Use of human amniotic epithelial cells in mouse models of bleomycin-induced lung fibrosis: A systematic review and meta-analysis

Alginate-polylysine-alginate (APA) microencapsulated transgenic human amniotic epithelial cells ameliorate fibrosis in hypertrophic scars

BACKGROUND

Hypertrophic scar (HS) is a severe skin fibrosis. Transplanting stem cells carrying anti-fibrotic cytokine genes, like interferon-gamma (IFN-γ), is a novel therapeutic strategy. Human amniotic epithelial cells (hAECs) are ideal seed cells and gene vectors. Microencapsulation creates a favorable environment for transplanted cells. This study investigates the effect of alginate-polylysine-alginate (APA)-microencapsulated hAECs modified with IFN-γ on HS fibrosis.

MATERIALS AND METHODS

hAECs were isolated from human placentas and characterized. The full-length IFN-γ gene was cloned into the pcDNA3.1 vector to create the recombinant plasmid IFN-γ-pcDNA3.1. This plasmid was then transfected into hAECs, resulting in the generation of IFN-γ-modified hAECs (IFN-γ-hAECs). Subsequently, these IFN-γ-hAECs were microencapsulated with APA to produce APA-IFN-γ-hAECs. In vitro, the release of IFN-γ, as well as the cellular and metabolic activities, growth, proliferation, migration, apoptosis, and trans-differentiation were assessed using HS-derived fibroblasts. In vivo, the weight loss of HS xenografts, collagen fiber arrangement, tissue oxidative stress, and inflammatory response were evaluated using a nude mouse model that had been transplanted with human HS tissues.

RESULTS

In vitro, APA-IFN-γ-hAECs exhibited significantly sustained and enhanced IFN-γ release, increased cellular vitality, and inhibited fibroblast growth, proliferation, migration, and trans-differentiation into myofibroblasts. APA-IFN-γ-hAECs also remarkably downregulated extracellular matrix (ECM) components and promoted apoptosis. In vivo, they significantly accelerated the weight reduction of HS xenografts, improved collagen fiber arrangement, and mitigated oxidative stress and inflammation.

CONCLUSIONS

This study suggests that APA-microencapsulated IFN-γ-hAECs may have potential in alleviating HS fibrosis, offering a new direction for exploring effective clinical HS management strategies.

Human Amniotic Epithelial Stem Cells Promote Colonic Recovery in Experimental Colitis via Exosomal MiR-23a-TNFR1-NF-κB Signaling

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, manifests as chronic intestinal inflammation with debilitating symptoms, posing a significant burden on global healthcare. Moreover, current therapies primarily targeting inflammation can lead to immunosuppression-related complications. Human amniotic epithelial stem cells (hAESCs), which exhibit low immunogenicity and ethical acceptability, have gained attention as potential therapeutics. In this study, it is demonstrated that their encapsulation in a hydrogel and administration via anal injection enhanced the colonic mucosal barrier repair in a murine colitis model induced by dextran sodium sulfate during the recovery phase. The underlying mechanism involved the release of exosomes from hAESCs enriched with microRNA-23a-3p, which post-transcriptionally reduced tumor necrosis factor receptor 1 expression, suppressing the nuclear factor-κB pathway in colonic epithelial cells, thus played a key role in inflammation. The novel approach shows potential for IBD treatment by restoring intestinal epithelial homeostasis without the immunosuppressive therapy-associated risks. Furthermore, the approach provides an alternative strategy to target the key molecular pathways involved in inflammation and promotes intestinal barrier function using hAESCs and their secreted exosomes. Overall, this study provides key insights to effectively treat IBD, addresses the unmet needs of patients, and reduces related healthcare burden.

Immunosuppressive Potential of Activated Human Amniotic Cells in an Experimental Murine Model of Skin Allo- and Xenotransplantation

Isolated human amniotic cells (hAC) could be used as a source of immunomodulatory factors in regenerative medicine and transplantation. However, in previous experimental studies, native hAC administered to skin graft recipients did not induce graft immunotolerance. To strengthen the immunomodulatory properties of hAC prior to administration to the recipient, we activated them ex vivo using pro-inflammatory cytokines. In this study, we compared the transplantation efficiency of skin allografts (mouse to mouse) and xnografts (rat to mouse) in recipient mice divided into three main groups receiving: 1. Placebo (control group); 2. Cyclosporine A (CsA) [10 or 50 mg/kg body weight (bw)]; 3. suspension of hAC activated ex vivo by IL-1β and INFγ, administered into a tail vein or subcutaneously. During 15 days of observation, hAC administered intravenously or subcutaneously after allotransplantation appeared to be as safe and efficient as CsA at the dose of 10 mg/kg bw in preventing rejection of skin allo- and xenografts. After xenotransplantation, however, only hAC administered intravenously prevented rejection to an extent comparable to CsA. Both CsA (10 mg/kg bw) and activated hAC reduced inflammatory infiltration in the skin (after intravenous injection) and did not increase the concentration of the inflammation marker SAP in serum or percentage of leukocytes in blood. Finally, we concluded that administration of activated hAC is safe and efficient in the presented animal model of skin allo- and xenotransplantation in a route-dependent manner. Activated hAC injected intravenously exhibit an immunosuppressive effect comparable to CsA administered at the dose of 10 mg/kg bw in both allo- and xenotransplantation.

The Roles of Different Stem Cells in Premature Ovarian Failure

Premature ovarian failure (POF) is characterized by amenorrhea, hypergonadotropism and hypoestrogenism before the age of 40, which affects 1% of women in the general population. POF is complex and heterogeneous due to its pathogenetic mechanisms. It is one of the significant causes of female infertility. Although many treatments are available for POF, these therapies are less efficient and trigger many side effects. Therefore, to find effective therapeutics for POF is urgently required. Due to stem cells having self-renewal and regeneration potential, they may be effective for the treatment of ovarian failure and consequently infertility. Recent studies have found that stem cells therapy may be able to restore the ovarian structure and function in animal models of POF and provide an effective treatment method. The present review summarizes the biological roles and the possible signaling mechanisms of the different stem cells in POF ovary. Further study on the precise mechanisms of stem cells on POF may provide novel insights into the female reproduction, which not only enhances the understanding of the physiological roles but also supports effective therapy for recovering ovarian functions against infertility.

Treatment of COVID-19 Pneumonia: the Case for Placenta-derived Cell Therapy

Nearly 500'000 fatalities due to COVID-19 have been reported globally and the death toll is still rising. Most deaths are due to acute respiratory distress syndrome (ARDS), as a result of an excessive immune response and a cytokine storm elicited by severe SARS-CoV-2 lung infection, rather than by a direct cytopathic effect of the virus. In the most severe forms of the disease therapies should aim primarily at dampening the uncontrolled inflammatory/immune response responsible for most fatalities. Pharmacological agents - antiviral and anti-inflammatory molecules - have not been able so far to achieve compelling results for the control of severe COVID-19 pneumonia. Cells derived from the placenta and/or fetal membranes, in particular amniotic epithelial cells (AEC) and decidual stromal cells (DSC), have established, well-characterized, potent anti-inflammatory and immune-modulatory properties that make them attractive candidates for a cell-based therapy of COVID19 pneumonia. Placenta-derived cells are easy to procure from a perennial source and pose minimal ethical issues for their utilization. In view of the existing clinical evidence for the innocuousness and efficiency of systemic administration of DSCs or AECs in similar conditions, we advocate for the initiation of clinical trials using this strategy in the treatment of severe COVID-19 disease.

The Role of MSC Therapy in Attenuating the Damaging Effects of the Cytokine Storm Induced by COVID-19 on the Heart and Cardiovascular System

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has led to 47 m infected cases and 1. 2 m (2.6%) deaths. A hallmark of more severe cases of SARS-CoV-2 in patients with acute respiratory distress syndrome (ARDS) appears to be a virally-induced over-activation or unregulated response of the immune system, termed a "cytokine storm," featuring elevated levels of pro-inflammatory cytokines such as IL-2, IL-6, IL-7, IL-22, CXCL10, and TNFα. Whilst the lungs are the primary site of infection for SARS-CoV-2, in more severe cases its effects can be detected in multiple organ systems. Indeed, many COVID-19 positive patients develop cardiovascular complications, such as myocardial injury, myocarditis, cardiac arrhythmia, and thromboembolism, which are associated with higher mortality. Drug and cell therapies targeting immunosuppression have been suggested to help combat the cytokine storm. In particular, mesenchymal stromal cells (MSCs), owing to their powerful immunomodulatory ability, have shown promise in early clinical studies to avoid, prevent or attenuate the cytokine storm. In this review, we will discuss the mechanistic underpinnings of the cytokine storm on the cardiovascular system, and how MSCs potentially attenuate the damage caused by the cytokine storm induced by COVID-19. We will also address how MSC transplantation could alleviate the long-term complications seen in some COVID-19 patients, such as improving tissue repair and regeneration.

Application of human amniotic epithelial cells in regenerative medicine: a systematic review

Human amniotic epithelial cells (hAECs) derived from placental tissues have gained considerable attention in the field of regenerative medicine. hAECs possess embryonic stem cell-like proliferation and differentiation capabilities, and adult stem cell-like immunomodulatory properties. Compared with other types of stem cell, hAECs have special advantages, including easy isolation, plentiful numbers, the obviation of ethical debates, and non-immunogenic and non-tumorigenic properties. During the past two decades, the therapeutic potential of hAECs for treatment of various diseases has been extensively investigated. Accumulating evidence has demonstrated that hAEC transplantation helps to repair and rebuild the function of damaged tissues and organs by different molecular mechanisms. This systematic review focused on summarizing the biological characteristics of hAECs, therapeutic applications, and recent advances in treating various tissue injuries and disorders. Relevant studies published in English from 2000 to 2020 describing the role of hAECs in diseases and phenotypes were comprehensively sought out using PubMed, MEDLINE, and Google Scholar. According to the research content, we described the major hAEC characteristics, including induced differentiation plasticity, homing and differentiation, paracrine function, and immunomodulatory properties. We also summarized the current status of clinical research and discussed the prospects of hAEC-based transplantation therapies. In this review, we provide a comprehensive understanding of the therapeutic potential of hAECs, including their use for cell replacement therapy as well as secreted cytokine and exosome biotherapy. Moreover, we showed that the powerful immune-regulatory function of hAECs reveals even more possibilities for their application in the treatment of immune-related diseases. In the future, establishing the optimal culture procedure, achieving precise and accurate treatment, and enhancing the therapeutic potential by utilizing appropriate preconditioning and/or biomaterials would be new challenges for further investigation.

Transcriptomic and computational analysis identified LPA metabolism, KLHL14 and KCNE3 as novel regulators of Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is a complex biological program between physiology and pathology. Here, amniotic epithelial cells (AEC) were used as in vitro model of transiently inducible EMT in order to evaluate the transcriptional insights underlying this process. Therefore, RNA-seq was used to identify the differentially expressed genes and enrichment analyses were carried out to assess the intracellular pathways involved. As a result, molecules exclusively expressed in AEC that experienced EMT (GSTA1-1 and GSTM3) or when this process is inhibited (KLHL14 and KCNE3) were identified. Lastly, the network theory was used to obtain a computational model able to recognize putative controller genes involved in the induction and in the prevention of EMT. The results suggested an opposite role of lysophosphatidic acid (LPA) synthesis and degradation enzymes in the regulation of EMT process. In conclusion, these molecules may represent novel EMT regulators and also targets for developing new therapeutic strategies.

Ginsenoside Rg1 as an Effective Regulator of Mesenchymal Stem Cells

Recently, breakthroughs have been made in the use of mesenchymal stem cells (MSCs) to treat various diseases. Several stem cell types have been authorized as drugs by the European Medicines Agency and the U.S. Food and Drug Administration. The Chinese official document “Notification of the management of stem cell clinical research (trial)” was also published in August 2015. Currently, China has approved 106 official stem cell clinical research filing agencies and 62 clinical research projects, which are mostly focused on MSC therapy. Hence, the optimization and development of stem cell drugs is imperative. During this process, maximizing MSC expansion, minimizing cell loss during MSC transplantation, improving the homing rate, precisely regulating the differentiation of MSCs, and reducing MSC senescence and apoptosis are major issues in MSC preclinical research. Similar to artemisinin extracted from the stems and leaves of Artemisia annua, ginsenoside Rg1 (Rg1) is purified from the root or stem of ginseng. In the human body, Rg1 regulates organ function, which is inseparable from its regulation of adult stem cells. Rg1 treatment may effectively regulate the proliferation, differentiation, senescence, and apoptosis of MSCs in different microenvironments in vitro or in vivo. In this review, we discuss recent advances in understanding the effect of Rg1 on MSCs and describe the issues that must be addressed and prospects regarding Rg1 regulation of MSCs in preclinical or clinical studies.

Construction of calcitonin gene-related peptide-modified mesenchymal stem cells and analysis of their effects on the migration and proliferation of vascular smooth muscle cells

Lentiviral expression vectors for calcitonin gene-related peptide (CGRP) were used to transfect rat bone marrow mesenchymal stem cells (MSCs). After assessing the biological characteristics of proliferation and aging in MSCs transfected with CGRP, we observed the effects of the CGRP-modified rat MSCs on the migration and proliferation of rat vascular smooth muscle cells (VSMCs) in vitro. Rat MSCs were isolated, cultured in vitro, and identified by flow cytometry. A CGRP recombinant lentivirus was transfected into MSCs. The transfection efficiency was determined by fluorescence microscopy and flow cytometry, and CGRP in MSCs was detected by real-time quantitative PCR, ELISA, and immunofluorescence. The proliferation and senescence of CGRP-modified MSCs were evaluated by MTT assay and beta-galactosidase staining. VSMCs were isolated, cultured in vitro, and identified by immunofluorescence. CGRP-modified MSCs and VSMCs were cocultured in a Transwell system. The proliferation and migration of VSMCs were evaluated by scratch testing and the MTT method. Rat bone marrow MSCs showed a spindle-shaped morphology, adherent growth in vitro, positive CD29 and CD90 expression, and negative CD45 expression. CGRP was stably expressed in MSCs after 48 h of recombinant lentivirus transfection. CGRP mRNA and protein secretion in CGRP recombinant lentivirus-transfected MSCs were higher than that in control MSCs. Immunofluorescence showed that CGRP protein could be expressed in CGRP-modified MSCs. The proliferation ability and senescence rates did not differ between lentivirus-transfected MSCs and untransfected MSCs. Rat VSMCs expressed α-SMA protein and exhibited a spindle-shaped morphology and adherent growth in vitro. In Transwell coculture experiments, scratch testing of VSMCs showed that CGRP-modified MSCs could reduce VSMC proliferation and migration. The CGRP gene can be stably expressed in MSCs after CGRP recombinant lentivirus transfection. CGRP recombinant lentivirus transfection has little effect on the proliferation or senescence of MSCs, and CGRP-modified MSCs can inhibit the proliferation and migration of VSMCs. These results lay a foundation for research on the use of CGRP gene-engineered MSCs in restenosis therapy.

The effect of human amniotic epithelial cells on urethral stricture fibroblasts

BACKGROUND

Urethral stricture disease (USD) is effectively managed by buccal mucosa (BM) urethroplasty. Lack of adequate healthy BM has led to the use of autologous tissue-engineered BM grafts. Such grafts are costly, not easily scalable and recurrence of the stricture is still a problem. Hence, there is a requirement for cost-effective, scalable cells with innate antifibrotic properties which seem to be fulfilled by human amniotic epithelial cells (HAMECs). The effect of HAMECs on USD is unknown.

AIM

To study the effect of HAMECs-CM on human urethral stricture fibroblast (USF) cells by using in-vitro migration assay and molecular techniques.

MATERIALS AND METHODS

USF cells were derived from six patients undergoing urethroplasty. HAMECs were derived from one placenta after delivery. The effect of HAMECs-CM on USF cell migration was observed using a standard in vitro scratch assay over a period of 3 days. The effect of HAMECs-CM on the expression levels of markers alpha-smooth muscle actin (α-SMA) and tissue inhibitor of metalloproteinases (TIMP-1) in USF cells was also examined.

RESULTS

The HAMECs-CM suppressed the migration of USF cells in in vitro scratch assay. The HAMECs-CM consistently downregulated α-SMA, but not TIMP-1.

CONCLUSIONS

HAMECs have shown antifibrotic activity on USF cells in this in vitro study.

RELEVANCE FOR PATIENTS

HAMECs could serve as an alternative cell source for tissue-engineered urethroplasty.

Icariside II affects hippocampal neuron axon regeneration and improves learning and memory in a chronic cerebral hypoperfusion rat model

Chronic cerebral hypoperfusion (CCH) is a basic pathological process that is comorbid with brain diseases, such as vascular Parkinsonism and Alzheimer's disease. Icariside II (ICS II), which is one of the main metabolites of icariin, has anti-inflammatory and antioxidant effects and protects against ischemic brain injury. This study aims to investigate the neuroprotective effects of ICS II on neuronal axon regeneration-related factors in a CCH rat model. Sprague-Dawley (SD) rats were divided into the following four groups: sham group, model group and 4 and 8 mg/kg/day ICS II administration groups. Learning and spatial memory functions were tested using a Morris water maze. Pathological changes were observed in the rat hippocampal tissue by hematoxylin and eosin (H&E) staining. Neuronal axon regeneration-related proteins (GAP-43, MAP-2 and Nogo-A) were observed by immunohistochemical staining and detected by the average optical density method. The results showed that 8 mg/kg/day of ICS II can effectively reduce the escape latency and prolong the target quadrant residence time at 12 weeks and that ICS II can improve the histopathological changes in the CA1 area of the rat hippocampus. Moreover, ICS II administration at 8 mg/kg/day significantly increased GAP-43 and MAP-2 expression and reduced Nogo-A expression in the CA1 area of the rat hippocampus at 12 weeks; however, significant differences were not observed at 4 and 8 weeks. Hence, ICS II at a dosage of 8 mg/kg/day could promote learning and memory abilities and improve histopathological changes in the rat hippocampus in a CCH rat model. These results may be related to the promotion of neuronal axon regeneration in the CA1 area of the hippocampus under increases in hippocampal GAP-43 and MAP-2 protein expression and decreased Nogo-A protein expression.