Paracrine Functions Research Articles

Musculoskeletal health in children and adolescents.

The purpose of this narrative review was to investigate the key determinants of musculoskeletal health in childhood and adolescence, with particular attention to the role of physical activity. First, we examined the importance of bone modeling and remodeling in maintaining the bone health and the integrity and mechanical characteristic of the skeleton. In addition, we reported the evidence on an appropriate calcium and vitamin D intake, as well as local load variation in achieving proper peak bone mass. Proteomic and transcriptomic studies identified the skeletal muscle "secretoma", consisting of several myokines involved in endocrine and paracrine functions. Among these, we explored the role of irisin, a myokine involved in the muscle-bone crosstalk, and in the regulation of metabolic pathways. It is known that physical activity during growing positively impacts on skeleton and can protect by bone loss in adulthood. However, there are still concerns about the optimal interval duration and exercise intensity, particularly at the pubertal growth spurt which represents a window of opportunity to increase skeletal strength. We reported data from clinical trials performed in the last 5 years analyzing the impact of the type and timing of physical activity during childhood on skeletal development. Finally, we reported recent data on the significance of physical activity in some rare diseases.

Enzyme-controlled, nutritive hydrogel for mesenchymal stromal cell survival and paracrine functions

Culture-adapted human mesenchymal stromal cells (hMSCs) are appealing candidates for regenerative medicine applications. However, these cells implanted in lesions as single cells or tissue constructs encounter an ischemic microenvironment responsible for their massive death post-transplantation, a major roadblock to successful clinical therapies. We hereby propose a paradigm shift for enhancing hMSC survival by designing, developing, and testing an enzyme-controlled, nutritive hydrogel with an inbuilt glucose delivery system for the first time. This hydrogel, composed of fibrin, starch (a polymer of glucose), and amyloglucosidase (AMG, an enzyme that hydrolyze glucose from starch), provides physiological glucose levels to fuel hMSCs via glycolysis. hMSCs loaded in these hydrogels and exposed to near anoxia (0.1% pO2) in vitro exhibited improved cell viability and angioinductive functions for up to 14 days. Most importantly, these nutritive hydrogels promoted hMSC viability and paracrine functions when implanted ectopically. Our findings suggest that local glucose delivery via the proposed nutritive hydrogel can be an efficient approach to improve hMSC-based therapeutic efficacy.

Intracellular delivery of nitric oxide enhances the therapeutic efficacy of mesenchymal stem cells for myocardial infarction.

Cell therapy by autologous mesenchymal stem cells (MSCs) is a clinically acceptable strategy for treating various diseases. Unfortunately, the therapeutic efficacy is largely affected by the low quality of MSCs collected from patients. Here, we showed that the gene expression of MSCs from patients with diabetes was differentially regulated compared to that of MSCs from healthy controls. Then, MSCs were genetically engineered to catalyze an NO prodrug to release NO intracellularly. Compared to extracellular NO conversion, intracellular NO delivery effectively prolonged survival and enhanced the paracrine function of MSCs, as demonstrated by in vitro and in vivo assays. The enhanced therapeutic efficacy of engineered MSCs combined with intracellular NO delivery was further confirmed in mouse and rat models of myocardial infarction, and a clinically relevant cell administration paradigm through secondary thoracotomy has been attempted.

Ligand-Screened Cerium-Based MOF Microcapsules Promote Nerve Regeneration via Mitochondrial Energy Supply.

Although mitochondria are crucial for recovery after spinal cord injury (SCI), therapeutic strategies to modulate mitochondrial metabolic energy to coordinate the immune response and nerve regeneration are lacking. Here, a ligand-screened cerium-based metal-organic framework (MOF) with better ROS scavenging and drug-loading abilities is encapsulated with polydopamine after loading creatine to obtain microcapsules (Cr/Ce@PDA nanoparticles), which reverse the energy deficits in both macrophages and neuronal cells by combining ROS scavenging and energy supplementation. It reprogrames inflammatory macrophages to the proregenerative phenotype via the succinate/HIF-1α/IL-1β signaling axis. It also promotes the regeneration and differentiation of neural cells by activating the mTOR pathway and paracrine function of macrophages. In vivo experiments further confirm the effect of the microcapsules in regulating early ROS-inflammation positive-feedback chain reactions and continuously promoting nerve regeneration. This study provides a new strategy for correcting mitochondrial energy deficiency in the immune response and nerve regeneration following SCI.

Lymphoma-Derived IL-10 Is a Key Immunomodulatory Factor at the Tumor Microenvironment of Activated B-Cell Diffuse Large B-Cell Lymphoma and Influences In Vivo Responses to Immunotherapy

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of aggressive non-Hodgkin's lymphoma with ~40% of patients experiencing refractory or relapsed disease to R-CHOP immunochemotherapy. These higher risk patients often exhibit gene expression profiles that resemble a late germinal center-derived activated B-cell (ABC) phenotype, where diverse specific mutations in genes along BCR and TLR signaling pathways converge into constitutive activation of the NF-κB pathway. Identification of factors that contribute to the survival of malignant ABC-DLBCL cells is crucial for designing specific interventions. In this setting, previous in vitro studies in DLBCL cell lines have evidenced that IL-10 is a direct target of NF-κB signaling that sustains lymphoma cell survival by an auto-stimulatory loop via STAT3 signaling. However, the action of IL-10 could be more complex within the lymphoma microenvironment, as IL-10 can have both stimulatory and inhibitory effects depending on the cellular source of IL-10, the timing of its secretion, and the type of immune cells that receives signals via IL-10 receptor (IL-10R). To explore in vivo the relevance of lymphoma-derived IL-10, we have generated a novel quintuple transgenic mouse model that we call pBIC10, after crossing our previous ABC-DLBCL-like pBIC mice carrying constitutive NF-κB signaling (Pascual et al., Blood 2019) to mice with a floxed Il10 gene for conditional knock-out of IL-10 specifically in malignant ABC-DLBCL cells. As expected, increased intracellular IL-10 signaling was detected in primary murine DLBCL cells from pBIC mice but not in IL-10 deficient pBIC10 mice, which promoted lymphoma cell survival ex vivo as revealed by perturbation studies of the IL-10/JAK1/STAT3 autocrine loop with blocking monoclonal antibodies or selected inhibitors. However, in vivo genetic deletion of lymphoma-derived IL-10 did not offer improved overall survival but, on the contrary, notably accelerated DLBCL progression in pBIC10 mice (Figure 1A, left). A comprehensive integration of multiparametric flow cytometry and transcriptomic analyses using bulk and single-cell RNA-seq of lymphoma cells and the tumor microenvironment coupled with BCR- and TCR-seq, identified lymphoma-derived IL-10 as a key immunomodulator of the DLBCL microenvironment, including unexpected protective paracrine functions in the progression of DLBCL. By comparing IL-10-proficient (pBIC) and -deficient (pBIC10) murine DLBCL models, we observed a multifaceted role of IL-10 produced by DLBCL cells, enabling immune-effector processes (facilitating immune chemotaxis, antigen presentation, and IFNγ responses) that yielded higher percentages of long-lived stem-like CD8 +TCF-1 +PD-1 lo/int T cells and dendritic cells, while restraining PD-1/LAG3-driven T-cell exhaustion and reducing immunosuppression by CD4 +CD25 +FOXP3 + regulatory T (Treg) cells. Thus, depletion of lymphoma-derived IL-10 decreased T-cell cytotoxicity and increased Treg-driven immunosuppression, which collectively accelerated lymphoma development. Consequently, T-cell targeted immune-checkpoint therapy (with anti-PD-1 antibodies) was effective only in IL-10-proficient DLBCL but not in IL-10-deficient pBIC10 mice (Figure 1A, right). Further comparative studies between pBIC and pBIC10 mice showed that tumor vascularization and expression of B-cell calcium channels, which have been previously associated with sensitivity to rituximab, were counteracted by lymphoma-derived IL-10. Accordingly, anti-CD20-based targeting of lymphoma cells (with rituximab surrogate antibodies) showed best in vivo responses in IL-10-deficient DLBCL mice with respect to pBIC mice (Figure 1A, right). Consistent with this preclinical data, analyses of transcriptional IL-10-associated hallmarks to stratify DLBCL patients (Schmitz et al., NEJM 2018) identified better clinical responses to R-CHOP in patients with pBIC10-like DLBCL phenotype (Figure 1B). Collectively, our study provides new functional and mechanistic insights into the role of lymphoma-derived IL-10 in the pathogenesis of DLBCL and the restraint of an immunosuppressed tumor microenvironment, which holds predictive potential as a biomarker for immunotherapy responses in DLBCL.

The role of charme in the phenotype and function of resident cardiac mesenchymal stromal cells

Abstract Background Charme is a murine long non-coding RNA with specific expression in striated muscles, presenting a human orthologue with 45% identity. Its depletion leads to incomplete muscle differentiation. Charme-/- mice display an altered cardiac phenotype with increased wall thickness and reduced chamber dimensions due to myocyte hyperplasia. Left ventricular dilatation and reduced fractional shortening are detected in aged Charme-/- mice. Embryonic myocardial architecture reveals aberrant compaction and ventricular hypotrabeculation, resembling some congenital cardiomyopathies. Cardiac mesenchymal stromal cells (CMSCs) play key roles in tissue homeostasis and pathophysiology, by maintaining the extracellular matrix and by paracrine action on all myocardial cells. Purpose To elucidate the phenotype, paracrine function, and myofibroblast differentiation capacity of resident CMSCs in the Charme-/- mouse model. Methods CMSCs were isolated from 5-week-old wild-type (WT) and Charme-/- mice by explant culture, pooling at least 4 different hearts per culture. Results Charme-/- CMSCs showed increased features of primitive phenotypes, such as enhanced spontaneous spheroid growth (123,6±11,9 vs 51,0±6,4 spheroids/well; N=8, p<0,0001) and clonogenesis efficiency (2,7±0,5-fold; N=7, p<0,05) compared to WT cells. Charme-/- CMSCs also showed increased migration ability (Charme-/-: 68,5±2,7% vs WT: 80,2±0,7% wound area; N=2). Flow cytometry identified a reduced proportion of lin-/Sca1+/CD90+ primitive mesenchymal cells in Charme-/- versus WT CMSCs (7,4±1,6% vs 56,9±6,5%; N=6, p<0,05). Western blot analysis on Charme-/- whole cardiac tissue showed reduced collagen I and collagen I/III protein ratio compared to WT hearts (0,17±0,03 vs 0,85±0,10 normalized OD; N=4, p<0,005). Stimulation with TGFb-1 resulted in lower expression of fibroblast activation markers compared to WT CMSCs, as assessed by immunofluorescence staining for aSMA (0,49±0,05 vs 0,76±0,10 mean fluorescence intensity; N=6-12, p<0,05) and collagen I/III mRNA expression ratio (1,3±0,1 vs 2,2±0,4 2^-DCt; N=3, p<0,01). The secretome of Charme-/- CMSCs revealed a general depletion in many cardioprotective cytokines, included in the KEGG term "PI3K-Akt signalling pathway" (FDR<0,0005) and classified in Gene Ontology categories of myoblast differentiation and fusion (GO:1901739, GO:1901741, GO:0045663, GO:0045661; FDR<0,05). In line with this, the secretome of TGFb1-stimulated Charme-/- CMSCs was less effective in sustaining cardiomyocyte survival versus the WT CMSC secretome (1,70±0,03 vs 1,90±0,04 normalized OD at 48h; N=5, p<0,005). Conclusions Charme-/- CMSCs show a less mature phenotype associated to reduced collagen I presence in situ, reduced activation and differentiation upon stimulation, and impaired cardioprotective paracrine functions, suggesting a key role of Charme in the physiology of the cardiac stroma, possibly mediating in part the altered cardiac phenotype of Charme-/- mice.

Autocrine/paracrine growth hormone in cancer progression.

It is now apparent that growth hormone (GH), an anterior pituitary hormone predominantly regulating postnatal somatic growth and metabolism, is also expressed in extrapituitary tissues. An extrapituitary synthetic site of GH that has garnered interest is the de novo or enhanced expression of GH in carcinoma or other cancers. In a number of cancers, including carcinoma of the mammary gland, endometrium, liver, prostate, and colon, the expression of GH is independently associated with more advanced clinicopathologic parameters of the cancer. In some of these cancers, tumor human growth hormone (hGH) expression portends worse survival outcomes for patients. Functionally, tumor-derived hGH exerts both autocrine and paracrine functions on carcinoma cells and cancer-associated stroma. Expression of autocrine/paracrine hGH in cancer drives tumor growth, angiogenesis, metastasis, and resistance to therapy by promotion of cancer cell proliferation, survival, epithelial-to-mesenchymal transition, motility, invasion, cancer stem cell-like behavior, and metastasis. Autocrine/paracrine hGH activates oncogenic signaling pathways and specific transcriptome signatures and enhances the expression of an oncogenic secretome to promote these functions. Hence, extrapituitary expression of GH in cancer promotes cancer progression independent of endocrine hGH, and may be considered as a validated target in oncology.

Exosome-loaded degradable polymeric microcapsules for the treatment of vitreoretinal diseases.

The therapeutic benefits of many cell types involve paracrine mechanisms. Inspired by the paracrine functions of exosomes and the sustained degradation properties of microcapsules, here we report the therapeutic benefits of exosome-loaded degradable poly(lactic-co-glycolic acid) microcapsules with micrometric pores for the treatment of vitreoretinal diseases. On intravitreal injection in a mouse model of retinal ischaemia-reperfusion injury, microcapsules encapsulating mouse mesenchymal-stem-cell-derived exosomes settled in the inferior vitreous cavity, released exosomes for over one month as they underwent degradation and led to the restoration of retinal thickness to nearly that of the healthy retina. In mice and non-human primates with primed mycobacterial uveitis, intravitreally injected microcapsules loaded with exosomes from monkey regulatory T cells resulted in a substantial reduction in the levels of inflammatory cells. The exosome-encapsulating microcapsules, which can be lyophilised, may offer alternative treatment options for vitreoretinal diseases.

Dual siRNA-Loaded Cell Membrane Functionalized Matrix Facilitates Bone Regeneration with Angiogenesis and Neurogenesis.

Vascularization and innervation play irreplaceable roles in bone regeneration and bone defect repair. However, the reconstruction of blood vessels and neural networks is often neglected in material design. This study aims to design a genetically functionalized matrix (GFM) and enable it to regulate angiogenesis and neurogenesis to accelerate the process of bone defect repair. The dual small interfering RNA (siRNA)-polyvinylimide (PEI)(siRP) complexes that locally knocked down soluble vascular endothelial growth factor receptor 1 (sFlt-1) and p75 neurotrophic factor receptor (p75NTR ) are prepared. The hybrid cell membrane (MM) loaded siRP is synthesized as siRNA@MMs to coat on polylactone (PCL) electrospun fibers for mimicking the natural bone matrix. The results indicates that siRNA@MMs could regulate the expression of vascular-related and neuro-related cytokines secreted by mesenchymal stem cells (MSCs). GFMs promote the expression of osteogenic differentiation through paracrine function in vitro. GFMs attenuates inflammation and promotes osseointegration by regulating the coupling of vascularization and innervation in vivo. This study uses the natural hybrid cell membrane to carry genetic material and assist in the vascularization and innervation function of two siRNA. The results present the significance of neuro-vascularized organoid bone and may provide a promising choice for the design of bone tissue engineering scaffold.

Adipose Tissue and Metabolic Health.

In this review, we provide a brief synopsis of the connections between adipose tissue and metabolic health and highlight some recent developments in understanding and exploiting adipocyte biology. Adipose tissue plays critical roles in the regulation of systemic glucose and lipid metabolism and secretes bioactive molecules possessing endocrine, paracrine, and autocrine functions. Dysfunctional adipose tissue has a detrimental impact on metabolic health and is intimately involved in key aspects of metabolic diseases such as insulin resistance, lipid overload, inflammation, and organelle stress. Differences in the distribution of fat depots and adipose characteristics relate to divergent degrees of metabolic dysfunction found in metabolically healthy and unhealthy obese individuals. Thermogenic adipocytes increase energy expenditure via mitochondrial uncoupling or adenosine triphosphate-consuming futile substrate cycles, while functioning as a metabolic sink and participating in crosstalk with other metabolic organs. Manipulation of adipose tissue provides a wealth of opportunities to intervene and combat the progression of associated metabolic diseases. We discuss current treatment modalities for obesity including incretin hormone analogs and touch upon emerging strategies with therapeutic potential including exosome-based therapy, pharmacological activation of brown and beige adipocyte thermogenesis, and administration or inhibition of adipocyte-derived factors.

Plasma aryl hydrocarbon receptor associated with epicardial adipose tissue in men: a cross-sectional study

BackgroundEpicardial adipose tissue (EAT) is a type of ectopic fat with endocrine and paracrine functions. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that responds to environmental stimuli. AhR expression is associated with obesity. In this cross-sectional study, we aimed to determine the relationship between circulating AhR concentrations and EAT.MethodsA total of 30 men with obesity and 23 age-matched men as healthy controls were enrolled. Plasma AhR concentrations were determined at fasting. The EAT thickness was measured on the free wall of the right ventricle from the basal short-axis plane by magnetic resonance imaging.ResultsThe participants with obesity had a higher plasma AhR level than the controls (81.0 ± 24.5 vs. 65.1 ± 16.4 pg/mL, P = 0.010). The plasma AhR level was positively correlated with EAT thickness (correlation coefficient = 0.380, P = 0.005). After adjusting for fasting glucose levels, plasma AhR levels were still significantly associated with EAT thickness (95% CI 0.458‒5.357, P = 0.021) but not with body mass index (P = 0.168).ConclusionPlasma AhR concentrations were positively correlated with EAT thickness on the free wall of the right ventricle in men. Further investigations are needed to evaluate the causal effects and underlying mechanisms between AhR and EAT.

Fragmented Dermo-Epidermal Units (FdeU) as an Emerging Strategy to Improve Wound Healing Process: An In Vitro Evaluation and a Pilot Clinical Study.

Innovative strategies have shown beneficial effects in healing wound management involving, however, a time-consuming and arduous process in clinical contexts. Micro-fragmented skin tissue acts as a slow-released natural scaffold and continuously delivers growth factors, and much other modulatory information, into the microenvironment surrounding damaged wounds by a paracrine function on the resident cells which supports the regenerative process. In this study, in vitro and in vivo investigations were conducted to ascertain improved effectiveness and velocity of the wound healing process with the application of fragmented dermo-epidermal units (FdeU), acquired via a novel medical device (Hy-Tissue® Micrograft Technology). MTT test; LDH test; ELISA for growth factor investigation (IL) IL-2, IL-6, IL-7 IL-8, IL-10; IGF-1; adiponectin; Fibroblast Growth Factor (FGF); Vascular Endothelial Growth Factor (VEGF); and Tumor Necrosis Factor (TNF) were assessed. Therefore, clinical evaluation in 11 patients affected by Chronic Wounds (CW) and treated with FdeU were investigated. Functional outcome was assessed pre-operatory, 2 months after treatment (T0), and 6 months after treatment (T1) using the Wound Bed Score (WBS) and Vancouver Scar Scale (VSS). In this current study, we demonstrate the potential of resident cells to proliferate from the clusters of FdeU seeded in a monolayer that efficiently propagate the chronic wound. Furthermore, in this study we report how the discharge of trophic/reparative proteins are able to mediate the in vitro paracrine function of proliferation, migration, and contraction rate in fibroblasts and keratinocytes. Our investigations recommend FdeU as a favorable tool in wound healing, displaying in vitro growth-promoting potential to enhance current therapeutic mechanisms.

Study the Effect of Some Adipokines and Interleukins in Hypo and Hyperthyroidism Patients

Introduction: Thyroid diseases have effects on metabolism and inflammation. Adipocytokines have autocrine, paracrine, and endocrine functions on several organs which have a central role in subclinical inflammation of adipose tissue, and obese adipose tiss

Secretome Derived from Mesenchymal Stem/Stromal Cells: A Promising Strategy for Diabetes and its Complications.

Diabetes is a complex metabolic disease with a high global prevalence. The health and quality of life of patients with diabetes are threatened by many complications, including diabetic foot ulcers, diabetic kidney diseases, diabetic retinopathy, and diabetic peripheral neuropathy. The application of mesenchymal stem/stromal cells (MSCs) in cell therapies has been recognized as a potential treatment for diabetes and its complications. MSCs were originally thought to exert biological effects exclusively by differentiating and replacing specific impaired cells. However, the paracrine function of factors secreted by MSCs may exert additional protective effects. MSCs secrete multiple compounds, including proteins, such as growth factors, chemokines, and other cytokines; nucleic acids, such as miRNAs; and lipids, extracellular vesicles (EVs), and exosomes (Exos). Collectively, these secreted compounds are called the MSC secretome, and usage of these chemicals in cell-free therapies may provide stronger effects with greater safety and convenience. Recent studies have demonstrated positive effects of the MSC secretome, including improved insulin sensitivity, reduced inflammation, decreased endoplasmic reticulum stress, enhanced M2 polarization of macrophages, and increased angiogenesis and autophagy; however, the mechanisms leading to these effects are not fully understood. This review summarizes the current research regarding the secretome derived from MSCs, including efforts to quantify effectiveness and uncover potential molecular mechanisms in the treatment of diabetes and related disorders. In addition, limitations and challenges are also discussed so as to facilitate applications of the MSC secretome as a cell-free therapy for diabetes and its complications.

Mesenchymal stem cells derived from the fibrotic tissue of atrophic nonunion or the bone marrow of iliac crest: A donor-matched comparison

PurposeAtrophic nonunion is one of the most difficult complications of fracture. The cellular factors that contribute to atrophic nonunion are poorly understood, and mesenchymal stem cells (MSCs) are recognized as the key contributor to bone formation. This study aimed to characterize the MSCs isolated from the fibrotic tissue of atrophic nonunion (AN-MSCs) from the perspective of proliferation, differentiation potential, senescence, and paracrine function. MethodsHuman atrophic fibrotic tissue was obtained from four donors aged 29–37 for isolating AN-MSCs, and donor-matched bone marrow acquired from the iliac crest for isolating MSCs (IC-MSCs) as control. The AN-MSCs or IC-MSCs in passage 3 were applied for the following evaluations. The surface markers expressed on the two cells were evaluated using flow cytometry. The proliferation of the two cells for up to 11 days was comparatively investigated. After osteogenic, chondrogenic, or adipogenic induction, multi-lineage differentiation of AN-MSCs or IC-MSCs was comparatively evaluated using lineage-specific stains and lineage-specific gene expression. Enzyme-linked immunosorbent assay (ELISA) assessment was applied to evaluate the paracrine function of AN-MSCs or IC-MSCs. Cellular senescence of AN-MSCs or IC-MSCs was evaluated using senescence-associated β-galactosidase (SA-β-gal) staining. ResultsAN-MSCs or IC-MSCs from the four donors showed morphologic and immunophenotypic characteristics of MSCs, with the expression of MSCs markers and negative expression of hematopoietic markers. In general, AN-MSCs showed similar proliferation and adipogenic capacity with IC-MSCs. In contrast, IC-MSCs showed significantly higher osteogenic and chondrogenic capacity compared to AN-MSCs. Moreover, the culture medium of IC-MSCs contains significantly higher levels of VEGF, TGF-β1, PDGF-BB, and IGF-1 than the culture medium of AN-MSCs. Lastly, the AN-MSCs are more prone to cellular senescence than the IC-MSCs. ConclusionsIn-vitro, AN-MSCs were similar to IC-MSCs in proliferation and adipogenic capacity, but inferior to IC-MSCs in osteogenic and chondrogenic capacity, paracrine function, and anti-senescence.

Combination of mesenchymal stem cells carried on artificial extracellular matrix with LIPUS is a potential therapy that may cure diabetes mellitus erectile dysfunction

Diabetes mellitus erectile dysfunction (DMED) is a common chronic disease in andrology, which often responds insufficiently to routine treatment. Mesenchymal stem cell (MSC) treatment, as an important regenerative therapy, has the potential to reverse pathological changes and cure ED, but it is not satisfactory due to the limitation of the survival rate and retention rate. Meanwhile, the artificial extracellular matrix (ECM) shows potent characteristics of enhancing the biological behavior and activity of stem cells. Low intensity pulsed ultrasound (LIPUS) has also been widely used in regenerative medicine, which can promote cell proliferation and tissue repair. LIPUS can also stimulate the paracrine function of MSCs. These technologies have their own unique mechanisms and are of great potentiality in stem cell research. We hypothesized that MSCs carried on artificial ECM combined with LIPUS may play a synergistic role, which further improved the curative effect on DMED. This concept of combined therapy may be a prospective direction of regenerative therapy to cure DMED.

Transcriptional Targets of TWIST1 in Human Mesenchymal Stem/Stromal Cells Mechanistically Link Stem/Progenitor and Paracrine Functions.

Despite extensive clinical testing, mesenchymal stem/stromal cell (MSC)-based therapies continue to underperform with respect to efficacy, which reflects the paucity of biomarkers that predict potency prior to patient administration. Previously, we reported that TWIST1 predicts inter-donor differences in MSC quality attributes that confer potency. To define the full spectrum of TWIST1 activity in MSCs, the present work employed integrated omics-based profiling to identify a high-confidence set of TWIST1 targets, which mapped to cellular processes related to ECM structure/organization, skeletal and circulatory system development, interferon gamma signaling, and inflammation. These targets are implicated in contributing to both stem/progenitor and paracrine activities of MSCs indicating these processes are linked mechanistically in a TWIST1-dependent manner. Targets implicated in extracellular matrix dynamics further implicate TWIST1 in modulating cellular responses to niche remodeling. Novel TWIST1-regulated genes identified herein may be prioritized for future mechanistic and functional studies.

The multiple functions of miR-574-5p in the neuroblastoma tumor microenvironment.

Neuroblastoma is the most common extracranial solid tumor in childhood and arises from neural crest cells of the developing sympathetic nervous system. Prostaglandin E2 (PGE2) has been identified as a key pro-inflammatory mediator of the tumor microenvironment (TME) that promotes neuroblastoma progression. We report that the interaction between the microRNA miR-574-5p and CUG-binding protein 1 (CUGBP1) induces the expression of microsomal prostaglandin E2 synthase 1 (mPGES-1) in neuroblastoma cells, which contributes to PGE2 biosynthesis. PGE2 in turn specifically induces the sorting of miR-574-5p into small extracellular vesicles (sEV) in neuroblastoma cell lines. sEV are one of the major players in intercellular communication in the TME. We found that sEV-derived miR-574-5p has a paracrine function in neuroblastoma. It acts as a direct Toll-like receptor 7/8 (TLR7/8) ligand and induces α-smooth muscle actin (α-SMA) expression in fibroblasts, contributing to fibroblast differentiation. This is particularly noteworthy as it has an opposite function to that in the TME of lung carcinoma, another PGE2 dependent tumor type. Here, sEV-derived miR-574-5p has an autokrine function that inhibits PGE2 biosynthesis in lung cancer cells. We report that the tetraspanin composition on the surface of sEV is associated with the function of sEV-derived miR-574-5p. This suggests that the vesicles do not only transport miRs, but also appear to influence their mode of action.

Promising effects of exosomes from menstrual blood-derived mesenchymal stem cells on endometriosis

Endometriosis as a non-malignant gynecological disease leads to dysregulation of numerous cellular functions including apoptosis, angiogenesis, migration, proliferation, and inflammation. Accumulating evidence has shed light on the importance of endometrial stem cells within the menstrual blood which are involved in the establishment and progression of endometriotic lesions in a retrograde manner. According to the fact that the therapeutic benefits of mesenchymal stem cells are provided through paracrine functions, we used exosomes from menstrual blood-derived stem cells (MenSCs) for treating endometriotic stem cells to inhibit their lesion formation tendency. Menstrual blood samples from healthy and endometriosis women were collected. Isolated MenSCs by the density-gradient centrifugation method were characterized by flow cytometry. Secreted exosomes were isolated from healthy MenSCs (NE-MenSCs) and used to treat endometriotic cells (E-MenSCs). 72 h after treatment, different mechanisms and pathways including inflammation, proliferation, apoptosis, migration, and angiogenesis were analyzed using Real-Time PCR, ELISA, immunocytochemistry, annexin V/PI, and scratching assay. Exosome treatment significantly reduce the expression level of markers related to inflammation, proliferation, migration, and angiogenesis in E-MenSCs which are aberrantly expressed in endometriosis. Moreover, apoptosis was induced in E-MenSCs after treatment which was evaluated in both gene and protein levels. In this study, we give preliminary evidence for the potential of MenSCs-Exo in ameliorating endometriosis. Regarding our results, we suggest that after relevant clinical trial, MenSCs-derived exosomes can be considered as a better treatment option to improve endometriosis compared to common and conventional treatments and show their potential as a cell-free product in endometriosis repair.

The Current Proceedings of PSC-Based Liver Fibrosis Therapy.

Liver fibrosis was initially considered to be an irreversible process which will eventually lead to the occurrence of liver cancer. So far there has been no effective therapeutic approach to treat liver fibrosis although scientists have put tremendous efforts into the underlying mechanisms of this disease. Therefore, in-depth research on novel and safe treatments of liver fibrosis is of great significance to human health. Pluripotent stem cells (PSCs) play important roles in the study of liver fibrosis due to their unique features in self-renewal ability, pluripotency, and paracrine function. This article mainly reviews the applications of PSCs in the study of liver fibrosis in recent years. We discuss the role of PSC-derived liver organoids in the study of liver fibrosis, and the latest research advances on the differentiation of PSCs into hepatocytes or macrophages. We also highlight the importance of exosomes of PSCs for the treatment of liver fibrosis.