IGFBP2 enhances adipogenic differentiation potentials of mesenchymal stem cells from Wharton's jelly of the umbilical cord via JNK and Akt signaling pathways

The role of IGF/IGF-1R signaling in the regulation of cancer stem cells

Cancer stem cells (CSCs) are a group of tumor cells with high tumorigenic ability and self-renewal potential similar to those of normal stem cells. CSCs are the key "seeds" for tumor development, metastasis, and recurrence. A better insight into the key mechanisms underlying CSC survival improves the efficiency of cancer therapy via specific targeting of CSCs. Insulin-like growth factor (IGF)/IGF-1 receptor (IGF-1R) signaling plays an important role in the maintenance of cancer stemness. However, the effect of IGF/IGF-1R signaling on stemness and CSCs and the underlying mechanisms are still controversial. Based on the similarity between CSCs and normal stem cells, this review discusses emerging data on the functions of IGF/IGF-1R signaling in normal stem cells and CSCs and dissects the underlying mechanisms by which IGF/IGF-1R signaling is involved in CSCs. On the other hand, this review highlighted the role of IGF/IGF-1R signaling blockade in multiple CSCs as a potential strategy to improve CSC-based therapy.

KDM4D enhances osteo/dentinogenic differentiation and migration of SCAPs via binding to RPS5

OBJECTIVES

Stem cells of the apical papilla (SCAPs) provide promising candidates for dental pulp regeneration. Despite great advances in the transcriptional controls of the SCAPs fate, little is known about the regulation of SCAP differentiation.

MATERIALS AND METHODS

Short hairpin RNAs and full-length RNA were used to deplete or overexpress lysine demethylase 4D (KDM4D) gene expression. Western blotting, real-time RT-PCR, alizarin red staining, and scratch migration assays were used to study the role of KDM4D and the ribosomal protein encoded by RPS5 in SCAPs. RNA microarray, chromatin Immunoprecipitation (ChIP), and co-immunoprecipitation (Co-IP) assays were performed to explore the underlying molecular mechanisms.

RESULTS

KDM4D enhanced the osteo/dentinogenic differentiation, migration, and chemotaxis of SCAPs. The microarray results revealed that 88 mRNAs were differentially expressed in KDM4D-overexpressed SCAPs. ChIP results showed knock-down of KDM4D increased the level of H3K9me2 and H3K9me3 in CNR1 promoter region. There were 37 possible binding partners of KDM4D. KDM4D was found to combine with RPS5, which also promoted the osteo/dentinogenic differentiation, migration, and chemotaxis of SCAPs.

CONCLUSIONS

KDM4D promoted the osteo/dentinogenic differentiation and migration potential of SCAPs in combination with RPS5, which provides a therapeutic clue for improving SCAPs-based dental tissue regeneration.

Quality Control Optimization for Minimizing Security Risks Associated with Mesenchymal Stromal Cell-Based Product Development

Mesenchymal stromal cells (MSCs) have been considered a therapeutic strategy in regenerative medicine because of their regenerative and immunomodulatory properties. The translation of MSC-based products has some challenges, such as regulatory and scientific issues. Quality control should be standardized and optimized to guarantee the reproducibility, safety, and efficacy of MSC-based products to be administered to patients. The aim of this study was to develop MSC-based products for use in clinical practice. Quality control assays include cell characterization, cell viability, immunogenicity, and cell differentiation; safety tests such as procoagulant tissue factor (TF), microbiological, mycoplasma, endotoxin, genomic stability, and tumorigenicity tests; and potency tests. The results confirm that the cells express MSC markers; an average cell viability of 96.9%; a low expression of HLA-DR and costimulatory molecules; differentiation potential; a high expression of TF/CD142; an absence of pathogenic microorganisms; negative endotoxins; an absence of chromosomal abnormalities; an absence of genotoxicity and tumorigenicity; and T-lymphocyte proliferation inhibition potential. This study shows the relevance of standardizing the manufacturing process and quality controls to reduce variability due to the heterogeneity between donors. The results might also be useful for the implementation and optimization of new analytical techniques and automated methods to improve safety, which are the major concerns related to MSC-based therapy.

The Molecular Regulatory Mechanism in Multipotency and Differentiation of Wharton's Jelly Stem Cells

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are isolated from Wharton's jelly tissue of umbilical cords. They possess the ability to differentiate into lineage cells of three germ layers. WJ-MSCs have robust proliferative ability and strong immune modulation capacity. They can be easily collected and there are no ethical problems associated with their use. Therefore, WJ-MSCs have great tissue engineering value and clinical application prospects. The identity and functions of WJ-MSCs are regulated by multiple interrelated regulatory mechanisms, including transcriptional regulation and epigenetic modifications. In this article, we summarize the latest research progress on the genetic/epigenetic regulation mechanisms and essential signaling pathways that play crucial roles in pluripotency and differentiation of WJ-MSCs.

Goose Hepatic IGFBP2 Is Regulated by Nutritional Status and Participates in Energy Metabolism Mainly through the Cytokine-Cytokine Receptor Pathway

Changes in the nutritional status of animals significantly affect their health and production performance. However, it is unclear whether insulin-like growth factor-binding protein 2 (IGFBP2) mediates these effects. This study aimed to investigate the impact of changes in nutritional and energy statuses on hepatic IGFBP2 expression and the mechanism through which IGFBP2 plays a mediating role. Therefore, the expression of IGFBP2 was first determined in the livers of fasting/refeeding and overfeeding geese. The data showed that overfeeding inhibited IGFBP2 expression in the liver compared with the control (normal feeding) group, whereas the expression of IGFBP2 in the liver was induced by fasting. Interestingly, the data indicated that insulin inhibited the expression of IGFBP2 in goose primary hepatocytes, suggesting that the changes in IGFBP2 expression in the liver in the abovementioned models may be partially attributed to the blood insulin levels. Furthermore, transcriptome sequencing analysis showed that the overexpression of IGFBP2 in geese primary hepatocytes significantly altered the expression of 337 genes (including 111 up-regulated and 226 down-regulated genes), and these differentially expressed genes were mainly enriched in cytokine-cytokine receptor, immune, and lipid metabolism-related pathways. We selected the most significant pathway, the cytokine-cytokine receptor pathway, and found that the relationship between the expression of these genes and IGFBP2 in goose liver was in line with the findings from the IGFBP2 overexpression assay, i.e., the decreased expression of IGFBP2 was accompanied by the increased expression of LOC106041919, CCL20, LOC106042256, LOC106041041, and IL22RA1 in the overfed versus normally fed geese, and the increased expression of IGFBP2 was accompanied by the decreased expression of these genes in fasting versus normally fed geese, and refeeding prevented or attenuated the effects of fasting. The association between the expression of these genes and IGFBP2 was verified by IGFBP2-siRNA treatment of goose primary hepatocytes, in which IGFBP2 expression was induced by low serum concentrations. In conclusion, this study suggests that IGFBP2 mediates the biological effects induced by changes in nutritional or energy levels, mainly through the cytokine-cytokine receptor pathway.

KRAS Affects the Lipid Composition by Regulating Mitochondrial Functions and MAPK Activation in Bovine Mammary Epithelial Cells

Kirsten rat sarcoma viral oncogene homolog (KRAS), or guanosine triphosphatase KRAS, is a proto-oncogene that encodes the small guanosine triphosphatase transductor protein. Previous studies have found that KRAS can promote cytokine secretion, cell chemotaxis, and survival. However, its effects on milk fat synthesis in bovine mammary epithelial cells are unclear. In this study, the effects of KRAS inhibition on cell metabolism, autophagy, oxidative stress, endoplasmic reticulum stress, mitochondrial function, and lipid composition as well as the potential mechanisms were detected in an immortalized dairy cow mammary epithelial cell line (MAC-T). The results showed that inhibition of KRAS changed the lipid composition (especially the triglyceride level), mitochondrial functions, autophagy, and endoplasmic reticulum stress in cells. Moreover, KRAS inhibition regulated the levels of the mammalian target of rapamycin and mitogen-activated protein kinase (extracellular regulated protein kinases, c-Jun N-terminal kinases, p38) activation. These results indicated that regulation of KRAS would affect the synthesis and composition of milk fat. These results are also helpful for exploring the synthesis and secretion of milk fat at the molecular level and provide a theoretical basis for improving the percentage of fat in milk and the yield of milk from cows.

Identification of Biomarkers That Modulate Osteogenic Differentiation in Mesenchymal Stem Cells Related to Inflammation and Immunity: A Bioinformatics-Based Comprehensive Study

Background: Inducing mesenchymal stem cells (MSCs) osteogenesis may be beneficial in a number of clinical applications. The aim of this study is to identify key novel biomarkers of this process and to analyze the possible regulatory effects on inflammation and immunity. Results: Seven datasets (GSE159137, GSE159138, GSE114117, GSE88865, GSE153829, GSE63754, GSE73087) were obtained from the Gene Expression Omnibus database and were assigned to either the training or the validation dataset. The least absolute shrinkage and selection operator (LASSO) logistic regression model was applied to the training data to select biomarkers of osteogenesis, which were then confirmed using the validation dataset. FK506 binding protein 5 (FKBP5), insulin-like growth factor binding protein (IGFBP2), prostaglandin E receptor 2 (PTGER2), SAM domain and HD domain-containing protein 1 (SAMHD1), and transmembrane tetratricopeptide 1 (TMTC1) were highlighted as potential biomarkers. In addition, the differential expressions of immunity and inflammation-related genes were examined and their correlations with the five identified biomarkers were analyzed. The results from performing RT-qPCR and Western blots confirmed that the levels of each of these biomarkers were all significantly increased following osteogenic differentiation of MSCs. Conclusions: Our results identify five biomarkers related to MSCs osteogenesis and allow us to identify their potential roles in immunoregulation and inflammation. Each biomarker was verified by in vitro experiments.

Human placental mesenchymal stromal cells are ciliated and their ciliation is compromised in preeclampsia

BACKGROUND

The development of the human placenta is tightly coordinated by a multitude of placental cell types, including human chorionic villi mesenchymal stromal cells (hCV-MSCs). Defective hCV-MSCs have been reported in preeclampsia (PE), a gestational hypertensive disease characterized by maternal endothelial dysfunction and systemic inflammation. Our goal was to determine whether hCV-MSCs are ciliated and whether altered ciliation is responsible for defective hCV-MSCs in preeclamptic placentas, as the primary cilium is a hub for signal transduction, which is important for various cellular activities.

METHODS

In the present work, we collected placental tissues from different gestational stages and we isolated hCV-MSCs from 1st trimester, term control, and preeclamptic placentas. We studied their ciliation, functionality, and impact on trophoblastic cell lines and organoids formed from human trophoblast stem cells (hTSCs) and from the trophoblastic cell line JEG-3 with various cellular and molecular methods, including immunofluorescence staining, gene analysis, spheroid/organoid formation, motility, and cellular network formation assay. The statistical evaluation was performed using a Student's t test (two-tailed and paired or homoscedastic) or an unpaired Mann-Whitney U test (two-tailed).

RESULTS

The results show that primary cilia appeared abundantly in normal hCV-MSCs, especially in the early development of the placenta. Compared to control hCV-MSCs, the primary cilia were truncated, and there were fewer ciliated hCV-MSCs derived from preeclamptic placentas with impaired hedgehog signaling. Primary cilia are necessary for hCV-MSCs' proper signal transduction, motility, homing, and differentiation, which are impaired in preeclamptic hCV-MSCs. Moreover, hCV-MSCs derived from preeclamptic placentas are significantly less capable of promoting growth and differentiation of placental organoids, as well as cellular network formation.

CONCLUSIONS

These data suggest that the primary cilium is required for the functionality of hCV-MSCs and primary cilia are impaired in hCV-MSCs from preeclamptic placentas.

Fibroblasts from different body parts exhibit distinct phenotypes in adult progeria Werner syndrome

Werner syndrome (WS), also known as adult progeria, is characterized by accelerated aging symptoms from a young age. Patients with WS experience painful intractable skin ulcers with calcifications in their extremities, subcutaneous lipoatrophy, and sarcopenia. However, there is no significant abnormality in the trunk skin, where the subcutaneous fat relatively accumulates. The cause of such differences between the limbs and trunk is unknown. To investigate the underlying mechanism behind these phenomena, we established and analyzed dermal fibroblasts from the foot and trunk of two WS patients. As a result, WS foot-derived fibroblasts showed decreased proliferative potential compared to that from the trunk, which correlated with the telomere shortening. Transcriptome analysis showed increased expression of genes involved in osteogenesis in the foot fibroblasts, while adipogenic and chondrogenic genes were downregulated in comparison with the trunk. Consistent with these findings, the adipogenic and chondrogenic differentiation capacity was significantly decreased in the foot fibroblasts in vitro. On the other hand, the osteogenic potential was mutually maintained and comparable in the foot and trunk fibroblasts. These distinct phenotypes in the foot and trunk fibroblasts are consistent with the clinical symptoms of WS and may partially explain the underlying mechanism of this disease phenotype.

Regulatory role of insulin-like growth factor-binding proteins in odontogenic mineralization in rats

Much information is currently available for molecules in early odontogenesis, but there is limited knowledge regarding terminal cytodifferentiation of ameloblasts and odontoblasts for the determination of normal crown morphology. The present differential display PCR (DD-PCR) revealed that insulin-like growth factor-binding protein 5 (IGFBP5) was differentially expressed in molar tooth germs between the cap (before crown mineralization) and root formation (after crown mineralization) stages. Real-time PCR confirmed that the expression levels of IGFBP1-4 were not significantly changed but those of IGFBP5-7 were upregulated in a time-dependent manner. Immunoreactivities for IGFBP5-7 were hardly seen in molar germs at the cap/early bell stage and protective-stage ameloblasts at the root formation stage. However, the reactivity was strong in odontoblasts and maturation-stage ameloblasts, which are morphologically and functionally characterized by wide intercellular space and active enamel matrix mineralization. The localization of each IGFBP was temporospatial. IGFBP5 was localized in the nuclei of fully differentiated odontoblasts and ameloblasts, while IGFBP6 was localized in the apical cytoplasm of ameloblasts and odontoblasts with dentinal tubules, and IGFBP7 was mainly found in the whole cytoplasm of odontoblasts and the intercellular space of ameloblasts. IGFBP silencing using specific siRNAs upregulated representative genes for dentinogenesis and amelogenesis, such as DMP1 and amelogenin, respectively, and augmented the differentiation media-induced mineralization, which was confirmed by alizarin red s and alkaline phosphatase staining. These results suggest that IGFBP5-7 may play independent and redundant regulatory roles in late-stage odontogenesis by modulating the functional differentiation of ameloblasts and odontoblasts.

In vitro preconditioning of equine adipose mesenchymal stem cells with prostaglandin E2, substance P and their combination changes the cellular protein secretomics and improves their immunomodulatory competence without compromising stemness

Mesenchymal stem cells (MSC) are modern tools in regenerative therapies of humans and animals owed to their immunomodulatory properties, which are activated in a pro-inflammatory environment. Different preconditioning strategies had been devised to enhance the immunomodulatory properties of MSC. In this research, we evaluated the immunological attributes of equine adipose MSC (eAMSC) before and after preconditioning in vitro with prostaglandin E₂ (PGE₂), substance P (SP), their combination and IFNγ. PGE₂/SP was the best combination to keep or enhance the mesodermal lineage differentiation of eAMSC. Alongside with this, preconditioning of eMSC with PGE₂ and SP did not affect expression of stemness MSC surface phenotype: CD90⁺, CD44⁺, MHC class I⁺, MHC class II^- and CD45^-, assessed by cytometry. Both naïve and preconditioned eAMSC expressed genes related with immune properties, such as MHC-I, PTGES, IL6, IL1A, TNFα and IL8 assessed by qPCR. Only TNFα was under expressed in treated cells, while the other markers were either overexpressed or not changed. In no cases MHC-II expression was detected. The antiproliferative effect of preconditioned eAMSC exposed to activated peripheral blood mononuclear cells (PBMC) showed that SP treatment significantly inhibited proliferation of LPS stimulated PBMC. When eAMSC were stimulated with Poly I:C, all the treatments significantly inhibited proliferation of stimulated PBMC (p < 0.05). Direct contact (coculture) between the preconditioned eAMSC and PBMC, induced a shift of significantly more (CD4/CD25/FOXP3)⁺ T-regulatory PBMC than naïve eAMSC. In the experiments of this research, we investigated the secreted proteomic profile of naïve and preconditioned eAMSC, 42 up-regulated and 40 down-regulated proteins were found in the proteomic assay. Our proteomic data revealed profound changes in the secretory pattern of MSC exposed to different treatments, compared to naïve eAMSC as well as among treatments. In overall, compared to naïve cells, the protein profile of preconditioned cells resembled the mesenchymal-epithelial transition (MET). Here we showed that the combined use of PGE₂ and SP provoked in overall the highest expression of anti-inflammatory markers as well as lead to an increased acquisition of a T-regulatory phenotype in preconditioned eAMSC without affecting their "stemness".

UNC-5 netrin receptor B regulates adipogenesis of human adipose-derived stem cells through JNK pathway

BACKGROUND

There is a balance between adipogenic differentiation and osteogenic differentiation of human adipose-derived stem cells (hASCs). It is essential to explore the mechanism of hASCs lineage commitment. In our previous study, UNC-5 netrin receptor B (UNC5B) was identified as a positive regulator for osteogenesis.

OBJECTIVE

To further explore the potential roles and mechanisms of UNC5B during adipogenic differentiation and to provide a new method to regulate adipogenesis and osteogenesis of hASCs.

METHODS

Lentivirus containing UNC5B shRNA was used for UNC5B knockdown. Plasmids overexpressing UNC5B gene were used for UNC5B upregulation. To investigate the role of UNC5B in adipogenesis in vitro and in vivo, Oil Red O staining, RT-qPCR and transplantation into nude mice were performed. Western blotting analyses were performed to explore the mechanisms of UNC5B in adipogenic differentiation.

RESULTS

UNC5B expression in hASCs was significantly increased during adipogenic differentiation. Knockdown of UNC5B enhanced adipogenic differentiation in vitro. Both H&E staining and Oil Red O staining showed more adipose tissue-like constructs in UNC5B-knockdown cells in vivo. Upregulation of UNC5B significantly impaired adipogenic differentiation in vitro. Downregulation of UNC5B could increase phosphorylation of JNK in hASCs. JNK inhibitors reduced adipogenic differentiation of hASCs.

CONCLUSION

Our findings showed that UNC5B inhibited adipogenesis of hASCs through JNK signalling. As a whole, UNC5B regulates both adipogenesis and osteogenesis of hASCs.

Hypoxia/reoxygenation activates the JNK pathway and accelerates synovial senescence

Hypoxia/reoxygenation (H/R) may play an important role via senescence in the mechanism of osteoarthritis (OA) development. The synovial membrane is highly sensitive to H/R due to its oxygen consumption feature. Excessive mechanical loads and oxidative stress caused by H/R induce a senescence-associated secretory phenotype (SASP), which is related to the development of OA. The aim of the present study was to investigate the differences of SASP manifestation in synovial tissue masses between tissues from healthy controls and patients with OA. The present study used tumor necrosis factor-α (TNF-α) to pre-treat synovial tissue and fibroblast-like synoviocytes (FLS) to observe the effect of inflammatory cytokines on the synovial membrane before H/R. It was determined that H/R increased interleukin (IL)-1β and IL-6 expression levels in TNF-α-induced cell culture supernatants, increased the proportion of SA-β-gal staining, and increased the expression levels of high mobility group box 1, caspase-8, p16, p21, matrix metalloproteinase (MMP)-3 and MMP-13 in the synovium. Furthermore, H/R opened the mitochondrial permeability transition pore, caused the loss of mitochondrial membrane potential (ΔΨm) and increased the release of reactive oxygen species (ROS). Moreover, H/R caused the expansion of the mitochondrial matrix and rupture of the mitochondrial extracorporeal membrane, with a decrease in the number of cristae. In addition, H/R induced activation of the JNK signaling pathway in FLS to induce cell senescence. Thus, the present results indicated that H/R may cause inflammation and escalate synovial inflammation induced by TNF-α, which may lead to the pathogenesis of OA by increasing changes in synovial SASP and activating the JNK signaling pathway. Therefore, further studies expanding on the understanding of the pathogenesis of H/R etiology in OA are required.

Carosella E, Benkirane-Jessel N, Moreau P, Rouas-Freiss N, Bensoussan D, Huselstein C. Are the Immune Properties of Mesenchymal Stem Cells from Wharton's Jelly Maintained during Chondrogenic Differentiation?

Background: Umbilical mesenchymal stem/stromal cells (MSCs), and especially those derived from Wharton’s jelly (WJ), are a promising engineering tool for tissue repair in an allogeneic context. This is due to their differentiation capacity and immunological properties, like their immunomodulatory potential and paracrine activity. Hence, these cells may be considered an Advanced Therapy Medicinal Product (ATMP). The purpose of this work was to differentiate MSCs from WJ (WJ-MSCs) into chondrocytes using a scaffold and to evaluate, in vitro, the immunomodulatory capacities of WJ-MSCs in an allogeneic and inflammatory context, mimicked by IFN-γ and TNF-α priming during the chondrogenic differentiation. Methods: Scaffolds were made from hydrogel composed by alginate enriched in hyaluronic acid (Alg/HA). Chondrogenic differentiation, immunological function, phenotype expression, but also secreted soluble factors were the different parameters followed during 28 days of culture. Results: During chondrocyte differentiation, even in an allogeneic context, WJ-MSCs remained unable to establish the immunological synapse or to induce T cell alloproliferation. Moreover, interestingly, paracrine activity and functional immunomodulation were maintained during cell differentiation. Conclusion: These results show that WJ-MSCs remained hypoimmunogenic and retained immunomodulatory properties even when they had undergone chondrocyte differentiation.

IGFBP5 promotes angiogenic and neurogenic differentiation potential of dental pulp stem cells

Dental stem cells for dental pulp regeneration have become a new strategy for pulpitis treatment. Angiogenesis and neurogenesis play a vital role in the pulp-dentin complex regeneration, and appropriate growth factors will promote the process of angiogenesis and neurogenesis. Insulin-like growth factor-binding protein 5 (IGFBP5) is involved in the regulation of tooth growth and development. A previous study showed that IGFBP5 enhanced osteo/odontogenic differentiation of dental stem cells. Our research intends to reveal the function of IGFBP5 in the angiogenic and neurogenic differentiation of human dental stem cells. Human dental pulp stem cells (DPSCs) were used in the present study. Lentiviral IGFBP5 shRNA was used to silence the IGFBP5. Retroviruses expressing Wild-type IGFBP5 were used to over-express IGFBP5. Angiogenic and neurogenic differentiation were carried out by in vitro study. Real-time RT-PCR and western blot results showed that over-expression of IGFBP5 upregulated the expressions of angiogenic markers, including VEGF, PDGFA and ANG-1, and neurogenic markers, including NCAM, TH, Nestin, βIII-tubulin, and TH, in DPSCs. Moreover, microscope observation confirmed that over-expression of IGFBP5 enhanced neurosphere formation in DPSCs in size and amount. Immunofluorescence staining results showed that over-expression of IGFBP5 also prompted the percentage of Nestin and βIII-tubulin positive neurospheres in DPSCs. While depletion of IGFBP5 downregulated the expressions of VEGF, PDGFA, ANG-1, NCAM, TH, Nestin, βIII-tubulin, and TH, it decreased the neurosphere formation and percentage of Nestin and βIII-tubulin positive neurospheres in DPSCs. In conclusion, our results revealed that IGFBP5 promoted angiogenic and neurogenic differentiation potential of DPSCs in vitro and provided the possible potential target for enhancing directed differentiation of dental stem cells and dental pulp-dentin functional regeneration.

Aspirin inhibits adipogenesis of tendon stem cells and lipids accumulation in rat injury tendon through regulating PTEN/PI3K/AKT signalling

Tendon injury repairs are big challenges in sports medicine, and fatty infiltration after tendon injury is very common and hampers tendon injury healing process. Tendon stem cells (TSCs), as precursors of tendon cells, have shown promising effect on injury tendon repair for their tenogenesis and tendon extracellular matrix formation. Adipocytes and lipids accumulation is a landmark event in pathological process of tendon injury, and this may induce tendon rupture in clinical practice. Based on this, it is important to inhibit TSCs adipogenesis and lipids infiltration to restore structure and function of injury tendon. Aspirin, as the representative of non‐steroidal anti‐inflammatory drugs (NSAIDs), has been widely used in tendon injury for its anti‐inflammatory and analgesic actions, but effect of aspirin on TSCs adipogenesis and fatty infiltration is still unclear. Under adipogenesis conditions, TSCs were treated with concentration gradient of aspirin. Oil red O staining was performed to observe changes of lipids accumulation. Next, we used RNA sequencing to compare profile changes of gene expression between induction group and aspirin‐treated group. Then, we verified the effect of filtrated signalling on TSCs adipogenesis. At last, we established rat tendon injury model and compared changes of biomechanical properties after aspirin treatment. The results showed that aspirin decreased lipids accumulation in injury tendon and inhibited TSCs adipogenesis. RNA sequencing filtrated PTEN/PI3K/AKT signalling as our target. After adding the signalling activators of VO‐Ohpic and IGF‐1, inhibited adipogenesis of TSCs was reversed. Still, aspirin promoted maximum loading, ultimate stress and breaking elongation of injury tendon. In conclusion, by down‐regulating PTEN/PI3K/AKT signalling, aspirin inhibited adipogenesis of TSCs and fatty infiltration in injury tendon, promoted biomechanical properties and decreased rupture risk of injury tendon. All these provided new therapeutic potential and medicine evidence of aspirin in treating tendon injury and tendinopathy.

MicroRNA-130a controls bone marrow mesenchymal stem cell differentiation towards the osteoblastic and adipogenic fate

Objectives

With age, bone marrow mesenchymal stem cells (BMSC) have reduced ability of differentiating into osteoblasts but have increased ability of differentiating into adipocytes which leads to age‐related bone loss. MicroRNAs (miRNAs) play major roles in regulating BMSC differentiation. This paper explored the role of miRNAs in regulating BMSC differentiation swift fate in age‐related osteoporosis.

Material and methods

Mice and human BMSC were isolated from bone marrow, whose miR‐130a level was measured. The abilities of BMSC differentiate into osteoblast or fat cell under the transfected with agomiR‐130a or antagomiR‐130a were analysed by the level of ALP, osteocalcin, Runx2, osterix or peroxisome proliferator‐activated receptorγ (PPARγ), Fabp4. Related mechanism was verified via qT‐PCR, Western blotting (WB) and siRNA transfection. Animal phenotype intravenous injection with agomiR‐130a or agomiR‐NC was explored by Micro‐CT, immunochemistry and calcein double‐labelling.

Results

MiR‐130a was dramatically decreased in BMSC of advanced subjects. Overexpression of miR‐130a increased osteogenic differentiation of BMSC and attenuated adipogenic differentiation in BMSC, conversely, Inhibition of miR‐130a reduced osteogenic differentiation and facilitated lipid droplet formation. Consistently, overexpression of miR‐130a in elderly mice dropped off the bone loss. Furthermore, the protein levels of Smad regulatory factors 2 (Smurf2) and PPARγ were regulated by miR‐130a with an negative effect through directly combining the 3'UTR of Smurf2 and PPARγ.

Conclusions

The results indicated that miR‐130a promotes osteoblastic differentiation of BMSC by negatively regulating Smurf2 expression and suppresses adipogenic differentiation of BMSC by targeting the PPARγ, and supply a new target for clinical therapy of age‐related bone loss.

Adipose-derived mesenchymal stromal/stem cells in systemic sclerosis: Alterations in function and beneficial effect on lung fibrosis are regulated by caveolin-1

The potential value of mesenchymal stromal/stem cell therapy in treating skin fibrosis in scleroderma (systemic sclerosis) and of the caveolin-1 scaffolding domain peptide in treating lung, skin, and heart fibrosis is known. To understand how these observations may relate to differences between mesenchymal stromal/stem cells from healthy subjects and subjects with fibrosis, we have characterized the fibrogenic and adipogenic potential of adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients, from mice with fibrotic lung and skin disease induced by systemic bleomycin treatment, and from healthy controls. Early passage systemic sclerosis adipose-derived mesenchymal stromal/stem cells have a profibrotic/anti-adipogenic phenotype compared to healthy adipose-derived mesenchymal stromal/stem cells (low caveolin-1, high α-smooth muscle actin, high HSP47, low pAKT, low capacity for adipogenic differentiation). This phenotype is mimicked by treating healthy adipose-derived mesenchymal stromal/stem cells with transforming growth factor beta or caveolin-1 small interfering RNA and is reversed in systemic sclerosis adipose-derived mesenchymal stromal/stem cells by treatment with caveolin-1 scaffolding domain peptide, but not scrambled caveolin-1 scaffolding domain peptide. Similar results were obtained with adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients and from bleomycin-treated mice, indicating the central role of caveolin-1 in mesenchymal stromal/stem cell differentiation in fibrotic disease.

Seven genes for the prognostic prediction in patients with glioma

PURPOSE

Glioma is a common malignant tumor of the central nervous system, which is characterized by a low cure rate, high morbidity, and high recurrence rate. Consequently, it is imperative to explore some indicators for prognostic prediction in glioma.

METHODS

We obtained glioma data from The Cancer Genome Atlas (TCGA). Differentially expressed genes (DEGs) were obtained by R software from TCGA data sets. Through Cox regression analysis, risk scores were obtained to assess the weighted gene-expression levels, which could predict the prognosis of patients with glioma. The validity and the prognostic value of this model in glioma were confirmed by the manifestation of receiver-operating characteristic (ROC) curves, area under the curve (AUC), and 5-year overall survival (OS).

RESULTS

In total, 920 DEGs of transcriptome genes in glioma were extracted from the TCGA database. We identified a novel seven-gene signature associated with glioma. Among them, AL118505.1 and SMOC1 were positively related to the 5-year OS of patients with glioma, showing a better prognosis for glioma; however, RAB42, SHOX2, IGFBP2, HIST1H3G, and IGF2BP3 were negatively related to 5-year OS, displaying a worse prognosis. In addition, according to risk scores, AL118505.1 was also a protective factor, while others were risk factors. Furthermore, the expression levels of SHOX2, IGFBP2, and IGF2BP3 were significantly positively correlated with glioma grades. Receiver-operating characteristic (ROC) curve assessed the accuracy and sensitivity of the gene signature. Each of the seven genes for patients with the distribution of the risk score was presented in the heat map.

CONCLUSION

We identified a novel seven-gene signature in patients with glioma, which could be used as a predictor for the prognosis of patients with glioma in the future.

Activation of JNK signaling in osteoblasts is inversely correlated with collagen synthesis in age-related osteoporosis

The age-related reduction in the function of osteoblasts plays a central role in the pathogenesis of bone loss and osteoporosis. Collagen synthesis is a primary function of differentiated osteoblasts, however, the mechanisms for age-related changes in collagen synthesis in human osteoblasts remain elusive. We use Gene Ontology (GO) analysis and Gene Set Enrichment Analysis (GSEA) analysis to exploit the transcriptional profiles of osteoblasts from young and old donors. A panel of collagen members was downregulated in aged osteoblasts, including COL12A1, COL5A1, COL5A3, COL8A1 and COL8A2. Co-expression analysis followed by GO analysis revealed that oxidoreductase activity and kinase activity were inversely correlated with collagen synthesis in osteoblasts. GESA analysis further showed that JNK signaling was upregulated in aged osteoblasts. Consistently, MAP3K4 and MAP4K2, upstream of JNK, were also increased in aged osteoblasts. Moreover, expression levels of MAP3K4 were significantly inversely correlated with levels of the collagen genes. Those transcriptomic results were further verified by examining clinical specimens of osteoporosis by immunohistochemistry. These results provide transcriptomic evidence that deregulated JNK signaling may impair collagen synthesis in osteoblasts and imply a therapeutic value of JNK inhibitors for treating osteoporosis and preventing skeletal aging by counteracting the age-related reduction in the function of osteoblasts.

Nitric oxide balances osteoblast and adipocyte lineage differentiation via the JNK/MAPK signaling pathway in periodontal ligament stem cells

Background

Critical tissues that undergo regeneration in periodontal tissue are of mesenchymal origin; thus, investigating the regulatory mechanisms underlying the fate of periodontal ligament stem cells could be beneficial for application in periodontal tissue regeneration. Nitric oxide (NO) regulates many biological processes in developing embryos and adult stem cells. The present study was designed to investigate the effects of NO on the function of human periodontal ligament stem cells (PDLSCs) as well as to elucidate the underlying molecular mechanisms.

Methods

Immunofluorescent staining and flow cytometry were used for stem cell identification. Western blot, reverse transcription polymerase chain reaction (RT-PCR), immunofluorescent staining, and flow cytometry were used to examine the expression of NO-synthesizing enzymes. The proliferative capacity of PDLSCs was determined by EdU assays. The osteogenic potential of PDLSCs was tested using alkaline phosphatase (ALP) staining, Alizarin Red staining, and calcium concentration detection. Oil Red O staining was used to analyze the adipogenic ability. Western blot, RT-PCR, and staining were used to examine the signaling pathway.

Results

Human PDLSCs expressed both inducible NO synthase (iNOS) and endothelial NO synthase (eNOS) and produced NO. Blocking the generation of NO with the NOS inhibitor l-N^G-monomethyl arginine (l-NMMA) had no influence on PDLSC proliferation and apoptosis but significantly attenuated the osteogenic differentiation capacity and stimulated the adipogenic differentiation capacity of PDLSCs. Increasing the physiological level of NO with NO donor sodium nitroprusside (SNP) significantly promoted the osteogenic differentiation capacity but reduced the adipogenic differentiation capacity of PDLSCs. NO balances the osteoblast and adipocyte lineage differentiation in periodontal ligament stem cells via the c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase (MAPK) signaling pathway.

Conclusions

NO is essential for maintaining the balance between osteoblasts and adipocytes in PDLSCs via the JNK/MAPK signaling pathway.

Graphical Abstract

NO balances osteoblast and adipocyte lineage differentiation via JNK/MAPK signaling pathway

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0869-2) contains supplementary material, which is available to authorized users.

Association of Growth Factors Genes with Miscarriage

BACKGROUND

The study was aimed to investigate the association of VEGFA gene polymorphic variants -2578C>A (rs699947) and -634G>C (rs2010963) and TGFB1 gene 915G>C (rs1800471) and gene expression level with miscarriage in the first trimester.

METHODS

288 women with different courses of pregnancy and 61 chorionic tissue samples were involved in case-control study. Allele-specific polymerase chain reaction in real time was used for genotyping. Next, gene-gene interactions were analyzed using the multifactor dimensionality reduction method. VEGFA and TGFB1 genes expression levels were determined by RT-PCR.

RESULTS

It was found that SNP rs699947 was associated with the miscarriage risk change (p=0.05). The CC genotype was associated with reduced risk of abortion in the first trimester, and the CA genotype with increased risk. Genotypes VEGFA -2578CC/VEGFA -634CG, VEGFA -2578AA/VEGFA -634CG,and VEGFA -2578CC/ VEGFA -634CG/TGFB1 936CC were associated with lowered risk of miscarriage in the first trimester. mRNA level of TGFB1 was significantly higher in decidual tissue compared to chorionic tissue in normally progressing pregnancy (p=0.003). VEGFA gene expression level was directly correlated with the TGFB1 mRNA level (R=0.60; p=0.038). In pregnancy loss, an inverse relationship was observed (R=-0.76; p=0.028).

CONCLUSION

The SNP rs699947 is associated with pregnancy loss in the first trimester. The MDR analysis data showed the significant relationship between VEGFA and TGFB1 genes in two-locus and three-locus models. A change in the ratio of the concentrations of growth factors can disrupt the processes of cell division, apoptosis and angiogenesis processes.