Placental stem cells: The promise of curing diseases before birth

Proteomic analysis of human Wharton's jelly mesenchymal stem/stromal cells and human amniotic epithelial stem cells: a comparison of therapeutic potential

Perinatal stem cells have prominent applications in cell therapy and regenerative medicine. Among them, human Wharton's jelly mesenchymal stem/stromal cells (hWJMSCs) and human amniotic epithelial stem cells (hAESCs) have been widely used. However, the distinction in the therapeutic potential of hWJMSCs and hAESCs is poorly understood. In this study, we reported the phenotypic differences between these two distinct cell types and provided the first systematic comparison of their therapeutic potential in terms of immunomodulation, extracellular matrix (ECM) remodelling, angiogenesis and antioxidative stress using proteomics. The results revealed that the two cell types presented different protein expression profiles and were both promising candidates for cell therapy. Both types of cells demonstrated angiogenic and antifibrotic potential, whereas hAESCs presented superior immunological tolerance and antioxidant properties, which were supported by a series of relevant in vitro assays. Our study provides clues for the selection of appropriate cell types for diverse indications in cell therapy, which contributes to the advancement of their clinical translation and application.

Mining human clinical waste as a rich source of stem cells for neural regeneration

Neural diseases are challenging to treat and are regarded as one of the major causes of disability and morbidity in the world. Stem cells can provide a solution, by offering a mechanism to replace damaged circuitry. However, obtaining sufficient cell sources for neural regeneration remains a significant challenge. In recent years, waste-derived stem(-like) cells (WDS-lCs) extracted from both prenatal and adult clinical waste tissues/products, have gained increasing attention for application in neural tissue repair and remodeling. This often-overlooked pool of cells possesses favorable characteristics; including self-renewal, neural differentiation, secretion of neurogenic factors, cost-effectiveness, and low ethical concerns. Here, we offer a perspective regarding the biological properties, extraction protocols, and preclinical and clinical treatments where prenatal and adult WDS-lCs have been utilized for cell replacement therapy in neural applications, and the challenges involved in optimizing these approaches toward patient led therapies.

Impact of Gestational Age on Neuroprotective Function of Placenta-Derived Mesenchymal Stromal Cells

INTRODUCTION

The Management of Myelomeningocele Study demonstrated that in utero repair of myelomeningocele improved motor outcomes compared with postnatal repair. However, even after in utero repair, many children were still unable to walk. We have previously demonstrated that augmentation of in utero repair with early-gestation placental mesenchymal stromal cells (PMSCs) improves motor outcomes in lambs compared with standard in utero repair. The neuroprotective potential of PMSCs of all gestational ages has not been evaluated previously.

METHODS

PMSCs were isolated from discarded first trimester (n = 3), second trimester (n = 3), and term (n = 3) placentas by explant culture. Cytokine array analysis was performed. Secretion of two neurotrophic factors, brain-derived neurotrophic factor and hepatocyte growth factor, was evaluated by enzyme-linked immunosorbent assay. An in vitro neuroprotective assay demonstrated to be associated with in vivo function was performed.

RESULTS

All cell lines secreted immunomodulatory and neuroprotective cytokines and secreted the neurotrophic factors evaluated. Increased neuroprotective capabilities relative to no PMSCs were demonstrated in two of the three first trimester cell lines (5.61, 4.96-6.85, P < 0.0001 and 2.67, 1.67-4.12, P = 0.0046), two of the three second trimester cell lines (2.82, 2.45-3.43, P = 0.0004 and 3.25, 2.62-3.93, P < 0.0001), and two of the three term cell lines (2.72, 2.32-2.92, P = 0.0033 and 2.57, 1.41-4.42, P = 0.0055).

CONCLUSIONS

We demonstrated variation in neuroprotective function between cell lines and found that some cell lines from each trimester had neuroprotective properties. This potentially expands the donor pool of PMSCs for clinical use. Further in-depth studies are needed to understand potential subtle differences in cell function at different gestational ages.

Conditioned medium from primary cytotrophoblasts, primary placenta-derived mesenchymal stem cells, or sub-cultured placental tissue promoted HUVEC angiogenesis in vitro

Background

As a large capillary network, the human placenta plays an important role throughout pregnancy. Placental vascular development is complex and delicate and involves many types of placental cells, such as trophoblasts, and mesenchymal stem cells. There has been no systematic, comparative study on the roles of these two groups of placental cells and the whole placental tissue in the placental angiogenesis. In this study, primary cytotrophoblasts (CTBs) from early pregnancy and primary human placenta-derived mesenchymal stem cells (hPDMSCs) from different stages of pregnancy were selected as the cell research objects, and full-term placental tissue was selected as the tissue research object to detect the effects of their conditioned medium (CM) on human umbilical vein endothelial cell (HUVEC) angiogenesis.

Methods

We successfully isolated primary hPDMSCs and CTBs, collected CM from these placental cells and sub-cultured placental tissue, and then evaluated the effects of the CM on a series of angiogenic processes in HUVECs in vitro. Furthermore, we measured the levels of angiogenic factors in the CM of placental cells or tissue by an angiogenesis antibody array.

Results

The results showed that not only placental cells but also sub-cultured placental tissue, to some extent, promoted HUVEC angiogenesis in vitro by promoting proliferation, adhesion, migration, invasion, and tube formation. We also found that primary placental cells in early pregnancy, whether CTBs or hPDMSCs, played more significant roles than those in full-term pregnancy. Placental cell-derived CM collected at 24 h or 48 h had the best effect, and sub-cultured placental tissue-derived CM collected at 7 days had the best effect among all the different time points. The semiquantitative angiogenesis antibody array showed that 18 of the 43 angiogenic factors had obvious spots in placental cell-derived CM or sub-cultured placental tissue-derived CM, and the levels of 5 factors (including CXCL-5, GRO, IL-6, IL-8, and MCP-1) were the highest in sub-cultured placental tissue-derived CM.

Conclusions

CM obtained from placental cells (primary CTBs or hPDMSCs) or sub-cultured placental tissue contained proangiogenic factors and promoted HUVEC angiogenesis in vitro. Therefore, our research is helpful to better understand placental angiogenesis regulation and provides theoretical support for the clinical application of placental components, especially sub-cultured placental tissue-derived CM, in vascular tissue engineering and clinical treatments.

Application of cattle placental stem cells for treating ovarian follicular cyst

BACKGROUND

High humidity and temperature in Taiwan have significant effects on the reproductivity of Holstein cattle, resulting in the occurrence of bovine ovarian follicular cyst (OFC). Because of economic loss from OFC, manual rupture and hormone injection have been advocated for the management of OFC. However, these incomplete treatments increase hormone resistance in cattle. Mesenchymal stem cells (MSCs) derived from placental stem cells (PSCs) demonstrate potential properties for the treatment of several diseases via promoting angiogenesis and immune modulation.

AIM

To establish the possibility of cattle placental stem cells (CPSCs) as a treatment modality for OFC of cows in Taiwan.

METHODS

The cows with OFC were divided into three groups: control (BC1 and BC2), hormone (H1 and H2), and CPSC (PS1 and PS2) treatment groups. In the hormone treatment group, the cows were given gonadotrophin-releasing hormone (GnRH)-prostaglandin-GnRH intramuscular injection with or without drainage of follicular fluid. In the CPSC treatment group, CPSCs were isolated from the placenta after labor. With the identification of surface antigen on stem cells, the cows were administered ovarian injection of 1 × 10⁶ or 6 × 10⁶ CPSCs with drainage. In all groups, OFC was scanned by ultrasound once a week for a total of seven times. The concentrations of estradiol and progesterone in serum were tested in the same period. The estrus cycle was analyzed by food intake and activity. If estrus was detected, artificial insemination was conducted. Then the cow was monitored by ultrasound for confirmation of pregnancy.

RESULTS

After 7 d of culture, CPSCs were successfully isolated from placental pieces. CPSCs significantly proliferated every 24 h and had high expression of MSC markers such as cluster of differentiation 44, as determined by flow cytometry. Ultrasound showed lower numbers of OFCs with drainage of follicular fluid. We achieved recovery rates of 0%, 50%, 50%, 75%, 75% and 75% in BC1, BC2, H1, H2, PS1, and PS2, respectively. Higher concentrations of progesterone were detected in the CPSC treatment groups. However, both hormone and CPSC treatment groups had no significant difference in the concentration of estradiol. The estrus rate was 0%, 100%, 25%, 75%, 75% and 75% in BC1, BC2, H1, H2, PS1, and PS2, respectively. The two fetuses were born in H2 and PS1. In brief, cows with CPSC injection achieved higher recovery, estrus, and inseminated conception rates.

CONCLUSION

CPSCs have efficacy in treating cows with OFC, and thus, may serve as an alternative treatment for reproductive disorders.

Therapeutic Potential of “Exosomes Derived Multiple Allogeneic Proteins Paracrine Signaling: Exosomes d-MAPPS” is Based on the Effects of Exosomes, Immunosuppressive and Trophic Factors

Due to their differentiation capacity and potent immunosuppressive and pro-angiogenic properties, mesenchymal stem cells (MSCs) have been considered as new therapeutic agents in regenerative medicine. Since most of MSC-mediated beneficent effects are a consequence of their paracrine action, we designed MSC-based product “Exosomes Derived Multiple Allogeneic Proteins Paracrine Signaling (Exosomes d-MAPPS), which activity is based on MSCs-derived growth factors and immunomodulatory cytokines capable to attenuate inflammation and to promote regeneration of injured tissues. Interleukin 1 receptor antagonist (IL-1Ra) and IL-27 were found in high concentrations in Exosomes d-MAPPS samples indicating strong anti-inflammatory and immunosuppressive potential of Exosomes d-MAPPS. Additionally, high concentrations of vascular endothelial growth factor receptor (VEGFR1) and chemokines (CXCL16, CCL21, CXCL14) were noticed at Exosomes d-MAPPS samples suggesting their potential to promote generation of new blood vessels and migration of CXCR6, CCR7 and CXCR4 expressing cells. Since all proteins which were found in high concentration in Exosomes d-MAPPS samples (IL-1Ra, CXCL16, CXCL14, CCL21, IL-27 and VEGFR1) are involved in modulation of lung, eye, and synovial inflammation, Exosomes d-MAPPS samples were prepared as inhalation and ophthalmic solutions in addition to injection formulations; their application in several patients suffering from chronic obstructive pulmonary disease, osteoarthritis, and dry eye syndrome resulted with significant improvement of biochemical and functional parameters. In conclusion, Exosomes d-MAPPS, due to the presence of important anti-inflammatory, immunomodulatory, and pro-angiogenic factors, represents potentially new therapeutic agent in regenerative medicine that should be further tested in large clinical studies.

Neurodevelopment at Age 10 Years of Children Born <28 Weeks With Fetal Growth Restriction

OBJECTIVES

We sought to evaluate the relationships between fetal growth restriction (FGR) (both severe and less severe) and assessments of cognitive, academic, and adaptive behavior brain function at age 10 years.

METHODS

At age 10 years, the Extremely Low Gestational Age Newborns Cohort Study assessed the cognitive function, academic achievement, social-communicative function, psychiatric symptoms, and overall quality of life of 889 children born before 28 weeks' gestation. A pediatric epileptologist also interviewed parents as part of a seizure evaluation. The 52 children whose birth weight z scores were <-2 were classified as having severe FGR, and the 113 whose birth weight z scores were between -2 and -1 were considered to have less severe FGR.

RESULTS

The more severe the growth restriction in utero, the lower the level of function on multiple cognitive and academic achievement assessments performed at age 10 years. Growth-restricted children were also more likely than their extremely preterm peers to have social awareness impairments, autistic mannerisms, autism spectrum diagnoses, difficulty with semantics and speech coherence, and diminished social and psychosocial functioning. They also more frequently had phobias, obsessions, and compulsions (according to teacher, but not parent, report).

CONCLUSIONS

Among children born extremely preterm, those with severe FGR appear to be at increased risk of multiple cognitive and behavioral dysfunctions at age 10 years, raising the possibility that whatever adversely affected their intrauterine growth also adversely affected multiple domains of cognitive and neurobehavioral development.

Mesenchymal stromal cells isolated from gestationally diabetic human placenta exhibit insulin resistance, decreased clonogenicity and angiogenesis

Pregnancy is known to be a diabetogenic state. With sedentary lifestyle and wrong dietary choices, gestational diabetes mellitus is on the rise. This raises a concern as placenta is becoming an acceptable choice, as a source of Mesenchymal Stromal Cells (MSCs). In our current study we questioned whether there exists a difference between MSCs isolated from normal and diabetic (Gd-P-MSCs) placenta, as the health of the cells used in therapy is of prime importance. We isolated and verified the Gd-P-MSCs based on their surface markers and differentiation potential. We looked at viability and proliferation and did not see a difference between the two. We analysed the glucose uptake potential of these cells by assessing the remnant glucose in the media, glucose within the cells by 2-NBDG and by glycogen storage. Despite only a slight downregulation of mRNA expression levels of glucose transporters, Gd-P-MSCs exhibited decreased glucose uptake even upon insulin stimulation and decreased glycogen storage, indicative of an insulin resistant state. We then assessed the colony forming ability of the cells and found a decreased clonogenicity in Gd-P-MSCs. We also examined the angiogenic potential of the cells by tube formation. Gd-P-MSCs showed decreased angiogenic potential when compared to normal cells. Thus we show for the first time, the effect of gestational diabetes on cells isolated from the chorionic villi of term placenta. Gd-P-MSCs are indeed insulin resistant, exhibit decreased clonogenicity and angiogenic potential. The present investigation is of relevance to the choice of sample for MSC isolation for therapeutic purposes.

Stem cell manipulation, gene therapy and the risk of cancer stem cell emergence

Stem cells (SCs) have been extensively studied in the context of regenerative medicine. Human hematopoietic stem cell (HSC)-based therapies have been applied to treat leukemic patients for decades. Handling of mesenchymal stem cells (MSCs) has also raised hopes and concerns in the field of tissue engineering. Lately, discovery of cell reprogramming by Yamanaka's team has profoundly modified research strategies and approaches in this domain. As we gain further insight into cell fate mechanisms and identification of key actors and parameters, this also raises issues as to the manipulation of SCs. These include the engraftment of manipulated cells and the potential predisposition of those cells to develop cancer. As a unique and pioneer model, the use of HSCs to provide new perspectives in the field of regenerative and curative medicine will be reviewed. We will also discuss the potential use of various SCs from embryonic to adult stem cells (ASCs), including induced pluripotent stem cells (iPSCs) as well as MSCs. Furthermore, to sensitize clinicians and researchers to unresolved issues in these new therapeutic approaches, we will highlight the risks associated with the manipulation of human SCs from embryonic or adult origins for each strategy presented.