Role of hepatocyte growth factor in the immunomodulation potential of amniotic fluid stem cells

Human amniotic fluid stem cells (hAFSCs) may be useful for regenerative medicine because of their potential to differentiate into all three germ layers and to modulate immune response with different types of secretion molecules. This last issue has not been completely elucidated. The aim of this study was to investigate the secretome profile of the hAFSC, focusing on the role of hepatocyte growth factor (HGF) in immunoregulation through short and long cocultures with human peripheral blood mononuclear cells. We found that HGF produced by hAFSCs exerts a cytoprotective role, inducing an increase in caspase-dependent apoptosis in human immune cells. This study provides evidence supporting the hypothesis that amniotic fluid is an ideal source of stem cells for expansion and banking properties for therapeutic use. hAFSCs not only are less immunogenic but also can secrete immunoregulatory factors that may be useful in autoimmune diseases or allogenic implants. SIGNIFICANCE: New information about the secretome pattern is reported in this paper. Human amniotic fluid stem cells (hAFSCs) possess immunomodulatory properties involving hepatocyte growth factor production. hAFSCs could be used in immunotherapies and might be able to avoid allogenic rejectio

Protective Effects of Borago officinalis (Borago) on Cold Restraint Stress-Induced Gastric Ulcers in Rats: A Pilot Study

Stress is a typical body's natural defense to a generic physical or psychic change. A specific linking mechanism between ulcer onset and psycho-physical stress prolonged exposure has been reported. We decided to investigate the possible effects of Borago officinalis L. (Borago) in preventing physical (stress)-induced gastric ulcers in a rat model. Eighty male Sprague-Dawley rats were randomly divided into 16 groups, pretreated with a control solution, omeprazole (20 mg/kg), Borago methanolic extract (25, 50, 100, 250, and 500 mg/kg), Borago organic extract (50, 100, 250, and 500 mg/kg), Borago aqueous extract (5, 10, 20, 30, and 40 mg/kg), and D(-)-2-Amino-5-phosphonovaleric acid (AP5) (25 mg/kg) and kept in stressful conditions such as water immersion and restraint-induced stress ulcers. The animals were sacrificed and their stomach scored for the severity and the number of gastric ulcers. Methanolic extract (500 mg/kg) significantly reduced both ulcer parameters (***p < 0.001 and **p < 0.01, respectively). Aqueous and organic extract significantly decreased severity score at 5 and 10 mg/kg (**p < 0.01 and ***p < 0.001, respectively), and at 250 and 500 mg/kg (***p < 0.001), respectively, while gastric ulcers' resulted number significantly reduced only at 10 mg/kg (*p < 0.05) and at 500 mg/kg (**p < 0.01), respectively. On the other hand, aqueous extract significantly increased the mucosal gastric content of cAMP (*p < 0.05) and NR2A and NR2B subunits (*p < 0.05 and **p < 0.01, respectively) at 5 mg/kg. Organic extract showed also a significant cytotoxic effect at 500 and 1,000 mg/kg with a 3T3 cell viability reduction of 43.6% (**p < 0.01) and 92.1% (***p < 0.001), respectively. Borago aqueous extract at 10 mg/kg could be considered as a potential protective agent against stress-induced ulcers, and it is reasonable to possibly ascribe such protective activity to a modulation of the NR2A and NR2B subunit expression

Improved sexual behavior in male rats treated with a Chinese herbal extract: hormonal and neuronal implications

Aim: To investigate the influence of an extract obtained from five Chinese medicinal plants on sexual behavior ofadult male rats. Methods: The extract was administered at doses of 30, 60 and 120 mg/kg by oral gavage, acutely (onetime, 45 min before mating test) or subchronically (daily for 10 days) in sexually potent and sexually sluggish/impotentrats. Sexual behavior, serum levels of luteinizing hormone (LH) and testosterone (T) were evaluated in treatedrats and compared with controls receiving vehicle. The effect of the extract on central dopaminergic neurotransmissionwas assessed in the nucleus accumbens using a microdialysis technique. Results: In sexually potent rats, bothacute and subchronic treatment with the extract dosed at 30 and 60 mg/kg reduced mount latency and intromissionlatency. In sluggish/impotent rats, the acutely administered extract at the dose of 60 mg/kg shortened ejaculationlatency, whereas subchronically administered at the doses of 30 and 60 mg/kg, reduced mount, intromission andejaculation latencies, increasing also the percentage of mounting and ejaculating rats. The extract dosed at 60 mg/kgsignificantly increased LH and T following acute and subchronic administration and increased 3,4-dihydroxyphenylaceticacid levels in the nucleus accumbens, 30 min after the acute administration. Conclusion: The improvement in bothappetitive and consummatory components of sexual behavior observed in male rats treated with the extract could beascribed to increased serum T level in parallel with the activation of the central dopaminergic system

Inhibition of nuclear nox4 activity by plumbagin: effect on proliferative capacity in human amniotic stem cells.

Human amniotic fluid stem cells (AFSC) with multilineage differentiation potential are novel source for cell therapy. However, in vitro expansion leads to senescence affecting differentiation and proliferative capacities. Reactive oxygen species (ROS) have been involved in the regulation of stem cell pluripotency, proliferation, and differentiation. Redox-regulated signal transduction is coordinated by spatially controlled production of ROS within subcellular compartments. NAD(P)H oxidase family, in particular Nox4, has been known to produce ROS in the nucleus; however, the mechanisms and the meaning of this function remain largely unknown. In the present study, we show that Nox4 nuclear expression (nNox4) increases during culture passages up to cell cycle arrest and the serum starvation causes the same effect. With the decrease of Nox4 activity, obtained with plumbagin, a decline of nuclear ROS production and of DNA damage occurs. Moreover, plumbagin exposure reduces the binding between nNox4 and nucleoskeleton components, as Matrin 3. The same effect was observed also for the binding with phospho-ERK, although nuclear ERK and P-ERK are unchanged. Taken together, we suggest that nNox4 regulation may have important pathophysiologic effects in stem cell proliferation through modulation of nuclear signaling and DNA damage

Human amniotic fluid-derived and dental pulp-derived stem cells seeded into collagen scaffold repair critical-size bone defects promoting vascularization

INTRODUCTION: The main aim of this study is to evaluate potential human stem cells, such as dental pulp stem cells and amniotic fluid stem cells, combined with collagen scaffold to reconstruct critical-size cranial bone defects in an animal model. METHODS: We performed two symmetric full-thickness cranial defects on each parietal region of rats and we replenished them with collagen scaffolds with or without stem cells already seeded into and addressed towards osteogenic lineage in vitro. After 4 and 8 weeks, cranial tissue samples were taken for histological and immunofluorescence analysis. RESULTS: We observed a new bone formation in all of the samples but the most relevant differences in defect correction were shown by stem cell–collagen samples 4 weeks after implant, suggesting a faster regeneration ability of the combined constructs. The presence of human cells in the newly formed bone was confirmed by confocal analysis with an antibody directed to a human mitochondrial protein. Furthermore, human cells were found to be an essential part of new vessel formation in the scaffold. CONCLUSION: These data confirmed the strong potential of bioengineered constructs of stem cell–collagen scaffold for correcting large cranial defects in an animal model and highlighting the role of stem cells in neovascularization during skeletal defect reconstruction

DEVELOPMENT OF A NOVEL METHOD FOR AMNIOTIC FLUID STEM CELL STORAGE

Background - Current procedures for collection of human Amniotic Fluid Stem Cells (hAFSCs) imply that amniotic fluid cells were cultured in flask for two weeks, than can be devoted to research purpose. However, hAFSCs could be retrieved directly from a small amount of amniotic fluid that can be obtained at the time of diagnostic amniocentesis. The aim of the study was to verify if a direct freezing of amniotic fluid cells is able to maintain and / or improve the potential of the sub-population of stem cells. Methods - We compared the potential of the hAFSCs depending on the moment in which they are frozen, cells obtained directly from amniotic fluid aspiration (D samples) and cells cultured in flask before freezing (C samples). Colony-forming-unit ability, proliferation, morphology, stemness-related marker expression, senescence, apoptosis, and differentiation potential of C and D samples were compared. Results - hAFSCs isolated from D samples expressed MSC markers until later passages, had a good proliferation rate, and exhibited differentiation capacity similar to hAFSCs of C samples. Interestingly, the direct freezing induce a higher concentration of cells positive for pluripotency stem cell markers, without teratoma formation in vivo. Conclusions - This study suggests that minimal processing may be adequate for the banking of amniotic fluid cells, avoiding in vitro passages before the storage and exposure to high oxygen concentration affecting stem cell properties. This technique might be a reasonable approach in terms of costs and for the process of accreditation in GMP for a stem cell bank

NADPH oxidase-4 and MATER expressions in granulosa cells: Relationships with ovarian aging

Aims Relevant roles in follicular development and ovulation are played by maternal antigen that embryos require (MATER), product of a maternal effect gene, and by reactive oxygen species (ROS), indispensable for the induction of ovulatory genes. At the moment, the relationship between these two biological systems and their involvement in the ovarian aging have not been still clarified. The aim of the current experimental study was to analyse the age-related changes of the MATER and NOX proteins. Materials and methods MATER and ROS homeostasis was studied in granulosa cells (GCs) and cumulus cells (CCs) of infertile patients who undergone oocyte retrieval for in vitro fertilization cycles using Western blot and confocal immunofluorescence analysis. Samples were obtained from subjects with age\ua0 65\ua040\ua0years (cases) and with age\ua0 64\ua037\ua0years (controls). Key findings The expression pattern of MATER and NOX observed in GCs was not different from that observed in CCs. High levels of both proteins were detected in the control samples. A significant lower expression of both MATER and NOX4 was observed in the case versus control samples. Significance The expression of MATER and NOX4 proteins are closely related to the follicular development and ovulation with particular regard for ovarian aging

Human Neuromuscular Junction on a Chip: Impact of Amniotic Fluid Stem Cell Extracellular Vesicles on Muscle Atrophy and NMJ Integrity

: Neuromuscular junctions (NMJs) are specialized synapses, crucial for the communication between spinal motor neurons (MNs) and skeletal muscle. NMJs become vulnerable in degenerative diseases, such as muscle atrophy, where the crosstalk between the different cell populations fails, and the regenerative ability of the entire tissue is hampered. How skeletal muscle sends retrograde signals to MNs through NMJs represents an intriguing field of research, and the role of oxidative stress and its sources remain poorly understood. Recent works demonstrate the myofiber regeneration potential of stem cells, including amniotic fluid stem cells (AFSC), and secreted extracellular vesicles (EVs) as cell-free therapy. To study NMJ perturbations during muscle atrophy, we generated an MN/myotube co-culture system through XonaTM microfluidic devices, and muscle atrophy was induced in vitro by Dexamethasone (Dexa). After atrophy induction, we treated muscle and MN compartments with AFSC-derived EVs (AFSC-EVs) to investigate their regenerative and anti-oxidative potential in counteracting NMJ alterations. We found that the presence of EVs reduced morphological and functional in vitro defects induced by Dexa. Interestingly, oxidative stress, occurring in atrophic myotubes and thus involving neurites as well, was prevented by EV treatment. Here, we provided and validated a fluidically isolated system represented by microfluidic devices for studying human MN and myotube interactions in healthy and Dexa-induced atrophic conditions-allowing the isolation of subcellular compartments for region-specific analyses-and demonstrated the efficacy of AFSC-EVs in counteracting NMJ perturbations

Inhibition of nuclear Nox4 activity: effect on proliferative capacity in human stem cells

Human amniotic fluid stem cells (AFSC) with multilineage differentiation capacity are novel sources for cell therapy. However, stem cell samples obtained form patients differ in cell proliferation activity. Futhermore in vitro expansion leads to senescence affecting differentiation and proliferative capacities. Reactive oxygen species (ROS) have been involved in the regulation of stem cell pluripotency, proliferation and differentiation. Redox-regulated signal transduction is coordinated by spatially controlled production of ROS within subcellular compartments. Transcription factors, and even kinases and phosphatases, have been described to be redox regulated in the nucleus. NAD(P)H oxidase family, and in particular Nox4, has been known to produce ROS in the nucleus, however the mechanisms and the meaning of this function remain largely unknown. In the present study we show that Nox4 localization in AFSC nuclei corresponds to speackle domains, as well as OCT4 (octamer-binding transcription factor 4) and SOX2 (SRY-box containing protein 2), two pluripotency regulating proteins. Stem cells isolated from different amniotic fluids exhibit a proliferation rate inversely coupled with Nox4 presence into the nuclei. Furthermore, Nox4 nuclear expression (nNox4) increases during culture passages up to cell cycle arrest and the serum starvation causes the same effect. With a decrease of Nox4 activity, obtained by protein downregulation or by inhibition with plumbagin, a decline of nuclear ROS production and of DNA damage occurs. Moreover plumbagin exposure reduces the binding between nNox4 nucleo-skeleton components, as lamin A/C and matrin. The same effect was observed also for the binding with phospho-ERK, although nuclear ERK and P-ERK are unchanged. Taken together, we purpose that nNox4 regulation may have important pathophysiologic effects in stem cell proliferation through modulation of nuclear signaling and DNA damage