interferes with the susceptibility of prostate cancer cells to metabolic stress.

BACKGROUND: Metformin is an inhibitor of oxidative phosphorylation that displays an array of anticancer activities. The interference of metformin with the activity of multi-drug resistance systems in cancer cells has been reported. However, the consequences of the acquired chemoresistance for the adaptative responses of cancer cells to metformin-induced stress and for their phenotypic evolution remain unaddressed. METHODS: Using a range of phenotypic and metabolic assays, we assessed the sensitivity of human prostate cancer PC-3 and DU145 cells, and their drug-resistant lineages (PC-3_DCX20 and DU145_DCX20), to combined docetaxel/metformin stress. Their adaptation responses have been assessed, in particular the shifts in their metabolic profile and invasiveness. RESULTS: Metformin increased the sensitivity of PC-3 wild-type (WT) cells to docetaxel, as illustrated by the attenuation of their motility, proliferation, and viability after the combined drug application. These effects correlated with the accumulation of energy carriers (NAD(P)H and ATP) and with the inactivation of ABC drug transporters in docetaxel/metformin-treated PC-3 WT cells. Both PC-3 WT and PC-3_DCX20 reacted to metformin with the Warburg effect; however, PC-3_DCX20 cells were considerably less susceptible to the cytostatic/misbalancing effects of metformin. Concomitantly, an epithelial-mesenchymal transition and Cx43 upregulation was seen in these cells, but not in other more docetaxel/metformin-sensitive DU145_DCX20 populations. Stronger cytostatic effects of the combined fenofibrate/docetaxel treatment confirmed that the fine-tuning of the balance between energy supply and expenditure determines cellular welfare under metabolic stress. CONCLUSIONS: Collectively, our data identify the mechanisms that underlie the limited potential of metformin for the chemotherapy of drug-resistant tumors. Metformin can enhance the sensitivity of cancer cells to chemotherapy by inducing their metabolic decoupling/imbalance. However, the acquired chemoresistance of cancer cells impairs this effect, facilitates cellular adaptation to metabolic stress, and prompts the invasive front formation.

The cardioprotective and anti-inflammatory effect of inhaled nitric oxide during Fontan surgery in patients with single ventricle congenital heart defects: a prospective randomized study.

BACKGROUND: Fontan surgery with cardiopulmonary bypass (CPB) causes tremendous systemic stress and inflammatory responses, affecting postoperative organ function, morbidity, and mortality. Although this reaction triggers partially protective anti-inflammatory responses, it is harmful in patients with single ventricle congenital heart defects. Despite decades of research, an effective anti-inflammatory and stress defense strategy is lacking. This study investigated the influence of inhaled nitric oxide (NO) during CPB on early clinical results, including the duration of postoperative respiratory support as a primary outcome and a panel of laboratory analytes. METHODS: In this study, 115 patients were randomized to the Fontan-NO group (n = 48) and the Fontan group (n = 49). Eighteen patients were excluded from the study. The Fontan-NO group received NO inhaled directly into the oxygenator during CPB. Clinical data were collected, and blood samples were drawn for analysis at repeated intervals. Multiplex assays were used to analyze a proteome profile of molecules involved in stress response, inflammation, metabolic reactions, as well as heart and lung protection. RESULTS: Fontan-NO patients had significantly shorter respiratory support time with a median of 9.3 h (7.0; 13,2) vs 13.9 h (3.7; 18.5) by the absolute difference of 4.6 h [95% confidence interval, - 30.9 to 12.3; (p = 0.03)]. In addition, they have a shorter time in intensive care (p = 0.04) and lower pulmonary artery pressure after CPB discontinuation (p = 0.04), 4 h (p = 0.03) and 8 h (p = 0.03) after surgery. Fontan-NO patients also had a lower concentration of lactates (p = 0.04) and glucose after separation from CPB (p = 0.02) and lower catecholamine index (p = 0.042). Plasma factors analysis has shown a significantly higher concentration of interleukin-10, and a lower concentration of interleukin-6, interleukin-8, interleukin-1ß, pentraxin, matrix metalloproteinase-8, troponin-I, creatine kinase myocardial band (CK-MB), and insulin in Fontan-NO group. CONCLUSIONS: NO inhaled into the oxygenator during CPB can improve short-term clinical outcomes. It shortens intubation time and intensive care time. It reduces inflammatory response, improves myocardial and lung protection, and diminishes metabolic stress in patients with a single ventricle undergoing Fontan surgery. TRIAL REGISTRATION NUMBER: The trial was preregistered, supervised, and supported by The Polish National Science Center ( NCN/01/B/NZ5/04246 ).

SB203580-A Potent p38 MAPK Inhibitor Reduces the Profibrotic Bronchial Fibroblasts Transition Associated with Asthma.

Subepithelial fibrosis is a component of the remodeling observed in the bronchial wall of patients diagnosed with asthma. In this process, human bronchial fibroblasts (HBFs) drive the fibroblast-to-myofibroblast transition (FMT) in response to transforming growth factor-ß1 (TGF-ß1), which activates the canonical Smad-dependent signaling. However, the pleiotropic properties of TGF-ß1 also promote the activation of non-canonical signaling pathways which can affect the FMT. In this study we investigated the effect of p38 mitogen-activated protein kinase (MAPK) inhibition by SB203580 on the FMT potential of HBFs derived from asthmatic patients using immunocytofluorescence, real-time PCR and Western blotting methods. Our results demonstrate for the first time the strong effect of p38 MAPK inhibition on the TGF-ß1-induced FMT potential throughout the strong attenuation of myofibroblast-related markers: α-smooth muscle actin (α-SMA), collagen I, fibronectin and connexin 43 in HBFs. We suggest the pleiotropic mechanism of SB203580 on FMT impairment in HBF populations by the diminishing of TGF-ß/Smad signaling activation and disturbances in the actin cytoskeleton architecture along with the maturation of focal adhesion sites. These observations justify future research on the role of p38 kinase in FMT efficiency and bronchial wall remodeling in asthma.

Processing and Ex Vivo Expansion of Adipose Tissue-Derived Mesenchymal Stem/Stromal Cells for the Development of an Advanced Therapy Medicinal Product for use in Humans.

Adipose tissue (AT) represents a commonly used source of mesenchymal stem/stromal cells (MSCs) whose proregenerative potential has been widely investigated in multiple clinical trials worldwide. However, the standardization of the manufacturing process of MSC-based cell therapy medicinal products in compliance with the requirements of the local authorities is obligatory and will allow us to obtain the necessary permits for product administration according to its intended use. Within the research phase (RD), we optimized the protocols used for the processing and ex vivo expansion of AT-derived MSCs (AT-MSCs) for the development of an Advanced Therapy Medicinal Product (ATMP) for use in humans. Critical process parameters (including, e.g., the concentration of enzyme used for AT digestion, cell culture conditions) were identified and examined to ensure the high quality of the final product containing AT-MSCs. We confirmed the identity of isolated AT-MSCs as MSCs and their trilineage differentiation potential according to the International Society for Cellular Therapy (ISCT) recommendations. Based on the conducted experiments, in-process quality control (QC) parameters and acceptance criteria were defined for the manufacturing of hospital exemption ATMP (HE-ATMP). Finally, we conducted a validation of the manufacturing process in a GMP facility. In the current study, we presented a process approach leading to the optimization of processing and the ex vivo expansion of AT-MSCs for the development of ATMP for use in humans.

Cinnamic Acid Derivatives as Cardioprotective Agents against Oxidative and Structural Damage Induced by Doxorubicin.

Doxorubicin (DOX) is a widely used anticancer drug. However, its clinical use is severely limited due to drug-induced cumulative cardiotoxicity, which leads to progressive cardiomyocyte dysfunction and heart failure. Enormous efforts have been made to identify potential strategies to alleviate DOX-induced cardiotoxicity; however, to date, no universal and highly effective therapy has been introduced. Here we reported that cinnamic acid (CA) derivatives exert a multitarget protective effect against DOX-induced cardiotoxicity. The experiments were performed on rat cardiomyocytes (H9c2) and human induced-pluripotent-stem-cell-derived cardiomyocytes (hiPSC-CMs) as a well-established model for cardiac toxicity assessment. CA derivatives protected cardiomyocytes by ameliorating DOX-induced oxidative stress and viability reduction. Our data indicated that they attenuated the chemotherapeutic's toxicity by downregulating levels of caspase-3 and -7. Pre-incubation of cardiomyocytes with CA derivatives prevented DOX-induced motility inhibition in a wound-healing assay and limited cytoskeleton rearrangement. Detailed safety analyses-including hepatotoxicity, mutagenic potential, and interaction with the hERG channel-were performed for the most promising compounds. We concluded that CA derivatives show a multidirectional protective effect against DOX-induced cardiotoxicity. The results should encourage further research to elucidate the exact molecular mechanism of the compounds' activity. The lead structure of the analyzed CA derivatives may serve as a starting point for the development of novel therapeutics to support patients undergoing DOX therapy.

Extracellular vesicles from human iPSCs enhance reconstitution capacity of cord blood-derived hematopoietic stem and progenitor cells.

Cord blood (CB) represents a source of hematopoietic stem and progenitor cells (CB-HSPCs) for bone marrow (BM) reconstitution, but clinical CB application is limited in adult patients due to the insufficient number of CB-HSCPCs and the lack of effective ex vivo approaches to increase CB-HSPC functionality. Since human-induced pluripotent stem cells (hiPSCs) have been indicated as donor cells for bioactive extracellular vesicles (EVs) modulating properties of other cells, we are the first to employ hiPSC-derived EVs (hiPSC-EVs) to enhance the hematopoietic potential of CB-derived CD45dimLin-CD34+ cell fraction enriched in CB-HSPCs. We demonstrated that hiPSC-EVs improved functional properties of CB-HSPCs critical for their hematopoietic capacity including metabolic, hematopoietic and clonogenic potential as well as survival, chemotactic response to stromal cell-derived factor 1 and adhesion to the model components of hematopoietic niche in vitro. Moreover, hiPSC-EVs enhanced homing and engraftment of CB-HSPCs in vivo. This phenomenon might be related to activation of signaling pathways in CB-HSPCs following hiPSC-EV treatment, as shown on both gene expression and the protein kinases activity levels. In conclusion, hiPSC-EVs might be used as ex vivo modulators of CB-HSPCs capacity to enhance their functional properties and augment future practical applications of CB-derived cells in BM reconstitution.

Towards water-soluble [60]fullerenes for the delivery of siRNA in a prostate cancer model.

This paper presents two water-soluble fullerene nanomaterials (HexakisaminoC60 and monoglucosamineC60, which is called here JK39) that were developed and synthesized as non-viral siRNA transfection nanosystems. The developed two-step Bingel-Hirsch reaction enables the chemical modification of the fullerene scaffold with the desired bioactive fragments such as D-glucosamine while keeping the crucial positive charged ethylenediamine based malonate. The ESI-MS and 13C-NMR analyses of JK39 confirmed its high Th symmetry, while X-ray photoelectron spectroscopy revealed the presence of nitrogen and oxygen-containing C-O or C-N bonds. The efficiency of both fullerenes as siRNA vehicles was tested in vitro using the prostate cancer cell line DU145 expressing the GFP protein. The HexakisaminoC60 fullerene was an efficient siRNA transfection agent, and decreased the GFP fluorescence signal significantly in the DU145 cells. Surprisingly, the glycofullerene JK39 was inactive in the transfection experiments, probably due to its high zeta potential and the formation of an extremely stable complex with siRNA.

Temozolomide Induces the Acquisition of Invasive Phenotype by O6-Methylguanine-DNA Methyltransferase (MGMT)+ Glioblastoma Cells in a Snail-1/Cx43-Dependent Manner.

Glioblastoma multiforme (GBM) recurrences after temozolomide (TMZ) treatment result from the expansion of drug-resistant and potentially invasive GBM cells. This process is facilitated by O6-Methylguanine-DNA Methyltransferase (MGMT), which counteracts alkylating TMZ activity. We traced the expansion of invasive cell lineages under persistent chemotherapeutic stress in MGMTlow (U87) and MGMThigh (T98G) GBM populations to look into the mechanisms of TMZ-induced microevolution of GBM invasiveness. TMZ treatment induced short-term, pro-invasive phenotypic shifts of U87 cells, in the absence of Snail-1 activation. They were illustrated by a transient induction of their motility and followed by the hypertrophy and the signs of senescence in scarce U87 sub-populations that survived long-term TMZ stress. In turn, MGMThigh T98G cells reacted to the long-term TMZ treatment with the permanent induction of invasiveness. Ectopic Snail-1 down-regulation attenuated this effect, whereas its up-regulation augmented T98G invasiveness. MGMTlow and MGMThigh cells both reacted to the long-term TMZ stress with the induction of Cx43 expression. However, only in MGMThigh T98G populations, Cx43 was directly involved in the induction of invasiveness, as manifested by the induction of T98G invasiveness after ectopic Cx43 up-regulation and by the opposite effect after Cx43 down-regulation. Collectively, Snail-1/Cx43-dependent signaling participates in the long-term TMZ-induced microevolution of the invasive GBM front. High MGMT activity remains a prerequisite for this process, even though MGMT-related GBM chemoresistance is not necessary for its initiation.

Responsiveness of human bronchial fibroblasts and epithelial cells from asthmatic and non-asthmatic donors to the transforming growth factor-ß1 in epithelial-mesenchymal trophic unit model.

BACKGROUND: The asthma-related airway wall remodeling is associated i.a. with a damage of bronchial epithelium and subepithelial fibrosis. Functional interactions between human bronchial epithelial cells and human bronchial fibroblasts are known as the epithelial-mesenchymal trophic unit (EMTU) and are necessary for a proper functioning of lung tissue. However, a high concentration of the transforming growth factor-ß1 (TGF-ß1) in the asthmatic bronchi drives the structural disintegrity of epithelium with the epithelial-to-mesenchymal transition (EMT) of the bronchial epithelial cells, and of subepithelial fibrosis with the fibroblast-to-myofibroblast transition (FMT) of the bronchial fibroblasts. Since previous reports indicate different intrinsic properties of the human bronchial epithelial cells and human bronchial fibroblasts which affect their EMT/FMT potential beetween cells derived from asthmatic and non-asthmatic patients, cultured separatelly in vitro, we were interested to see whether corresponding effects could be obtained in a co-culture of the bronchial epithelial cells and bronchial fibroblasts. In this study, we investigate the effects of the TGF-ß1 on the EMT markers of the bronchial epithelial cells cultured in the air-liquid-interface and effectiveness of FMT in the bronchial fibroblast populations in the EMTU models. RESULTS: Our results show that the asthmatic co-cultures are more sensitive to the TGF-ß1 than the non-asthmatic ones, which is associated with a higher potential of the asthmatic bronchial cells for a profibrotic response, analogously to be observed in '2D' cultures. They also indicate a noticeable impact of human bronchial epithelial cells on the TGF-ß1-induced FMT, stronger in the asthmatic bronchial fibroblast populations in comparison to the non-asthmatic ones. Moreover, our results suggest the protective effects of fibroblasts on the structure of the TGF-ß1-exposed mucociliary differentiated bronchial epithelial cells and their EMT potential. CONCLUSIONS: Our data are the first to demonstrate a protective effect of the human bronchial fibroblasts on the properties of the human bronchial epithelial cells, which suggests that intrinsic properties of not only epithelium but also subepithelial fibroblasts affect a proper condition and function of the EMTU in both normal and asthmatic individuals.

Graphene-based materials enhance cardiomyogenic and angiogenic differentiation capacity of human mesenchymal stem cells in vitro - Focus on cardiac tissue regeneration.

Cell-based therapies have recently emerged as promising strategies for the treatment of cardiovascular disease. Mesenchymal stem cells (MSCs) are a promising cell type that represent a class of adult stem cells characterized by multipotency, high proliferative capacity, paracrine activity, and low immunogenicity. To improve the functional and therapeutic efficacy of MSCs, novel biomaterials are considered as scaffolds/surfaces that promote MSCs growth and differentiation. One of them are graphene-based materials, including graphene oxide (GO) and reduced graphene oxide (rGO). Due to the unique physical, chemical, and biological properties of graphene, scaffolds comprising GO/rGO have been examined as novel platforms to improve the differentiation potential of human MSCs in vitro. We verified different i) size of GO flakes, ii) reduction level, and iii) layer thickness to select the most suitable artificial niche for MSCs culture. The results revealed that graphene-based substrates constitute non-toxic substrates for MSCs. Surfaces with large flakes of GO as well as low reduced rGO are the most biocompatible for MSCs propagation and do not affect their proliferation and survival. Interestingly, small GO flakes and highly reduced rGO decreased MSCs proliferation and induced their apoptosis. We also found that GO and rGO substrates did not alter the MSCs phenotype, cell cycle progression and might modulate the adhesive capabilities of these cells. Importantly, we demonstrated that both materials promoted the cardiomyogenic and angiogenic differentiation capacity of MSCs in vitro. Thus, our data indicates that graphene-based surfaces represent promising materials that may influence the therapeutic application of MSCs via supporting their pro-regenerative potential.

Lipofection-Based Delivery of DNA Vaccines.

The preventive and therapeutic potential of DNA vaccines combined with benefits of lipid-based delivery (lipofection) allow efficient nucleic acid transfer and immunization applicable in treatment of infections, cancer or autoimmune disorders. Lipofecting compositions consisting of cationic and neutral lipids can be used for both in vitro and in vivo applications and may also play the role of adjuvants. Here we describe a simple protocol of DNA vaccine carrier preparation based on cationic polyprenyl derivatives (PTAI-trimethylpolyprenylammonium iodides) and commonly used helper lipids with use of basic laboratory equipment. Such formulas have proven effective for immunization of animals as well as for cell transfection.

Polyprenol-Based Lipofecting Agents for In Vivo Delivery of Therapeutic DNA to Treat Hypertensive Rats.

Development of efficient vectors for transfection is one of the major challenges in genetic engineering. Previous research demonstrated that cationic derivatives of polyisoprenoids (PTAI) may serve as carriers of nucleic acids. In the present study, the effectiveness of two PTAI-based formulations (PTAI-6-8 and 10-14) was investigated and compared to the commercial reagents. The purpose of applied gene therapy was to enhance the expression of vascular endothelial growth factor (VEGF-A) in the renal medulla of spontaneously hypertensive rats (SHR) and to test its potential as a novel antihypertensive intervention. In the first part of the study (in vitro), we confirmed that PTAI-based lipoplexes efficiently transfect XC rat sarcoma cells and are stable in 37 °C for 7 days. In the in vivo experiments, we administered selected lipoplexes directly to the kidneys of conscious SHR (via osmotic pumps). There were no blood pressure changes and VEGF-A level in renal medulla was significantly higher only for PTAI-10-14-based formulation. In conclusion, despite the promising results, we were not able to achieve VEGF-A expression level high enough to verify VEGF-A gene therapy usefulness in SHR. However, results of our study give important indications for the future development of PTAI-based DNA carriers and kidney-targeted gene delivery.