Human Placenta-derived Mesenchymal Stem Cells Research Articles

Secretome from estrogen-responding human placenta-derived mesenchymal stem cells rescues ovarian function and circadian rhythm in mice with cyclophosphamide-induced primary ovarian insufficiency

BackgroundPrimary ovarian insufficiency (POI) is an early decline in ovarian function that leads to ovarian failure. Conventional treatments for POI are inadequate, and treatments based on mesenchymal stem cells (MSCs) have emerged as an option. However, the lack of consideration of the estrogen niche in ovarian tissue significantly reduces the therapeutic efficacy, with an unclear mechanism in the MSCs in POI treatment. Furthermore, the disruption of circadian rhythm associated with POI has not been previously addressed.MethodsConditioned medium (CM) and estradiol-conditioned medium (E2-CM) were generated from estrogen receptor positive MSCs (ER+pcMSCs). Chemotherapy-induced POI models were established using C57BL/6 mice (in vivo) and KGN cells (in vitro) treated with cyclophosphamide (CTX) or 4-hydroperoxycyclophosphamide (4-OOH-CP). Gene/protein expressions were detected using RT-qPCR, Western blotting, and immunohistochemistry assays. Locomotor activity was monitored for behavioral circadian rhythmicity. Cytokine arrays and miRNA analysis were conducted to analyze potential factors within CM/E2-CM.ResultsThe secretome of ER+pcMSCs (CM and E2-CM) significantly reduced the CTX-induced defects in ovarian folliculogenesis and circadian rhythm. CM/E2-CM also reduced granulosa cell apoptosis and rescued angiogenesis in POI ovarian tissues. E2-CM had a more favorable effect than the CM. Notably, ER+pcMSC secretome restored CTX-induced circadian rhythm defects, including the gene expressions associated with the ovarian circadian clock (e.g., Rora, E4bp4, Rev-erbα, Per2 and Dbp) and locomotor activity. Additionally, the cytokine array analysis revealed a significant increase in cytokines and growth factors associated with immunomodulation and angiogenesis, including angiogenin. Neutralizing the angiogenin in CM/E2-CM significantly reduced its ability to promote HUVEC tube formation in vitro. Exosomal miRNA analysis revealed the miRNAs involved in targeting the genes associated with POI rescue (PTEN and PDCD4), apoptosis (caspase-3, BIM), estrogen synthesis (CYP19A1), ovarian clock regulation (E4BP4, REV-ERBα) and fibrosis (COL1A1).ConclusionThis study is the first to demonstrate that, in considering the estrogen niche in ovarian tissue, an estrogen-priming ER+pcMSC secretome achieved ovarian regeneration and restored the circadian rhythm in a CTX-induced POI mouse model. The potential factors involved include angiogenin and exosomal miRNAs in the ER+pcMSC secretome. These findings offer insights into potential stem cell therapies for chemotherapy-induced POI and circadian rhythm disruption.

TGF-β1 Induces Endoplasmic Reticulum Stress-Dependent Apoptosis in Human Placental Mesenchymal Stem Cells of Fetal Origin through PERK Signaling Pathway

Background: Mesenchymal Stem Cells (MSCs) are pivotal in immunomodulation, hematopoiesis, and tissue repair. The interplay between MSCs and the pathological microenvironment influences their proliferation and differentiation. Transforming Growth Factor-Beta 1 (TGF- β1) serves as a key cytokine in the MSC microenvironment. This study aimed to scrutinize the impact of TGF-β1 on human placenta-derived MSCs of fetal origin (fPMSCs) and elucidate its underlying mechanism. Methods: fPMSCs were isolated, and surface markers were identified by flow cytometry. Cell proliferation in fPMSCs was assessed using Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2’-Deoxy Uridine (EdU). Apoptosis was detected via Annexin V/PI staining, and apoptosis-related proteins were detected by western blot. Endoplasmic reticulum (ER) stress-related proteins were detected by western blot, and Flou-4 AM staining was utilized to assess intracellular Ca2+ levels under TGF-β1 exposure. The impact of 4-PBA treatment on ER stress and apoptosis was assessed by western blot and Annexin V/PI staining. Additionally, the PERK and p-PERK expressions were evaluated via Western blot. Results: CCK-8 and EdU assays revealed inhibited proliferation of fPMSCs under TGF-β1 exposure. Annexin V/PI staining demonstrated a significant induction of apoptosis in fPMSCs following TGF-β1 treatment. Furthermore, TGF-β1 treatment significantly elevated intracellular Ca2+ levels and the expressions of GRP78, p-eIF2α, and CHOP. Interruption of ER stress with 4-PBA mitigated TGF-β1-induced apoptosis in fPMSCs. Moreover, TGF-β1 increased p-PERK expression. Inhibition of PERK autophosphorylation with GSK2606414 suppressed TGF-β1-induced apoptosis and ER stress in fPMSCs. Conclusion: Our findings indicated that TGF-β1 induced ER stress-dependent apoptosis in fPMSCs through the PERK signaling pathway. These results offer insights into enhancing the therapeutic efficacy of fPMSCs by modulating TGF-β1-induced apoptosis.

ROS-responsive nanoparticle delivery of obeticholic acid mitigate primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a challenging cholestatic liver disease marked by progressive bile duct inflammation and fibrosis that has no FDA-approved therapy. Although obeticholic acid (OCA) has been sanctioned for PSC, its clinical utility in PSC is constrained by its potential hepatotoxicity. Here, we introduce a novel therapeutic construct consisting of OCA encapsulated within a reactive oxygen species (ROS)-responsive, biodegradable polymer, further cloaked with human placenta-derived mesenchymal stem cell (hP-MSC) membrane (MPPFTU@OCA). Using PSC patient-derived organoid models, we assessed its cellular uptake and cytotoxicity. Moreover, using a PSC mouse model induced by 3,5-diethoxycarbonyl-1,4-dihydro-collidine (DDC), we demonstrated that intravenous administration of MPPFTU@OCA not only improved cholestasis via the FXR-SHP pathway but also reduced macrophage infiltration and the accumulation of intracellular ROS, and alleviated mitochondria-induced apoptosis. Finally, we verified the ability of MPPFTU@OCA to inhibit mitochondrial ROS thereby alleviating apoptosis by measuring the mitochondrial adenosine triphosphate (ATP) concentration, ROS levels, and membrane potential (ΔΨm) using H2O2-stimulated PSC-derived organoids. These results illuminate the synergistic benefits of integrating an ROS-responsive biomimetic platform with OCA, offering a promising therapeutic avenue for PSC.

Placenta-derived mesenchymal stem cells promote diabetic wound healing via exosomal protein interaction networks.

There is a lack of effective treatment options for diabetic refractory wounds, which presents a critical clinical issue that needs to be addressed urgently. Our research has demonstrated that human placenta-derived mesenchymal stem cells (plaMSCs) facilitate the migration and proliferation of HaCat cells, thereby enhancing diabetic wound healing primarily via the exosomes derived from plaMSCs (plaMSCs-Ex). Using label-free proteomics, plaMSCs and their exosomes were analysed for proteome taxonomic content in order to explore the underlying effective components mechanism of plaMSCs-Ex in diabetic wound healing. Differentially expressed proteins enriched in plaMSCs-Ex were identified and underwent bioinformatics analysis including GO annotation, KEGG pathway enrichment, gene set enrichment analysis (GSEA) and protein-protein interaction analysis (PPI). Results showed that the proteins enriched in plaMSCs-Ex are significantly involved in extracellular matrix organisation, epithelium morphogenesis, cell growth, adhesion, proliferation and angiogenesis. PPI analysis filtered 2 wound healing-related clusters characterised by hub proteins such as POSTN, FN1, SPARC, TIMP1, SERPINE1, LRP1 and multiple collagens. In brief, the exosomal proteins derived from plaMSCs reveal diverse functions of regeneration and tissue remodelling based on proteomics analysis and potentially play a role in diabetic wound healing.

Therapeutic Effects of Engineered Exosomes from RAW264.7 Cells Overexpressing hsa-let-7i-5p against Sepsis in Mice-A Comparative Study with Human Placenta-Derived Mesenchymal Stem Cell Exosomes.

This study compared the therapeutic effects of engineered exosomes derived from RAW264.7 cells overexpressing hsa-let-7i-5p (engineered exosomes) to exosomes from human placenta-derived mesenchymal stem cells (hpMSC exosomes) against sepsis-induced acute lung injury. Adult male C57BL/6 mice were divided into lipopolysaccharide (LPS), LPS plus engineered exosome (LEExo), or LPS plus hpMSC exosome (LMExo) groups, alongside control groups. The results showed that lung injury scores (based on pathohistological characteristics) and the levels of lung function alterations, tissue edema, and leukocyte infiltration in LEExo and LMExo groups were comparable and significantly lower than in the LPS group (all p < 0.05). Furthermore, the levels of inflammation (nuclear factor-κB activation, cytokine upregulation), macrophage activation (hypoxia-inducible factor-1α activation, M1 phase polarization), oxidation, and apoptosis were diminished in LEExo and LMExo groups compared to the LPS group (all p < 0.05). Inhibition of hsa-let-7i-5p attenuated the therapeutic effects of both engineered and hpMSC exosomes. These findings underscore the potent therapeutic capacity of engineered exosomes enriched with hsa-let-7i-5p and their potential as an alternative to hpMSC exosomes for sepsis treatment. Continued research into the mechanisms of action and optimization of engineered exosomes could pave the way for their future clinical application.

Human Placenta-Derived Mesenchymal Stem Cells Improve Neurological Function in Rats with Intrauterine Hypoxic-Ischaemic Encephalopathy by Reducing Apoptosis and Inflammatory Reactions.

Hypoxic-ischaemic encephalopathy (HIE) is a major cause of neonatal disability and mortality. Although hypothermia therapy offers some neuroprotection, the recovery of neurological function is limited. Therefore, new synergistic therapies are necessary to improve the prognosis. Mesenchymal stem cell-based therapy is emerging as a promising treatment option for HIE. In this study, we studied the therapeutic efficacy of human placenta-derived mesenchymal stem cells (PD-MSCs) in the HIE rat model and analyzed the underlying therapeutic mechanisms. Rats were divided into 6 groups (n = 9 for each) as follows: control, HIE model, HIE + normal saline, and HIE + PD-MSC transplantation at days 7, 14 and 28 postpartum. Following PD-MSC transplantation, neurological behavior was evaluated using rotarod tests, traction tests, and the Morris water maze test. The degree of brain tissue damage was assessed by histological examination and Nissl staining. Expression levels of apoptosis-related proteins and inflammatory factors were quantified by Western blotting and enzyme-linked immunosorbent assays. Immunofluorescence was used to investigate the ability of PD-MSCs to repair the morphology and function of hippocampal neurons with hypoxic-ischaemic (HI) injury. PD-MSC transplantation enhanced motor coordination and muscle strength in HIE rats. This treatment also improved spatial memory ability by repairing pathological damage and preventing the loss of neurons in the cerebral cortex. The most effective treatment was observed in the HIE + PD-MSC transplantation at day 7 group. Expression levels of microtubule-associated protein-2 (MAP-2), B-cell lymphoma-2 (BCL-2), interleukin (IL)-10, and transforming growth factor (TGF -β1) were significantly higher in the HIE + PD-MSC treatment groups compared to the HIE group, whereas the levels of BCL-2-associated X protein (BAX), BCL-2-associated agonist of cell death (BAD), IL-1β and tumour necrosis factor α (TNF-α) were significantly lower. We demonstrated that intravenous injection of PD-MSC at 7, 14 and 28 days after intrauterine HI damage in a rat model could improve learning, memory, and motor function, possibly by inhibiting apoptosis and inflammatory damage. These findings indicate that autologous PD-MSC therapy could have potential application for the treatment of HIE.

Human mesenchymal stem cells increase LLC metastasis and stimulate or decelerate tumor development depending on injection method and cell amount.

Mesenchymal stem cells (MSCs) being injected into the body can stimulate or decelerate carcinogenesis. Here, the direction of influence of human placenta-derived MSCs (P-MSCs) on the Lewis lung carcinoma (LLC) tumor development and metastatic potential is investigated in C57BL/6 mice depending on the injection method. After intramuscular co-inoculation of LLC and P-MSCs (LLC + P-MSCs), the growth of primary tumor and angiogenesis are slowed down compared to the control LLC on the 15th day. This is explained by the fact of a decrease in the secretion of proangiogenic factors during in vitro co-cultivation of an equal amount of LLC and P-MSCs. When P-MSCs are intravenously (i.v.) injected in the mice with developing LLC (LLC + P-MSCs(i.v.)), the tumor growth and angiogenesis are stimulated on the 15th day. A highly activated secretion of proangiogenic factors by P-MSCs in a similar in vitro model can explain this. In both the models compared to the control on the 23rd day, there is no significant difference in the tumor growth, while angiogenesis remains correspondingly decelerated or stimulated. However, in both the models, the total volume and number of lung metastases constantly increase compared to the control: it is mainly due to small-size metastases for LLC + P-MSCs(i.v.) and larger ones for LLC + P-MSCs. The increase in the rate of LLC cell dissemination after the injection of P-MSCs is explained by the disordered polyploidy and chromosomal instability, leading to an increase in migration and invasion of cancer cells. After LLC + P-MSCs co-inoculation, the tumor cell karyotype has the most complex and heterogeneous chromosomal structure. These findings indicate a bidirectional effect of P-MSCs on the growth of LLC in the early periods after injection, depending on the injection method, and, correspondingly, the number of contacting cells. However, regardless of the injection method, P-MSCs are shown to increase LLC aggressiveness related to cancer-associated angiogenesis and metastasis activation in the long term.

Human Placenta-Derived Mesenchymal Stem Cells Combined With Artificial Dermal Scaffold Enhance Wound Healing in a Tendon-Exposed Wound of a Rabbit Model.

To overcome the difficulty of vascular regeneration in exposed tendon wounds, we combined human placenta-derived mesenchymal stem cells (hPMSCs) with an artificial dermal scaffold and assessed their role in promoting vascular regeneration and wound healing in vivo. hPMSCs were isolated from the human placenta and characterized based on their morphology, phenotypic profiles, and pluripotency. New Zealand rabbits were used to establish an exposed tendon wound model, and hPMSCs and artificial dermal scaffolds were transplanted into the wounds. The results of gross wound observations and pathological sections showed that hPMSCs combined with artificial dermal scaffold transplantation increased the vascularization area of the wound, promoted wound healing, and increased the survival rate of autologous skin transplantation. Following artificial dermal scaffold transplantation, hPMSCs accelerated the vascularization of the dermal scaffold, and the number of fibroblasts, collagen fibers, and neovascularization in the dermal scaffold after 1 week were much higher than those in the control group. Immunohistochemical staining further confirmed that the expression of the vascular endothelial cell marker, CD31, was significantly higher in the combined transplantation group than in the dermal scaffold transplantation group. Our findings demonstrated that hPMSCs seeded onto artificial dermal scaffold could facilitate vascularization of the dermal scaffold and improve tendon-exposed wound healing.

Fucoxanthin diminishes oxidative stress damage in human placenta-derived mesenchymal stem cells through the PI3K/Akt/Nrf-2 pathway

Placenta-derived mesenchymal stem cells (PL-MSCs) have therapeutic potential in various clinical contexts due to their regenerative and immunomodulatory properties. However, with increasing age or extensive in vitro culture, their viability and function are gradually lost, thus restricting their therapeutic application. The primary cause of this deterioration is oxidative injury from free radicals. Therefore, enhancing cell viability and restoring cellular repair mechanisms of PL-MSCs in an oxidative stress environment are crucial in this context. Fucoxanthin, a carotenoid derived from brown seaweed, demonstrates antioxidant activity by increasing the production of antioxidant enzymes and lowering the levels of reactive oxygen species (ROS). This study aimed to determine whether fucoxanthin protects PL-MSCs from hydrogen peroxide (H2O2)-induced oxidative stress. After characterization, PL-MSCs were co-treated with fucoxanthin and H2O2 for 24 h (co-treatment) or pre-treated with fucoxanthin for 24 h followed by H2O2 for 24 h (pre-treatment). The effects of fucoxanthin on cell viability and proliferation were examined using an MTT assay. The expression of antioxidant enzymes, PI3K/Akt/Nrf-2 and intracellular ROS production were investigated in fucoxanthin-treated PL-MSCs compared to the untreated group. The gene expression and involvement of specific pathways in the cytoprotective effect of fucoxanthin were investigated by high-throughput NanoString nCounter analysis. The results demonstrated that co-treatment and pre-treatment with fucoxanthin restored the viability and proliferative capacity of PL-MSCs. Fucoxanthin treatment increased the expression of antioxidant enzymes in PL-MSCs cultured under oxidative stress conditions and decreased intracellular ROS accumulation. Markedly, fucoxanthin treatment could restore PI3K/Akt/Nrf-2 expression in H2O2-treated PL-MSCs. High-throughput analysis revealed up-regulation of genes involved in cell survival pathways, including cell cycle and proliferation, DNA damage repair pathways, and down-regulation of genes in apoptosis and autophagy pathways. This study demonstrated that fucoxanthin protects and rescues PL-MSCs from oxidative stress damage through the PI3K/Akt/Nrf-2 pathway. Our data provide the supporting evidence for the use of fucoxanthin as an antioxidant cytoprotective agent to improve the viability and proliferation capacity of PL-MSCs both in vitro and in vivo required to increase the effectiveness of MSC expansion for therapeutic applications.

Human placenta-derived mesenchymal stem cells stimulate neuronal regeneration by promoting axon growth and restoring neuronal activity.

In the last decades, mesenchymal stem cells (MSCs) have become the cornerstone of cellular therapy due to their unique characteristics. Specifically human placenta-derived mesenchymal stem cells (hPMSCs) are highlighted for their unique features, including ease to isolate, non-invasive techniques for large scale cell production, significant immunomodulatory capacity, and a high ability to migrate to injuries. Researchers are exploring innovative techniques to overcome the low regenerative capacity of Central Nervous System (CNS) neurons, with one promising avenue being the development of tailored mesenchymal stem cell therapies capable of promoting neural repair and recovery. In this context, we have evaluated hPMSCs as candidates for CNS lesion regeneration using a skillful co-culture model system. Indeed, we have demonstrated the hPMSCs ability to stimulate damaged rat-retina neurons regeneration by promoting axon growth and restoring neuronal activity both under normoxia and hypoxia conditions. With our model we have obtained neuronal regeneration values of 10%-14% and axonal length per neuron rates of 19-26, μm/neuron. To assess whether the regenerative capabilities of hPMSCs are contact-dependent effects or it is mediated through paracrine mechanisms, we carried out transwell co-culture and conditioned medium experiments confirming the role of secreted factors in axonal regeneration. It was found that hPMSCs produce brain derived, neurotrophic factor (BDNF), nerve-growth factor (NGF) and Neurotrophin-3 (NT-3), involved in the process of neuronal regeneration and restoration of the physiological activity of neurons. In effect, we confirmed the success of our treatment using the patch clamp technique to study ionic currents in individual isolated living cells demonstrating that in our model the regenerated neurons are electrophysiologically active, firing action potentials. The outcomes of our neuronal regeneration studies, combined with the axon-regenerating capabilities exhibited by mesenchymal stem cells derived from the placenta, present a hopeful outlook for the potential therapeutic application of hPMSCs in the treatment of neurological disorders.

Small RNA sequencing of exosomal microRNAs reveals differential expression of microRNAs in preeclampsia.

Preeclampsia (PE) is one of the most common hypertensive disorders of pregnancy. It is a dangerous condition with a high mortality rate in mothers and fetuses and is associated with a lack of early diagnosis and effective treatment. While the etiology of the disease is complex and obscure, it is now clear that the placenta is central to disease progression. Exosomal microRNAs (miRNAs) are possible mediators that regulate placenta-related physiological and pathological processes. Placental mesenchymal stem cells have considerable potential to help us understand the pathogenesis and treatment of pregnancy-related diseases. Here, we investigate the exosomal miRNA profiles of human placenta-derived mesenchymal stem cells between healthy pregnant women and those with PE. We performed small RNA sequencing to obtain miRNA profiles, and conducted enrichment analysis of the miRNA target genes to identify differentially expressed miRNAs associated with PE. Overall, we detected 1795 miRNAs; among them, 206 were differentially expressed in women with PE, including 35 upregulated and 171 downregulated miRNAs, when compared with healthy pregnant women. Moreover, we identified possible functions and pathways associated with PE, including angiogenesis, cell proliferation, migration and invasion, and the coagulation-fibrinolysis balance. Eventually, we proposed hsa-miR-675-5p, hsa-miR-3614-5p, and hsa-miR-615-5p as potential regulators of the pathogenesis of PE, and constructed a miRNA-target gene network. Our study identifies possible candidate biomarkers for the diagnosis of PE, and introduces a new direction for further understanding the pathogenesis of PE.

Polyaniline doped silk fibroin-PCL Electrospunfiber: An electroactive fibrous sheet for full-thickness wound healing study

The conductive electroactive properties of polyaniline (PANi) make it a promising polymer for a wide range of therapeutic applications, including wound care and treatment. In the present work, 0.3 wt% of PANI, denoted as p, content is incorporated in a high silk fibroin (S) loaded polycaprolactone (PCL) fiber in HFIP without/with FA and denoted as BpS and EpS. The effect of p in the HFIP without/with FA solvent (homogeneous & emulsion) resulted with different pH (pH-9/3) and produced fiber with different topography. Both, BpS and EpS fibers physico-chemical characterization were studied to confirm the presence of polymers in the composition and effect of p in different solvent. Electroactive “smart” fiber made from BpS (pH 9) is more mechanically stable than fiber made from EpS (pH 3) as shown by the fiber's mechanical properties. Human placenta-derived mesenchymal stem cells (hPMSCs) were used to assess cellular compatibility, and they showed significantly higher proliferation rate on BpS fiber substrate than on EpS. The in vivo evaluation for full-thickness wound model treated with BpS and EpS fibers were also studied. The IHC staining, biochemical analysis and RT-PCR were also observed to understand various mechanisms involved at different phases of the wound healing progression. The mechanical strength and electroactive property of BpS resulted in enhanced wound healing and complete wound closure than EpS and Tegaderm treated wound. Further, BpS treated wound at 7 days showed high gene expression of IL-1β, IFNγ, Col III and EGF. After 14 days, BpS treated wounds had increased gene expression of TGF-1, Col I, and FGF. Therefore BpS treated wound showed to be a potential wound dressing material with effective skin remodelling.

Human placenta-derived mesenchymal stem cells ameliorate diabetic kidney disease by modulating the T helper 17 cell/ regulatory T-cell balance through the programmed death 1 / programmed death-ligand 1 pathway.

To investigate the therapeutic effects and immunomodulatory mechanisms of human placenta-derived mesenchymal stem cells (PMSCs) in diabetic kidney disease (DKD). Streptozotocin-induced DKD rats were administered an equivalent volume of saline or PMSCs (1 × 106 in 2 mL phosphate-buffered saline per rat) for 3 weeks. Eight weeks after treatment, we examined the biochemical parameters in the blood and urine, the ratio of T helper 17 cells (Th17) and regulatory T cells (Treg) in the blood, cytokine levels in the kidney and blood, and renal histopathological changes. In addition, we performed PMSC tracing and renal transcriptomic analyses using RNA-sequencing. Finally, we determined whether PMSCs modulated the Th17/Treg balance by upregulating programmed death 1 (PD-1) in vitro. The PMSCs significantly improved renal function, which was assessed by serum creatinine levels, urea nitrogen, cystatin C levels, urinary albumin-creatinine ratio, and the kidney index. Further, PMSCs alleviated pathological changes, including tubular vacuolar degeneration, mesangial matrix expansion, and glomerular filtration barrier injury. In the DKD rats in our study, PMSCs were mainly recruited to immune organs, rather than to the kidney or pancreas. PMSCs markedly promoted the Th17/Treg balance and reduced the levels of pro-inflammatory cytokines (interleukin [IL]-17A and IL-1β) in the kidney and blood of DKD rats. In vitro experiments showed that PMSCs significantly reduced the proportion of Th17 cells and increased the proportion of Treg cells by upregulating PD-1 in a cell-cell contact manner and downregulating programmed death-ligand 1 (PD-L1) expression in PMSCs, which reversed the Th17/Treg balance. We found that PMSCs improved renal function and pathological damage in DKD rats and modulated Th17/Treg balance through the PD-1/PD-L1 pathway. These findings provide a novel mechanism and basis for the clinical use of PMSCs in the treatment of DKD.

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.

Human placenta-derived mesenchymal stem cell administration protects against acute lung injury in a mouse model.

This study aims to investigate the effect of placenta-derived mesenchymal stem cells (PMSCs) administration on tissue repair following acute lung injury (ALI). PMSCs were transplanted intravenously to a mouse model of lipopolysaccharide-induced ALI. The therapeutic effects were determined by evaluating several indicators, including pathology; the wet/dry ratio of the lungs; blood gas analysis; the total protein content, cell numbers, and the activity of myeloperoxidase (MPO) in bronchial alveolar lavage fluid (BALF); and the levels of anti-inflammatory and proinflammatory cytokines in serum and BALF. To investigate the underlying mechanism, PMSC-derived exosomes were used for ALI treatment. Administration of PMSCs improved the degree of lung injury, reduced inflammation, increased the expression levels of anti-inflammatory cytokines, and protected lung function. As expected, the effects of PMSC-derived exosomes in the ALI model were similar to those of PMSCs, both in terms of improved lung function and reduced inflammation. These findings suggest that PMSCs have ameliorating effects on ALI that are potentially mediated via their secreted exosomes.

BMP-2 functional polypeptides relieve osteolysis via bi-regulating bone formation and resorption coupled with macrophage polarization

Osteolysis caused by wear debris around the prosthesis is the main reason for aseptic loosening. Extending prosthetic service life is still challenging. In this study, we first synthesized a bone morphogenetic protein-2 (BMP-2) functional polypeptide (BMP2pp), and evaluated the effects of BMP2pp on macrophage polarization and impaired osteogenesis caused by titanium (Ti) particles in vitro. Then, we delineated the impact of BMP2pp on bone formation and resorption in a mouse calvarial bone osteolysis model induced by Ti particles. The results showed that BMP2pp not only alleviated the Ti-induced inhibition of osteoblastic differentiation in human placenta-derived mesenchymal stem cells (hPMSCs) but also prevented Ti-induced M1 macrophage polarization and promoted M2 macrophage differentiation in mice. Conditioned medium from BMP2pp-activated macrophages increased the osteogenesis of hPMSCs. The western blot results indicated a significant decrease in the expression of NF-κB inducing kinase (NIK) and phospho-NF-κB p65 in bone marrow-derived macrophages treated with BMP2pp. Furthermore, we clarified the protective effect of BMP2pp on bone formation and the reduction in bone resorption coupled with the immunomodulatory properties of calvarial osteolysis in mice. In summary, BMP2pp ameliorated the Ti-mediated impairment in osteogenic potential of hPMSCs, suppressed the M1 polarization of macrophages by inhibiting the activation of the NF-κB signaling pathway, and ameliorated Ti-induced bone osteolysis. Our research suggests that BMP2pp may be a potential option for treating prosthetic loosening induced by wear debris from prostheses.

Bovine dentin collagen/poly(lactic acid) scaffolds for teeth tissue regeneration

Electrospun scaffolds with diameter fibers compared to those in the extracellular matrix were produced with poly(lactic acid) (PLA) and non-denatured collagen from bovine dentin (DCol). DCol was obtained through an improved version of the Longin method by acid erosion of the hydroxyapatite of the roots of teeth from a 2-year-old cattle. The dentin collagen was characterized by energy dispersive X-ray spectroscopy (EDS), and carbon, nitrogen, and oxygen were found to be the main elements of the protein. Infrared analysis revealed the typical bands of collagen at about 3300, 1631, 1539, and 1234 cm−1 for amides A, I, II, and III, respectively. Calorimetric and infrared analyses also demonstrated that the collagen was non-denatured. With scanning electron microscopy, it was found that the thinnest fibers with a diameter comparable to that of fibers in the extracellular matrix were obtained when dentin collagen and acetic acid (AAc) were added to the solution of PLA in trifluoroethanol (TFE). The scaffolds with the thinnest diameter had also the highest porosity, and we considered that they could be beneficial in the growth of dentin cell. Human placenta-derived mesenchymal stem cells were seeded onto electrospun scaffolds. After 24, 48 and 96 h of culture, cell proliferation was evaluated by two independent strategies. In both assays, it was found that the pl-MSCs were capable of adhering and proliferating in different scaffolds. It was also observed that cell adhesion and proliferation increased significantly in scaffolds containing collagen, although the addition of AAc slightly decreased this effect on all scaffolds.Graphical abstract

893: EXOSOMES FROM MESENCHYMAL STEM CELLS ALLEVIATE ASPIRATION-INDUCED LUNG INJURY IN MICE

Introduction: With acidic fluid, the particulate component of the aspirate and pepsin, and bacteria from the oral cavity, gastric or oropharyngeal contents aspiration readily induces lung injury. Effective therapy remains lacking to date. The exaggerated inflammatory response has been identified as one crucial mechanism that mediates the development of lung injury in this regard. Exosomes from mesenchymal stem cells (MSCs) possess a potent anti-inflammation capacity. Based on these data, we thus conjectured that exosomes from MSCs may mitigate aspiration-induced acute lung injury. To elucidate further on this issue, we thus conducted this murine study. Methods: Adult male C57BL/6 mice were randomly allocated to the Sham group (oropharyngeal aspiration of normal saline), the AP group (oropharyngeal aspiration of mimic gastric content) or the AP-EXO group (AP plus exosomes) (n=6 in each group). The mimic gastric content consisted an acidic (pH 1.6) mixture of 12mg/mL ThickenUp®, 25μL pepsin (2mg/mL) and 20μL lipopolysaccharide (2.5mg/mL). In the AP-EXO group, mice received exosomes (1x10^8 particles/mouse, intratracheal, isolated from human placenta-derived MSCs) at 2 and 24 hours after aspiration. All mice were closely monitored for 48 hours, and each group’s lung injury level was measured. Results: Aspiration induces significant alterations in respiratory function, as our data revealed significantly higher airway resistance and lower forced expiratory volume in 0.1 seconds (FEV0.1) and dynamic compliance in mice of the AP group compared with the Sham group (all p< 0.001). Aspiration also induces significant airway inflammation, lung tissue edema and lung injury, as our data revealed significantly higher cell numbers in bronchoalveolar fluid, wet/dry weight ratio of lung tissue and lung injury score in mice of the AP group compared with the Sham group (all p< 0.001). These adverse effects of aspiration were mitigated by exosomes from MSCs, as our data demonstrated significantly lower airway resistance and, in contrast, higher FEV0.1 and dynamic compliance. Also, cell number in BALF, wet/dry weight ratio of lung tissues and lung injury score decreased in mice of the AP-EXO group compared with the AP group (all p< 0.001). Conclusions: Exosomes from MSCs mitigate aspiration-induced acute lung injury in mice.

The Role of Extracellular Vesicles in Optic Nerve Injury: Neuroprotection and Mitochondrial Homeostasis.

Stem cell therapies hold great promise as alternative treatments for incurable optic nerve disorders. Although mesenchymal stem cells exhibit various tissue regeneration and recovery capabilities that may serve as valuable therapies, the clinical applications remain limited. Thus, we investigated the utility of extracellular vesicles (EVs) from human placenta-derived mesenchymal stem cells (hPSCs) in this context. Hypoxically preconditioned hPSCs (HPPSCs) were prepared via short-term incubation under 2.2% O2 and 5.5% CO2. The EVs were then isolated. R28 cells (retinal precursor cells) were exposed to CoCl2 and treated with EVs for 24 h. Cell proliferation and regeneration were measured using a BrdU assay and immunoblotting; ATP quantification revealed the extent of the mitochondrial function. The proteome was determined via liquid chromatography-tandem mass spectroscopy. Differentially expressed proteins (DEPs) were detected and their interactions identified. HPPSC_EVs functions were explored using animal models of optic nerve compression. HPPSC_EVs restored cell proliferation and mitochondrial quality control in R28 cells damaged by CoCl2. We identified DEPs (p < 0.05) that aided recovery. The mitochondrial DEPs included LONP1; PARK7; VDAC1, 2, and 3; HSPD1; and HSPA9. EVs regulated the levels of mitophagic proteins in R28 cells injured by hypoxia; the protein levels did not increase in LONP1 knockdown cells. LONP1 is a key mediator of the mitophagy that restores mitochondrial function after hypoxia-induced optic nerve injury.

Long non-coding RNA SNHG16 promotes human placenta-derived mesenchymal stem cell proliferation capacity through the PI3K/AKT pathway under hypoxia.

BACKGROUNDThe effect of hypoxia on mesenchymal stem cells (MSCs) is an emerging topic in MSC biology. Although long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) are reported to play a critical role in regulating the biological characteristics of MSCs, their specific expression and co-expression profiles in human placenta-derived MSCs (hP-MSCs) under hypoxia and the underlying mech anisms of lncRNAs in hP-MSC biology are unknown.AIMTo reveal the specific expression profiles of lncRNAs in hP-MSCs under hypoxia and initially explored the possible mechanism of lncRNAs on hP-MSC biology.METHODSHere, we used a multigas incubator (92.5% N2, 5% CO2, and 2.5% O2) to mimic the hypoxia condition and observed that hypoxic culture significantly promoted the proliferation potential of hP-MSCs. RNA sequencing technology was applied to identify the exact expression profiles of lncRNAs and mRNAs under hypoxia.RESULTSWe identified 289 differentially expressed lncRNAs and 240 differentially expressed mRNAs between the hypoxia and normoxia groups. Among them, the lncRNA SNHG16 was upregulated under hypoxia, which was also validated by reverse transcription-polymerase chain reaction. SNHG16 was confirmed to affect hP-MSC proliferation rates using a SNHG16 knockdown model. SNHG16 overexpression could significantly enhance the proliferation capacity of hP-MSCs, activate the PI3K/AKT pathway, and upregulate the expression of cell cycle-related proteins.CONCLUSIONOur results revealed the specific expression characteristics of lncRNAs and mRNAs in hypoxia-cultured hP-MSCs and that lncRNA SNHG16 can promote hP-MSC proliferation through the PI3K/AKT pathway.