Clinical predictors of polyps recurring in patients with chronic rhinosinusitis and nasal polyps: a systematic review and meta-analysis

BACKGROUND

Identification of perioperative risk factors for recurrent nasal polyps (RNPs) is important for selection of further treatment and determination of appropriate follow-up period. However, the relative prognostic significance of these risk factors has not been investigated.

METHODOLOGY

We compared the nasal symptoms, endoscopic polyp and Lund-Mackey computed tomography scores, and the laboratory and pathological findings of RNP and non-RNP patients. The risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Patients with poor nasal symptom scores and olfactory dysfunctions and high Lund-Mackey computed tomography scores were at higher risk of postoperative RNPs, as were those with allergic conditions and elevated tissue and serum eosinophil levels. The tissue neutrophil counts/percentages were significantly lower in the RNP than the other group. The tissue eosinophil level was of higher diagnostic utility than the serum eosinophil level. The RNP diagnostic odds ratio afforded by the tissue eosinophil count or percentage was 54.1247. The area under the receiver operating characteristic curve was 0.936. The sensitivity and specificity were 0.8809 and 0.8834, respectively.

CONCLUSION

The tissue eosinophil level reliably predicts RNP after endoscopic sinus surgery.

Increased Hepatocyte Growth Factor Secretion by Placenta-Derived Mesenchymal Stem Cells Improves Ovarian Function in an Ovariectomized Rat Model via Vascular Remodeling by Wnt Signaling Activation

The vascular network contributes to the development of follicles. However, the therapeutic mechanism between vascular remodeling and ovarian functions is still unclear. Therefore, we demonstrated whether increased HGF by placenta-derived mesenchymal stem cells (PD-MSCs) improves ovarian function in an ovariectomized rat model via vascular remodeling by Wnt signaling activation. We established a half-ovariectomized rat model in which damaged ovaries were induced by ovariectomy of half of each ovary, and PD-MSCs (5 × 105 cells) were transplanted by intravenous injection. Three weeks after transplantation, rats in all groups were sacrificed. We examined the secretion of HGF by PD-MSCs through culture medium. The vascular structure in injured ovarian tissues was restored to a greater extent in the PD-MSC transplantation (Tx) group than in the nontransplantation (NTx) group (* p < 0.05). The expression of genes related to Wnt signaling (e.g., LRP6, GSK3β, β-catenin) was significantly increased in the Tx group compared to the NTx group (* p < 0.05). However, the expression of genes related to vascular permeability (e.g., Asef, ERG3) was significantly decreased in the Tx group compared to the NTx group (* p < 0.05). Follicular development was improved in the Tx group compared to the NTx group (* p < 0.05). Furthermore, to evaluate vascular function, we cocultivated PD-MSCs after human umbilical vein endothelial cells (HUVECs) with lipopolysaccharide (LPS), and we analyzed the vascular formation assay and dextran assay in HUVECs. Cocultivation of PD-MSCs with injured HUVECs enhanced vascular formation and decreased endothelial cell permeability (* p < 0.05). Also, cocultivation of PD-MSCs with explanted ovarian tissues improved follicular maturation compared to cocultivation of the Wnt inhibitor-treated PD-MSCs with explanted ovarian tissues. Therefore, HGF secreted by PD-MSCs improved ovarian function in rats with ovarian dysfunction by decreasing vascular permeability via Wnt signaling.

Deficiency of HtrA4 in BeWo cells downregulates angiogenesis through IL-6/JAK/STAT3 signaling

In a previous study, we investigated the effects of high-temperature requirement factor A4 (HtrA4) deficiency on trophoblasts using the BeWo KO cell line. However, the effects of this deficiency on angiogenesis remain unclear. To explore the role of HtrA4 in angiogenesis, HUVECs were co-cultured with wild-type BeWo cells (BeWo WT), BeWo KO, and HtrA4-rescued BeWo KO (BeWo KO-HtrA4 rescue) cells. Dil staining and dextran analysis revealed that HUVECs co-cultured with BeWo KO formed tubes, but they were often disjointed compared to those co-cultured with BeWo WT, BeWo KO-HtrA4 rescue, and HUVECs controls. RT-PCR, ELISA, and western blot analysis were performed to assess angiogenesis-related factors at the mRNA and protein levels. HtrA4 deficiency inhibited IL-6 expression in trophoblasts, and the reduced secretion of IL-6 decreases VEGFA expression in HUVECs by modulating the JAK2/STAT3 signaling pathway to prevent tube formation. Moreover, rescuing HtrA4 expression restored the HUVEC tube formation ability. Interestingly, IL-6 expression was lower in supernatants with only cultured HUVECs than in co-cultured HUVECs with BeWo WT cells, but the HUVEC tube formation ability was similar. These findings suggest that the promoting angiogenesis-related signaling pathway differs between only HUVECs and co-cultured HUVECs, and that the deficiency of HtrA4 weakens the activation of the IL-6/JAK/STAT3/VEGFA signaling pathway, reducing the ability of tube formation in HUVECs. HtrA4 deficiency in trophoblasts hinders angiogenesis and may contribute to placental dysfunction.

The Dose-Related Efficacy of Human Placenta-Derived Mesenchymal Stem Cell Transplantation on Antioxidant Effects in a Rat Model with Ovariectomy

Oxidative stress initiates various degenerative diseases, and it is caused by excessive reactive oxygen species (ROS) production. Oxidative stress is a key factor that causes infertility by inducing ovarian dysfunction, characterized by irregular hormone levels, lower quality of mature follicles, and loss of follicles. Hence, stem cell therapy has been actively studied as an approach to overcome the side effects of hormone replacement therapy (HRT) on ovarian dysfunction. However, there is a lack of evidence about the appropriate number of cells required for stem cell therapy. Therefore, based on the antioxidant effects investigated in this study, we focused on determining the appropriate dose of stem cells for transplantation in an animal model with ovarian dysfunction. One week after half-ovariectomy, placenta-derived mesenchymal stem cells (PD-MSCs, 1 × 105 cells, 5 × 105 cells, or 2.5 × 106 cells) were injected intravenously into the Tx groups through the tail vein. As a result, the mRNA expression of hAlu gradually increased as the transplanted cell concentration increased. Compared with no transplantation (NTx), the transplantation of PD-MSCs improved folliculogenesis, including the levels of secreted hormones and numbers of follicles, by exerting antioxidant effects. Also, the levels of oxidized glutathione in the serum of animal models after transplantation were significantly increased (* p < 0.05). These results indicated that PD-MSC transplantation improved ovarian function in half-ovariectomized rats by exerting antioxidant effects. According to our data, increasing the number of transplanted cells did not proportionally increase the effectiveness of the treatment. We suggest that low-dose PD-MSC transplantation has the same therapeutic effect as described in previous studies. These findings provide new insights for further understanding reproductive systems and provide evidence for related clinical trials.

Hypoxia disrupt tight junctions and promote metastasis of oral squamous cell carcinoma via loss of par3

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a highly malignant tumor that is frequently associated with lymph node metastasis, resulting in poor prognosis and survival in patients. In the tumor microenvironment, hypoxia plays an important role in regulating cellular responses such as progressive and rapid growth and metastasis. In these processes, tumor cells autonomously undergo diverse transitions and acquire functions. However, hypoxia-induced transition of OSCC and the involvement of hypoxia in OSCC metastasis remain unclear. Therefore, in this study, we aimed to elucidate the mechanism of hypoxia-induced OSCC metastasis and particularly, its impact on tight junctions (TJs).

METHODS

The expression of hypoxia-inducible factor 1-alpha (HIF-1α) was detected in tumor tissues and adjacent normal tissues from 29 patients with OSCC using reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry (IHC). The migration and invasion abilities of OSCC cell lines treated with small interfering (si)RNA targeting HIF-1α or cultured in hypoxic conditions were analyzed using Transwell assays. The effect of HIF-1α expression on in vivo tumor metastasis of OSCC cells was evaluated using lung metastasis model.

RESULTS

HIF-1α was overexpressed in patients with OSCC. OSCC metastasis was correlated with HIF-1α expression in OSCC tissues. Hypoxia increased the migration and invasion abilities of OSCC cell lines by regulating the expression and localization of partitioning-defective protein 3 (Par3) and TJs. Furthermore, HIF-1α silencing effectively decreased the invasion and migration abilities of OSCC cell lines and restored TJ expression and localization via Par3. The expression of HIF-1α was positively regulated the OSCC metastasis in vivo.

CONCLUSIONS

Hypoxia promotes OSCC metastasis by regulating the expression and localization of Par3 and TJ proteins. HIF-1α positively correlates to OSCC metastasis. Lastly, HIF-1α expression could regulate the expression of Par3 and TJs in OSCC. This finding may aid in elucidating the molecular mechanisms of OSCC metastasis and progression and developing new diagnostic and therapeutic approaches for OSCC metastasis.

Increased PRL-1 in BM-derived MSCs triggers anaerobic metabolism via mitochondria in a cholestatic rat model

Mesenchymal stem cell (MSC) therapy in chronic liver disease is associated with mitochondrial anaerobic metabolism. Phosphatase of regenerating liver-1 (PRL-1), known as protein tyrosine phosphatase type 4A, member 1 (PTP4A1), plays a critical role in liver regeneration. However, its therapeutic mechanism remains obscure. The aim of this study was to establish genetically modified bone marrow (BM)-MSCs overexpressing PRL-1 (BM-MSCs^PRL-1) and to investigate their therapeutic effects on mitochondrial anaerobic metabolism in a bile duct ligation (BDL)-injured cholestatic rat model. BM-MSCs^PRL-1 were generated with lentiviral and nonviral gene delivery systems and characterized. Compared with naive cells, BM-MSCs^PRL-1 showed an improved antioxidant capacity and mitochondrial dynamics and decreased cellular senescence. In particular, mitochondrial respiration in BM-MSCs^PRL-1 generated using the nonviral system was significantly increased as well as mtDNA copy number and total ATP production. Moreover, transplantation of BM-MSCs^PRL-1 generated using the nonviral system had predominantly antifibrotic effects and restored hepatic function in a BDL rat model. Decreased cytoplasmic lactate and increased mitochondrial lactate upon the administration of BM-MSCs^PRL-1 indicated significant alterations in mtDNA copy number and ATP production, activating anaerobic metabolism. In conclusion, BM-MSCs^PRL-1 generated by a nonviral gene delivery system enhanced anaerobic mitochondrial metabolism in a cholestatic rat model, improving hepatic function.

Increased phosphatase regenerating liver-1 trigger vascular remodeling in injured ovary via platelet-derived growth factor signaling pathway

Background

Vascular abnormalities in the ovary cause infertility accompanied by ovarian insufficiency due to a microenvironment of barren ovarian tissues. Placenta-derived mesenchymal stem cells (PD-MSCs, Naïve) treatment in ovarian dysfunction shows angiogenic effect, however, the therapeutic mechanism between ovarian function and vascular remodeling still unclear. Therefore, we examined whether by phosphatase regenerating liver-1 (PRL-1), which is correlated with angiogenesis in reproductive systems, overexpressed PD-MSCs could maximize the angiogenic effects in an ovarian tissues injured of rat model with partial ovariectomy and their therapeutic mechanism by enhanced vascular function via PDGF signaling.

Methods

PD-MSCs^PRL-1 (PRL-1) were generated by nonviral AMAXA gene delivery system and analyzed the vascular remodeling and follicular development in ovary. One week after Sprague–Dawley (SD) rats ovariectomy, Naïve and PRL-1 was transplanted. The animals were sacrificed at 1, 3 and 5 weeks after transplantation and vascular remodeling and follicular development were analyzed. Also, human umbilical vein endothelial cells (HUVECs) and ovarian explantation culture were performed to prove the specific effects and mechanism of PRL-1.

Results

Vascular structures in ovarian tissues (e.g., number of vessels, thickness and lumen area) showed changes in the Naïve and PRL-1-overexpressed PD-MSC (PRL-1) transplantation (Tx) groups compared to the nontransplantation (NTx) group. Especially, PRL-1 induce to increase the expression of platelet-derived growth factor (PDGF), which plays a role in vascular remodeling as well as follicular development, compared to the NTx. Also, the expression of genes related to pericyte and vascular permeability in arteries was significantly enhanced in the PRL-1 compared to the NTx (p < 0.05). PRL-1 enhanced the vascular formation and permeability of human umbilical vein endothelial cells (HUVECs) via activated the PDGF signaling pathway.

Conclusions

Our results show that PRL-1 restored ovarian function by enhanced vascular function via PDGF signaling pathway. These findings offer new insight into the effects of functionally enhanced stem cell therapy for reproductive systems and should provide new avenues to develop more efficient therapies in degenerative medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02772-9.

Increased Phosphatase of Regenerating Liver-1 by Placental Stem Cells Promotes Hepatic Regeneration in a Bile-Duct-Ligated Rat Model

Phosphatase of regenerating liver-1 (PRL-1) controls various cellular processes and liver regeneration. However, the roles of PRL-1 in liver regeneration induced by chorionic-plate-derived mesenchymal stem cells (CP-MSCs) transplantation remain unknown. Here, we found that increased PRL-1 expression by CP-MSC transplantation enhanced liver regeneration in a bile duct ligation (BDL) rat model by promoting the migration and proliferation of hepatocytes. Engrafted CP-MSCs promoted liver function via enhanced hepatocyte proliferation through increased PRL-1 expression in vivo and in vitro. Moreover, higher increased expression of PRL-1 regulated CP-MSC migration into BDL-injured rat liver through enhancement of migration-related signals by increasing Rho family proteins. The dual effects of PRL-1 on proliferation of hepatocytes and migration of CP-MSCs were substantially reduced when PRL-1 was silenced with siRNA-PRL-1 treatment. These findings suggest that PRL-1 may serve as a multifunctional enhancer for therapeutic applications of CP-MSC transplantation.

Expression of miRNAs Targeting ATP Binding Cassette Transporter 1 (ABCA1) among Patients with Significant Carotid Artery Stenosis

Background: Carotid artery stenosis is a dynamic process associated with an increased risk of cardiovascular events. However, knowledge of biomarkers useful for identifying and quantifying high-risk carotid plaques associated with the increased incidence of cerebrovascular events is insufficient. Therefore, the objectives of this study were to evaluate the expression of ATP binding cassette transporter 1 (ABCA1) and validate its target microRNA (miRNA) candidates in human carotid stenosis arteries to identify its potential as a biomarker. Methods: In human carotid stenosis arterial tissues and plasma, the expression of ABCA1 and its target miRNAs (miRNA-33a-5p, 33b-5p, and 148a-3p) were evaluated by quantitative real time-polymerase chain reaction (qRT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA). Results: The expression of ABCA1 was significantly decreased in the plasma of stenosis patients, but its expression was not different in arterial tissues (p < 0.05). However, significantly more target miRNAs were secreted by stenosis patients than normal patients (p < 0.05). Interestingly, lipotoxicity induced by the oleic and palmitic acid (OAPA) or lipopolysaccharide (LPS) treatment of human umbilical vein endothelial cells (HUVECs) dramatically enhanced the gene expression of adipogenic and inflammatory factors, whereas ABCA1 expression was significantly decreased. Conclusions: Therefore, miRNA-33a-5p, 33b-5p, and 148a-3p represent possible biomarkers of carotid artery stenosis by directly targeting ABCA1.

PRL-1 overexpressed placenta-derived mesenchymal stem cells suppress adipogenesis in Graves' ophthalmopathy through SREBP2/HMGCR pathway

Background

Graves’ ophthalmopathy (GO) is a disorder, in which orbital connective tissues get in inflammation and increase in volume. Stimulants such as thyroid-stimulating hormone (TSH), insulin-like growth factor 1(IGF-1), IL-1, interferon γ, and platelet-derived growth factor cause differentiation into adipocytes of orbital fibroblasts (OFs) in the orbital fat and extraocular muscles. Human placental mesenchymal stem cells (hPMSCs) are known to have immune modulation effects on disease pathogenesis. Some reports suggest that hPMSCs can elicit therapeutic effects, but to date, research on this has been insufficient. In this study, we constructed PRL-1 overexpressed hPMSCs (hPMSCs^PRL-1) in an attempt to enhance the suppressive function of adipogenesis in GO animal models.

Methods

In order to investigate the anti-adipogenic effects, primary OFs were incubated with differentiation medium for 10 days. After co-culturing with hPMSCs^PRL-1, the characteristics of the OFs were analyzed using Nile red stain and quantitative real-time polymerase chain reaction. We then examined the in vivo regulatory effectiveness of hPMSCs^PRL-1 in a GO mouse model that immunized by leg muscle electroporation of pTriEx1.1Neo-hTSHR A-subunit plasmid. Human PMSCs^PRL-1 injection was performed in left orbit. We also analyzed the anti-adipogenic effects of hPMSCs^PRL-1 in the GO model.

Results

We found that hPMSCs^PRL-1 inhibited adipogenic activation factors, specifically PPARγ, C/EBPα, FABP4, SREBP2, and HMGCR, by 75.1%, 50%, 79.6%, 81.8%, and 87%, respectively, compared with naïve hPMSCs in adipogenesis-induced primary OFs from GO. Moreover, hPMSCs^PRL-1 more effectively inhibited adipogenic factors ADIPONECTIN and HMGCR by 53.2% and 31.7%, respectively, than hPMSCs, compared with 15.8% and 29.8% using steroids in the orbital fat of the GO animal model.

Conclusion

Our findings suggest that hPMSCs^PRL-1 would restore inflammation and adipogenesis of GO model and demonstrate that they could be applied as a novel treatment for GO patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02337-2.

MIT-001 Restores Human Placenta-Derived Mesenchymal Stem Cells by Enhancing Mitochondrial Quiescence and Cytoskeletal Organization

Inflammation is a major cause of several chronic diseases and is reported to be recovered by the immuno-modulation of mesenchymal stem cells (MSCs). While most studies have focussed on the anti-inflammatory roles of MSCs in stem cell therapy, the impaired features of MSCs, such as the loss of homeostasis by systemic aging or pathologic conditions, remain incompletely understood. In this study, we investigated whether the altered phenotypes of human placenta-derived MSCs (hPD-MSCs) exposed to inflammatory cytokines, including TNF-α and IFN-γ, could be protected by MIT-001, a small anti-inflammatory and anti-necrotic molecule. MIT-001 promoted the spindle-like shape and cytoskeletal organization extending across the long cell axis, whereas hPD-MSCs exposed to TNF-α/IFN-γ exhibited increased morphological heterogeneity with an abnormal cell shape and cytoskeletal disorganization. Importantly, MIT-001 improved mitochondrial distribution across the cytoplasm. MIT-001 significantly reduced basal respiration, ATP production, and cellular ROS levels and augmented the spare respiratory capacity compared to TNF-α/IFN-γ-exposed hPD-MSCs, indicating enhanced mitochondrial quiescence and homeostasis. In conclusion, while TNF-α/IFN-γ-exposed MSCs lost homeostasis and mitochondrial quiescence by becoming over-activated in response to inflammatory cytokines, MIT-001 was able to rescue mitochondrial features and cellular phenotypes. Therefore, MIT-001 has therapeutic potential for clinical applications to treat mitochondrion-related inflammatory diseases.

PEDF-Mediated Mitophagy Triggers the Visual Cycle by Enhancing Mitochondrial Functions in a H2O2-Injured Rat Model

Retinal degenerative diseases result from oxidative stress and mitochondrial dysfunction, leading to the loss of visual acuity. Damaged retinal pigment epithelial (RPE) and photoreceptor cells undergo mitophagy. Pigment epithelium-derived factor (PEDF) protects from oxidative stress in RPE and improves mitochondrial functions. Overexpression of PEDF in placenta-derived mesenchymal stem cells (PD-MSCs; PD-MSCs^PEDF) provides therapeutic effects in retinal degenerative diseases. Here, we investigated whether PD-MSCs^PEDF restored the visual cycle through a mitophagic mechanism in RPE cells in hydrogen peroxide (H₂O₂)-injured rat retinas. Compared with naïve PD-MSCs, PD-MSCs^PEDF augmented mitochondrial biogenesis and translation markers as well as mitochondrial respiratory states. In the H₂O₂-injured rat model, intravitreal administration of PD-MSCs^PEDF restored total retinal layer thickness compared to that of naïve PD-MSCs. In particular, PTEN-induced kinase 1 (PINK1), which is the major mitophagy marker, exhibited increased expression in retinal layers and RPE cells after PD-MSC^PEDF transplantation. Similarly, expression of the visual cycle enzyme retinol dehydrogenase 11 (RDH11) showed the same patterns as PINK1 levels, resulting in improved visual activity. Taken together, these findings suggest that PD-MSCs^PEDF facilitate mitophagy and restore the loss of visual cycles in H₂O₂-injured rat retinas and RPE cells. These data indicate a new strategy for next-generation MSC-based treatment of retinal degenerative diseases.

Vascular remodeling by placenta-derived mesenchymal stem cells restores ovarian function in ovariectomized rat model via the VEGF pathway

Angiogenesis plays an important role in damaged organ or tissue and cell regeneration and ovarian development and function. Primary ovarian insufficiency (POI) is a prevalent pathology in women under 40. Conventional treatment for POI involves hormone therapy. However, due to its side effects, an alternative approach is desirable. Human mesenchymal stem cells (MSCs) from various sources restore ovarian function; however, they have many limitations as stem cell sources. Therefore, it is desirable to study the efficacy of placenta-derived MSCs (PD-MSCs), which possess many advantages over other MSCs, in a rat model of ovarian dysfunction. Here, we investigated the restorative effect of PD-MSCs on injured ovaries in ovariectomized (OVX) rats and the ability of intravenous transplantation (Tx) of PD-MSCs (5 × 105) to enhance ovarian vasculature and follicular development. ELISA analysis of serum revealed that compared to the non-transplantation (NTx) group, the Tx group showed significantly increased levels of anti-Müllerian hormone, follicle stimulating hormone, and estradiol (E2) (*P < 0.05). In addition, histological analysis showed more mature follicles and less atresia and restoration of expanded blood vessels in the ovaries of the OVX PD-MSC Tx group than those of the NTx group (*P < 0.05). Furthermore, folliculogenesis-related gene expression was also significantly increased in the PD-MSC Tx group (*P < 0.05). Vascular endothelial growth factor (VEGF) and VEGF receptor 2 expressions were increased in the ovaries of the OVX PD-MSC Tx group compared to the NTx group through PI3K/AKT/mTOR and GSK3β/β-catenin pathway activation. Interestingly, ex vivo cocultivation of damaged ovaries and PD-MSCs or treatment with recombinant VEGF (50 ng/ml) increased folliculogenic factors and VEGF signaling pathways. Notably, compared to recombinant VEGF, PD-MSCs significantly increased folliculogenesis and angiogenesis (*P < 0.05). These findings suggest that VEGF secreted by PD-MSCs promotes follicular development and ovarian function after OVX through vascular remodeling. Therefore, these results provide fundamental data for understanding the therapeutic effects and mechanism of stem cell therapy based on PD-MSCs and provide a theoretical foundation for their application for obstetrical and gynecological diseases, including infertility and menopause.

Efficacy of Gene Modification in Placenta-Derived Mesenchymal Stem Cells Based on Nonviral Electroporation

Mesenchymal stem cell (MSC)-based therapy using gene delivery systems has been suggested for degenerative diseases. Although MSC-based clinical applications are effective and safe, the mode of action remains unclear. Researchers have commonly applied viral-based gene modification because this system has efficient vehicles. While viral transfection carries many risks, such as oncogenes and chromosomal integration, nonviral gene delivery techniques are less expensive, easier to handle, and safe, although they are less efficient. The electroporation method, which uses Nucleofection technology, provides critical opportunities for hard-to-transfect primary cell lines, including MSCs. Therefore, to improve the therapeutic efficacy using genetically modified MSCs, researchers must determine the optimal conditions for the introduction of the Nucleofection technique in MSCs. Here, we suggest optimal methods for gene modification in PD-MSCs using an electroporation gene delivery system for clinical application.

Human placenta-derived mesenchymal stem cells induce trophoblast invasion via dynamic effects on mitochondrial function

The trophoblast is a critical cell for placental development and embryo implantation in the placenta. We previously reported that placenta‐derived mesenchymal stem cells (PD‐MSCs) increase trophoblast invasion through several signaling pathways. However, the paracrine effects of PD‐MSCs on mitochondrial function in trophoblasts are still unclear. Therefore, the objective of the study was to analyze the mitochondrial function of trophoblasts in response to cocultivation with PD‐MSCs. The results showed that PD‐MSCs regulate the balance between cell survival and death and protect damaged mitochondria in trophoblasts from oxidative stress. Moreover, PD‐MSCs upregulate factors involved in mitochondrial autophagy in trophoblast cells. Finally, PD‐MSCs improve trophoblast invasion. Taken together, the data indicate that PD‐MSCs can regulate trophoblast invasion through dynamic effects on mitochondrial energy metabolism. These results support the fundamental role of mitochondrial energy mechanism in trophoblast invasion and suggest a new therapeutic strategy for infertility.

Formyl Peptide Receptor 2 Alleviates Hepatic Fibrosis in Liver Cirrhosis by Vascular Remodeling

Hexapeptide WKYMVm (Trp-Lys-Tyr-Met-Val-D-Met), a ligand of formyl peptide receptor 2, exhibits anti-inflammatory and angiogenic properties in disease models. However, the therapeutic effects of WKYMVm on hepatic fibrosis have not been evaluated to date. Therefore, we investigated whether WKYMVm exerts antifibrotic effects and induces vascular regeneration in a rat model of bile duct ligation (BDL). The antifibrotic and angiogenic effects of WKYMVm on liver regeneration in the BDL rat model were analyzed using biochemical assays, qRT-PCR, western blotting, immunofluorescence, and immunohistochemistry. To determine the effects of WKYMVm on hepatic fibrosis and angiogenesis in vitro, we measured the expression levels of fibrotic factors in hepatic stellate cells (HSCs) and angiogenic factors in human umbilical vein endothelial cells (HUVECs). WKYMVm attenuated the expression of collagen type I (Col I) and α-smooth muscle actin (α-SMA) and significantly increased the levels of angiogenetic factors in the BDL model (p < 0.05). WKYMVm reduced fibrotic marker expression in transforming growth factor (TGF)-β-induced HSCs and promoted angiogenic activity through tube formation in 5-Fluorouracil (FU)-treated HUVECs (p < 0.05). Also, WKYMVm administration enhanced hepatocyte proliferation in BDL rats (p < 0.05). The WKYMVm alleviates hepatic fibrosis by inhibiting HSC activation and promotes hepatic regeneration via vascular remodeling. These data suggest that the WKYMVm may be a new therapeutic agent for liver fibrosis.

Alteration of Pituitary Tumor Transforming Gene 1 by MicroRNA-186 and 655 Regulates Invasion Ability of Human Oral Squamous Cell Carcinoma

Background: Pituitary tumor-transforming gene 1 (PTTG1) was recently shown to be involved in the progression as well as the metastasis of cancers. However, their expression and function in the invasion of oral squamous cell carcinoma (SCC) remain unclear. Methods: The expressions of PTTG1 and PTTG1-targeted miRNA in oral SCC cell lines and their invasion capability depended on PTTG1 expression were analyzed by quantitative RT-PCR, Western blots, the transwell insert system and Zymography. Results: Invasion abilities were decreased in oral SCC cells treated with siRNA-PTTG1. When PTTG1 were downregulated in oral SCC cells treated with microRNA-186 and -655 inhibited their invasion abilities via MMP-9 activity. Conclusions: These results indicate that alteration of expression of PTTG1 in oral SCC cells by newly identified microRNA-186 and -655 can regulate invasion activity. Therefore, these data offer new insights into further understanding PTTG1 function in oral SCC and should provide new strategies for diagnostic markers for oral SCC.

Overexpression of pigment epithelium-derived factor in placenta-derived mesenchymal stem cells promotes mitochondrial biogenesis in retinal cells

Pigment epithelium-derived factor (PEDF) plays a role in protecting retinal pigment epithelial (RPE) cells from oxidative stress (OS), a causative factor of RPE cell death. Genetically modified mesenchymal stem cells (MSCs) can be used to treat critical and incurable retinal diseases. Here, we overexpressed PEDF in placenta-derived MSCs (PD-MSCsPEDF, PEDF+) using a nonviral gene delivery system and evaluated the characteristics of PD-MSCsPEDF and their potential regenerative effects on RPE cells damaged by H2O2-induced OS. PD-MSCsPEDF maintained their stemness, cell surface marker, and differentiation potential characteristics. Compared to naive cells, PD-MSCsPEDF promoted mitochondrial respiration by enhancing biogenesis regulators (e.g., NRF1, PPARGC1A, and TFAM) as well as antioxidant enzymes (e.g., HMOXs, SODs, and GPX1). Compared to OS-damaged RPE cells cocultured with naive cells, OS-damaged RPE cells cocultured with PD-MSCsPEDF showed PEDF upregulation and VEGF downregulation. The expression levels of antioxidant genes and RPE-specific genes, such as RPE65, RGR, and RRH, were significantly increased in RPE cells cocultured with PD-MSCsPEDF. Furthermore, OS-damaged RPE cells cocultured with PD-MSCsPEDF had dramatically enhanced mitochondrial functions, and antiapoptotic effects improved due to cell survival signaling pathways. In the H2O2-induced retinal degeneration rat model, compared to administration of the naive counterpart, intravitreal administration of PD-MSCsPEDF alleviated proinflammatory cytokines and restored retinal structure and function by increasing PEDF expression and decreasing VEGF expression. Intravitreal administration of PD-MSCsPEDF also protected retinal degeneration against OS by increasing antioxidant gene expression and regulating the mitochondrial ROS levels and biogenesis. Taken together, PEDF overexpression in PD-MSCs improved the mitochondrial activities and induced OS-damaged RPE cell regeneration by regulating the oxidative status and mitochondrial biogenesis in vitro and in vivo. These data suggest that genetic modification of PEDF in PD-MSCs might be a new cell therapy for the treatment of retinal degenerative diseases.

Human placenta-derived mesenchymal stem cells trigger repair system in TAA-injured rat model via antioxidant effect

Oxidative stress induces damages of various cell types or tissues through a repetitive imbalance between the systemic manifestation of reactive oxygen species (ROS) and detoxification of the reactive intermediates. Thioacetamide (TAA) is well known for causing several degenerative diseases by oxidative stress. However, study of the antioxidant mechanisms of stem cells in TAA-injured rat model is insufficient. Therefore, we investigated the effect of placenta-derived mesenchymal stem cells (PD-MSCs) transplantation on liver and ovary of TAA-injured rat models to study the antioxidant effect in degenerative diseases. In TAA-injured rat model, PD-MSCs engrafted into damaged organ including liver and ovary in PD-MSCs transplanted groups (Tx) compared with non-transplanted groups (NTx) (*p<0.05). Transplanted PD-MSCs reduced inflammatory factors and upregulated oxidative stress factors in Tx compared with NTx (*p<0.05). Also, transplanted PD-MSCs enhanced antioxidants factors and organ functional restoration factors in Tx compared with NTx. These data show that PD-MSC transplantation triggers the regeneration of organ (e.g., liver and ovary) damaged by oxidative stress from TAA treatment via activating antioxidant factors. Therefore, these data suggest the therapeutic potential via antioxidant effect and help understand the therapeutic mechanism of PD-MSCs in damaged tissues such as in liver and reproductive system.

Upregulation of C-Reactive Protein by Placenta-Derived Mesenchymal Stem Cells Promotes Angiogenesis in A Rat Model with Cirrhotic Liver

Background and Objectives

Liver cirrhosis is accompanied by abnormal vascular shunts. The Wnt pathway is essential for endothelial cell survival and proliferation. C-reactive protein (CRP), which is produced by hepatocyte, activates angiogenesis in cardiovascular diseases.

Methods and Results

The expression of CRP in CCl₄-injured rat livers was detected using qRT-PCR and Western blotting after transplantation of placenta-derived mesenchymal stem cells (PD-MSCs) into rats. To determine whether CRP functions in hepatic regeneration by promoting angiogenesis through the Wnt pathway, we detected VEGF and β-catenin in liver tissues and BrdU and β-catenin in hepatocytes by immunofluorescence. The expression levels of CRP, Wnt pathway-related and angiogenic factors were increased in CCl₄-injured and PD-MSCs transplanted rat livers. In vitro, the expression levels of Wnt signaling and angiogenic factors were decreased in siRNA-CRP-transfected rat hepatocytes.

Conclusions

CRP upregulation by PD-MSCs participates in vascular remodeling to promote liver regeneration via the Wnt signaling pathway during hepatic failure.

Enhanced PRL-1 expression in placenta-derived mesenchymal stem cells accelerates hepatic function via mitochondrial dynamics in a cirrhotic rat model

BACKGROUND

Placenta-derived mesenchymal stem cells (PD-MSCs) have been highlighted as an alternative cell therapy agent that has become a next-generation stem cell treatment. Phosphatase of regenerating liver-1 (PRL-1), an immediate early gene, plays a critical role during liver regeneration. Here, we generated enhanced PRL-1 in PD-MSCs (PD-MSCs^PRL-1, PRL-1+) using lentiviral and nonviral gene delivery systems and investigated mitochondrial functions by PD-MSC^PRL-1 transplantation for hepatic functions in a rat bile duct ligation (BDL) model.

METHODS

PD-MSCs^PRL-1 were generated by lentiviral and nonviral AMAXA gene delivery systems and analyzed for their characteristics and mitochondrial metabolic functions. Liver cirrhosis was induced in Sprague-Dawley (SD) rats using common BDL for 10 days. PKH67+ naïve and PD-MSCs^PRL-1 using a nonviral sysyem (2 × 10⁶ cells/animal) were intravenously administered into cirrhotic rats. The animals were sacrificed at 1, 2, 3, and 5 weeks after transplantation and engraftment of stem cells, and histopathological analysis and hepatic mitochondrial functions were performed.

RESULTS

PD-MSCs^PRL-1 were successfully generated using lentiviral and nonviral AMAXA systems and maintained characteristics similar to those of naïve cells. Compared with naïve cells, PD-MSCs^PRL-1 improved respirational metabolic states of mitochondria. In particular, mitochondria in PD-MSCs^PRL-1 generated by the nonviral AMAXA system showed a significant increase in the respirational metabolic state, including ATP production and mitochondrial biogenesis (*p < 0.05). Furthermore, transplantation of PD-MSCs^PRL-1 using a nonviral AMAXA system promoted engraftment into injured target liver tissues of a rat BDL cirrhotic model and enhanced the metabolism of mitochondria via increased mtDNA and ATP production, thereby improving therapeutic efficacy.

CONCLUSIONS

Our findings will further our understanding of the therapeutic mechanism of enhanced MSCs and provide useful data for the development of next-generation MSC-based cell therapy and therapeutic strategies for regenerative medicine in liver disease.

Microenvironmental changes induced by placenta-derived mesenchymal stem cells restore ovarian function in ovariectomized rats via activation of the PI3K-FOXO3 pathway

Background

Translational studies have explored the therapeutic potential and feasibility of mesenchymal stem cells (MSCs) in several degenerative diseases; however, mechanistic studies of the function of these cells have been insufficient. As ovarian failure causes anovulation as well as ovarian steroid hormonal imbalances, the specific aims of this study were to analyze the therapeutic role of placenta-derived MSCs (PD-MSCs) in an ovarian failure ovariectomy (OVX) rat model and evaluate whether PD-MSC transplantation (Tx) improved folliculogenesis and oocyte maturation in the injured ovary through PI3K/Akt and FOXO signaling.

Methods

Blood and ovary tissue were collected and analyzed after various PD-MSC Tx treatments in an ovariectomized rat model. Changes in the expression of folliculogenesis- and ovary regeneration-related genes induced by PD-MSC treatments were analyzed by qRT-PCR, Western blotting, and histological analysis.

Results

The levels of hormones related to ovary function were significantly increased in the PD-MSC Tx groups compared with those in the nontransplantation group (NTx). The follicle numbers in the ovarian tissues were increased along with the increased expression of genes related to folliculogenesis in the PD-MSC Tx groups compared with the NTx groups. Furthermore, Tx PD-MSCs induced follicle maturation by increasing the phosphorylation of GSK3 beta and FOXO3 (p < 0.05) and shifting the balance of growth and apoptosis in oocytes.

Conclusions

Taken together, these results show that PD-MSC Tx can restore ovarian function and induce ovarian folliculogenesis via the PI3K/Akt and FOXO signaling pathway.

Mitochondrial Dynamics in Placenta-Derived Mesenchymal Stem Cells Regulate the Invasion Activity of Trophoblast

Mitochondrial dynamics are involved in many cellular events, including the proliferation, differentiation, and invasion/migration of normal as well as cancerous cells. Human placenta-derived mesenchymal stem cells (PD-MSCs) were known to regulate the invasion activity of trophoblasts. However, the effects of PD-MSCs on mitochondrial function in trophoblasts are still insufficiently understood. Therefore, the objectives of this study are to analyze the factors related to mitochondrial function and investigate the correlation between trophoblast invasion and mitophagy via PD-MSC cocultivation. We assess invasion ability and mitochondrial function in invasive trophoblasts according to PD-MSC cocultivation by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and extracellular flux (XF) assay. Under PD-MSCs co-cultivation, invasion activity of a trophoblast is increased via activation of the Rho signaling pathway as well as Matrix metalloproteinases (MMPs). Additionally, the expression of mitochondrial function (e.g., reactive oxygen species (ROS), calcium, and adenosine triphosphate (ATP) synthesis) in trophoblasts are increased via PD-MSCs co-cultivation. Finally, PD-MSCs regulate mitochondrial autophagy factors in invasive trophoblasts via regulating the balance between PTEN-induced putative kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PARKIN) expression. Taken together, these results demonstrate that PD-MSCs enhance the invasion ability of trophoblasts via altering mitochondrial dynamics. These results support the fundamental mechanism of trophoblast invasion via mitochondrial function and provide a new stem cell therapy for infertility.

Human placenta-derived mesenchymal stem cells stimulate ovarian function via miR-145 and bone morphogenetic protein signaling in aged rats

Background

Aging has detrimental effects on the ovary, such as a progressive reduction in fertility and decreased hormone production, that greatly reduce the quality of life of women. Thus, the current study was undertaken to investigate whether human placenta-derived mesenchymal stem cell (hPD-MSC) treatment can restore the decreases in folliculogenesis and ovarian function that occur with aging.

Methods

Acclimatized 52-week-old female SD rats were randomly divided into four groups: single hPD-MSC (5 × 10⁵) therapy, multiple (three times, 10-day intervals) hPD-MSC therapy, control (PBS), and non-treated groups. hPD-MSC therapy was conducted by tail vein injection into aged rats. The rats were sacrificed 1, 2, 3, and 5 weeks after the last injection. hPD-MSC tracking and follicle numbers were histologically confirmed. The serum levels of sex hormones and circulating miRNAs were detected by ELISA and qRT-PCR, respectively. TGF-β superfamily proteins and SMAD proteins in the ovary were detected by Western blot analysis.

Results

We observed that multiple transplantations of hPD-MSCs more effectively promoted primordial follicle activation and ovarian hormone (E₂ and AMH) production than a single injection. After hPD-MSC therapy, the levels of miR-21-5p, miR-132-3p, and miR-212-3p, miRNAs associated with the ovarian reserve, were increased in the serum. Moreover, miRNAs (miR-16-5p, miR-34a-5p, and miR-191-5p) with known adverse effects on folliculogenesis were markedly suppressed. Importantly, the level of miR-145-5p was reduced after single- or multiple-injection hPD-MSC therapy, and we confirmed that miR-145-5p targets Bmpr2 but not Tgfbr2. Interestingly, downregulation of miR-145-5p led to an increase in BMPR2, and activation of SMAD signaling concurrently increased primordial follicle development and the number of primary and antral follicles.

Conclusions

Our study verified that multiple intravenous injections of hPD-MSCs led to improved ovarian function via miR-145-5p and BMP-SMAD signaling and proposed the future therapeutic potential of hPD-MSCs to promote ovarian function in women at advanced age to improve their quality of life during climacterium.

Functionally enhanced placenta-derived mesenchymal stem cells inhibit adipogenesis in orbital fibroblasts with Graves' ophthalmopathy

BACKGROUND

Placenta-derived mesenchymal stem cells (PD-MSCs) have unique immunomodulatory properties. Phosphatase of regenerating liver-1 (PRL-1) regulates the self-renewal ability of stem cells and promotes proliferation. Graves' ophthalmopathy (GO) is an autoimmune inflammatory disease of the orbit and is characterized by increased orbital levels of adipose tissue. Here, we evaluated the therapeutic mechanism for regulation of adipogenesis by PRL-1-overexpressing PD-MSCs (PD-MSCs^PRL-1, PRL-1+) in orbital fibroblast (OF) with GO patients.

METHODS

PD-MSCs isolated from human placenta were transfected with the PRL-1 gene using nonviral transfection method. Primary OFs were isolated from orbital adipose tissue specimens from GO patients. After maturation as adipogenic differentiation, normal and GO-derived OFs were cocultured with naïve and PD-MSCs^PRL-1. We analyzed the protein levels of adipogenesis markers and their signaling pathways in OFs from GO patients.

RESULTS

The characteristics of PD-MSCs^PRL-1 were similar to those of naïve cells. OFs from GO patients induced adipocyte differentiation and had significantly decreased a lipid accumulation after coculture with PD-MSCs^PRL-1 compared to naïve cells. The mRNA and protein expression of adipogenic markers was decreased in PD-MSCs^PRL-1. Insulin-like growth factor-binding proteins (IGFBPs) secreting PD-MSCs^PRL-1 downregulated the phosphorylated PI3K/AKT/mTOR expression in OFs from GO patients. Interestingly, IGFBP2, - 4, - 6, and - 7 expression in PD-MSCs^PRL-1, which was mediated by integrin alpha 4 (ITGA4) and beta 7 (ITGB7), was higher than that in naïve cells and upregulated phosphorylated FAK downstream factor.

CONCLUSION

In summary, IGFBPs secreting PD-MSC^PRL-1 inhibit adipogenesis in OFs from GO patients by upregulating phosphorylated FAK and downregulating PI3K/AKT/mTOR signaling pathway. The functional enhancement of PD-MSCs by nonviral gene modification provides a novel therapeutic strategy for the treatment of degenerative diseases.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Recent trends in stem cell therapy for premature ovarian insufficiency and its therapeutic potential: a review

Stem cell therapy is attracting attention in the field of regenerative medicine and is advancing rapidly. Many recent studies have applied stem cell therapy to treat reproductive system diseases; however, data are not yet available as to whether this therapy shows enhanced therapeutic effects. This paper analyzes recent preclinical studies on stem cell therapy for ovarian dysfunction in several types of animal models. Several clinical trials and pending projects are also discussed. This review will provide a background for developing stem cell therapies to enhance ovarian function.

Identification of microRNAs and their target genes in the placenta as biomarkers of inflammation

OBJECTIVE

Recently, microRNA (miRNA) has been identified both as a powerful regulator involved in various biological processes through the regulation of numerous genes and as an effective biomarker for the prediction and diagnosis of various disease states. The objective of this study was to identify and validate miRNAs and their target genes involved in inflammation in placental tissue.

METHODS

Microarrays were utilized to obtain miRNA and gene expression profiles from placentas with or without inflammation obtained from nine normal pregnant women and 10 preterm labor patients. Quantitative real-time polymerase chain reaction and Western blots were performed to validate the miRNAs and differentially-expressed genes in the placentas with inflammation. Correlations between miRNA and target gene expression were confirmed by luciferase assays in HTR-8/SVneo cells.

RESULTS

We identified and validated miRNAs and their target genes that were differentially expressed in placentas with inflammation. We also demonstrated that several miRNAs (miR-371a-5p, miR-3065-3p, miR-519b-3p, and miR-373-3p) directly targeted their target genes (LEF1, LOX, ITGB4, and CD44). However, some miRNAs and their direct target genes showed no correlation in tissue samples. Interestingly, miR-373-3p and miR-3065-3p were markedly regulated by lipopolysaccharide (LPS) treatment, although the expression of their direct targets CD44 and LOX was not altered by LPS treatment.

CONCLUSION

These results provide candidate miRNAs and their target genes that could be used as placental biomarkers of inflammation. These candidates may be useful for further miRNA-based biomarker development.

Alteration of fatty acid oxidation by increased CPT1A on replicative senescence of placenta-derived mesenchymal stem cells

Background

Human placenta-derived mesenchymal stem cells (PD-MSCs) are powerful sources for cell therapy in regenerative medicine. However, a limited lifespan by senescence through mechanisms that are well unknown is the greatest obstacle. In the present study, we first demonstrated the characterization of replicative senescent PD-MSCs and their possible mitochondrial functional alterations.

Methods

Human PD-MSCs were cultured to senescent cells for a long period of time. The cells of before passage number 8 were early cells and after passage number 14 were late cells. Also, immortalized cells of PD-MSCs (overexpressed hTERT gene into PD-MSCs) after passage number 14 were positive control of non-senescent cells. The characterization and mitochondria analysis of PD-MSCs were explored with long-term cultivation.

Results

Long-term cultivation of PD-MSCs exhibited increases of senescent markers such as SA-β-gal and p21 including apoptotic factor, and decreases of proliferation, differentiation potential, and survival factor. Mitochondrial dysfunction was also observed in membrane potential and metabolic flexibility with enlarged mitochondrial mass. Interestingly, we founded that fatty acid oxidation (FAO) is an important metabolism in PD-MSCs, and carnitine palmitoyltransferase1A (CPT1A) overexpressed in senescent PD-MSCs. The inhibition of CPT1A induced a change of energy metabolism and reversed senescence of PD-MSCs.

Conclusions

These findings suggest that alteration of FAO by increased CPT1A plays an important role in mitochondrial dysfunction and senescence of PD-MSCs during long-term cultivation.

Dynamic Regulation of miRNA Expression by Functionally Enhanced Placental Mesenchymal Stem Cells PromotesHepatic Regeneration in a Rat Model with Bile Duct Ligation

Placenta-derived mesenchymal stem cells (PD-MSCs) were highlighted as therapeutic sources in several degenerative diseases. Recently, microRNAs (miRNAs)were found to mediate one of the therapeutic mechanisms of PD-MSCs in regenerative medicine. To enhance the therapeutic effects of PD-MSCs, we established functionally enhanced PD-MSCs with phosphatase of regenerating liver-1 overexpression (PRL-1(+)). However, the profile and functions of miRNAs induced by PRL-1(+) PD-MSCs in a rat model with hepatic failure prepared by bile duct ligation (BDL) remained unclear. Hence, the objectives of the present study were to analyze the expression of miRNAs and investigate their therapeutic mechanisms for hepatic regeneration via PRL-1(+) in a rat model with BDL. We selected candidate miRNAs based on microarray analysis. Under hypoxic conditions, compared with migrated naïve PD-MSCs, migrated PRL-1(+) PD-MSCs showed improved integrin-dependent migration abilitythrough Ras homolog (RHO) family-targeted miRNA expression (e.g., hsa-miR-30a-5p, 340-5p, and 146a-3p). Moreover, rno-miR-30a-5p and 340-5p regulated engraftment into injured rat liver by transplantedPRL-1(+) PD-MSCs through the integrin family. Additionally, an increase inplatelet-derived growth factor receptor A (PDGFRA) by suppressing rno-miR-27a-3p improved vascular structure in rat liver tissues after PRL-1(+) PD-MSC transplantation. Furthermore, decreased rno-miR-122-5p was significantly correlated with increased proliferation of hepatocytes in liver tissues by PRL-1(+) PD-MSCs byactivating the interleukin-6 (IL-6) signaling pathway through the repression of rno-miR-21-5p. Taken together, these findings improve the understandingof therapeutic mechanisms based on miRNA-mediated stem-cell therapy in liver diseases.

Biological effects of melatonin on human adipose‑derived mesenchymal stem cells

Mesenchymal stem cells (MSCs) are capable of differentiating into other cell types and exhibit immunomodulatory effects. MSCs are affected by several intrinsic and extrinsic signaling modulators, including growth factors, cytokines, extracellular matrix and hormones. Melatonin, produced by the pineal gland, is a hormone that regulates sleep cycles. Recent studies have shown that melatonin improves the therapeutic effects of stem cells. The present study aimed to investigate whether melatonin enhances the biological activities of human adipose-derived MSCs. The results demonstrated that treatment with melatonin promoted cell proliferation by inducing SRY-box transcription factor 2 gene expression and preventing replicative senescence. In addition, melatonin exerted anti-adipogenic effects on MSCs. PCR analysis revealed that the expression of the CCAAT enhancer binding protein a gene, a key transcription factor in adipogenesis, was decreased following melatonin treatment, resulting in reduced adipogenic differentiation in an in vitro assay. The present study also examined the effect of melatonin on the immunomodulatory response using a co-culture system of human peripheral blood mononuclear cells and MSCs. Activated T cells were strongly inhibited following melatonin exposure compared with those in the control group. Finally, the favorable effects of melatonin on MSCs were confirmed using luzindole, a selective melatonin receptor antagonist. The proliferation-promoting, anti-inflammatory effects of melatonin suggested that melatonin-treated MSCs may be used for effective cell therapy.

Histone deacetylase inhibition has cardiac and vascular protective effects in rats with pressure overload cardiac hypertrophy

Histone deacetylase (HDAC) inhibitors have shown beneficial effects in animal models of cardiovascular diseases. We hypothesized that HDAC inhibitor, sodium valproate (VPA), has cardiac and vascular protective effects in rats with pressure overload cardiac hypertrophy induced by transverse aortic constriction (TAC). Sections of the heart were visualized after hematoxylin and eosin staining, picrosirius red staining and immunohistochemistry. The expression of genes related to cardiac hypertrophy, fibrosis, and oxidative stress was determined by quantitative real-time polymerase chain reaction. The aortic ring tension analysis was conducted using both the ascending aorta and descending thoracic aorta. TAC increased the expression of hypertrophic, fibrotic, and oxidative stress genes, which was attenuated by VPA. In the ascending aorta with intact endothelium, there was a significant decrease in the relaxation response, which was recovered by VPA treatment. These results indicate that VPA has cardiac and vascular protective effects in rats with pressure overload cardiac hypertrophy.

Immunomodulatory Effects of Placenta-derived Mesenchymal Stem Cells on T Cells by Regulation of FoxP3 Expression

The immunomodulatory effects of mesenchymal stem cells (MSCs) are an important mediator of their therapeutic effects in stem cell therapy and regenerative medicine. The regulation mechanism of MSCs is orchestrated by several factors in both intrinsic and extrinsic events. Recent studies have shown that the dynamic expression of cytokines secreted from MSCs control T cell function and maturation by regulating the expression of FoxP3, which figures prominently in T cell differentiation. However, there is no evidence that placenta-derived mesenchymal stem cells (PD-MSCs) have strong immunomodulatory effects on T cell function and maturation via FoxP3 expression. Therefore, we compared the expression of FoxP3 in activated T cells isolated from peripheral blood and co-cultured with PD-MSCs or bone marrow-derived mesenchymal stem cells (BM-MSCs) and analyzed their effect on T cell proliferation and cytokine profiles. Additionally, we verified the immunomodulatory function of PD-MSCs by siRNA-mediated silencing of FoxP3. MSCs, including PD-MSCs and BM-MSCs, promoted differentiation of naive peripheral blood T cells into CD4+CD25+FoxP3+ regulatory T (Treg) cells. Intriguingly, the population of CD4+CD25+FoxP3+ Treg cells co-cultured with PD-MSCs was significantly expanded in comparison to those co-cultured with BM-MSCs or WI38 cells (p＜0.05, p＜0.001). Dynamic expression patterns of several cytokines, including anti- and pro-inflammatory cytokines and members of the transforming growth factor-beta (TGF-β) family secreted from PD-MSCs according to FoxP3 expression were observed. The results suggest that PD-MSCs have an immunomodulatory effect on T cells by regulating FoxP3 expression.

3D-cultured human placenta-derived mesenchymal stem cell spheroids enhance ovary function by inducing folliculogenesis

Placenta-derived mesenchymal stem cells (PD-MSCs) have numerous advantages over other adult MSCs that make them an attractive cell source for regenerative medicine. Here, we demonstrate the therapeutic effect of PD-MSCs in ovariectomized (Ovx) rats and compare their efficacy when generated via a conventional monolayer culture system (2D, naïve) and a spheroid culture system (3D, spheroid). PD-MSC transplantation significantly increased the estradiol level in Ovx rats compared with the non-transplantation (NTx) group. In particular, the estradiol level in the Spheroid group was significantly higher than that in the Naïve group at 2 weeks. Spheroid PD-MSCs exhibited a significantly higher efficiency of engraftment onto ovarian tissues at 2 weeks. The mRNA and protein expression levels of Nanos3, Nobox, and Lhx8 were also significantly increased in the Spheroid group compared with those in the NTx group at 1 and 2 weeks. These results suggest that PD-MSC transplantation can restore ovarian function in Ovx rats by increasing estrogen production and enhancing folliculogenesis-related gene expression levels and further indicate that spheroid-cultured PD-MSCs have enhanced therapeutic potential via increased engraftment efficiency. These findings improve our understanding of stem-cell-based therapies for reproductive systems and may suggest new avenues for developing efficient therapies using 3D cultivation systems.

Dual Effects of Human Placenta-Derived Neural Cells on Neuroprotection and the Inhibition of Neuroinflammation in a Rodent Model of Parkinson's Disease

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disease in the elderly and the patients suffer from uncontrolled movement disorders due to loss of dopaminergic (DA) neurons on substantia nigra pars compacta (SNpc). We previously reported that transplantation of human fetal midbrain-derived neural precursor cells restored the functional deficits of a 6-hydroxy dopamine (6-OHDA)-treated rodent model of PD but its low viability and ethical issues still remain to be solved. Albeit immune privilege and neural differentiation potentials suggest mesenchymal stem cells (MSCs) from various tissues including human placenta MSCs (hpMSCs) for an alternative source, our understanding of their therapeutic mechanisms is still limited. To expand our knowledge on the MSC-mediated PD treatment, we here investigated the therapeutic mechanism of hpMSCs and hpMSC-derived neural phenotype cells (hpNPCs) using a PD rat model. Whereas both hpMSCs and hpNPCs protected DA neurons in the SNpc at comparable levels, the hpNPC transplantation into 6-OHDA treated rats exhibited longer lasting recovery in motor deficits than either the saline or the hpMSC treated rats. The injected hpNPCs induced delta-like ligand (DLL)1 and neurotrophic factors, and influenced environments prone to neuroprotection. Compared with hpMSCs, co-cultured hpNPCs more efficiently protected primary neural precursor cells from midbrain against 6-OHDA as well as induced their differentiation into DA neurons. Further experiments with conditioned media from hpNPCs revealed that the secreted factors from hpNPCs modulated immune responses and neural protection. Taken together, both DLL1-mediated contact signals and paracrine factors play critical roles in hpNPC-mediated improvement. First showing here that hpMSCs and their neural derivative hpNPCs were able to restore the PD-associated deficits via dual mechanisms, neuroprotection and immunosuppression, this study expanded our knowledge of therapeutic mechanisms in PD and other age-related diseases.

Effects of selenium on the survival and invasion of trophoblasts

Objective

Placental oxidative stress is known to be a factor that contributes to pregnancy failure. The aim of this study was to determine whether selenium could induce antioxidant gene expression and regulate invasive activity and mitochondrial activity in trophoblasts, which are a major cell type of the placenta.

Methods

To understand the effects of selenium on trophoblast cells exposed to hypoxia, the viability and invasive activity of trophoblasts were analyzed. The expression of antioxidant enzymes was assessed by reverse-transcription polymerase chain reaction. In addition, the effects of selenium treatment on mitochondrial activity were evaluated in terms of adenosine triphosphate production, mitochondrial membrane potential, and reactive oxygen species levels.

Results

Selenium showed positive effects on the viability and migration activity of trophoblast cells when exposed to hypoxia. Interestingly, the increased heme oxygenase 1 expression under hypoxic conditions was decreased by selenium treatment, whereas superoxide dismutase expression was increased in trophoblast cells by selenium treatment for 72 hours, regardless of hypoxia. Selenium-treated trophoblast cells showed increased mitochondrial membrane potential and decreased reactive oxygen species levels under hypoxic conditions for 72 hours.

Conclusion

These results will be used as basic data for understanding the mechanism of how trophoblast cells respond to oxidative stress and how selenium promotes the upregulation of related genes and improves the survival rate and invasive ability of trophoblasts through regulating mitochondrial activity. These results suggest that selenium may be used in reproductive medicine for purposes including infertility treatment.

Bunch-by-bunch position measurement and analysis at PLS-II

A bunch-by-bunch measurement system has been developed at Pohang Light Source II. The system consists of a four-channel button pick-up, 20 GHz sampling oscilloscope and an 800 MHz low-pass digital filter. Upon measuring a bunch-by-bunch spatio-temporal beam motion matrix over many turns, singular-value decomposition analysis is used to reveal the dominant coupled-bunch modes. The system can diagnose injection oscillations due to kicker errors and the effect of resistive-wall impedance that gives rise to instability during operation.

Localized insulin amyloidosis with use of concentrated insulin: a potential complication

BACKGROUND

Insulin-derived amyloidosis is a rare form of amyloidosis composed of insulin fibrils. The pH and concentration of insulin are known to influence the conformational state of the insulin hormone, with an increasing concentration favouring a more complex conformation. Concentrated insulin delivers a large amount of insulin to a localized area, raising the possibility of inducing conformational changes, forming insulin fibrils and leading to localized insulin amyloidosis.

CASE REPORT

A middle-aged woman with long history of Type 2 diabetes mellitus, treated with concentrated human insulin (U-500 insulin) presented with nodular lesions at the site of her daily insulin injections. A punch biopsy of the nodules showed skin with dermal amyloidosis staining favourably with Congo Red stain. The amyloid tumours were resected and areas positive for Congo Red stain were sent for liquid chromatography tandem mass spectrometry, which showed a peptide profile consistent with amyloid insulin.

CONCLUSION

Concentrated insulin was first introduced in 1952, however, it is only over the last two decades that it has been used increasingly, in congruence with the increasing incidence of obesity and diabetes mellitus seen in the USA. Only a few cases of insulin amyloidosis at the site of injection have been described in literature. With the increase in the use of insulin, this complication seems to be occurring more frequently. This is the first case report of a person with diabetes mellitus who developed localized insulin amyloidosis with the use of concentrated insulin, and points towards a potential complication of developing insulin amyloidosis with the use of concentrated insulin.

Decreased C-reactive protein induces abnormal vascular structure in a rat model of liver dysfunction induced by bile duct ligation

Background/Aims

Chronic liver disease leads to liver fibrosis, and although the liver does have a certain regenerative capacity, this disease is associated with dysfunction of the liver vessels. C-reactive protein (CRP) is produced in the liver and circulated from there for metabolism. CRP was recently shown to inhibit angiogenesis by inducing endothelial cell dysfunction. The objective of this study was to determine the effect of CRP levels on angiogenesis in a rat model of liver dysfunction induced by bile duct ligation (BDL).

Methods

The diameter of the hepatic vein was analyzed in rat liver tissues using hematoxylin and eosin (H&E) staining. The expression levels of angiogenic factors, albumin, and CRP were analyzed by real-time PCR and Western blotting. A tube formation assay was performed to confirm the effect of CRP on angiogenesis in human umbilical vein endothelial cells (HUVECs) treated with lithocholic acid (LCA) and siRNA-CRP.

Results

The diameter of the hepatic portal vein increased significantly with the progression of cirrhosis. The expression levels of angiogenic factors were increased in the cirrhotic liver. In contrast, the expression levels of albumin and CRP were significantly lower in the liver tissue obtained from the BDL rat model than in the normal liver. The CRP level was correlated with the expression of albumin in hepatocytes treated with LCA and siRNA-CRP. Tube formation was significantly decreased in HUVECs when they were treated with LCA or a combination of LCA and siRNA-CRP.

Conclusion

CRP seems to be involved in the abnormal formation of vessels in hepatic disease, and so it could be a useful diagnostic marker for hepatic disease.

Aberrant expression of plasma microRNA-33a in an atherosclerosis-risk group

In order to investigate whether plasma microRNA-33a (miR-33a) can be a biomarker for the early detection of atherosclerosis and to reexamine the assumption that miR-33a represses the expression of ABCA1, we compared the expression levels of miR-33a and ATP-binding cassette A1 (ABCA1) using human plasma and supernatants of macrophage cultured media. We first separated ample number of plasma samples from left-over whole blood samples based on the criteria for normal or dyslipidemia, and stored them at -20 °C until use. Then we selected 18 plasma samples for each normal, athero-risk and treated group using a metabolic disease cohort in which candidate subjects have participated. For classifying into three groups, we primarily relied on the records of physicians' comments, prescriptions, treatment history, lipid profiles and test results from medical equipment aimed at the diagnosis for atherosclerosis or cardiovascular disease. After collecting the final 54 plasma samples, we analyzed and compared the expression levels of miR-33a and ABCA1 at the plasma levels. In the comparison of plasma levels of the three groups, the miR-33a expression level of athero-risk group was 5.01-fold higher than that of normal group. Meanwhile, in the culture of foam cells transfected with anti-miR-33a oligonucleotides, the miR-33a level significantly decreased, while ABCA1 level significantly increased. The results suggest that enhanced expression of miR-33a might induce cholesterol accumulation and aggravate inflammation in vessel walls by suppressing the expression of ABCA1 in macrophages. Thus, plasma miR-33a can be considered as a candidate biomarker of atherosclerosis.

Aminoacyl-tRNA synthetase interacting multi-functional protein 1 attenuates liver fibrosis by inhibiting TGFβ signaling

The aminoacyl-tRNA synthetase interacting multi-functional protein 1 (AIMP1) participates in a variety of cellular processes, including translation, cell proliferation, inflammation and wound healing. Previously, we showed that the N-terminal peptide of AIMP1 (6-46 aa) induced ERK phosphorylation. Liver fibrosis is characterized by excessive deposition of extracellular matrix, which is induced by TGFβ signaling, and activated ERK is known to induce the phosphorylation of SMAD, thereby inhibiting TGFβ signaling. We assessed whether the AIMP1 peptide can inhibit collagen synthesis in hepatic stellate cells (HSCs) by activating ERK. The AIMP1 peptide induced phosphorylation of SMAD2 via ERK activation, and inhibited the nuclear translocation of SMAD, resulting in a reduction of the synthesis of type I collagen. The AIMP1 peptide attenuated liver fibrosis induced by CCl4, in a dose-dependent manner. Masson-Trichrome staining showed that the AIMP1 peptide reduced collagen deposition. Immunohistochemical staining showed that the levels of α-SMA, TGFβ and type I collagen were all reduced by the AIMP1 peptide. Liver toxicity analysis showed that the AIMP1 peptide improved the levels of relevant biological parameters in the blood. These results suggest that AIMP1 peptide may have potential for development as a therapeutic agent to treat liver fibrosis.

Adherence with renal dosing recommendations in outpatients undergoing haemodialysis

WHAT IS KNOWN AND OBJECTIVE

Adjustment of drug dosage in patients with end-stage renal disease prevents serious adverse effects, which occur due to the accumulation of drugs or other toxic metabolites. Nevertheless, dosing errors occur most commonly among patients with end-stage renal disease. The aim of this study was to assess the quality of care for end-stage renal disease outpatients using their renal dosing adjustment status.

METHODS

A cross-sectional study was performed using the data collected from 43 South Korean medical institutions via questionnaires. A total of 2428 patients on haemodialysis, who were at least 18 years of age, were included. Among these patients, the study population was confined to patients who were taking medications and required renal dosing adjustments from three therapeutic classes: antihypertensives, antihyperglycaemics and lipid-modifying agents. The study population (n = 828) was prescribed a total of 1097 drug orders for the target drugs. Determination of appropriate dosage adjustment was based on GFR (glomerular filtration rate) using the Modification of Diet in Renal Disease revised 4-variable equation. The primary outcome was non-adherence to drug dosing requirements for end-stage renal disease patients with consideration to their renal function.

RESULTS AND DISCUSSION

Among the study population (n = 828), 469 haemodialysis patients were identified as having drug orders that were adherent to renal dosing recommendations. There were significant differences between the patient groups who received recommendation-adherent and non-adherent drug orders in the characteristics of the medical institutions they visited, causes of chronic renal failure and prevalence of concurrent diabetes mellitus. The primary factor of non-adherence to renal dosing adjustment recommendations was characteristics of medical institutions. Compared to tertiary hospitals, secondary hospitals and primary care clinics were 1·16 and 1·22 times, respectively, more non-adherent in accordance with the multivariate analysis (OR: 1.16, 95% CI: 1.02-1.20, OR: 1.22, 95% CI: 1·00-1·36, respectively).

WHAT IS NEW AND CONCLUSIONS

Dosing error is one of the most common problems among patients with renal failure. To decrease the dosing errors, an improvement needs to be made in medical institutions. This can be accomplished by implementing the clinical decision support systems that educate physicians on appropriate renal dosing and help them prescribe appropriate drug dosages.

Microenvironmental Interaction Between Hypoxia and Endothelial Cells Controls the Migration Ability of Placenta-Derived Mesenchymal Stem Cells via α4 Integrin and Rho Signaling

Mesenchymal stem cells (MSCs) are a powerful source for cell therapy in degenerative diseases. The migration ability of MSCs is an important factor that enhances the therapeutic effect of the cells when they are transplanted into target tissues or organs. Hypoxia and the endothelial barrier, which are representative migration microenvironmental factors, are known to be regulated by the integrin-mediated pathway in several cancers. However, their regulatory mechanisms in MSCs remain unclear. Here, the objectives of the study were to compare the expression of markers related to integrin-mediated signaling in placenta-derived MSCs (PDMSCs) dependent on hypoxia and co-cultured with human umbilical vein endothelial cells (HUVECs) and to evaluate their correlations between migration ability and microenvironmetal factors including hypoxia and endothelial cells. The migration abilities of PDMSCs exposed to hypoxic conditions were significantly increased compared with normal fibroblasts (WI-38) and control (P < 0.05). Interestingly, decreased integrin α4 in PDMSCs under hypoxia induce to increase migration abilities of PDMSCs. Also, Rho family-related markers were significantly increased in PDMSCs under hypoxic conditions compared with normoxia (P < 0.05). Furthermore, the migration ability of PDMSCs was decreased by Rho kinase inhibitor treatment (Y-27632) and co-culturing with HUVECs in an ex vivo system. ROCK activity was increased by inhibiting integrin α4 with HUVECs and hypoxia compared with the absence of HUVECs and under normoxia. The findings suggest microenvironment event by hypoxia and the interaction with endothelial cells may be useful as a regulator of MSC migration and provide insight into the migratory mechanism of MSCs in stem cell-based therapy.

MicroRNA125b-mediated Hedgehog signaling influences liver regeneration by chorionic plate-derived mesenchymal stem cells

Although chorionic plate-derived mesenchymal stem cells (CP-MSCs) were shown to promote liver regeneration, the mechanisms underlying the effect remain unclear. Hedgehog (Hh) signaling orchestrates tissue reconstruction in damaged liver. MSCs release microRNAs mediating various cellular responses. Hence, we hypothesized that microRNAs from CP-MSCs regulated Hh signaling, which influenced liver regeneration. Livers were obtained from carbon tetrachloride (CCl₄)-treated rats transplanted with human CP-MSCs (Tx) or saline (non-Tx). Sonic Hh, one of Hh ligands, increased in CCl₄-treated liver, whereas it decreased in CP-MSC-treated liver with CCl₄. The expression of Hh-target genes was significantly downregulated in the Tx. Reduced expansion of progenitors and regressed fibrosis were observed in the liver of the Tx rats. CP-MSCs suppressed the expression of Hh and profibrotic genes in co-cultured LX2 (human hepatic stellate cell) with CP-MSCs. MicroRNA-125b targeting smo was retained in exosomes of CP-MSCs. CP-MSCs with microRNA-125b inhibitor failed to attenuate the expression of Hh signaling and profibrotic genes in the activated HSCs. Therefore, these results demonstrated that microRNA-125b from CP-MSCs suppressed the activation of Hh signaling, which promoted the reduced fibrosis, suggesting that microRNA-mediated regulation of Hh signaling contributed to liver regeneration by CP-MSCs.

Epigenetic Alterations of IL-6/STAT3 Signaling by Placental Stem Cells Promote Hepatic Regeneration in a Rat Model with CCl4-induced Liver Injury

BACKGROUND

Human chorionic plate-derived mesenchymal stem cells (CP-MSCs) isolated from the placenta have been reported to demonstrate therapeutic effects in animal models of liver injury; however, the underlying epigenetic mechanism of this effect has not been elucidated. Thus, we investigated whether CP-MSCs influence epigenetic processes during regeneration of the injured liver.

METHODS

CP-MSCs were engrafted into a carbon tetrachloride (CCl4)-injured rat model through direct transplantation into the liver (DTX), intrasplenic transplantation (STX), and intravenous transplantation via the tail vein (TTX). Non-transplanted (NTX) rats were maintained as sham controls. Liver tissues were analyzed after transplantation using immunohistochemistry, western blot analysis, and quantitative methylation-specific polymerase chain reaction. Proliferation and human interleukin-6 (hIL-6) enzyme-linked immunosorbent assays were performed using CCl4-treated hepatic cells that were co-cultured with CP-MSCs.

RESULTS

The Ki67 labeling index, cell cyclins, albumin, IL-6, and gp130 levels were elevated in the CP-MSC transplantation groups. The concentration of hIL-6 in supernatants and the proliferation of CCl4-treated rat hepatic cells were enhanced by co-culturing with CP-MSCs (p<0.05), while the methylation of IL-6/IL-6R and STAT3 by CP-MSC transplantation decreased.

CONCLUSION

These results suggest that administration of CP-MSCs promotes IL-6/STAT3 signaling by decreasing the methylation of the IL-6/SATA3 promoters and thus inducing the proliferation of hepatic cells in a CCl4-injured liver rat model. These data advance our understanding of the therapeutic mechanisms in injured livers, and can facilitate the development of cell-based therapies using placenta-derived stem cells.

Significance of serum antibody test for toxocariasis in healthy healthcare examinees with eosinophilia in Seoul and Gyeongsangnam-do, Korea

There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck®, Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group<350/µL, 10.0% (11/110) in the group 350-500/µL, and 12.4% (24/194) in the group>500/µL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.

The role of autophagy in the placenta as a regulator of cell death

The placenta is a temporary fetomaternal organ capable of supporting fetal growth and development during pregnancy. In particular, abnormal development and dysfunction of the placenta due to cha nges in the proliferation, differentiation, cell death, and invasion of trophoblasts induce several gynecological diseases as well as abnormal fetal development. Autophagy is a catalytic process that maintains cellular structures by recycling building blocks derived from damaged microorganelles or proteins resulting from digestion in lysosomes. Additionally, autophagy is necessary to maintain homeostasis during cellular growth, development, and differentiation, and to protect cells from nutritional deficiencies or factors related to metabolism inhibition. Induced autophagy by various environmental factors has a dual role: it facilitates cellular survival in normal conditions, but the cascade of cellular death is accelerated by over-activated autophagy. Therefore, cellular death by autophagy has been known as programmed cell death type II. Autophagy causes or inhibits cellular death via the other mechanism, apoptosis, which is programmed cell death type I. Recently, it has been reported that autophagy increases in placenta-related obstetrical diseases such as preeclampsia and intrauterine growth retardation, although the mechanisms are still unclear. In particular, abnormal autophagic mechanisms prevent trophoblast invasion and inhibit trophoblast functions. Therefore, the objectives of this review are to examine the characteristics and functions of autophagy and to investigate the role of autophagy in the placenta and the trophoblast as a regulator of cell death.

Human placenta-derived mesenchymal stem cells promote hepatic regeneration in CCl4 -injured rat liver model via increased autophagic mechanism

Mesenchymal stem cells (MSCs) have great potential for cell therapy in regenerative medicine, including liver disease. Even though ongoing research is dedicated to the goal of bringing MSCs to clinical applications, further understanding of the complex underlying mechanisms is required. Autophagy, a type II programmed cell death, controls cellular recycling through the lysosomal system in damaged cells or tissues. However, it is still unknown whether MSCs can trigger autophagy to enhance regeneration and/or to provide a therapeutic effect as cellular survival promoters. We therefore investigated autophagy's activation in carbon tetrachloride (CCl4 )-injured rat liver following transplantation with chorionic plate-derived MSCs (CP-MSCs) isolated from placenta. The expression markers for apoptosis, autophagy, cell survival, and liver regeneration were analyzed. Whereas caspase 3/7 activities were reduced (p < .05), the expression levels of hypoxia-inducible factor-1α (HIF-1α) and factors for autophagy, survival, and regeneration were significantly increased by CP-MSCs transplantation. Decreased necrotic cells (p < .05) and increased autophagic signals (p < .005) were observed in CCl4 -treated primary rat hepatocytes during in vitro coculture with CP-MSCs. Furthermore, the upregulation of HIF-1α promotes the regeneration of damaged hepatic cells through an autophagic mechanism marked by increased levels of light chain 3 II (LC 3II). These results suggest that the administration of CP-MSCs promotes repair by systemically concomitant mechanisms involving HIF-1α and autophagy. These findings provide further understanding of the mechanisms involved in these processes and will help develop new cell-based therapeutic strategies for regenerative medicine in liver disease.