Pluripotency markers in tissue and cultivated cells in vitro of different regions of human amniotic epithelium

Obtaining Tissues of Human Amniotic Membrane and Identification of Pluripotent Markers

The immunofluorescence technique has been used to identify pluripotent markers in the human amniotic epithelial cells (hAEC). hAEC belonging to human fetal membranes, specificamently to amnion layer, and are arising by epiblast, this sugest that the hAEC have characteristics of epiblast cells, in other words, characteristcs of pluripotent stem cells. Here we describe obtaining human amnion tissue and identifying pluripotent markers by immunofluorescence.

Inter-placental variability is not a major factor affecting the healing efficiency of amniotic membrane when used for treating chronic non-healing wounds

This study aimed to evaluate the efficacy of cryopreserved amniotic membrane (AM) grafts in chronic wound healing, including the mean percentage of wound closure per one AM application, and to determine whether the healing efficiency differs between AM grafts obtained from different placentas. A retrospective study analyzing inter-placental differences in healing capacity and mean wound closure after the application of 96 AM grafts prepared from nine placentas. Only the placentas from which the AM grafts were applied to patients suffering from long-lasting non-healing wounds successfully healed by AM treatment were included. The data from the rapidly progressing wound-closure phase (p-phase) were analyzed. The mean efficiency for each placenta, expressed as an average of wound area reduction (%) seven days after the AM application (baseline, 100%), was calculated from at least 10 applications. No statistical difference between the nine placentas' efficiency was found in the progressive phase of wound healing. The 7-day average wound reduction in particular placentas varied from 5.70 to 20.99% (median from 1.07 to 17.75) of the baseline. The mean percentage of wound surface reduction of all analyzed defects one week after the application of cryopreserved AM graft was 12.17 ± 20.12% (average ± SD). No significant difference in healing capacity was observed between the nine placentas. The data suggest that if there are intra- and inter-placental differences in AM sheets' healing efficacy, they are overridden by the actual health status of the subject or even the status of its individual wounds.

Progesterone modulates extracellular heat-shock proteins and interlukin-1β in human choriodecidual after Escherichia coli infection

INTRODUCTION

Chorioamnionitis is an adverse condition in human pregnancy caused by many bacterial pathogens including Escherichia coli (E. coli); which has been associated with higher risk of preterm birth. We recently reported that human maternal decidua (MDec) tissue responds to E. coli infection by secreting extracellular heat-shock proteins (eHsp)-60, -70 and interlukin-1β (IL-1β). Previous studies have shown that progesterone (P4) regulates the immune response, but it is unknown whether P4 inhibits the secretion of eHsp. The aim of this investigation was to determine the role of P4 on the secretion of eHsp-27, -60, -70 and IL-1β in MDec after 3, 6, and 24 h of E. coli infection.

METHODS

Nine human feto-maternal interface (HFMi) tissues were included and mounted in the Transwell culture system. Only the maternal decidua (MDec) was stimulated for 3, 6 and 24 h with E. coli alone or in combination with progesterone and RU486. After each treatment, the HFMi tissue was recovered to determine histological changes and the culture medium recovered to evaluate the levels of eHsp-27, -60, -70 and IL-1β by ELISA and mRNA expression by RT-PCR.

RESULTS

No structural changes were observed in the HFMi tissue treated with P4 and RU486. However, stimulation with E. coli produces diffuse inflammation and ischemic necrosis. E. coli induced infection decreases, in time- and dose-dependent manner, eHsp-27 and increases eHsp-60, eHsp-70 and IL-1β levels. In contrast, incubation of HFMi tissue with E. coli + P4 reversed eHsp and IL-1β secretion levels relative to E. coli stimulation group but not relative to the control group. The same profile was observed on the expression of eHsp-27 and eHsp-60.

DISCUSSION

we found that progesterone modulates the anti-inflammatory (eHsp-27) and pro-inflammatory (eHsp-60 and eHsp-70) levels of eHsp induced by E. coli infection in human choriodecidual tissue. eHsp-60 and eHsp-70 levels were not completely reversed; maintaining the secretion of IL-1β, which has been associated with adverse events during pregnancy.

A Survey and Critical Evaluation of Isolation, Culture, and Cryopreservation Methods of Human Amniotic Epithelial Cells

Human amniotic epithelial cells (hAECs), derived from an epithelial cell layer of the human amniotic membrane, possess embryonic stem-like properties and are known to maintain multilineage differentiation potential. Unfortunately, an inability to expand hAECs without significantly compromising their stem cell potency has precluded their widespread use for regenerative therapies. This article critically evaluates the methods used for isolation, expansion, and cryopreservation of hAECs. We assessed the impact of these methods on ex-vivo expansion and stem cell phenotype of hAECs. Moreover, the progress and challenges to optimize clinically suitable culture conditions for an efficient ex-vivo expansion and storage of these cells are highlighted. Additionally, we also reviewed the currently used hAECs isolation and characterization methods employed in clinical trials. Despite the developments made in the last decade, significant challenges still exist to overcome limitations of ex-vivo expansion and retention of stemness of hAECs in both xenogeneic and xenofree culture conditions. Therefore, optimization and standardization of culture conditions for robust ex-vivo maintenance of hAECs without affecting tissue regenerative properties is an absolute requirement for their successful therapeutic manipulation. This review may help the researchers to optimize the methods that support ex-vivo survival, proliferation, and self-renewal properties of the hAECs.Abbreviations: AM: Human amniotic membrane; CM-HBSS: Ca⁺⁺ and Mg⁺⁺ free HBSS; DMEM: Dulbecco's Modified Eagle Medium; DMEM-HG: DMEM-high glucose; EMEM: Eagle's Modified Essential Medium; EMT: Epithelial-to-mesenchymal transition; EpM: Epi-life complete media; ESC: Embryonic stem cells; ESCM: Epithelial cell surface markers; hAECs: Human amniotic epithelial cells; HLA: Human leukocyte antigen; IM: Immunogenicity markers; iPSC: Induced pluripotent stem cells; KOSR; KSR: Knockout serum replacement; KSI: Key success indicators; CHM: Cell heterogeneity markers; Nanog: NANOG homeobox; Oct-4: Octamer binding transcription factor 4; OR: Operation room; P: Passage; PM: Pluripotency markers; SCM: Stem cell markers for non-differentiated cells; Sox-2: Sry-related HMG box gene 2; SSEA-4: Stage-specific embryonic antigen; TRA: Tumor rejection antigen; UC: Ultra-culture; XF: Xenogeneic free.

Differential localization of serotoninergic system elements in human amniotic epithelial cells†

Serotonin or 5-hydroxytryptamine (5-HT) is a biogenic amine involved in regulating several functions, including development. However, its impact on human embryo development has been poorly studied. The present work investigated the expression and distribution of the main components of the serotoninergic system in human amniotic tissue and human amniotic epithelial cells (hAEC) in vitro, as an alternative model of early human embryo development. Amniotic membranes from full-term healthy pregnancies were used. Human amnion tissue or hAEC isolated from the amnion was processed for reverse transcription-polymerase chain reaction and immunofluorescence analyses of the main components of the serotoninergic system. We found the expression of tryptophan hydroxylase type 1 (TPH1), type 2 (TPH2), serotonin transporter (SERT), monoamine oxidase-A (MAOA), as well as HTR1D and HTR7 receptors at mRNA level in amnion tissue as well in hAEC. Interestingly, we found the presence of 5-HT in the nucleus of the cells in amnion tissue, whereas it was located in the cytoplasm of isolated hAEC. We detected TPH1, TPH2, and HTR1D receptor in both the nucleus and cytoplasm. SERT, MAOA, and HTR7 receptor were only observed in the cytoplasm. The results presented herein show, for the first time, the presence of the serotoninergic system in human amnion in vivo and in vitro.

Sub-Regional Differences of the Human Amniotic Membrane and Their Potential Impact on Tissue Regeneration Application

For more than 100 years, the human amniotic membrane (hAM) has been used in multiple tissue regeneration applications. The hAM consists of cells with stem cell characteristics and a rich layer of extracellular matrix. Undoubtedly, the hAM with viable cells has remarkable properties such as the differentiation potential into all three germ layers, immuno-modulatory, and anti-fibrotic properties. At first sight, the hAM seems to be one structural entity. However, by integrating its anatomical location, the hAM can be divided into placental, reflected, and umbilical amniotic membrane. Recent studies show that cells of these amniotic sub-regions differ considerably in their properties such as morphology, structure, and content/release of certain bioactive factors. The aim of this review is to summarize these findings and discuss the relevance of these different properties for tissue regeneration. In summary, reflected amnion seems to be more immuno-modulatory and could have a higher reprogramming efficiency, whereas placental amnion seems to be pro-inflammatory, pro-angiogenic, with higher proliferation and differentiation capacity (e.g., chondrogenic and osteogenic), and could be more suitable for certain graft constructions. Therefore, we suggest that the respective hAM sub-region should be selected in consideration of its desired outcome. This will help to optimize and fine-tune the clinical application of the hAM.